The task-irrelevant information could either maintain the same perceptual or- ganization from Display 1 to Display 2 (e.g., in both cases the circles would be grouped by lightness similarity into rows) or change from Display 1 to Display 2 (e.g., change from grouping into rows to grouping into columns).

Note that, independent of whether the organization of the cir- cles was maintained or not, all circles changed their gray- scale value from Display 1 to Display 2 to control for the possibility that changes in organization could be detected from changes in the lightness of each circle.


Our central finding is that the reaction time in the ipsi- lesional matrix task is influenced by the change in or main- tenance of the organization of the ignored task-irrelevant circles in the contralateral field.

Thus, "same" responses to the checkerboard matrix were faster when the organiza- tion of the task-irrelevant circles remained the same (e.g., organized into rows in both Displays 1 and 2) than when the task-irrelevant organization differed (e.g., organized into rows on Display 1 but into columns on Display 2), and vice versa for task-relevant "different" responses.

Not only was the extent of the congruency effect equivalent for the pa- tients and the controls, but the magnitude of the congruency effect was statistically equivalent for patients who were mildly neglectful and for those who were more severely neglectful.

Finally, and importantly, for all individuals, the magnitude of the congruency effect was equivalent when the task-irrelevant circles were presented in the left field and, in another control condition, in the right visual field to- gether with the change detection matrix, demonstrating that implicit perceptual organization is as good in the unaware contralesional field as in the ipsilesional field.


MM, while acknowledging that perception might in- deed occur without awareness under some conditions (as they themselves have demonstrated in the past), challenge our conclusion that patients with neglect evince percep- tual grouping in the absence of attention.

Moreover, they assert that we have "anosagnosia" (a condition in which a person who suffers disability seems unaware of or denies the existence of his or her disability) to methodological de- tail and that researchers (including us) need to be mindful of details across the entire methodological space.

While MM's assertions are witty, the arguments themselves are weak.

They raise two key issues, which, they suggest, pre- vent us from reaching our conclusion.

One issue concerns the assessment of the patients' attentional abilities on a task different from that used to infer inattentional group- ing, and the second is that neglect is not uniform across the neglected field and so patients may be explicitly able to process some of the supposed unattended information.

We deal with each issue in turn.


MM argue that one cannot be confident about the status of the attentional impairment in the key experi- digms, as is also true in our paradigm, independent of any change in the target matrix, the perceptual organiza- tion of the background can change or remain the same across two successive displays.

These studies all report that the status of the background organization influenced the speed and accuracy of change judgments for the central matrix task, even though the status of the back- ground organization (continuity or change) could not be explicitly reported when probed with surprise questions as in Mack and Rock's (1998) inattention blindness stud- ies.

That the observers were unable to report the status of the task-irrelevant circles was taken as evidence that the observers were unaware of the perceptual organiza- tion of the background, yet congruency effects were still obtained.

Crucially, these experiments were conducted with normal observers who are usually attentive to the entire field.

Even though the checkerboard matrix was essentially embedded into the center of the task-irrelevant background, there is general agreement that the matrix change detection task is so absorbing/demanding and of such high attentional load (Lavie, 1995) that no attention can "leak" to the background display.

In our version of the paradigm, the matrix and task-irrelevant grid were spatially separated, making it even more unlikely that the contralateral task-irrelevant information was processed.

Thus, the chances of attention "leaking" to the neglected field were extra ordinarily slim.


In addition to separating the change detection matrix and the distractor grid spatially, we imposed additional, carefully controlled, constraints on our task to make it even more unlikely that the patients could process the distractors in the contralesional field.

In particular, we manipulated the exposure duration of the first display of the trial (see Figure 2A in Shomstein et al., 2010) via a staircasing procedure that yielded 85% accuracy in the matrix change detection task.

Thus, the observers had limited exposure to the initial display, requiring them to focus on the relevant, and not on the irrelevant, task.

Additionally, we know that patients with neglect tend to be more rightward oriented in their gaze (and attention) (Behrmann, Barton, Watt, & Black, 1997; Karnath & Fet- ter, 1995), further ensuring their ipsilesional bias: Indeed, the average spontaneous gaze position of a group of pa- tients with neglect was 46º to the right (Berger, Pross, Ilg, & Karnath, 2006).

If this ipsilesional bias, or something akin to it, was true in our sample of patients, this further decreases the probability of the patients' processing of the distractor circles.


Furthermore, if, for argument's sake, we were to enter- tain the possibility that, notwithstanding the constraints of our design, patients had some residual attention to be allocated to the task-irrelevant distractor, we might have predicted modulation of the distractor congruency effect with the severity of neglect (normal, good detectors, poor detectors).

As is evident from our findings, this predic- tion was not upheld: The extent to which task-irrelevant distractors affected target processing did not differ as a function of neglect severity in the patients, and, even more our sample of neglect patients and, therefore, that our re- sults are strengthened, not weakened as MM suggest, by our findings of highly correlated impairment across both traditional and psychophysical measures of attentional abilities in the patients.


MM also claim that because the assessment of neglect is not done in the context of the detection task, we do not know about the patients' attentional status during the ac- tual experimental paradigm.

In other words, they argue that our conclusions for inattentional grouping of contra- lesional information are not warranted, because the ne- glect evinced by our patients may not be uniform across the field during the experiment itself.

Thus, the patients may still have been able to utilize some of the information from the left field and this information might have given rise to the observed congruency effects.

They suggest that if this is true, then the effect of contralesional informa- tion on the matrix task cannot be interpreted as evidence for processing in the absence of attention.

MM appeal to several studies showing that some neglect patients are still able to detect targets placed well into the left hemifield.

They also illustrate their point in a figure by showing that even partial information, such as that placed just to the left of the central midline, may have been enough to give rise to the congruency effects we report.

We were well aware of this possibility when we designed the experiment and went to great lengths to constrain the paradigm and limit attention "leaking" to the neglected field.

We submit that our paradigm makes it highly improbable that patients could make use of left-sided information, and that in the highly unlikely case that some attention had "leaked" through, this could not suffice to give rise to the findings we have obtained.


The experimental paradigm we adopted has been used previously to demonstrate grouping in the absence of visual attention.

Indeed, Driver, Davis, Russell, Turatto, and Freeman (2001) have argued that it is only in the con- text of indirect tasks such as this one (and essentially we use the same task that they did), where the observer is not directly questioned and where the limitation of self- report is circumvented, that conclusions about processing in the absence of attention can be reached.

This type of matrix comparison task, in the presence of task-irrelevant distractors, has been used in other recent studies, too.

In all these studies, normal participants perform a demand- ing change detection task on a small black-and-white ma- trix at fixation, and task-irrelevant background elements are arranged by color similarity into columns, rows, or simple shapes (Kimchi & Razpurker-Apfeld, 2004; Rus- sell & Driver, 2005), or the background is composed of alternating regions organized into figures and grounds by convexity (Kimchi & Peterson, 2008).


In these para- 625 Figure 1)-and perhaps two pairs of vertically adjacent dots located on the middle of the next to the rightmost col- umn.

No other pair of horizontally adjacent dots or verti- cally adjacent dots on the rightmost portion of the display, nor even the whole rightmost column, provides predictive information.

Thus, in this condition, not only do the pa- tients have to focus on the same orientation across suc- cessive displays, they also have to focus on the precise two adjacent dots that can provide the useful information.

Given these constraints, the chances that the contrast be- tween two adjacent dots in the rightmost portion of the display would serve as a valid cue on all trials are clearly low.

Nonetheless, we again obtained reliable congruency effects in this condition, and most importantly, there is no difference in congruency effects between this condition and the rows/columns condition (or between cross-field and within-field trials).


It is clear then that just attending to a small, rightmost portion of the distractor grid is not sufficient for reliably distinguishing between the grids, particularly across con- ditions.

Rather, the robust congruency effects that we ob- tained in the two organization conditions most likely arose from changes in the perceptual grouping of the distractor circles, strongly supporting our conclusion that perceptual grouping can take place in the absence of attention.


MM suggest that one way we might have provided firm evidence for the absence of attention in the contralesional field would have been to create a control condition in which the patients were required to perform a task on the distractor circles in the presence of the checkerboard ma- trix (i.e., reversing the task).

They argue that this condition would have yielded a measure of the extent of left-sided attention (or lack thereof) under the same conditions as the experimental grouping paradigm.

MM themselves adopted this approach in a study in which they explored whether pictorial information presented in the neglected field was processed sufficiently well to prime lexical de- cision targets presented centrally (McGlinchey-Berroth et al., 1993).

In addition to the patients' completing the pictorial semantic priming task, their patients performed a control task requiring forced-choice discrimination of the very pictures used in the semantics task.

The results revealed that pictures presented to the neglected field yielded faster lexical decision times to the central probe when the picture and word were related than when they were not related (semantic priming).

Moreover, because, in the discrimination condition, the patients could not reli- ably identify the left-sided pictures, McGlinchey-Berroth et al. ( 1993) concluded that the neglected/unattended in- formation can indeed be processed semantically.


In a comprehensive review on perception without awareness, Farah (1994) argued that the conclusions from McGlinchey-Berroth et al. ( 1993) were not defini- tive in and of themselves and she challenged the findings of both the experimental task and the control task.

First, in semantic priming paradigms with pictures used as the convincingly, the patients' performance was not statisti- cally different from that of controls.


MM concede that the entire task-irrelevant distractor grid might not have been processed but then ask whether partial access to the rightmost portion of the grid might have sufficed to allow the participants to discriminate be- tween the grids and to establish whether the grids changed or remained the same across successive displays.

MM pro- vide examples of a possible scenario in which the patients have access to two adjacent dots.


On MM's account, the observer need only see whether the contrast between two dots remains the same or changes in order to distinguish between the grids: If the contrast between the two dots remains the same across two successive displays, the grids remain the same, whereas if the contrast changes, the grids change.

However, for the contrast between two dots to be a valid cue for distinguishing between the grids, it is necessary that the patients are indeed able to compare the contrast between the pair of dots on Display 1 and Display 2 and, critically, that they are able (under care- fully titrated limited exposure) to zero in on the precise two dots in their neglected contralesional field.


Let us il- lustrate the situation first for the rows/columns condition.

Imagine, for example, that the patients focus on the two horizontally adjacent dots on the upper right corner of the distractor grid on Display 1 and Display 2 (as depicted in MM, Figure 1).

In this case, the contrast between two dots might serve as a valid cue, and congruency effects could possibly arise. But what if, on some of the trials, the patients focus on adjacent dots of different orientations in successive displays-for example, on the two horizontally adjacent dots on the upper right corner on Display 1 and on the two vertically adjacent dots on the upper right cor- ner on Display 2? In such a case, the contrast between two adjacent dots is no longer a valid cue for distinguishing between the distractor grids, because the contrast between the pair changes across successive displays when the grid organization remains the same.

Thus, just detecting whether the contrast between two adjacent dots changes or remains the same is not sufficient for distinguishing between the distractor grids; the pair of two adjacent dots across successive displays needs to be of identical orienta- tion.


It follows, then, that the contrast between two adja- cent dots can be a valid cue on some trials and invalid on others, depending on whether or not the patient focused on the pair in the same orientation.

Nevertheless, our results showed reliable congruency effects in this condition.


The probability of the contrast between two adjacent dots serving as a valid cue for distinguishing between the distractor grids is even lower in the square/cross condition.

In this condition, there is only one pair of horizontally ad- jacent dots on the rightmost portion of the distractor grid that can provide useful information-the two rightmost horizontal dots located on the midline (depicted in MM, is not straightforward, and reaching conclusions about the true status of attention during the experimental task is not trivial.


In conclusion, MM caution us and other researchers about the need for extraordinarily careful attention to the sophistication of the visual system and the importance of being mindful across the entire methodological space when designing experiments to examine perception without at- tention.

We wholeheartedly agree with these cautionary warnings, which is exactly why we were unprecedented in the characterization of our patient sample with multiple clinical, psychophysical, and experimental measures; in our use of a stringent, rigidly controlled paradigm specifi- cally designed for investigating perceptual grouping with- out awareness (even in typical observers); in our modifi- cation of this procedure to make it even more stringent (staircasing the display, separating the task-relevant and task-irrelevant information); and in our specific method- ological choices for comparison/control conditions within this experimental paradigm.

Thus, we are confident in our findings and conclusion that perceptual grouping can occur in the absence of attention.


Shomstein, Kimchi, Hammer, and Behrmann (2010) try to capitalize on the apparent dissociation between vision and the processes that seem to mediate neglect patients’ attentional selection and awareness to investigate the processing of perceptual grouping in the absence of visual attention.

We argue that to assess this type of dissociation requires specific methodological adaptations to determine whether visual attention is in operation.

We caution that Shomstein et al. ’s article does not present convincing evidence of grouping without attentional selection because they do not directly assess attentional selection in their experimental task.


It is really no surprise that the clinical phenomenon of hemispatial neglect periodically catches the attention of cognitive scientists who are interested in the foundational question of how visual consciousness and perception interact: In neglect, there appears to be a dissociation between the two so that patients behave as if they are blind to the visual world contained in the contralesional hemifield (usually left), though it can be shown that basic vision is, in fact, largely intact.

Hemispatial neglect, as we will refer to it here, is often caused by a stroke that damages neural tissues within several structures of the right cerebral hemisphere, often in the parietal/posterior temporal lobe area.

This lesion spares primary visual cortex and most of the pathways that carry visual information to it, including most of the optic radiations originating in the ipsilesional lateral geniculate nucleus.

Whether tested by the wiggle of a single finger placed at different points in the patients’ visual field or by formal perimetry, it is usually possible to demonstrate that hemispatial neglect is not the result of a primary sensory deficit.

Hemispatial neglect patients can often detect a simple moving finger, or blinked dots of light in the very areas of the contralesional visual hemifield that they seem not to see or use when navigating around a room, eating food on a plate, or combing their hair in a mirror.

Neglect patients will rack up bruises on the left sides of their bodies, have eyeglasses with the left lens broken, knock knickknacks off of furniture to the left of their routes, and eat only from the right side of a plate, as if their contralesional visual world does not exist.

Tragically, they often deny that anything is wrong, sometimes passionately so.

Their “anosognosia” for these problems makes treatment and rehabilitation difficult, if not impossible.


Shomstein, Kimchi, Hammer, and Behrmann (2010) try to capitalize on the apparent dissociation between vision and the processes that seem to mediate such patients’ use of visual information to investigate cognitive processes (i.e., perceptual grouping) in the absence of visual attention (i.e., using hemispatial neglect patients as participants).

As we will review below, this simple dissociation is not the nature of hemispatial neglect.

On the basis of patients’ performance across two tasks, Shomstein et al. conclude that “perceptual grouping” occurred without attention or awareness.

Although this may be true under certain circumstances, it cannot and should not be drawn from the data presented.

Our point of contention rests on the validity of Shomstein et al. ’s (2010) critical claim that the congruity effect observed on their sequential matching task occurred without “attentional selection.” This is a questionable assertion because assessment and determination of patients’ attentional selection abilities was based on a completely different task (i.e., the “attentional cuing” task) from the one used to infer the influence of perceptual grouping.


There are two reasons why one cannot be confident that evidence of attentional selection provided by one task may be used to infer the level of attentional selection in another.

First, the relationship among tasks sensitive to neglect tends to be highly variable and often weak; and second, neglect itself tends not to be uniform across the neglected field, especially if the tasks are not equally sensitive to symptoms.

The literature is full of examples of the psychometric variability among measures of neglect.

Different standard neglect measures vary greatly in sensitivity [1], in how they covary, and in their consequent factor structure [1][2].

For example, Azouvi et al. examined the correlations among typical clinical measures of neglect (e.g., line bisection, cancellation), finding correlations that ranged from as low as r = .10 (for figure copying vs. 5-cm line bisection) to r = .78 (for naming of overlapping figures vs. reading) with a mean correlation (between the Bells test and other measures) around r = .56, suggesting only about 30% common variance.

Furthermore, in a study of 120 patients with hemispatial neglect, McGlinchey-Berroth, Bullis, et al. found groups of patients who performed poorly either on line bisection or on search tasks but not on both, indicating that impairments can occur on one task independently of the other.


For their claim to be valid, one would have to assume that in the Shomstein et al. ( 2010) study, the sensitivity to attentional selection in the cuing task was less than or equal to what would have been required in order to discriminate between the grid patterns presented in the left hemifield in the sequential matching task.

Unfortunately, Shomstein et al. do not assess how accurately the participants discriminated the distractor patterns presented in the cross-field condition of the sequential matching task.

In order to infer a lack of attentional selection in the sequential matching task, one would have to bet that patients would perform worse on that task than on the cuing task.

Such a bet would be ill advised, not only because of the issue of task variability, but also because there is reason to believe that the patients had a pretty good chance of telling whether the patterns were the same or different using intact attentional selection, as we will demonstrate below.


One of the mysteries of neglect is that symptoms can vary with the frame of reference in which attention is deployed.

Some patients seem to neglect the left side of space, defined by their subjective visual midlines; some show neglect for the left side of objects even when the objects are placed to the right of midline; and some patients show evidence of visual allesthesia, transposing information present in the left hemifield into the right.

These phenomena have been well documented in the literature [3] and studied experimentally [4], reflecting the variability in how attention may be deployed in this patient population.

Recent attempts to study the quantitative distribution of attention in neglect document not only that the likelihood of attentional selection is highly variable within the neglected hemifield, but that such selection often shows a clear gradient, with the greatest likelihood of signal detection occurring close to the midline, dropping off toward the left and bottom of the field [5][6].


Deouell, Sacher, and Soroker (2005) presented a sophisticated analysis of this phenomenon measuring reaction time and accuracy to detect a small circular target presented against a changing array of distractors across the visual fields of right- and left-hemisphere stroke patients.

Only for right-hemisphere patients did they find that the detection of targets could be equivalent within several degrees on either side of the central midline, with some patients detecting targets well into the left hemifield.

Given these findings, one could ask whether partial access to the grids in the sequential grouping task provided enough information to allow the participants to discriminate between the stimuli, even if the entire grid was not available to attentional selection.

An inspection of Figure 2 in Shomstein et al. ( 2010) suggests that the answer to this question is “yes”; it may be possible to distinguish between same and different trials using only the rightmost portion (next to midline) of the overall design for left hemifield grids.

For the reader’s convenience, Figure 1 shows occluded views of Shomstein et al. ’s figures, leaving only two dots visible on the right side of the designs.

It is clear that it is only necessary to see that two adjacent dots have the same or different contrast to distinguish the grids.

Although the grayscale levels may change from trial to trial, the contrast between pairs of horizontally adjacent dots may have served as a cue to the condition.


We assert that if the patients can attend to even a small portion of the design that proves to be sufficient to distinguish between conditions, the effects on the target cannot be interpreted as evidence of any sort of perceptual processing without attentional selection.

Nevertheless, the demonstration of perceptual processing in the “absence of attention” is not without precedent [7][8][9][10].

There is even some evidence of the existence of what were termed “preattentive grouping mechanisms” in a study of illusory contours in patients with neglect [11].

These studies had to confront the same complex clinical phenomenology using experimental methods like Shomstein et al. ’s (2010), and suggest that there is some methodological redress for the issues that we have raised here.


One solution is to create a control condition requiring attentional selection of the distractor grids juxtaposed to stimuli that are similar to those that were used as targets (basically reversing the task).

This was the standard used in the first experimental demonstration that pictorial information in the neglected field could semantically prime lexical decision targets that were presented centrally [8].

Not only was it demonstrated that patients could not reliably identify the pictures in a forced choice task presented under conditions identical to the priming paradigm, but data were presented showing that patients with actual visual hemifield deficits did not prime.

In the context of the Shomstein et al. study, if patients cannot make same/different judgments at a level greater than chance and still show a congruency effect on the main task, the authors will have a convincing demonstration that grouping can occur without attention.

Until then, the acceptance of these data as evidence of grouping without attentional selection would require a kind of anosagnosia to methodological detail on the part of the reader.


Hemispatial neglect can, indeed, provide a window into the complex interaction between consciousness and visual perception.

However, such investigation requires extraordinarily careful attention to the inherent sophistication of the visual system to adapt to natural and experimental challenges.

It is imperative when using hemispatial neglect as a model for normal processing without awareness that investigators be mindful across the entire methodological space.


Milberg and McGlinchey (2010) claim that the conclusions we reach in “Perceptual Grouping Operates Independently of Attentional Selection: Evidence From Hemispatial Neglect” are unwarranted.

Specifically, it is asserted that insufficient methodological control was exerted over the attentional status of the patients and that partial attention to the contralesional field could have resulted in the congruency effects we observe.

Although we agree with their methodological cautions in general, we argue that our investigation is, in fact, methodologically sound.

In particular, we reiterate and highlight that our investigation is unprecedented in the characterization of a patient sample with multiple clinical, psychophysical, and experimental measures; in our use of a stringent, rigidly controlled paradigm specifically designed for investigating perceptual grouping without awareness; in our modification of the experimental procedure to make it even more stringent; and in our specific methodological choices for comparison/control conditions within this experimental paradigm.

We also demonstrate that partial attention to the contralesional left cannot support the robust congruency effects we observe.

In light of this, we remain confident of our interpretation of our findings and suggest that perceptual grouping can indeed operate in the absence of attention.


In their critique of our article “Perceptual Grouping Operates Independently of Attentional Selection: Evidence From Hemispatial Neglect” (Shomstein, Kimchi, Hammer, & Behrmann, 2010), Milberg and McGlinchey (2010; MM) accurately capture the key characteristics of hemispatial neglect.

Additionally, and rightly, they point out that this neuropsychological disorder is of great interest to vision scientists, given the dissociation between the patients’ apparent perception of the visual world concurrent with their lack of conscious awareness of the very same perceptual information.

The study of the extent to which perceptual information can be processed in the absence of attention and awareness has a long and controversial history in psychological science [1, 2, 3] and in neuropsychology [4, 5], and this issue is still heavily debated.

It is the case, however, that MM’s core criticisms of our methodological choices, including the way we characterize the attentional abilities of our neglect patients and our choice of paradigm and control/comparison conditions do not fundamentally challenge our core findings and, moreover, do not challenge our conclusion that perceptual grouping can indeed occur in the absence of attention.


Neglect As a Model for Investigating Perceptual Grouping Without Awareness


One of the longstanding problems that continues to plague researchers interested in “perception without awareness” is the difficulty in ensuring that the observer is indeed unaware of the information s/he is purported to have processed perceptually.

The study of the nature and extent of perceptual processing in the contralesional field in individuals with hemispatial neglect is especially appealing, then, because it offers a methodological alternative to circumvent the need to ensure that “unattended” information is indeed “unattended.” Given that these patients do not orient to the contralesional side and that they do not volitionally report the information on the unattended side, the assumption is that they are simply not aware of this information.

One can then ask how much perceptual processing takes place under these conditions of inattention.


Since the early studies of Volpe, Ledoux, and Gazzaniga (1979) and Marshall and Halligan (1988), many neuropsychological investigations have examined the fate of the unattended contralateral information, and MM and their collaborators have contributed substantially to this literature [6, 7, 8].

Our study is conducted within this neuropsychological tradition and focuses on whether contralesional perceptual information (appearing on the left side in patients with a right-hemisphere lesion) can be grouped or organized perceptually in the absence of attention.

We also explore whether the perceptual fate of this unattended information varies with the severity of the hemispatial neglect.


To address this issue, we adopt a procedure that has been extensively and successfully used in investigations that ask similar questions with normal observers.

In brief, in our study, 8 patients with hemispatial neglect (diagnosed using a standardized, normed bedside battery, and confirmed and quantified using a covert spatial attentional paradigm) performed a matrix change detection task on a black and white checkerboard placed in their intact ipsilesional field.

The matrix could remain the same across two successive displays, or a single square could be shifted.

Concurrent with this demanding perceptual task, task-irrelevant information, consisting of grayscale circles, was presented in the contralesional field.

The task-irrelevant information could either maintain the same perceptual organization from Display 1 to Display 2 (e.g., in both cases the circles would be grouped by lightness similarity into rows) or change from Display 1 to Display 2 (e.g., change from grouping into rows to grouping into columns).

Note that, independent of whether the organization of the circles was maintained or not, all circles changed their grayscale value from Display 1 to Display 2 to control for the possibility that changes in organization could be detected from changes in the lightness of each circle.


Our central finding is that the reaction time in the ipsilesional matrix task is influenced by the change in or maintenance of the organization of the ignored task-irrelevant circles in the contralateral field.

Thus, “same” responses to the checkerboard matrix were faster when the organization of the task-irrelevant circles remained the same (e.g., organized into rows in both Displays 1 and 2) than when the task-irrelevant organization differed (e.g., organized into rows on Display 1 but into columns on Display 2), and vice versa for task-relevant “different” responses.

Not only was the extent of the congruency effect equivalent for the patients and the controls, but the magnitude of the congruency effect was statistically equivalent for patients who were mildly neglectful and for those who were more severely neglectful.

Finally, and importantly, for all individuals, the magnitude of the congruency effect was equivalent when the task-irrelevant circles were presented in the left field and, in another control condition, in the right visual field together with the change detection matrix, demonstrating that implicit perceptual organization is as good in the unaware contralesional field as in the ipsilesional field.


MM, while acknowledging that perception might indeed occur without awareness under some conditions (as they themselves have demonstrated in the past), challenge our conclusion that patients with neglect evince perceptual grouping in the absence of attention.

Moreover, they assert that we have “anosagnosia” (a condition in which a person who suffers disability seems unaware of or denies the existence of his or her disability) to methodological detail and that researchers (including us) need to be mindful of details across the entire methodological space.

While MM’s assertions are witty, the arguments themselves are weak.

They raise two key issues, which, they suggest, prevent us from reaching our conclusion.

One issue concerns the assessment of the patients’ attentional abilities on a task different from that used to infer inattentional grouping, and the second is that neglect is not uniform across the neglected field and so patients may be explicitly able to process some of the supposed unattended information.

We deal with each issue in turn.


Assessment and Determination of Attentional Abilities Was Established on a Task Different From That Used to Infer the Influence of Inattentional Grouping


Of note too, the covert attentional paradigm task (adopted from Posner, Snyder, & Davidson, 1980) was not used to determine simply whether the participants did or did not have neglect; that determination was made on the basis of the BIT scores.

The covert attentional task was used: (1) to confirm the presence of attentional neglect with a sensitive psychophysical test, thereby increasing our confidence in the neglect diagnosis; and (2) to determine the severity of attentional neglect for each individual, a point that is not acknowledged by MM.

We also confirmed that the BIT neglect scores and an index of attentional dysfunction (derived from the covert cuing paradigm) of the patients were highly correlated.

We note, too, that previous studies have documented a strong association between clinical measures of neglect and performance on the cued attentional paradigm that we have used [11].

There is no question, then, that the diagnosis of neglect in the patients was correct and, moreover, that the quantification of the extent of the neglect, as derived from the BIT and cuing task, was accurate and reliable.

Our approach of diagnosing and quantifying the severity of the neglect impairment across multiple tasks goes well beyond what is typically done in the existing literature.

With few exceptions, the characterization of neglect in existing neuropsychological studies of perception without awareness is done on the basis of lesion site, clinical observation, and/or some bedside testing (horizontal line bisection, line cancellation, figure drawing, single word reading).

We are confident that we have thoroughly characterized the nature and severity of the attentional impairments in our sample of neglect patients and, therefore, that our results are strengthened, not weakened as MM suggest, by our findings of highly correlated impairment across both traditional and psychophysical measures of attentional abilities in the patients.


Patients Able to Detect Some Left-Sided Information


MM also claim that because the assessment of neglect is not done in the context of the detection task, we do not know about the patients’ attentional status during the actual experimental paradigm.

In other words, they argue that our conclusions for inattentional grouping of contralesional information are not warranted, because the neglect evinced by our patients may not be uniform across the field during the experiment itself.

Thus, the patients may still have been able to utilize some of the information from the left field and this information might have given rise to the observed congruency effects.

They suggest that if this is true, then the effect of contralesional information on the matrix task cannot be interpreted as evidence for processing in the absence of attention.

MM appeal to several studies showing that some neglect patients are still able to detect targets placed well into the left hemifield.

They also illustrate their point in a figure by showing that even partial information, such as that placed just to the left of the central midline, may have been enough to give rise to the congruency effects we report.

We were well aware of this possibility when we designed the experiment and went to great lengths to constrain the paradigm and limit attention “leaking” to the neglected field.

We submit that our paradigm makes it highly improbable that patients could make use of left-sided information, and that in the highly unlikely case that some attention had “leaked” through, this could not suffice to give rise to the findings we have obtained.


Experimental Changes to Limit Attentional “Leaking” to the Contralateral Field


The experimental paradigm we adopted has been used previously to demonstrate grouping in the absence of visual attention.

Indeed, Driver, Davis, Russell, Turatto, and Freeman (2001) have argued that it is only in the context of indirect tasks such as this one (and essentially we use the same task that they did), where the observer is not directly questioned and where the limitation of self-report is circumvented, that conclusions about processing in the absence of attention can be reached.

This type of matrix comparison task, in the presence of task-irrelevant distractors, has been used in other recent studies, too.

In all these studies, normal participants perform a demanding change detection task on a small black-and-white matrix at fixation, and task-irrelevant background elements are arranged by color similarity into columns, rows, or simple shapes [12, 13], or the background is composed of alternating regions organized into figures and grounds by convexity [14].

In these paradigms, as is also true in our paradigm, independent of any change in the target matrix, the perceptual organization of the background can change or remain the same across two successive displays.


These studies all report that the status of the background organization influenced the speed and accuracy of change judgments for the central matrix task, even though the status of the background organization (continuity or change) could not be explicitly reported when probed with surprise questions as in Mack and Rock’s (1998) inattention blindness studies.

That the observers were unable to report the status of the task-irrelevant circles was taken as evidence that the observers were unaware of the perceptual organization of the background, yet congruency effects were still obtained.

Crucially, these experiments were conducted with normal observers who are usually attentive to the entire field.

Even though the checkerboard matrix was essentially embedded into the center of the task-irrelevant background, there is general agreement that the matrix change detection task is so absorbing/demanding and of such high attentional load [15] that no attention can “leak” to the background display.

In our version of the paradigm, the matrix and task-irrelevant grid were spatially separated, making it even more unlikely that the contralateral task-irrelevant information was processed.

Thus, the chances of attention “leaking” to the neglected field were extraordinarily slim.


In addition to separating the change detection matrix and the distractor grid spatially, we imposed additional, carefully controlled, constraints on our task to make it even more unlikely that the patients could process the distractors in the contralesional field.

In particular, we manipulated the exposure duration of the first display of the trial (see Figure 2A in Shomstein et al., 2010) via a staircasing procedure that yielded 85% accuracy in the matrix change detection task.

Thus, the observers had limited exposure to the initial display, requiring them to focus on the relevant, and not on the irrelevant, task.

Additionally, we know that patients with neglect tend to be more rightward oriented in their gaze (and attention) [16, 17], further ensuring their ipsilesional bias: Indeed, the average spontaneous gaze position of a group of patients with neglect was 46º to the right [18].

If this ipsilesional bias, or something akin to it, was true in our sample of patients, this further decreases the probability of the patients’ processing of the distractor circles.


Furthermore, if, for argument’s sake, we were to entertain the possibility that, notwithstanding the constraints of our design, patients had some residual attention to be allocated to the task-irrelevant distractor, we might have predicted modulation of the distractor congruency effect with the severity of neglect (normal, good detectors, poor detectors).

As is evident from our findings, this prediction was not upheld: The extent to which task-irrelevant distractors affected target processing did not differ as a function of neglect severity in the patients, and, even more convincingly, the patients’ performance was not statistically different from that of controls.


Was Any Contralateral Information Useful for Discriminating the Grids Without Invoking Perceptual Grouping?


MM concede that the entire task-irrelevant distractor grid might not have been processed but then ask whether partial access to the rightmost portion of the grid might have sufficed to allow the participants to discriminate between the grids and to establish whether the grids changed or remained the same across successive displays.

MM provide examples of a possible scenario in which the patients have access to two adjacent dots.

On MM’s account, the observer need only see whether the contrast between two dots remains the same or changes in order to distinguish between the grids: If the contrast between the two dots remains the same across two successive displays, the grids remain the same, whereas if the contrast changes, the grids change.

However, for the contrast between two dots to be a valid cue for distinguishing between the grids, it is necessary that the patients are indeed able to compare the contrast between the pair of dots on Display 1 and Display 2 and, critically, that they are able (under carefully titrated limited exposure) to zero in on the precise two dots in their neglected contralesional field.


Let us illustrate the situation first for the rows/columns condition.

Imagine, for example, that the patients focus on the two horizontally adjacent dots on the upper right corner of the distractor grid on Display 1 and Display 2 (as depicted in MM, Figure 1).

In this case, the contrast between two dots might serve as a valid cue, and congruency effects could possibly arise. But what if, on some of the trials, the patients focus on adjacent dots of different orientations in successive displays—for example, on the two horizontally adjacent dots on the upper right corner on Display 1 and on the two vertically adjacent dots on the upper right corner on Display 2? In such a case, the contrast between two adjacent dots is no longer a valid cue for distinguishing between the distractor grids, because the contrast between the pair changes across successive displays when the grid organization remains the same.


Thus, just detecting whether the contrast between two adjacent dots changes or remains the same is not sufficient for distinguishing between the distractor grids; the pair of two adjacent dots across successive displays needs to be of identical orientation.

It follows, then, that the contrast between two adjacent dots can be a valid cue on some trials and invalid on others, depending on whether or not the patient focused on the pair in the same orientation.

Nevertheless, our results showed reliable congruency effects in this condition.


The probability of the contrast between two adjacent dots serving as a valid cue for distinguishing between the distractor grids is even lower in the square/cross condition.

In this condition, there is only one pair of horizontally adjacent dots on the rightmost portion of the distractor grid that can provide useful information—the two rightmost horizontal dots located on the midline (depicted in MM, Figure 1)—and perhaps two pairs of vertically adjacent dots located on the middle of the next to the rightmost column.

No other pair of horizontally adjacent dots or vertically adjacent dots on the rightmost portion of the display, nor even the whole rightmost column, provides predictive information.

Thus, in this condition, not only do the patients have to focus on the same orientation across successive displays, they also have to focus on the precise two adjacent dots that can provide the useful information.

Given these constraints, the chances that the contrast between two adjacent dots in the rightmost portion of the display would serve as a valid cue on all trials are clearly low.

Nonetheless, we again obtained reliable congruency effects in this condition, and most importantly, there is no difference in congruency effects between this condition and the rows/columns condition (or between cross-field and within-field trials).


It is clear then that just attending to a small, rightmost portion of the distractor grid is not sufficient for reliably distinguishing between the grids, particularly across conditions.

Rather, the robust congruency effects that we obtained in the two organization conditions most likely arose from changes in the perceptual grouping of the distractor circles, strongly supporting our conclusion that perceptual grouping can take place in the absence of attention.


An Appropriate “Control Condition”?


MM suggest that one way we might have provided firm evidence for the absence of attention in the contralesional field would have been to create a control condition in which the patients were required to perform a task on the distractor circles in the presence of the checkerboard matrix (i.e., reversing the task).

They argue that this condition would have yielded a measure of the extent of left-sided attention (or lack thereof) under the same conditions as the experimental grouping paradigm.

MM themselves adopted this approach in a study in which they explored whether pictorial information presented in the neglected field was processed sufficiently well to prime lexical decision targets presented centrally [7].

In addition to the patients’ completing the pictorial semantic priming task, their patients performed a control task requiring forced-choice discrimination of the very pictures used in the semantics task.

The results revealed that pictures presented to the neglected field yielded faster lexical decision times to the central probe when the picture and word were related than when they were not related (semantic priming).

Moreover, because, in the discrimination condition, the patients could not reliably identify the left-sided pictures, McGlinchey-Berroth et al. ( 1993) concluded that the neglected/unattended information can indeed be processed semantically.


In a comprehensive review on perception without awareness, Farah (1994) argued that the conclusions from McGlinchey-Berroth et al. ( 1993) were not definitive in and of themselves and she challenged the findings of both the experimental task and the control task.

First, in semantic priming paradigms with pictures used as the prime, normal observers typically show more priming (faster reaction time for semantically related than for semantically unrelated picture primes preceding letter string probes) when the picture prime is presented in the left field than when the picture prime is presented in the right field.

However, the neglect patients in the McGlinchey-Berroth et al. ( 1993) study showed equal priming from the picture primes presented to the left and to the right of fixation.

The absence of the normal left field priming advantage in the neglect patients suggests that processing of neglected information in the contralesional left field might not be normal and, as such, may undermine their claim of preserved semantic processing under inattention.


It is also possible that the observed semantic facilitation might not result from the pictures’ being semantically processed in the absence of attention and that an alternative mechanism might be at play.

Thus, rather than the pictorial information (say, a picture of an eye in the left field) priming the lexical decision to the letter string “nose” presented centrally, it remains possible that backward priming occurred from the central letter string.

On this account, the letter string “nose,” represented well (given its central location), activated its semantic associates and then backwardly primed the poorly perceived pictorial information “eye” in the neglected left field.

The activation of the “eye,” in turn, speeded the lexical decision response time.

It has previously been shown that even contralesional information that is greatly degraded by the presence of neglect can still be recovered by top-down pattern completion (akin to backward priming).

Thus, activation of the letter string “nose” and its activated semantic associates can lead to pattern completion of the impoverished representation of the picture of the “eye” in the left field.

This pattern completion would not occur for unrelated semantic information; the letter string “ship” has no semantic means to activate the representation of the picture of an “eye.

” This type of pattern completion and its ability to offset the neglect impairment has been demonstrated in empirical findings as well as in computational investigations of these neglect phenomena [19, 20].


Farah (1994) also challenged the conclusions of McGlinchey-Berroth et al. ( 1993) on the basis of their control condition.

In the forced-choice discrimination control condition, when the pictures were on the left, the neglect patients performed roughly at chance (56%), indicating minimal, if any, discrimination of the pictorial information on the left, and supporting the claim of insufficient attention to information in the left field.

However, Farah pointed out that the discrimination accuracy for the pictorial information presented in the right field was only 74%, raising concern that performance on this control task might have been limited by factors other than the neglect per se.

The implication is that confirming that attention is not deployed contralesionally, under conditions that resemble those of the experimental paradigm, is not straightforward, and reaching conclusions about the true status of attention during the experimental task is not trivial.


Conclusion


In conclusion, MM caution us and other researchers about the need for extraordinarily careful attention to the sophistication of the visual system and the importance of being mindful across the entire methodological space when designing experiments to examine perception without attention.

We wholeheartedly agree with these cautionary warnings, which is exactly why we were unprecedented in the characterization of our patient sample with multiple clinical, psychophysical, and experimental measures; in our use of a stringent, rigidly controlled paradigm specifically designed for investigating perceptual grouping without awareness (even in typical observers); in our modification of this procedure to make it even more stringent (staircasing the display, separating the task-relevant and task-irrelevant information); and in our specific methodological choices for comparison/control conditions within this experimental paradigm.

Thus, we are confident in our findings and conclusion that perceptual grouping can occur in the absence of attention.


Investigations of relative sea-level changes at local and regional scales are important to distinguish the impact of land tectonics and isostasy from those of eustatic sea level changes.

This works aims to comment and provide alternative interpretations to the data used by Castro et al. ( 2014) to discuss the behavior of the paleo-sea level at Rio de Janeiro coast during the Mid to Late Holocene.


Castro et al. ( 2014) paper presents new relevant information to aid with Holocene relative sea- level (RSL) reconstructions along the coast of Rio de Janeiro.

The data set is extensive (29 listed indicators, out of which 14 were used in the sea level curve) and from different sources.

However, there are several problems that compromise the authors' interpretations and final conclusions.


The first concerns, and perhaps the most compromising, is related to the paleo-sea level reconstruction.

The authors mistake the altitude of the indicators as the paleo-sea level.

As a result, their final paleo-sea level curve is not a relative curve but a curve showing the altitude of the paleo- sea level indicators (vermetids and beachrock shells).


Castro et al. ( 2014) postulate that one of the greatest challenges in generating an RSL curve is ) compares the upper limit of former urchin holes with the upper limit of living urchins.

As this distance is around 2 m the author correctly concludes that the older urchin holes indicate a paleo-sea level 2 m higher than the present one.

Hence, there is no need to determine the present mean-sea level.

This procedure was largely accepted and is described in several manuals on sea-level reconstructions (e.g. Martin et al. 1982, Van de Plassche 1986, Pirazzoli 1996).


Castro et al. ( 2014) also postulate that several investigations conducted on the South American coasts regarding relative sea-level variations have not clearly or precisely defined the reference level of the samples used in the vertical plane.

This is true because it is not necessary.

The authors stress that the absence of this information yields potential inaccuracies regarding the height of the marine paleo-levels of the proposed curves.

That, on the other hand, is incorrect because the inaccuracies in defining paleo-sea levels are related to the intrinsic characteristics of the given indicator, its vertical spread and the uncertainty related to where, within this spread, the remains are from.

It is not related to the accuracy of determining the present mean- sea level.


On the same line the authors also stress that the field method applied for estimating the elevations of the samples (GPS trackers) has a very small margin of error and therefore suggest that the method employed in this study would need to be applied to other parts of the Brazilian coastline.

We emphasize that this procedure is not necessary, and that efforts must concentrate on the determination of the vertical distance between the paleo-sea level indicators and their living homologous one.


Moreover, the error inherent to the paleo-sea level indicator is tens to hundreds of times larger than the measurement error associated with GPS trackers.


Other worth-mentioning confusions in the paper are:


(1) The authors assertion that their results confirm other data already obtained elsewhere along the Atlantic coast of South America.

This is not possible because along the Atlantic coast of South America there are divergent data (e.g. Martin et al. 2003, Angulo et al. 2006), including a former Castro et al. ( 2012) paper where it is postulated that at 13,130 calibrated years before present (cal a BP) sea-level at Cabo Frio was 1.5 m above present sea- level.

Furthermore, it is remarkable that those two comprehensive papers about Holocene sea-level changes along the Brazilian coast (Martin et al. 2003, Angulo et al. 2006) have not been referenced.

In addition, several paleo-sea level reconstructions from the state of Rio de Janeiro were not even mentioned, including those from Cabo Frio region published in former works (Laborel 1969, Delibrias and Laborel 1969, Martin et al. 1979, 1979/80, 1983, 1984, 1996, 1997, Martin and Suguio 1978, 1989, Maia et al. 1984, Table I) and used by Angulo et al. ( 2006) to build the Brazilian sea-level envelope from Pernambuco to Paraná (Fig. 1)


(2) The authors inform that the vermetid used as a paleo-sea level indicator corresponds to Laguncularia racemosa.

This is a mangrove, not vermetid, species.

Probably the vermetid found at Cabo Frio corresponds to Petaloconchus (Macorphragma) varians, the most common vermetid species along the Brazilian coast.


(3) The authors inform that eight percussion drills were performed perpendicular to the coastline within the study area, but no data or interpretation of those cores are presented in the paper.


(4) The authors inform that in total, 29 (or 22) samples were radiocarbon dated for conventional method but we can only identify 14 dated samples in the curve.

Besides, there is no clear indication 2107 as to which listed samples the points in the curve correspond to.

To use the beachrock, or any coastal sedimen- tary deposit, as an indication of paleo-sea levels de- mands knowledge of its sedimentary facies associ- ation.

No information about the beachrock facies is provided by Castro et al. ( 2014).

The authors only inform that the sedimentological and stratigraphic characteristics of the beach environment, which include a tabular morphology with smooth dips be- low >3° and a micro-tidal regime with variations of <1.0 m on the coast of the state of Rio de Ja- neiro, confer accuracy to these rocks as indicators of the mean sea-level.

Consequently, they infer that all altitude samples correspond to former mean-sea level.

It is well known that beachrocks have differ- ent origins and can be formed at several altitudes (see e.g. Stoddart and Cann 1965, Hopley 1986, Turner 2005, Vousdoukas et al. 2007).

One of the samples used by Castro et al. ( 2014) to build their curve corresponds to mollusk shell fragments from Jaconé beachrock described and dated by Mansur et al. ( 2011).


After analyzing the beachrock facies, Mansur et al. ( 2011) concluded that the dated shells fragments were deposited at the lower part of the beach face at a time when sea-level was a little low- er than the present one.

Hence, it can be suggested that sea-level was a little lower (0.5 m, according Castro et al. 2014) than the present one between 8198-7827 cal a BP (age of shell fragments) and 6008-5786 cal a BP (age of beachrock cement, Mansur et al. 2011, Table II), which again fits with the eustatic sea-level curve produced by Milne et al. ( 2005).


We argue that the dates presented by Castro et al. ( 2014), when correctly interpreted, are compatible with the eustatic sea-level curve proposed by Milne et al. ( 2005) for the coast of Rio de Janeiro, with the sea-level envelope proposed by Angulo et al. ( 2006) for the Brazilian coast between Pernambuco 2110 RODOLFO J. ANGULO, PAULO C.F. GIANNINI, MARIA CRISTINA DE SOUZA and GUILHERME C. LESSA and Santa Catarina and with former data published from the coast of Rio de Janeiro.

In summary, it can be stated that: (a) the paleo-sea levels inferred by vermetid remains show that sea-level has fallen over the past 4400 cal a BP; at least (b) the paleo- sea level inferred by the beachrock facies and dated shells of Jaconé shows that sea-level was near the present elevation between 8198 and 5786 cal a BP; and (c) several shells from other beachrocks were deposited probably thousands of years after the specimens died and consequently do not allow precise reconstructions of paleo-sea levels.


Interpretation of sea-level indicators is essential when studying paleo sea-level fluctuations during the Holocene.

Sea-level indicators may have different origins, such as geological (beachrocks) and biological (vermetids and barnacles).

In order to reconstruct paleo sea-level, it is necessary to attribute an indicative meaning to each sea-level indicator.

This paper aims to discuss issues raised by Angulo et al. ( 2016) regarding to the sea-level fluctuations curve proposed by Castro et al. ( 2014) to the Rio de Janeiro State coast, Brazilian southeast.

The key issue that deserves posing is that local or regional curves cannot be built based on large scale (global) RSL geophysical models even in places of steady crust like Brazil.

Here, we put into question the relative sea-level fluctuation curve model proposed by Angulo et al. ( 2006, 2016) to the coast of Rio de Janeiro State and Pernambuco State.

It is strengthened the proposal of using different origins indicators on RSL vertical variation, georeferenced by high precision altitude GPS, adjusted by Brazilian Geodetic System benchmarks, maintained by the Brazilian Institute of Geography and Statistics - IBGE.

All issues regarding the curve drawn by Castro et al. ( 2014) are answered based on field data, laboratory analytical techniques, radiocarbon dating as well as relevant literature.

We appreciate Angulo et al. ( 2016) comments and the opportunity to discuss some important aspects related to sea-level fluctuation and coastal evolution in southeastern Brazil.

Data confrontation and controversy involving interpretation related to sea-level changes at the Brazilian coast during the Holocene are a challenge for the advancement of scientific knowledge about the subject.


In the 1980s curves of relative sea-level changes worldwide during Holocene have revealed great surprises and brought up unconceivable discussions before that time.

Among them the fact that there is no single curve of global variation even in regions of stable crust like Brazil [1].

This finding has pushed for new researches aiming RSL curves all around the world.

Suguio et al. ( 1985) have proposed that paleo sea-level have dropped from 4.0 m to 5.0 m in the last 5,500 years in the Brazilian east coast [2].

The idea of paleo sea-level higher than the current during Holocene was accepted with a degree of reluctance since it was contrary to the United States east coast curve, which shows an ongoing ascension at the same time interval.

From the end of last century till nowadays divergences have arisen regarding data interpretation about relative sea-level curves at the Brazilian coast.

Tomazelli et al. ( 1998) has sketched out a curve to Rio Grande do Sul State coast that diverges in some aspects from curves proposed by Suguio et al. ( 1985) for other regions along the Brazilian coast [3].

The Rio Grande do Sul State curve shows that the sea would have risen in the last 2,000 yrs.

According to curves of Salvador (Bahia State), Santos (São Paulo State) and Itajaí (Santa Catarina State) the sea-level would have dropped in the same time interval.

Angulo et al. ( 2006) expressed doubts on the high frequency oscillations of 200 to 300 years proposed in those curves [4].

Martin et al. ( 1998) have questioned the application of a single indicator for paleo sea-level reconstruction presenting a number of counterpoints and inconsistencies [1].

Bezerra et al. ( 2003) developed an envelope curve of relative sea-level fluctuation in the coast of Rio Grande do Norte State, meso tide dominated, showing oscillations after maximum Holocene high stand, which occurred at ~5000 cal yrs BP [5].

This curve shows remarkable deviations compared with average curve to the central-south Brazilian coast.

Castro et al. ( 2014) have proposed a RSL curve to Rio de Janeiro coast, involving the Holocene [6].

From the very first time in the Brazilian coast it was identified a negative record of RSL in the late Pleistocene and early Holocene.

As indicator it was used alignment of paleo beaches composed of submerged beachrocks.

After that transition, a process of relatively fast sea-level rise started, like in other curves proposed to the Brazilian east coast.

All indicators of RSL vertical variation identified, among them beachrocks, vermetids and barnacles, were georeferenced by high precision altitude GPS, adjusted by Brazilian Geodetic System benchmarks (RRNN), maintained by the Brazilian Institute of Geography and Statistics (IBGE).

In order to mitigate the influence of possible sedimentological factors and regional tide gauge, the proposed curve was built on a restricted segment of the coast with relatively homogeneous oceanographical, geological and geomorphological characteristics.


One fact that stands out in Angulo et al. ( 2006, 2016) is the altimetric data from ancient positions of relative sea-level were plotted based on a global model of curves made by geophysical simulations proposed by Milne et al. ( 2005) at the Caribbean and South America [7].

Such model covers a wide geographical extension between Jamaica (Caribbean) and Beagle Channel (Argentina).

In this model the spatial variation is dominated by the influence of ice and ocean mass redistribution on sea-level change with the ice-induced effect dominating the observed north - south trend [7].

Placement of indicators of few meters regarding the current zero sea-level cannot be adjusted to a global scale model of geophysical simulation since distortions and uncertainties are unavoidable.

Such distortion and uncertainty are visible in the curves shown by Angulo et al. ( 2006) based on works of geophysical simulation by Peltier (1988) and Milne et al. ( 2005) around the world, including Rio de Janeiro and Pernambuco coast [8].

The RSL global model of postglacial shows distortions in its own conception.

The main one is that relative sea-level curves in solid lines involving Pernambuco and Rio de Janeiro coasts points out altitude of +4.0 m over current sea-level around 7,500 years BP.

Such altimetric positioning contradicts almost all RSL literature in the Brazilian coastline [2, 5, 6, 9].

The Rio de Janeiro coastline is dominated by micro tide system with average spring tide of 0.90 m and neap tide between 0.06 and 0.025 m [6].

The Pernambuco coastline is characterized by meso tide system with average spring tide of 2.0 m and neap tide of 0.7 m. Levels of reduced tide gauge in both places are different.

Oceanographical, geological and geomorphological characteristics of both states are also completely different.

Therefore, curves of such distinct coastline segments cannot be the same.

The manuscript by Angulo et al. ( 2006) is no more than a reproduction of the geophysical simulation model initially proposed by Peltier (1988) and then by Milne et al. ( 2005) [8].

Factors such as fluvial sediment input in the inner continental shelf as well as tide gauge variations locally affect sea-level behavior.

Works developed in tide gauge stations over the wide Brazilian coastline shows, even in short-term scale, shows differences in the sea-level behavior from place to place.

Of course, known factors such as glacioeustasy, tectonoeustasy and geoidoeustasy are keys to understand and interpret global scale sea-level curves.

Below, we address the issues raised by Angulo et al. ( 2016) in detail: 1) We agree with Angulo et al. ( 2016) in regard with their data and our data.

Divergences and inconsistencies rely on many questions.

Angulo et al. ( 2006, 2016) do not explain, from the methodological point of view, how vermetids altimetric position was obtained.

By convenience it was used other authors altimetric information.

In the curves proposed by Angulo et al. ( 2006, 2016) to Rio de Janeiro and Pernambuco coastline, altimetric data were positioned based on global model of geophysical simulation, initially proposed by Peltier (1988) and then by Milne et al. ( 2005) [8].

Indicators of few meters regarding the current zero sea-level cannot be adjusted to a global scale model of geophysical simulation since distortions and uncertainties are unavoidable.


2) We are sure that vermetids are indicators of vertical fluctuation of paleo sea-level.

Nevertheless, indiscriminate use of certain species of Vermetidae could compromise information plotted in the vertical axis of relative sea-level fluctuation curve - RSL.

According to Oliveira (2016) there are some species of Vermetidae whereby distribution related to depth could vary from middle littoral or upper part of infra littoral to 100 m depth [10].

From 16 taxa existing in the Brazilian coastline, two species are wide used as indicators of vertical variation of paleo sea-level, Dendropoma irregulare and Petaloconchus varians.

According to Oliveira (2016), in the south of Cabo Frio, Rio de Janeiro State, there are no current correspondent of Petaloconchus varians to obtain the relationship between those species and the current relative sea-level.

Thus, it is used Phragmatopoma caudata to estimate paleo sea-level at the time corresponding to fossil vermetids.

However, Spotorno-Oliveira et al. ( 2016) have recorded the occurrence of Petaloconchus varians in several places of the region of Ilha Grande Bay, south coast of Rio de Janeiro State [11].

They are characterized by a complex structure formed by alive individuals in the upper layer and dead individuals in the lower layer along with the bedrock.

From the geomorphological point of view, they are positioned in the middle littoral on the rocky coasts and on the infra littoral they form “microatoll”.

The presence of alive homologous in this Brazilian coastline segment was also recorded by Spotorno-Oliveira et al. ( 2016) and Oliveira (2016) [10, 11].

It was possible to obtain at the field vertical ranges of occurrence of species relating to alive homologous at current sea-level and fossil vermetids, all placed above that level.

After being identified, it was defined altimetric ranges by high precision GPS (static method), proposed by Castro et al. ( 2014) [6].

Adjustments were made based on the Brazilian Geodetic System benchmarks (RRNN), maintained by the Brazilian Institute of Geography and Statistics - IBGE.

With respect to Angulo et al. ( 2016) question about Laguncularia racemosa as Vermetidae specie, please note that it is just a typing error in the article by Castro et al. ( 2014) [6].

We have advised a master thesis involving vermetids and sea-level variations which means that we would not make that kind of serious mistake.


3) Today we have no doubt that beachrocks (except the organic category) are great indicators of RSL.

This observation is supported by the doctoral thesis of Malta (2017) about genesis, petrography, lithification process, δ13C - δ18O stable isotopes and geochronology of beachrocks from Rio de Janeiro State coastline [12].

It also corroborates with information obtained by Mauz et al. ( 2015) and Malta (2017) [12, 13].

From the genetic view, beachrocks can be divided into four categories according to its process of lithification: (a) precipitation of highly magnesian calcite and aragonite from seawater due to high temperature, oversaturation and/or CaCO3 evaporation; (b) precipitation of calcite and aragonite from mixture of groundwater and seawater; (c) precipitation of magnesian calcite and aragonite by CO2 degassing from sediment and pore water; (d) precipitation of micrite calcium carbonate as a product of microbiologic activity [13, 12].

We considered that the lithification process of beachrocks (paleo beach) fit into (a), (b) and (c) categories.

Most part of beachrocks from Rio de Janeiro State fits into categories (b) and (c).

They were lithified in inter tide zone, exhibiting paleo beach or post-paleo beach environment.

This observation was supported by modern analytical techniques such as cathodoluminescence, stable isotopes, SEM and EDS.

It is considered that all beachrock outcrops used in RSL curve proposed by Castro et al. ( 2014) are geological indicators of relative sea-level fluctuation during Holocene [6].

Angulo et al. ( 2016) made a misunderstanding regarding beachrocks’ age suggesting that they were formed in thousands of yrs.

According to Malta (2017) beachrocks can be formed only in hundreds of years [12].

Indeed, it is not rare the occurrence of modern objects completely cemented by carbonate cement [12].

Beachrock sedimentary structures and their texture characteristics are representative of beach depositional environment due to hydrodynamic conditions during deposition and are usually well preserved.

Radiocarbon age differences between cement and mollusk shell in beachrocks are not very substantial.

It was verified on the worldwide literature that these rocks are almost all from Holocene [12].

In Brazil the beachrocks’ age vary from ~1,250 to 11,900 cal yrs BP.

The oldest ones can be found in the Rio de Janeiro coastline and the newest ones in the Brazilian northeast.

At the Rio de Janeiro coastline all outcrops were lithified before coastal upwelling, around 3,000 cal yrs BP [12].

They are laid out submerged and surfaced aligned parallel to the current coastline.

In the light of that information complemented by measurements obtained by geodesic GPS of high precision as well as depth data assessed by echobathimeter, it can be inferred that those beachrocks were lithified in conditions of sea-level between -4.5 m in the transition from Pleistocene to Holocene and +1.5 m before coastal upwelling arrival, when lithification process was interrupted.

The paleoenvironmental reconstitution model developed by Castro et al. ( 2012) suggests that most submerged beachrocks in the Rio de Janeiro coastline are part of ancient drowned barrier island [14].

However, it is not ruled out that neotectonics of late Pleistocene have contributed with altimetric and bathymetric position of those rocks.

Therefore, we are sure that beachrocks are great indicators of vertical sea-level variation, except the organic category (d) resulting from precipitation of micrite calcium carbonate as a product of microbiologic activity.

With respect to beachrocks age in Castro et al. ( 2012) we can inform that all adjustment was made based on new radiocarbon dating and can be found in the work by Castro et al. ( 2014) [6, 14].


4) We are convinced that mollusk shell cannot give precise information about vertical variations of paleo sea-level.

However, they could give very important indirect information about upper limit (horizontal plane) of sea-level.

Castro et al. ( 2014) have associated horizontal projection of maximum Holocene transgression in the Rio de Janeiro State coastline based on the presence of mollusk shell deposited in ancient lacustrine system edge [6].

Cunha (2016) suggest that accumulation of mollusk shell deposited in current coastal marsh edge represents the most important record of positive oscillation of relative sea-level during Holocene in the Brazilian southeast [9].

Radiocarbon dating 14C in Anomalocardia brasiliana mollusk shell have shown ages between 6,335 and 4,800 cal yrs BP.

According to Cunha (2016) this time interval corresponds to the beginning of marine transgression, maximum Holocene peak (climatic optimum) and the sudden relative sea-level lowering [9].

According to Castro et al. ( 2014) and Cunha (2016) the sudden sea-level lowering in this region has caused widespread killing of mollusk shells many of them in position of life [6, 9].

The subsequent relative sea-level lowering has caused the formation of paleo lagoons, beach ridges and marsh resulting the progradation of coastline till nowadays.

The Holocene marine transgression in most part of Rio de Janeiro coastline was controlled by geological and geomorphological conditions imposed by the Paleoproterozoic basement, Barreiras Formation, as well as beach ridges surrounding the hydrographic basins of Una, São João, Macaé and Paraíba do Sul rivers.

The paleoenvironmental model proposed by Castro et al. ( 2014) and Cunha (2016) shows the basins of Una river and São João river flooded by Holocene marine transgression which has occurred between 6,335 and 4,800 cal yrs BP [6, 9].

During this episode, the relative sea-level has reached a maximum height between +2.50 and +3.0 m above the current level.


5) On the use of geodesic GPS of high precision when studying relative sea-level variations: whereas Angulo et al. ( 2016) acknowledge we have used “GPS trackers”, they fail to mention specifically post-processing GPS orthometric corrections, which not only lower positional error but also levels data to a common orthometric datum.

Further, they argue paleo-sea level are “not related to the accuracy of determining the present mean-sea level”, which while true, does not preclude present-day sea-level to be precisely defined in order to apply the knowledge of the sea-level variation to coastal management (e.g. NOAA’s Vertical Datum Transformation effort and Natural Resources Canada’s Height Reference System Modernization).

NOAA anticipated using the GPS for sea-level measurements: “data from new altimeter satellites combined with Global Positioning System geodesic data will soon clarify this uncertain situation”.

Moreover, NOAA states that “for application to climate change scenarios and to inundation analyses and modeling, it is critical that all elevations and depths be referenced to the same datum, regardless of source”.

They also recommend survey-grade equipment using GPS data in a kinematic differential mode to obtain orthometric heights precise to 30 mm - 40 mm RMSE, as we have used.

In summary, while we agree with Angulo et al. ( 2016) that “paleo-sea level reconstructions must consider the vertical distance between a given indicator and its present homologous one”, we also recognize several other factors that could have a role in this distance (e.g. neotectonics).

We did not yet attempt to model such factors but we strongly believe having measurements tied to an orthometric datum will help future analysis.

According to Castro et al. ( 2014), altimetric data collection on the ellipsoid as well as millimetric precise coordinates (x,y) were carried out by GPS Pro Mark 2 [6].

On the occasion of survey surfaced indicators (beachrocks) it was used static method based on echo bathimeter.

Unfortunately, we are forced to strongly disagree with Angulo et al. ( 2016).

We believe the data shown in our work were misinterpreted.

Such criticism does not contribute for the scientific knowledge progress around the topic discussed.

We must highlight the criticism made is not supported by field work in the Rio de Janeiro State coastline.

We also believe that our results are convincing and have been used to support many doctoral and master theses.

In this way, it contributes to better understanding of the relative sea-level fluctuations in the Rio de Janeiro coastline.

Moreover, such research includes high precision altimetric data collection, scuba diving, laboratory analytical techniques and geochronological information complemented by clear and objective methodological procedures.

The curve proposed by Angulo et al. ( 2006) to the Rio de Janeiro coastline reproduces the geophysical simulation model initially proposed by Peltier (1988) and then Milne et al. ( 2005) which was applied in many places around the world including Rio de Janeiro and Pernambuco’s coastline [8].

Tide gauge levels in both coastal segments are distinct.

Geological and oceanographical characteristics are also distinct, therefore the curve could not be the same for both sites.

We support the suggestion of using indicators from different origins when studying RSL vertical variation, especially beachrocks of the three inorganic categories above identified as well as vermetids of Dendropoma irregular and Petaloconchus varians species.

Although Anomalocardia brasiliana mollusk shell does not provide accurate information about paleo sea-level vertical position, it could be useful to define upper limit (horizontal position) of ancient sea-level.

The great sea flood caused by the maximum Holocene transgression in the Rio de Janeiro coastline is identified by the presence of mollusk shell deposited on the edge of ancient lagoon and bay systems.

Every RSL indicators must be georeferenced by high precision altitude GPS and adjusted by Brazilian geodetic system benchmarks or other system with similar properties in other parts of the world.

Therefore, RSL studies would be also useful when predicting future sea-level for coastal management programs.


Discussions are useful to the advance of science, and we appreciate the opportunity to discuss the paper by Castro et al. ( 2014) for the second time.

Here we maintain the interpretations presented in our discussion paper [1].

In the discussion paper we emphasized that the vertical position of a paleo-sea level indicator is not the position of the paleo-sea level.

We pointed out that: (1) to reconstruct paleo-sea levels it is crucial to determine the vertical distance between the indicators to their present homologous one; (2) margin of errors can only be established if considering the indicator’s intrinsic characteristics and (3) the interpretation of a sea level 3.0 to 4.5 m below the present one at 11.9 to-11.1 ka BP is in strong contradiction with worldwide established data and would require a detailed discussion [2].

We consider that Castro et al. ( 2018) do not properly address or answer the comments we made in the discussion paper.

More work and discussions are necessary to elucidate several questions that still remain about the sea level behavior in the Holocene.


Sealevel higher than present along the Brazilian coast were recognized by pioneer researchers.

Hartt (1870) described sea urchin holes elevated above the present living zone at Rio de Janeiro coast and Branner (1902) at Pernambuco coast.

The first datings confirming Holocene sealevels higher than present were published at the seminal paper by Van-Andel and Laborel (1964) on the State of Pernambuco coast.

Also at that time the monumental work of Fairbridge (1961) was published with global sea-level curves.


This paper issued a large discussion on the existence of small eustatic oscillations since the middle Holocene, with authors pointing out to the broad disparities of Holocene sea level curves around the world [3].

The first sketch of a curve in Brazil was published in 1975 with sparse data from Cananeia, and in 1980 the first paleo-sea level curve was published for the region of Salvador.

In 1985 new curves were presented for the States of Pernambuco and Santa Catarina.

These curves were widely accepted, and some divergences appeared in the 1990’s and others in the first decade of the XXI century [1].

After that a new curve for Rio de Janeiro was published by Castro et al. ( 2014) which generated our [1] and Castro et al. ( 2018) comments and the present reply.


As Edgard Morin (1996) wrote, “(Karl) Popper changed the science perspective; it was believed that science advanced by accumulating truths; he showed that progress is achieved especially by eliminating errors in the search of truth”.

The power of the scientific method is that it allows for the advance of knowledge independently of an individual researcher’s opinions.

We believe that this ongoing discussion will contribute to improve the understanding of paleo-sea level changes along the Brazilian coast.


Here we maintain the interpretations presented in our discussion paper [1].

The main issue amongst those raised in our paper, and which was not properly addressed in the reply, was the methodology used by Castro et al. ( 2014) to determine paleo-sea levels.

They write: “The margin of error for the sample altitudes was minimal.

Several investigations conducted on the South American coasts regarding relative sea-level variations have not clearly or precisely defined the reference level of the samples used in the vertical plane (…).

The absence of this information yields potential inaccuracies regarding the height of the marine paleo-levels of the proposed curves.

(…) Secondly, the method employed in this study would need to be applied to other parts of the Brazilian coastline”.


In the discussion paper we pointed out that the vertical position of a paleo-sea level indicator (e.g. biological remain or facies contact) is not the position of the paleo-sea level.

To reconstruct paleo-sea levels it is crucial to determine the relationship of a given indicator to the present homologous one.

In this way relative paleo-sea levels can be inferred without knowing the elevation of the mean sea level or other datum.

Alternatively, the paleo-sea level can also be determined adding (or subtracting) the altitude of the indicator to the altitude (or depth) of the present homologous indicator, but this was not made by Castro et al. ( 2014), who simply took the elevation of the remains or sedimentary deposits and assumed that those altitudes corresponded to paleo-sea levels.


Castro et al. ( 2018) make two incorrect statements, being 1) “Angulo et al. ( 2006a, 2016b) do not explain, from the methodological point of view, how vermetids altimetric position were obtained.

By convenience it was used other authors altimetric information”; and 2) “altimetric data were positioned based on global model of geophysical simulation” Again, Angulo’s et al (2006) paper did not address the altimetry of the paleo-sea level indicators.

That paper explains in detail how each relative paleo-sea level was obtained from each indicator, after measuring the vertical distance between the indicators to their present homologous one.

We did not use the global altimetry model to determine the elevation of our samples; we compared the empiric data with the modeled curve to show how well they fit.


Another important point in our discussion paper regards the margin of error, which can only be established if considering the indicator’s intrinsic characteristics.

For example, the vermetid vertical distribution is affected by wave energy and coastal morphology [4].

Therefore, changes in any of these characteristics since the lifetime of ancient vermetids can enlarge the error margin on paleo-sea level estimates [5].

Also the vermetid remains may not correspond to the upper limit of living vermetids and can also increase the error [5].


We agree with Castro et al. ( 2018) that the vermetids vertical position varies with the species, which in turn vary along the Brazilian coast, as defined by Spotorno-Oliveira et al. ( 2012).

Whenever possible Angulo (1993) and Angulo et al. ( 1999, 2002) compared the paleo remains with their homologous (same specie) one.

When bioconstructions of living Petaloconchus varians was not found (as in southern São Paulo, Paraná and Santa Catarina coasts), the Phragmatopoma lapidosa (a subjective synonym of Phragmatopoma caudata) was used as an homologous because the highest elevation of their bioconstructions are similar on rocky coasts [5].


We also agree with Castro et al. ( 2018) on their general comments on beachrocks, but we point out that to infer a paleo-sea level from a beachrock it is necessary to identify their facies and facies contacts, as well as to measure the vertical distance between the ancient and present homologous facies contacts [6].

In addition, it should also be taken into consideration that the time of deposition could differ from the age of the bioclasts and the cement [7].


Castro et al. ( 2014) did not consider these aspects, which are critical for their assertion: “for the first time on the Brazilian coast it was identified a negative record of relative sea-level during Late Pleistocene and Early Holocene transition”.


The interpretation of a sea level 3.0 to 4.5 m below the present one at 11.9 to 11.1 ka (Beta Analytic no 248722 and 248721) BP is in strong contradiction with worldwide established data [3] for this time period, and would require a detailed discussion.

Because this discussion is absent, it is fair to assume their paleo-sea level interpretation based on beachrock altimetry and isotopic datating is not robust enough to sustain such a claim.


We agree with the conclusion of Spotorno-Oliveira et al. ( 2016, with Castro as one of the co-authors), who after studying that same area in Rio de Janeiro and analyzing samples with similar ages (from 13,130 to 11,149 cal.

years BP) and depths (- 4.5 to + 1.5m), stated: “The altitude of the studied grainstone (…) confirms that these samples formed in a high hydrodynamic energy setting that cannot be related to the sea level at that age”.


We consider that Castro et al. ( 2018) do not properly address or answer all the comments we made in the discussion paper.

More work and discussions are necessary to elucidate several questions that still remain about the sea level behavior in the Holocene.


I n recent years, holmium laser enucleation of the pros- tate (HoLEP) has emerged as an attractive alternative to transurethral resection of prostate (TURP) for the manage- ment of bladder outlet obstruction because of benign prostatic hyperplasia (BPH).

HoLEP involves complete enucleation of the prostatic adenoma through laser dissection and subsequent removal of the prostatic tissue through morcellation in the bladder.

This technique carries many advantages when com- pared with TURP and open prostatectomy, including effec- tiveness in the setting of massive (>100 g) glands, greater postoperative Qmax, improved reduction of subjective symp- tom scores, shortened catheterization times and hospital stay times, and decreased postoperative complication rates.

1 Peri- operative complication rates are low with the most common cited complications including capsular perforation, superficial bladder mucosal injury, ureteral orifice injury, and morcellator malfunction.

2 To date, there has been one reported case of acute abdominal compartment syndrome involving massive fluid leakage into the retroperitoneal space during a HoLEP.

3 We present two cases of intraoperative extraperitoneal fluid leakage during HoLEP.


Patient 1 is a 74-year-old male who underwent HoLEP for refractory bladder outlet obstruction and bladder stones.

His medical history included BPH complicated by recurrent urinary tract infections and bladder stones, elevated prostate specific antigen (biopsy negative), hyperlipidemia, and hy- pertension.

Preoperative transrectal ultrasound (TRUS) esti- mated prostate volume to be 150 cc.

HoLEP was performed utilizing a two-incision technique.

Owing to the large amount of adenoma, extended time was spent during morcellation (120 minutes) because of poor observation secondary to bladder neck bleeding.

There was noted to be an area of capsular perforation at the 5 o'clock position in the mid gland.

When the operative drapes were removed, significant abdominal distention was noted.


In discussion with anesthetist, the patient's airway pres- sures upon induction ranged from 10 to 20, however, at this point in the procedure, the airway pressures had increased >30.

The patient was also experiencing systolic pressures ranging from 80 to 90, whereas preoperatively he was >110 systolic.


The drapes were removed at this time and the ab- domen appeared distended and was firm on examination.

Given the significant abdominal distention and concern for a bladder injury secondary to poor observation during mor- cellation, general surgery was consulted intraoperatively.


Per the recommendation of general surgery, they elected to proceed with a subumbilical minilaparotomy, after initial laparoscopy was unsuccessful because of increased open- ing pressures with the Veress needle.


Less than 400 cc of bloody-colored fluid was suctioned out of the abdomen, and an intraoperative cystogram was performed that revealed retroperitoneal extravasation without intraperitoneal bladder injury or perforation.


As there was not a significant amount of intraperitoneal fluid, it was theorized that the capsular per- foration resulted in extraperitonealization of intraoperative saline.


Thus, a 10F Jackson Pratt drain was placed in the pelvis, and the fascia and skin were closed.

He was given 20 mg of IV Lasix intraoperatively.


The patient was extubated effectively and transferred postoperatively to the ICU for hemodynamic monitoring and observation.

In the ICU, cardiology was consulted because of a prolonged PR interval and bradycardia that ultimately warranted no further work-up.

On postoperative day (POD) 1, the patient was progressing well, and he was transferred to the floor in stable condition.

The Jackson-Pratt drain output was 710 cc on POD 0, 81 cc on POD 1, and then removed on POD 2 after draining 20 cc.

The patient was discharged on POD 3.

His catheter was removed on POD 10.

Pathologic analysis of the specimen revealed no evidence of malignancy and 167 g specimen.


Patient 2 is a 78-year-old male who was experiencing per- sistent lower urinary tract symptoms despite combined medical therapy with alpha blockade and 5-alpha reductase inhibitors.

His medical history included coronary artery disease status post-coronary artery bypass grafting and percutaneous cor- onary intervention, and a history of pneumonia.

Preoperative cystoscopy revealed enlarged median and lateral lobes, as well as severe trabeculations of the bladder with a TRUS measuring a 41 cc prostate.

HoLEP was carried out utilizing a two-incision technique.

Upon completion of morcellation, it was noted that the patient's abdomen was distended, but his peak airway pressures were normal, the abdomen was soft, and the catheter drainage was noted to be clear.

In addition, there was no sus- picion for a significant mismatch between irrigation used and fluid output collected in the drainage system.


Given the previous similar presentation in Case 1 with no suspicion of bladder injury, we suspected that the patient had extraperitoneal extravasation of the saline irrigation through a capsular perforation as occurred in Case 1.

The decision was made for the patient to be awakened, extubated, and transferred to the recovery room where he was further monitored.

A stat noncontrast abdominal CT scan was per- formed that revealed a moderate amount of free fluid in the pelvis and upper abdomen; the fluid in the pelvis and lower abdomen was distributed in the extraperitoneal region with no evidence of hematoma (Fig. 1).

The patient remained hemodynamically stable and was transferred to the floor with continuous bladder irrigation.

The patient was given a 40 mg dose of Lasix *8 hours after the operation was completed.

Overnight, there were no acute events.

On POD 1, the pa- tient's abdomen was soft and significantly less distended.

The Foley catheter drained 3950 cc of urine overnight without evidence of hematuria.

The patient was discharged with a catheter on POD 1.


The patient had his catheter removed on POD 9.

A postoperative CT cystogram revealed no evidence of leak with resolution of the pelvic and perivesical fluid (Fig. 2).

Thirty grams of benign prostate tissue was removed on final pathology analysis.

The patient was noted to have a bladder neck contracture seen on cystoscopy 4 months after his procedure for which he underwent cystourethroscopy and laser incision of bladder neck contracture.


Although HoLEP has emerged as a standard treatment of BPH, there remains a well-established steep learning curve associated with the operation.

2 The most common cited com- plications include capsular perforation, superficial bladder mucosal injury, ureteral orifice injury, and morcellator mal- function.

2 Capsular perforation rates have been documented from 0.3% to 10% and can potentially pose as a serious complication of HoLEP.

2 This report increases the urolo- gist's ability to recognize and conservatively manage a cap- sular perforation, resulting in a distended abdomen.

Potential risk factors include cases with larger glands (>100 cc), prostates with thin capsules, or early surgeon's experience with longer operative times and suboptimal observation.