1
|
Kim T, Pasupathy A. Neural Correlates of Crowding in Macaque Area V4. J Neurosci 2024; 44:e2260232024. [PMID: 38670806 PMCID: PMC11170949 DOI: 10.1523/jneurosci.2260-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 03/29/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
Visual crowding refers to the phenomenon where a target object that is easily identifiable in isolation becomes difficult to recognize when surrounded by other stimuli (distractors). Many psychophysical studies have investigated this phenomenon and proposed alternative models for the underlying mechanisms. One prominent hypothesis, albeit with mixed psychophysical support, posits that crowding arises from the loss of information due to pooled encoding of features from target and distractor stimuli in the early stages of cortical visual processing. However, neurophysiological studies have not rigorously tested this hypothesis. We studied the responses of single neurons in macaque (one male, one female) area V4, an intermediate stage of the object-processing pathway, to parametrically designed crowded displays and texture statistics-matched metameric counterparts. Our investigations reveal striking parallels between how crowding parameters-number, distance, and position of distractors-influence human psychophysical performance and V4 shape selectivity. Importantly, we also found that enhancing the salience of a target stimulus could alleviate crowding effects in highly cluttered scenes, and this could be temporally protracted reflecting a dynamical process. Thus, a pooled encoding of nearby stimuli cannot explain the observed responses, and we propose an alternative model where V4 neurons preferentially encode salient stimuli in crowded displays. Overall, we conclude that the magnitude of crowding effects is determined not just by the number of distractors and target-distractor separation but also by the relative salience of targets versus distractors based on their feature attributes-the similarity of distractors and the contrast between target and distractor stimuli.
Collapse
Affiliation(s)
- Taekjun Kim
- Department of Biological Structure, University of Washington, Seattle, Washington 98195
- Washington National Primate Research Center, University of Washington, Seattle, Washington 98195
| | - Anitha Pasupathy
- Department of Biological Structure, University of Washington, Seattle, Washington 98195
- Washington National Primate Research Center, University of Washington, Seattle, Washington 98195
| |
Collapse
|
2
|
Bertamini M, Oletto CM, Contemori G. The Role of Uniform Textures in Making Texture Elements Visible in the Visual Periphery. Open Mind (Camb) 2024; 8:462-482. [PMID: 38665546 PMCID: PMC11045036 DOI: 10.1162/opmi_a_00136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 02/25/2024] [Indexed: 04/28/2024] Open
Abstract
There are important differences between central and peripheral vision. With respect to shape, contours retain phenomenal sharpness, although some contours disappear if they are near other contours. This leads to some uniform textures to appear non-uniform (Honeycomb illusion, Bertamini et al., 2016). Unlike other phenomena of shape perception in the periphery, this illusion is showing how continuity of the texture does not contribute to phenomenal continuity. We systematically varied the relationship between central and peripheral regions, and we collected subjective reports (how far can one see lines) as well as judgments of line orientation. We used extended textures created with a square grid and some additional lines that are invisible when they are located at the corners of the grid, or visible when they are separated from the grid (control condition). With respects to subjective reports, we compared the region of visibility for cases in which the texture was uniform (Exp 1a), or when in a central region the lines were different (Exp 1b). There were no differences, showing no role of objective uniformity on visibility. Next, in addition to the region of visibility we measured sensitivity using a forced-choice task (line tilted left or right) (Exp 2). The drop in sensitivity with eccentricity matched the size of the region in which lines were perceived in the illusion condition, but not in the control condition. When participants were offered a choice to report of the lines were present or absent (Exp 3) they confirmed that they did not see them in the illusion condition, but saw them in the control condition. We conclude that mechanisms that control perception of contours operate differently in the periphery, and override prior expectations, including that of uniformity. Conversely, when elements are detected in the periphery, we assign to them properties based on information from central vision, but these shapes cannot be identified correctly when the task requires such discrimination.
Collapse
|
3
|
Lu X, Jiang R, Song M, Wu Y, Ge Y, Chen N. Seeing in crowds: Averaging first, then max. Psychon Bull Rev 2024:10.3758/s13423-024-02468-6. [PMID: 38337141 DOI: 10.3758/s13423-024-02468-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2024] [Indexed: 02/12/2024]
Abstract
Crowding, a fundamental limit in object recognition, is believed to result from excessive integration of nearby items in peripheral vision. To understand its pooling mechanisms, we measured subjects' internal response distributions in an orientation crowding task. Contrary to the prediction of an averaging model, we observed a pattern suggesting that the perceptual judgement is made based on choosing the largest response across the noise-perturbed items. A model featuring first-stage averaging and second-stage signed-max operation predicts the diverse errors made by human observers under various signal strength levels. These findings suggest that different rules operate to resolve the bottleneck at early and high-level stages of visual processing, implementing a combination of linear and nonlinear pooling strategies.
Collapse
Affiliation(s)
- Xincheng Lu
- Department of Psychology, School of Social Sciences, Tsinghua University, Room 506, Weiqing Building, Beijing, 100084, People's Republic of China
| | - Ruijie Jiang
- Department of Psychology, School of Social Sciences, Tsinghua University, Room 506, Weiqing Building, Beijing, 100084, People's Republic of China
| | - Meng Song
- Department of Psychology, School of Social Sciences, Tsinghua University, Room 506, Weiqing Building, Beijing, 100084, People's Republic of China
| | - Yiting Wu
- Khoury College of Computer Sciences, Northeastern University, 360 Huntington Ave, Boston, MA, 02115, USA
| | - Yiran Ge
- Department of Psychology, School of Social Sciences, Tsinghua University, Room 506, Weiqing Building, Beijing, 100084, People's Republic of China
| | - Nihong Chen
- Department of Psychology, School of Social Sciences, Tsinghua University, Room 506, Weiqing Building, Beijing, 100084, People's Republic of China.
- IDG/McGovern Institute for Brain Research at Tsinghua University, Beijing, 100084, People's Republic of China.
| |
Collapse
|
4
|
Moore CM, Zheng Q. Limited midlevel mediation of visual crowding: Surface completion fails to support uncrowding. J Vis 2024; 24:11. [PMID: 38294775 PMCID: PMC10839818 DOI: 10.1167/jov.24.1.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 12/10/2023] [Indexed: 02/01/2024] Open
Abstract
Visual crowding refers to impaired object recognition that is caused by nearby stimuli. It increases with eccentricity. Image-level explanations of crowding maintain that it is caused by information loss within early encoding processes that vary in functionality with eccentricity. Alternative explanations maintain that the interference is not limited to two-dimensional image-level interactions but that it is mediated within representations that reflect three-dimensional scene structure. Uncrowding refers to when adding stimulus information to a display, which increases the noise at an image level, nonetheless decreasing the amount of crowding that occurs. Uncrowding has been interpreted as evidence of midlevel mediation of crowding because the additional information tends to provide an opportunity for perceptually organizing stimuli into distinct and therefore protected representations. It is difficult, however, to rule out image-level explanations of crowding and uncrowding when stimulus differences exist between conditions. We adapted displays of a specific form of uncrowding to minimize stimulus differences across conditions, while retaining the potential for perceptual organization, specifically perceptual surface completion. Uncrowding under these conditions would provide strong support for midlevel mediation of crowding. In five experiments, however, we found no evidence of midlevel mediation of crowding, indicating that at least for this version of uncrowding, image-level explanations cannot be ruled out.
Collapse
Affiliation(s)
- Cathleen M Moore
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, USA
| | - Qingzi Zheng
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, USA
| |
Collapse
|
5
|
Nador J, Reeves A. Crowding expands and is less sensitive to target-flanker differences during a shift of visual attention. Vision Res 2023; 212:108305. [PMID: 37515890 DOI: 10.1016/j.visres.2023.108305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 06/02/2023] [Accepted: 07/20/2023] [Indexed: 07/31/2023]
Abstract
Target-flanker similarity and critical spacing control visual crowding when attention is pre-allocated, but these have not been studied when attention shifts. Flanked target Gabors appeared 8° left and right of central fixation throughout each 1.5 s trial. Subjects reported target Gabor tilt. In Expt. 1, target blinks increased accuracy, and flanker blinks decreased it, but only when attention shifted left or right from a central RSVP cue, hardly before it, indicating an exogenous/endogenous synergy. Whether parallel or orthogonal, flankers of the same wavelength as the target crowded substantially. Parallel half-wavelength flankers also crowded, but orthogonal half-wavelength ones did not. In Expt. 2, crowding when attention shifts was the same for targets and flankers within Bouma's bound (2.5° apart) as outside it (5.0° apart.) In Expt. 3, Bouma's bound was restored when attention was focused continuously on the target. We conclude that crowding temporarily expands and becomes less discriminative when attention shifts.
Collapse
Affiliation(s)
- Jeff Nador
- Dept. of Psychology, Northeastern University, 360 Huntingdon Ave., Boston, MA 02115, USA; Dept. of Psychology, Université de Fribourg, Faucigny 2, 1700 Fribourg, Switzerland.
| | - Adam Reeves
- Dept. of Psychology, Northeastern University, 360 Huntingdon Ave., Boston, MA 02115, USA.
| |
Collapse
|
6
|
Choung OH, Gordillo D, Roinishvili M, Brand A, Herzog MH, Chkonia E. Intact and deficient contextual processing in schizophrenia patients. Schizophr Res Cogn 2022; 30:100265. [PMID: 36119400 PMCID: PMC9477851 DOI: 10.1016/j.scog.2022.100265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 07/09/2022] [Accepted: 07/09/2022] [Indexed: 11/25/2022] Open
Abstract
Schizophrenia patients are known to have deficits in contextual vision. However, results are often very mixed. In some paradigms, patients do not take the context into account and, hence, perform more veridically than healthy controls. In other paradigms, context deteriorates performance much more strongly in patients compared to healthy controls. These mixed results may be explained by differences in the paradigms as well as by small or biased samples, given the large heterogeneity of patients' deficits. Here, we show that mixed results may also come from idiosyncrasies of the stimuli used because in variants of the same visual paradigm, tested with the same participants, we found intact and deficient processing.
Collapse
Affiliation(s)
- Oh-Hyeon Choung
- Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Corresponding author. http://lpsy.epfl.ch
| | - Dario Gordillo
- Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Maya Roinishvili
- Laboratory of Vision Physiology, Ivane Beritashvili Centre of Experimental Biomedicine, Tbilisi, Georgia
- Institute of Cognitive Neurosciences, Free University of Tbilisi, Tbilisi, Georgia
| | - Andreas Brand
- Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Michael H. Herzog
- Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Eka Chkonia
- Department of Psychiatry, Tbilisi State Medical University, Tbilisi, Georgia
| |
Collapse
|
7
|
Herzog MH, Sayim B. Crowding: Recent advances and perspectives. J Vis 2022; 22:15. [DOI: 10.1167/jov.22.12.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Michael H. Herzog
- Laboratory of Psychophysics, Brain Mind Institute, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne, Switzerland
| | - Bilge Sayim
- Sciences Cognitives et Sciences Affectives (SCALab), CNRS, UMR 9193, University of Lille, Lille, France
- Institute of Psychology, University of Bern, Bern, Switzerland
| |
Collapse
|
8
|
Herzog MH. The Irreducibility of Vision: Gestalt, Crowding and the Fundamentals of Vision. Vision (Basel) 2022; 6:vision6020035. [PMID: 35737422 PMCID: PMC9228288 DOI: 10.3390/vision6020035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 05/25/2022] [Accepted: 05/31/2022] [Indexed: 11/16/2022] Open
Abstract
What is fundamental in vision has been discussed for millennia. For philosophical realists and the physiological approach to vision, the objects of the outer world are truly given, and failures to perceive objects properly, such as in illusions, are just sporadic misperceptions. The goal is to replace the subjectivity of the mind by careful physiological analyses. Continental philosophy and the Gestaltists are rather skeptical or ignorant about external objects. The percepts themselves are their starting point, because it is hard to deny the truth of one own′s percepts. I will show that, whereas both approaches can well explain many visual phenomena with classic visual stimuli, they both have trouble when stimuli become slightly more complex. I suggest that these failures have a deeper conceptual reason, namely that their foundations (objects, percepts) do not hold true. I propose that only physical states exist in a mind independent manner and that everyday objects, such as bottles and trees, are perceived in a mind-dependent way. The fundamental processing units to process objects are extended windows of unconscious processing, followed by short, discrete conscious percepts.
Collapse
Affiliation(s)
- Michael H Herzog
- Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| |
Collapse
|
9
|
Rummens K, Sayim B. Multidimensional feature interactions in visual crowding: When configural cues eliminate the polarity advantage. J Vis 2022; 22:2. [PMID: 35503508 PMCID: PMC9078080 DOI: 10.1167/jov.22.6.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 03/21/2022] [Indexed: 11/24/2022] Open
Abstract
Crowding occurs when surrounding objects (flankers) impair target perception. A key property of crowding is the weaker interference when target and flankers strongly differ on a given dimension. For instance, identification of a target letter is usually superior with flankers of opposite versus the same contrast polarity as the target (the "polarity advantage"). High performance when target-flanker similarity is low has been attributed to the ungrouping of target and flankers. Here, we show that configural cues can override the usual advantage of low target-flanker similarity, and strong target-flanker grouping can reduce - instead of exacerbate - crowding. In Experiment 1, observers were presented with line triplets in the periphery and reported the tilt (left or right) of the central line. Target and flankers had the same (uniform condition) or opposite contrast polarity (alternating condition). Flanker configurations were either upright (||), unidirectionally tilted (\\ or //), or bidirectionally tilted (\/ or /\). Upright flankers yielded stronger crowding than unidirectional flankers, and weaker crowding than bidirectional flankers. Importantly, our results revealed a clear interaction between contrast polarity and flanker configuration. Triplets with upright and bidirectional flankers, but not unidirectional flankers, showed the polarity advantage. In Experiments 2 and 3, we showed that emergent features and redundancy masking (i.e. the reduction of the number of perceived items in repeating configurations) made it easier to discriminate between uniform triplets when flanker tilts were unidirectional (but not when bidirectional). We propose that the spatial configurations of uniform triplets with unidirectional flankers provided sufficient task-relevant information to enable a similar performance as with alternating triplets: strong-target flanker grouping alleviated crowding. We suggest that features which modulate crowding strength can interact non-additively, limiting the validity of typical crowding rules to contexts where only single, independent dimensions determine the effects of target-flanker similarity.
Collapse
Affiliation(s)
- Koen Rummens
- University of Bern, Institute of Psychology, Bern, Switzerland
| | - Bilge Sayim
- University of Bern, Institute of Psychology, Bern, Switzerland
- Université de Lille, CNRS, UMR 9193 - SCALab - Sciences Cognitives et Sciences Affectives, Lille, France
| |
Collapse
|
10
|
Mixture-modeling approach reveals global and local processes in visual crowding. Sci Rep 2022; 12:6726. [PMID: 35468981 PMCID: PMC9038733 DOI: 10.1038/s41598-022-10685-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 04/11/2022] [Indexed: 11/21/2022] Open
Abstract
Crowding refers to the inability to recognize objects in clutter, setting a fundamental limit on various perceptual tasks such as reading and facial recognition. While prevailing models suggest that crowding is a unitary phenomenon occurring at an early level of processing, recent studies have shown that crowding might also occur at higher levels of representation. Here we investigated whether local and global crowding interference co-occurs within the same display. To do so, we tested the distinctive contribution of local flanker features and global configurations of the flankers on the pattern of crowding errors. Observers (n = 27) estimated the orientation of a target when presented alone or surrounded by flankers. Flankers were grouped into a global configuration, forming an illusory rectangle when aligned or a rectangular configuration when misaligned. We analyzed the error distributions by fitting probabilistic mixture models. Results showed that participants often misreported the orientation of a flanker instead of that of the target. Interestingly, in some trials the orientation of the global configuration was misreported. These results suggest that crowding occurs simultaneously across multiple levels of visual processing and crucially depends on the spatial configuration of the stimulus. Our results pose a challenge to models of crowding with an early single pooling stage and might be better explained by models which incorporate the possibility of multilevel crowding and account for complex target-flanker interactions.
Collapse
|