-
Investigative Ophthalmology & Visual... Jun 2021We introduce a set of dichoptic training tasks that differ in terms of (1) the presence of external noise and (2) the visual feature implicated (motion, orientation),... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
We introduce a set of dichoptic training tasks that differ in terms of (1) the presence of external noise and (2) the visual feature implicated (motion, orientation), examining the generality of training effects between the different training and test cues and their capacity for driving changes in sensory eye dominance and stereoscopic depth perception.
METHODS
We randomly assigned 116 normal-sighted observers to five groups (four training groups and one no training group). All groups completed both pre- and posttests, during which they were tested on dichoptic motion and orientation tasks under noisy and noise-free conditions, as well as a binocular phase combination task and two depth tasks to index sensory eye dominance and binocular function. Training groups received visual training on one of the four dichoptic tasks over 3 consecutive days.
RESULTS
Training under noise-free conditions supported generalization of learning to noise-free tasks involving an untrained feature. By contrast, there was a symmetric learning transfer between the signal-noise and no-noise tasks within the same visual feature. Further, training on all tasks reduced sensory eye dominance but did not improve depth perception.
CONCLUSIONS
Training-driven changes in sensory eye balance do not depend on the stimulus feature or whether the training entails the presence of external noise. We conjecture that dichoptic visual training acts to balance interocular suppression before or at the site of binocular combination.
Topics: Adult; Contrast Sensitivity; Cues; Depth Perception; Discrimination Learning; Dominance, Ocular; Female; Humans; Male; Noise; Outcome Assessment, Health Care; Photic Stimulation; Sensory Thresholds; Signal Detection, Psychological; Task Performance and Analysis; Vision, Binocular; Visual Perception
PubMed: 34106211
DOI: 10.1167/iovs.62.7.12 -
Scientific Reports Aug 2020We perceive the roughness of an object through our eyes and hands. Many crossmodal studies have reported that there is no clear visuo-tactile interaction in roughness...
We perceive the roughness of an object through our eyes and hands. Many crossmodal studies have reported that there is no clear visuo-tactile interaction in roughness perception using static visual cues. One exception is that the visual observation of task-irrelevant hand movements, not the texture of task-relevant objects, can enhance the performance of tactile roughness discrimination. Our study investigated whether task-irrelevant visual motion without either object roughness or bodily cues can influence tactile roughness perception. Participants were asked to touch abrasive papers while moving their hand laterally and viewing moving or static sine wave gratings without being able to see their hand, and to estimate the roughness magnitude of the tactile stimuli. Moving gratings with a low spatial frequency induced smoother roughness perceptions than static visual stimuli when the visual grating moved in the direction opposite the hand movements. The effects of visual motion did not appear when the visual stimuli had a high spatial frequency or when the participants touched the tactile stimuli passively. These results indicate that simple task-irrelevant visual movement without object roughness or bodily cues can modulate tactile roughness perception with active body movements in a spatial-frequency-selective manner.
Topics: Adult; Cues; Female; Hand; Humans; Male; Middle Aged; Motion; Motion Perception; Photic Stimulation; Psychomotor Performance; Time Perception; Touch; Touch Perception; Visual Perception
PubMed: 32811859
DOI: 10.1038/s41598-020-70831-3 -
Journal of Cognitive Neuroscience Apr 2023Selective attention prioritizes information that is relevant to behavioral goals. Previous studies have shown that attended visual information is processed and...
Selective attention prioritizes information that is relevant to behavioral goals. Previous studies have shown that attended visual information is processed and represented more efficiently, but distracting visual information is not fully suppressed, and may also continue to be represented in the brain. In natural vision, to-be-attended and to-be-ignored objects may be present simultaneously in the scene. Understanding precisely how each is represented in the visual system, and how these neural representations evolve over time, remains a key goal in cognitive neuroscience. In this study, we recorded EEG while participants performed a cued object-based attention task that involved attending to target objects and ignoring simultaneously presented and spatially overlapping distractor objects. We performed support vector machine classification on the stimulus-evoked EEG data to separately track the temporal dynamics of target and distractor representations. We found that (1) both target and distractor objects were decodable during the early phase of object processing (∼100 msec to ∼200 msec after target onset), and (2) the representations of both objects were sustained over time, remaining decodable above chance until ∼1000-msec latency. However, (3) the distractor object information faded significantly beginning after about 300-msec latency. These findings provide information about the fate of attended and ignored visual information in complex scene perception.
Topics: Humans; Visual Perception; Brain; Attention; Cues; Motivation; Photic Stimulation
PubMed: 36735619
DOI: 10.1162/jocn_a_01972 -
Journal of Vision Dec 2023Gestalten in visual perception are defined by emergent properties of the whole, which cannot be predicted from the sum of its parts; rather, they arise by virtue of... (Review)
Review
Gestalten in visual perception are defined by emergent properties of the whole, which cannot be predicted from the sum of its parts; rather, they arise by virtue of inherent principles, the Laws of Seeing. This review attempts to assign neurophysiological correlates to select emergent properties in motion and contour perception and proposes parallels to the processing of local versus global attributes by classical versus contextual receptive fields. The aim is to identify Gestalt neurons in the visual system to account for the Laws of Seeing in causal terms and to explain "Why do things look as they do" (Koffka, 1935, p. 76).
Topics: Humans; Visual Perception; Neurons; Form Perception; Motion Perception
PubMed: 38091030
DOI: 10.1167/jov.23.14.4 -
Scientific Reports Mar 2020Contrast sensitivity is mostly used as a tool for testing aspects of visual functions. Infantile nystagmus is a pathological phenomenon that affects the spatial-temporal...
Contrast sensitivity is mostly used as a tool for testing aspects of visual functions. Infantile nystagmus is a pathological phenomenon that affects the spatial-temporal visual functions due to spontaneous oscillating movements of the eyes. We examined the spatial-temporal aspects of nystagmus perception, aiming to investigate the mechanisms underlying the deterioration of their visual performance. We tested the monocular and binocular contrast sensitivity of nystagmus and normally sighted subjects by measuring contrast detection of a Gabor target with spatial frequencies slightly above the cutoff threshold of each subject (nystagmus ~3; controls = 9cpd; presentation times 60-480 ms). The dominant eye of nystagmus revealed large differences over the non-dominant eye, highlighting the superiority of the dominant over the non-dominant eye in nystagmus. In addition, binocular summation mechanism was impaired in majority of the nystagmus subjects. Furthermore, these differences are not attributed to differences in visual acuity. Moreover, the visual performance in nystagmus continue to improve for longer presentation time compared with controls and was longer in the poor eye. Since the results are not due to differences in eye movements and strabismus, we suggest that the differences are due to developmental impairment in the visual system during the critical period.
Topics: Adolescent; Adult; Child, Preschool; Contrast Sensitivity; Eye Movements; Female; Humans; Male; Middle Aged; Nystagmus, Congenital; Vision, Binocular; Vision, Monocular; Visual Acuity; Visual Perception; Young Adult
PubMed: 32188906
DOI: 10.1038/s41598-020-61914-2 -
Journal of Vision Mar 2021With the rise of machines to human-level performance in complex recognition tasks, a growing amount of work is directed toward comparing information processing in humans... (Comparative Study)
Comparative Study
With the rise of machines to human-level performance in complex recognition tasks, a growing amount of work is directed toward comparing information processing in humans and machines. These studies are an exciting chance to learn about one system by studying the other. Here, we propose ideas on how to design, conduct, and interpret experiments such that they adequately support the investigation of mechanisms when comparing human and machine perception. We demonstrate and apply these ideas through three case studies. The first case study shows how human bias can affect the interpretation of results and that several analytic tools can help to overcome this human reference point. In the second case study, we highlight the difference between necessary and sufficient mechanisms in visual reasoning tasks. Thereby, we show that contrary to previous suggestions, feedback mechanisms might not be necessary for the tasks in question. The third case study highlights the importance of aligning experimental conditions. We find that a previously observed difference in object recognition does not hold when adapting the experiment to make conditions more equitable between humans and machines. In presenting a checklist for comparative studies of visual reasoning in humans and machines, we hope to highlight how to overcome potential pitfalls in design and inference.
Topics: Artificial Intelligence; Humans; Image Processing, Computer-Assisted; Learning; Pattern Recognition, Automated; Pattern Recognition, Visual; Problem Solving; Recognition, Psychology; Visual Perception
PubMed: 33724362
DOI: 10.1167/jov.21.3.16 -
Psychological Science Feb 2022Visual scene context is well-known to facilitate the recognition of scene-congruent objects. Interestingly, however, according to predictive-processing accounts of brain...
Visual scene context is well-known to facilitate the recognition of scene-congruent objects. Interestingly, however, according to predictive-processing accounts of brain function, scene congruency may lead to reduced (rather than enhanced) processing of congruent objects, compared with incongruent ones, because congruent objects elicit reduced prediction-error responses. We tested this counterintuitive hypothesis in two online behavioral experiments with human participants ( = 300). We found clear evidence for impaired perception of congruent objects, both in a change-detection task measuring response times and in a bias-free object-discrimination task measuring accuracy. Congruency costs were related to independent subjective congruency ratings. Finally, we show that the reported effects cannot be explained by low-level stimulus confounds, response biases, or top-down strategy. These results provide convincing evidence for perceptual congruency costs during scene viewing, in line with predictive-processing theory.
Topics: Humans; Pattern Recognition, Visual; Perception; Photic Stimulation; Reaction Time; Recognition, Psychology; Visual Perception
PubMed: 35020519
DOI: 10.1177/09567976211032676 -
International Journal of Environmental... Jan 2023The purpose of this study was to assess the influence of a moderate breath-alcohol content (BrAC of 0.40 mg/L) on binocular visual performance for different visual...
The purpose of this study was to assess the influence of a moderate breath-alcohol content (BrAC of 0.40 mg/L) on binocular visual performance for different visual functions after inducing different levels of interocular differences with the use of filters. A total of 26 healthy young subjects were enrolled. The participants participated in two sessions: one without alcohol consumption and another after alcohol consumption. In each session and for the different filter conditions (subjects were wearing Bangerter foil of 0.8 and BPM2 fog filter on the dominant eye), monocular and binocular visual function was evaluated by measuring visual acuity, contrast sensitivity, visual discrimination capacity (and successively by calculating their corresponding binocular summations) and stereopsis (near and distance stereoacuity). In addition, interocular differences were calculated for different retinal-image quality and straylight parameters. All monocular and binocular visual functions were analyzed and stereopsis was significantly impaired by alcohol and filters ( < 0.05). Interocular differences for different ocular parameters and binocular summations for visual parameters were negatively affected by filters but not alcohol. Significant correlations (averaging all the experimental conditions analyzed) were found, highlighting: the higher the interocular differences, the lower the binocular summation and the poorer the stereopsis and, therefore, the worse the binocular visual performance.
Topics: Humans; Visual Acuity; Vision, Binocular; Depth Perception; Visual Perception; Alcohol Drinking
PubMed: 36767115
DOI: 10.3390/ijerph20031751 -
Current Biology : CB Oct 2021Recent studies have shown that neuronal representations gradually change over time despite no changes in the stimulus, environment, or behavior. However, such...
Recent studies have shown that neuronal representations gradually change over time despite no changes in the stimulus, environment, or behavior. However, such representational drift has been assumed to be a property of high-level brain structures, whereas earlier circuits, such as sensory cortices, have been assumed to stably encode information over time. Here, we analyzed large-scale optical and electrophysiological recordings from six visual cortical areas in behaving mice that were repeatedly presented with the same natural movies. Contrary to the prevailing notion, we found representational drift over timescales spanning minutes to days across multiple visual areas, cortical layers, and cell types. Notably, neural-code stability did not reflect the hierarchy of information flow across areas. Although individual neurons showed time-dependent changes in their coding properties, the structure of the relationships between population activity patterns remained stable and stereotypic. Such population-level organization may underlie stable visual perception despite continuous changes in neuronal responses.
Topics: Animals; Mice; Neurons; Parietal Lobe; Visual Cortex; Visual Perception
PubMed: 34433077
DOI: 10.1016/j.cub.2021.07.062 -
ELife Aug 2021The pupil provides a rich, non-invasive measure of the neural bases of perception and cognition and has been of particular value in uncovering the role of arousal-linked...
The pupil provides a rich, non-invasive measure of the neural bases of perception and cognition and has been of particular value in uncovering the role of arousal-linked neuromodulation, which alters both cortical processing and pupil size. But pupil size is subject to a multitude of influences, which complicates unique interpretation. We measured pupils of observers experiencing perceptual multistability-an ever-changing subjective percept in the face of unchanging but inconclusive sensory input. In separate conditions, the endogenously generated perceptual changes were either task-relevant or not, allowing a separation between perception-related and task-related pupil signals. Perceptual changes were marked by a complex pupil response that could be decomposed into two components: a dilation tied to task execution and plausibly indicative of an arousal-linked noradrenaline surge, and an overlapping constriction tied to the perceptual transient and plausibly a marker of altered visual cortical representation. Constriction, but not dilation, amplitude systematically depended on the time interval between perceptual changes, possibly providing an overt index of neural adaptation. These results show that the pupil provides a simultaneous reading on interacting but dissociable neural processes during perceptual multistability, and suggest that arousal-linked neuromodulator release shapes action but not perception in these circumstances.
Topics: Adult; Arousal; Attention; Humans; Pupil; Visual Perception; Young Adult
PubMed: 34378532
DOI: 10.7554/eLife.66161