scholarly journals Moderate Alcohol Intake Changes Visual Perception by Enhancing V1 Inhibitory Surround Interactions

2021 ◽  
Vol 15 ◽  
Author(s):  
Huan Wang ◽  
Zhengchun Wang ◽  
Yifeng Zhou ◽  
Tzvetomir Tzvetanov
Keyword(s):  
Visual Perception ◽  
Alcohol Intoxication ◽  
Discrimination Performance ◽  
Orientation Discrimination ◽  
Order Effects ◽  
Inhibitory System ◽  
V1 Neurons ◽  
Behavioral Evidence ◽  
Contextual Stimuli ◽  
Moderate Alcohol Intake

Moderate alcohol consumption is considered to enhance the cortical GABA-ergic inhibitory system and it also variously affects visual perception. However, little behavioral evidence indicates changes of visual perception due to V1 modulated by alcohol intoxication. In this study, we investigated this issue by using center-surround tilt illusion (TI) as a probe of V1 inhibitory interactions, by taking into account possible higher-order effects. Participants conducted TI measures under sober, moderate alcohol intoxication, and placebo states. We found alcohol significantly increased repulsive TI effect and weakened orientation discrimination performance, which is consistent with the increase of lateral inhibition between orientation sensitive V1 neurons caused by alcohol intoxication. We also observed no visible changes in the data for global orientation processing but a presence of global attentional modulation. Thus, our results provide psychophysics evidence that alcohol changed V1 processing, which affects visual perception of contextual stimuli.

scholarly journals Contextual Influence on Orientation Discrimination of Humans and Responses of Neurons in V1 of Alert Monkeys

2000 ◽  
Vol 83 (2) ◽  
pp. 941-954 ◽  
Author(s):  
Wu Li ◽  
Peter Thier ◽  
Christian Wehrhahn
Keyword(s):  
Target Line ◽  
Orientation Discrimination ◽  
Orientation Tuning ◽  
Neuronal Responses ◽  
V1 Neurons ◽  
Tuning Width ◽  
Segregation Process ◽  
Human Orientation ◽  
Contextual Stimuli ◽  
Straight Lines

We studied the effects of various patterns as contextual stimuli on human orientation discrimination, and on responses of neurons in V1 of alert monkeys. When a target line is presented along with various contextual stimuli (masks), human orientation discrimination is impaired. For most V1 neurons, responses elicited by a line in the receptive field (RF) center are suppressed by these contextual patterns. Orientation discrimination thresholds of human observers are elevated slightly when the target line is surrounded by orthogonal lines. For randomly oriented lines, thresholds are elevated further and even more so for lines parallel to the target. Correspondingly, responses of most V1 neurons to a line are suppressed. Although contextual lines inhibit the amplitude of orientation tuning functions of most V1 neurons, they do not systematically alter the tuning width. Elevation of human orientation discrimination thresholds decreases with increasing curvature of masking lines, so does the inhibition of V1 neuronal responses. A mask made of straight lines yields the strongest interference with human orientation discrimination and produces the strongest suppression of neuronal responses. Elevation of human orientation discrimination thresholds is highest when a mask covers only the immediate vicinity of the target line. Increasing the masking area results in less interference. On the contrary, suppression of neuronal responses in V1 increases with increasing mask size. Our data imply that contextual interference observed in human orientation discrimination is in part directly related to contextual inhibition of neuronal activity in V1. However, the finding that interference with orientation discrimination is weaker for larger masks suggests a figure-ground segregation process that is not located in V1.

scholarly journals Hidden by bias: how standard psychophysical procedures conceal crucial aspects of peripheral visual appearance

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fazilet Zeynep Yildirim ◽  
Daniel R. Coates ◽  
Bilge Sayim
Keyword(s):  
Visual Perception ◽  
Line Pair ◽  
Crucial Aspect ◽  
Time And Space ◽  
Contextual Modulation ◽  
Visual Appearance ◽  
Single Time ◽  
Visual Periphery ◽  
Contextual Stimuli ◽  
Biased Perception

AbstractThe perception of a target depends on other stimuli surrounding it in time and space. This contextual modulation is ubiquitous in visual perception, and is usually quantified by measuring performance on sets of highly similar stimuli. Implicit or explicit comparisons among the stimuli may, however, inadvertently bias responses and conceal strong variability of target appearance. Here, we investigated the influence of contextual stimuli on the perception of a repeating pattern (a line triplet), presented in the visual periphery. In the neutral condition, the triplet was presented a single time to capture its minimally biased perception. In the similar and dissimilar conditions, it was presented within stimulus sets composed of lines similar to the triplet, and distinct shapes, respectively. The majority of observers reported perceiving a line pair in the neutral and dissimilar conditions, revealing ‘redundancy masking’, the reduction of the perceived number of repeating items. In the similar condition, by contrast, the number of lines was overestimated. Our results show that the similar context did not reveal redundancy masking which was only observed in the neutral and dissimilar context. We suggest that the influence of contextual stimuli has inadvertently concealed this crucial aspect of peripheral appearance.

Responses of monkey inferior temporal neurons to luminance-, motion-, and texture-defined gratings

1995 ◽  
Vol 73 (4) ◽  
pp. 1341-1354 ◽  
Author(s):  
G. Sary ◽  
R. Vogels ◽  
G. Kovacs ◽  
G. A. Orban
Keyword(s):  
Visual Perception ◽  
Relative Motion ◽  
Discrimination Task ◽  
Stimulus Presentation ◽  
Response Strength ◽  
The Other ◽  
Orientation Discrimination ◽  
Macaque Monkeys ◽  
Tuning Width ◽  
Visual Cortical

1. We recorded from neurons responsive to gratings in the inferior temporal (IT) cortices of macaque monkeys. One of the monkeys performed an orientation discrimination task; the other maintained fixation during stimulus presentation. Stimuli consisted of gratings based on discontinuities in luminance, relative motion, and texture. 2. IT cells responded well to gratings defined solely by relative motion, implying either direct or indirect motion input into IT, an area that is part of the ventral visual cortical pathway. 3. Response strength in general did not depend on the cue used to define the gratings. Latency values observed for the two static grating types (luminance- and texture-defined gratings) were similar, but significantly shorter than those measured for the kinetic gratings. 4. Stimulus orientation had a significant effect in 27%, 27%, and 9% of the cells tested with luminance-, kinetic-, and texture-defined gratings, respectively. 5. Only a small proportion of cells were orientation sensitive for more than one defining cue. The average preferred orientation for luminance and kinetic gratings matched; the tuning width was similar for the two cues. 6. Our results indicate that IT cells may contribute to cue-invariant coding of boundaries and edges. We discuss the relevance of these results to visual perception.

scholarly journals The observant mind: self-awareness of attentional status

2010 ◽  
Vol 277 (1699) ◽  
pp. 3421-3426 ◽  
Author(s):  
Noriko Yamagishi ◽  
Stephen J. Anderson ◽  
Mitsuo Kawato
Keyword(s):  
Threshold Model ◽  
Discrimination Performance ◽  
Attentional Focus ◽  
Orientation Discrimination ◽  
Self Awareness ◽  
Neural Basis ◽  
Attentional Processes ◽  
Delay Times ◽  
Linear Rise ◽  
High Level

Visual perception is dependent not only on low-level sensory input but also on high-level cognitive factors such as attention. In this paper, we sought to determine whether attentional processes can be internally monitored for the purpose of enhancing behavioural performance. To do so, we developed a novel paradigm involving an orientation discrimination task in which observers had the freedom to delay target presentation—by any amount required—until they judged their attentional focus to be complete. Our results show that discrimination performance is significantly improved when individuals self-monitor their level of visual attention and respond only when they perceive it to be maximal. Although target delay times varied widely from trial-to-trial (range 860 ms–12.84 s), we show that their distribution is Gaussian when plotted on a reciprocal latency scale. We further show that the neural basis of the delay times for judging attentional status is well explained by a linear rise-to-threshold model. We conclude that attentional mechanisms can be self-monitored for the purpose of enhancing human decision-making processes, and that the neural basis of such processes can be understood in terms of a simple, yet broadly applicable, linear rise-to-threshold model.

Bar orientation discrimination in the cat

1990 ◽  
Vol 4 (3) ◽  
pp. 257-268 ◽  
Author(s):  
Peter De Weerd ◽  
Erik Vandenbussche ◽  
Guy A. Orban
Keyword(s):  
Human Performance ◽  
Discrimination Performance ◽  
Oblique Effect ◽  
Orientation Discrimination ◽  
Human Orientation

AbstractWe have measured orientation-discrimination thresholds of 4 deg in the cat, confirming an earlier study of Vandenbussche and Orban (1983). Unlike Vandenbussche and Orban (1983), we found that orientation-discrimination performance is not better at principal, as compared to oblique, reference orientations (no oblique effect). Despite the absence of the oblique effect, and despite the discrimination thresholds which were elevated by a factor of 4 compared to humans, orientation-discrimination performance of cats and humans is qualitatively similar in a number of aspects. First, orientation-discrimination performance as a function of length and contrast is qualitatively similar to human performance. Second, as in humans, detection and discrimination of the stimuli are closely related. Finally, randomizing the contrast between the stimuli does not affect orientation-discrimination performance. This suggests that similar computations underlay orientation-discrimination performance in both species. In summary, our results confirm that the cat is a useful model for human orientation-discrimination performance.

scholarly journals Dynamics of visual perceptual processing in freely behaving mice

2020 ◽  
Author(s):  
Wen-Kai You ◽  
Shreesh P. Mysore
Keyword(s):  
Visual Perception ◽  
Time Course ◽  
Neural Circuit ◽  
Short Term Memory ◽  
Human Perception ◽  
Orientation Discrimination ◽  
Sensory Encoding ◽  
Stimulus Features ◽  
Two Stages ◽  
Speed Accuracy

ABSTRACTMice are being used increasing commonly to study visual behaviors, but the time-course of their perceptual dynamics is unclear. Here, using conditional accuracy analysis, a powerful method used to analyze human perception, and drift diffusion modeling, we investigated the dynamics and limits of mouse visual perception with a 2AFC orientation discrimination task. We found that it includes two stages – a short, sensory encoding stage lasting ∼300 ms, which involves the speed-accuracy tradeoff, and a longer visual short-term memory-dependent (VSTM) stage lasting ∼1700 ms. Manipulating stimulus features or adding a foil affected the sensory encoding stage, and manipulating stimulus duration altered the VSTM stage, of mouse perception. Additionally, mice discriminated targets as brief as 100 ms, and exhibited classic psychometric curves in a visual search task. Our results reveal surprising parallels between mouse and human visual perceptual processes, and provide a quantitative scaffold for exploring neural circuit mechanisms of visual perception.

scholarly journals Targeted comodulation supports flexible and accurate decoding in V1

2021 ◽  
Author(s):  
Caroline Haimerl ◽  
Douglas A. Ruff ◽  
Marlene R. Cohen ◽  
Cristina Savin ◽  
Eero P. Simoncelli
Keyword(s):  
Orientation Discrimination ◽  
Physiological Data ◽  
Visual Orientation ◽  
Strongly Correlated ◽  
Neural Responses ◽  
Stimulus Information ◽  
Behavioral Task ◽  
V1 Neurons ◽  
Stochastic Modulation ◽  
And Task

AbstractSensory-guided behavior requires reliable encoding of stimulus information in neural responses, and task-specific decoding through selective combination of these responses. The former has been the topic of intensive study, but the latter remains largely a mystery. We propose a framework in which shared stochastic modulation of task-informative neurons serves as a label to facilitate downstream decoding. Theoretical analysis and computational simulations demonstrate that a decoder that exploits such a signal can achieve flexible and accurate readout. Using this theoretical framework, we analyze behavioral and physiological data obtained from monkeys performing a visual orientation discrimination task. The responses of recorded V1 neurons exhibit strongly correlated modulation. This modulation is stronger in those neurons that are most informative for the behavioral task and it is substantially reduced in a control condition where recorded neurons are uninformative. We demonstrate that this modulator label can be used to improve downstream decoding within a small number of training trials, consistent with observed behavior. Finally, we find that the trial-by-trial modulatory signal estimated from V1 populations is also present in the activity of simultaneously recorded MT units, and preferentially so if they are task-informative, supporting the hypothesis that it serves as a label for the selection and decoding of relevant downstream neurons.

scholarly journals Where we perceive before we look: The distribution of presaccadic attention assessed with dynamic 1/f noise

2022 ◽  
Author(s):  
Nina M Hanning ◽  
Heiner Deubel
Keyword(s):  
Visual Field ◽  
Visual Information ◽  
Discrimination Performance ◽  
Orientation Discrimination ◽  
Pink Noise ◽  
Local Orientation ◽  
Eye Fixation ◽  
Test Items ◽  
Saccade Onset ◽  
Orientation Signal

Already before the onset of a saccadic eye movement, we preferentially process visual information at the upcoming eye fixation. This 'presaccadic shift of attention' is typically assessed via localized test items, which potentially bias the attention measurement. Here we show how presaccadic attention shapes perception from saccade origin to target when no scene-structuring items are presented. Participants made saccades into a 1/f ('pink') noise field, in which we embedded a brief orientation signal at various locations shortly before saccade onset. Local orientation discrimination performance served as a proxy for the allocation of attention. Results demonstrate that (1) saccades are preceded by shifts of attention to their goal location even if they are directed into an unstructured visual field, but the spread of attention, compared to target-directed saccades, is broad; (2) the presaccadic attention shift is accompanied by considerable attentional costs at the presaccadic eye fixation; (3) objects markedly shape the distribution of presaccadic attention, demonstrating the relevance of an item-free approach for measuring attentional dynamics across the visual field.

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