scholarly journals Normalization models of cue combination in touch

2018 ◽  
Author(s):  
Md. Shoaibur Rahman ◽  
Jeffrey M. Yau
Keyword(s):  
Stimulus Feature ◽  
Cue Combination ◽  
Divisive Normalization

Bimanual touch may require combining what is felt on the hands with where the hands are located in space. The computations supporting bimanual touch are poorly understood. We found that tactile cue combination patterns and their sensitivity to the locations of the hands differed according to the attended stimulus feature. These idiosyncratic perceptual patterns can be explained by distinct cue combination models that each involve divisive normalization, a canonical computation.

An Accelerated Cue Combination Principle Accounts for Multi-cue Depth Perception

2020 ◽  
Vol 3 (1) ◽  
pp. 10501-1-10501-9
Author(s):  
Christopher W. Tyler
Keyword(s):  
Belief Propagation ◽  
Probability Distributions ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Fusion Model ◽  
Cue Combination ◽  
Depth Estimate ◽  
Appropriate Behavior ◽  
Depth Cues ◽  
Bayesian Averaging

Abstract For the visual world in which we operate, the core issue is to conceptualize how its three-dimensional structure is encoded through the neural computation of multiple depth cues and their integration to a unitary depth structure. One approach to this issue is the full Bayesian model of scene understanding, but this is shown to require selection from the implausibly large number of possible scenes. An alternative approach is to propagate the implied depth structure solution for the scene through the “belief propagation” algorithm on general probability distributions. However, a more efficient model of local slant propagation is developed as an alternative.The overall depth percept must be derived from the combination of all available depth cues, but a simple linear summation rule across, say, a dozen different depth cues, would massively overestimate the perceived depth in the scene in cases where each cue alone provides a close-to-veridical depth estimate. On the other hand, a Bayesian averaging or “modified weak fusion” model for depth cue combination does not provide for the observed enhancement of perceived depth from weak depth cues. Thus, the current models do not account for the empirical properties of perceived depth from multiple depth cues.The present analysis shows that these problems can be addressed by an asymptotic, or hyperbolic Minkowski, approach to cue combination. With appropriate parameters, this first-order rule gives strong summation for a few depth cues, but the effect of an increasing number of cues beyond that remains too weak to account for the available degree of perceived depth magnitude. Finally, an accelerated asymptotic rule is proposed to match the empirical strength of perceived depth as measured, with appropriate behavior for any number of depth cues.

Displaying Depth in Computer Systems: Lessons from Two-Dimensional Works of Art

2005 ◽  
Vol 49 (17) ◽  
pp. 1583-1587
Author(s):  
Skye Lee Pazuchanics ◽  
Douglas J. Gillan
Keyword(s):  
Visual System ◽  
Computer Systems ◽  
Cue Integration ◽  
Two Dimensional ◽  
Cue Combination ◽  
Design Decisions ◽  
Works Of Art ◽  
Pictorial Cues

Virtual depth displays depend on static, monocular cues. Models of integrating monocular cues may be continuous (additive) or discontinuous. Previous research using simple displays and a small number of cues supported continuous cue integration. The present research is designed to expand the understanding of how the visual system integrates information from multiple pictorial cues by investigating combinations of one to ten pictorial cues in visually-rich, two-dimensional displays (paintings and photographs). Participants estimated depth in target paintings and photographs relative to a standard two dimensional display. Certain results suggest that the visual system integrates cues in a largely additive way, but after a number of cues are present there may be an additional boost in perceived depth resulting in a best-fittingdiscontinuous model of cue combination. However, this discontinuous effect may be due to designdecisions made by the painters rather than exclusively to the perceptual processes of the viewers. Analyses of these design decisions provide lessons for the design of two-dimensional displays.

scholarly journals Normalization in human somatosensory cortex

2015 ◽  
Vol 114 (5) ◽  
pp. 2588-2599 ◽  
Author(s):  
Gijs Joost Brouwer ◽  
Vanessa Arnedo ◽  
Shani Offen ◽  
David J. Heeger ◽  
Arthur C. Grant
Keyword(s):  
Somatosensory Cortex ◽  
Middle Finger ◽  
Functional Magnetic Resonance ◽  
Stimulus Amplitude ◽  
Target Digit ◽  
Divisive Normalization ◽  
Postcentral Gyrus ◽  
Baseline Response ◽  
The Right ◽  
Stimulation Of

Functional magnetic resonance imaging (fMRI) was used to measure activity in human somatosensory cortex and to test for cross-digit suppression. Subjects received stimulation (vibration of varying amplitudes) to the right thumb (target) with or without concurrent stimulation of the right middle finger (mask). Subjects were less sensitive to target stimulation (psychophysical detection thresholds were higher) when target and mask digits were stimulated concurrently compared with when the target was stimulated in isolation. fMRI voxels in a region of the left postcentral gyrus each responded when either digit was stimulated. A regression model (called a forward model) was used to separate the fMRI measurements from these voxels into two hypothetical channels, each of which responded selectively to only one of the two digits. For the channel tuned to the target digit, responses in the left postcentral gyrus increased with target stimulus amplitude but were suppressed by concurrent stimulation to the mask digit, evident as a shift in the gain of the response functions. For the channel tuned to the mask digit, a constant baseline response was evoked for all target amplitudes when the mask was absent and responses decreased with increasing target amplitude when the mask was concurrently presented. A computational model based on divisive normalization provided a good fit to the measurements for both mask-absent and target + mask stimulation. We conclude that the normalization model can explain cross-digit suppression in human somatosensory cortex, supporting the hypothesis that normalization is a canonical neural computation.

scholarly journals Correlated individual differences suggest a common mechanism underlying metacognition in visual perception and visual short-term memory

2017 ◽  
Vol 284 (1867) ◽  
pp. 20172035 ◽  
Author(s):  
Jason Samaha ◽  
Bradley R. Postle
Keyword(s):  
Individual Differences ◽  
Visual Perception ◽  
Short Term Memory ◽  
Adaptive Behaviour ◽  
Common Mechanism ◽  
Stimulus Feature ◽  
Relevant Stimulus ◽  
Short Term ◽  
Term Memory ◽  
Visual Short Term Memory

Adaptive behaviour depends on the ability to introspect accurately about one's own performance. Whether this metacognitive ability is supported by the same mechanisms across different tasks is unclear. We investigated the relationship between metacognition of visual perception and metacognition of visual short-term memory (VSTM). Experiments 1 and 2 required subjects to estimate the perceived or remembered orientation of a grating stimulus and rate their confidence. We observed strong positive correlations between individual differences in metacognitive accuracy between the two tasks. This relationship was not accounted for by individual differences in task performance or average confidence, and was present across two different metrics of metacognition and in both experiments. A model-based analysis of data from a third experiment showed that a cross-domain correlation only emerged when both tasks shared the same task-relevant stimulus feature. That is, metacognition for perception and VSTM were correlated when both tasks required orientation judgements, but not when the perceptual task was switched to require contrast judgements. In contrast with previous results comparing perception and long-term memory, which have largely provided evidence for domain-specific metacognitive processes, the current findings suggest that metacognition of visual perception and VSTM is supported by a domain-general metacognitive architecture, but only when both domains share the same task-relevant stimulus feature.

scholarly journals Perceptual decisions are biased toward relevant prior choices

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helen Feigin ◽  
Shira Baror ◽  
Moshe Bar ◽  
Adam Zaidel
Keyword(s):  
Sensory Information ◽  
Irrelevant Stimulus ◽  
Stimulus Feature ◽  
Serial Dependence ◽  
Low Level ◽  
Subsequent Test ◽  
Key Factor ◽  
High Level ◽  
Motor Actions ◽  
The Brain

AbstractPerceptual decisions are biased by recent perceptual history—a phenomenon termed 'serial dependence.' Here, we investigated what aspects of perceptual decisions lead to serial dependence, and disambiguated the influences of low-level sensory information, prior choices and motor actions. Participants discriminated whether a brief visual stimulus lay to left/right of the screen center. Following a series of biased ‘prior’ location discriminations, subsequent ‘test’ location discriminations were biased toward the prior choices, even when these were reported via different motor actions (using different keys), and when the prior and test stimuli differed in color. By contrast, prior discriminations about an irrelevant stimulus feature (color) did not substantially influence subsequent location discriminations, even though these were reported via the same motor actions. Additionally, when color (not location) was discriminated, a bias in prior stimulus locations no longer influenced subsequent location discriminations. Although low-level stimuli and motor actions did not trigger serial-dependence on their own, similarity of these features across discriminations boosted the effect. These findings suggest that relevance across perceptual decisions is a key factor for serial dependence. Accordingly, serial dependence likely reflects a high-level mechanism by which the brain predicts and interprets new incoming sensory information in accordance with relevant prior choices.

The Effects of Cue Reliability on Crossmodal Recalibration in Adults and Children

2021 ◽  
pp. 1-19
Author(s):  
Sophie Rohlf ◽  
Patrick Bruns ◽  
Brigitte Röder
Keyword(s):  
Multisensory Integration ◽  
Sound Localization ◽  
Visual Stimulus ◽  
Cue Combination ◽  
Single Exposure ◽  
Visual Cue ◽  
Cue Reliability ◽  
Adults And Children ◽  
Ventriloquist Effect

Abstract Reliability-based cue combination is a hallmark of multisensory integration, while the role of cue reliability for crossmodal recalibration is less understood. The present study investigated whether visual cue reliability affects audiovisual recalibration in adults and children. Participants had to localize sounds, which were presented either alone or in combination with a spatially discrepant high- or low-reliability visual stimulus. In a previous study we had shown that the ventriloquist effect (indicating multisensory integration) was overall larger in the children groups and that the shift in sound localization toward the spatially discrepant visual stimulus decreased with visual cue reliability in all groups. The present study replicated the onset of the immediate ventriloquist aftereffect (a shift in unimodal sound localization following a single exposure of a spatially discrepant audiovisual stimulus) at the age of 6–7 years. In adults the immediate ventriloquist aftereffect depended on visual cue reliability, whereas the cumulative ventriloquist aftereffect (reflecting the audiovisual spatial discrepancies over the complete experiment) did not. In 6–7-year-olds the immediate ventriloquist aftereffect was independent of visual cue reliability. The present results are compatible with the idea of immediate and cumulative crossmodal recalibrations being dissociable processes and that the immediate ventriloquist aftereffect is more closely related to genuine multisensory integration.

scholarly journals A linear cue combination framework for understanding selective attention

10.1167/3.2.2 ◽  
2003 ◽  
Vol 3 (2) ◽  
pp. 2 ◽  
Author(s):  
Richard F. Murray ◽  
Allison B. Sekuler ◽  
Patrick J. Bennett
Keyword(s):  
Selective Attention ◽  
Cue Combination

A Canonical Neural Circuit for Cortical Nonlinear Operations

2008 ◽  
Vol 20 (6) ◽  
pp. 1427-1451 ◽  
Author(s):  
Minjoon Kouh ◽  
Tomaso Poggio
Keyword(s):  
Neural Circuit ◽  
Neural Responses ◽  
Energy Models ◽  
Divisive Normalization ◽  
Primate Visual Cortex ◽  
Neurophysiological Data ◽  
Ventral Pathway ◽  
Response Profiles ◽  
Parameter Values ◽  
Good Agreement

A few distinct cortical operations have been postulated over the past few years, suggested by experimental data on nonlinear neural response across different areas in the cortex. Among these, the energy model proposes the summation of quadrature pairs following a squaring nonlinearity in order to explain phase invariance of complex V1 cells. The divisive normalization model assumes a gain-controlling, divisive inhibition to explain sigmoid-like response profiles within a pool of neurons. A gaussian-like operation hypothesizes a bell-shaped response tuned to a specific, optimal pattern of activation of the presynaptic inputs. A max-like operation assumes the selection and transmission of the most active response among a set of neural inputs. We propose that these distinct neural operations can be computed by the same canonical circuitry, involving divisive normalization and polynomial nonlinearities, for different parameter values within the circuit. Hence, this canonical circuit may provide a unifying framework for several circuit models, such as the divisive normalization and the energy models. As a case in point, we consider a feedforward hierarchical model of the ventral pathway of the primate visual cortex, which is built on a combination of the gaussian-like and max-like operations. We show that when the two operations are approximated by the circuit proposed here, the model is capable of generating selective and invariant neural responses and performing object recognition, in good agreement with neurophysiological data.

scholarly journals Early temporal dynamics of cue combination for slant from stereo and texture

2010 ◽  
Vol 5 (8) ◽  
pp. 400-400
Author(s):  
B. T. Backus ◽  
J. M. Hillis ◽  
J. Frumkin ◽  
J. A. Saunders
Keyword(s):  
Temporal Dynamics ◽  
Cue Combination
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