scholarly journals Self-operated stimuli improve subsequent visual motion processing

2020 ◽  
Author(s):  
Giulia Sedda ◽  
David J. Ostry ◽  
Vittorio Sanguineti ◽  
Silvio P. Sabatini
Keyword(s):  
Visual Information ◽  
Visual Motion ◽  
Internal Representation ◽  
Fine Tuning ◽  
Motion Processing ◽  
Stimulus Motion ◽  
Directional Information ◽  
Movement Training ◽  
Visual Motion Processing ◽  
Perceptual Changes

Proper interpretation of visual information requires capturing the structural regularities in the visual signal and this frequently occurs in conjunction with movement. Perceptual interpretation is complicated both by transient perceptual changes that accompany motor activity, and as found in audition and somatosensation, by more persistent changes that accompany the learning of new movements. Here we asked whether motor learning also results in sustained changes to visual perception. We designed a reaching task in which participants directly controlled the visual information they received, which we term self-operated stimuli. Specifically, they trained to make movements in a number of directions. Directional information was provided by the motion of an intrinsically ambiguous moving stimulus which was directly tied to motion of the hand. We find that movement training improves perception of coherent stimulus motion, and that changes in movement are correlated with the perceptual change. No perceptual changes are observed in passive observers even when they are provided with an explicit strategy to solve perceptual grouping. Comparison of empirical perceptual data with simulations based on a Bayesian generative model of motion perception suggests that movement training promotes the fine-tuning of the internal representation of stimulus geometry. These results emphasize the role of sensorimotor interaction in determining the persistent properties in space and time that define a percept.

scholarly journals Visual motion and decision-making in dyslexia: Evidence of reduced accumulation of sensory evidence and related neural dynamics

2021 ◽  
Author(s):  
Catherine Manning ◽  
Cameron D Hassall ◽  
Laurence T Hunt ◽  
Anthony M Norcia ◽  
Eric-Jan Wagenmakers ◽  
...  
Keyword(s):  
Decision Making ◽  
Visual Information ◽  
Visual Motion ◽  
Motion Processing ◽  
Global Motion ◽  
Perceptual Decision Making ◽  
Behavioural Responses ◽  
Visual Motion Processing ◽  
Decision Making Processes ◽  
Sensory Evidence

Children with and without dyslexia differ in their behavioural responses to visual information, particularly when required to pool dynamic signals over space and time. Importantly, multiple processes contribute to behavioural responses. Here we investigated which processing stages are affected in children with dyslexia when performing visual motion processing tasks, by combining two methods that are sensitive to the dynamic processes leading to responses. We used a diffusion model which decomposes response time and accuracy into distinct cognitive constructs, and high-density EEG. 50 children with dyslexia and 50 typically developing children aged 6 to 14 years judged the direction of motion as quickly and accurately as possible in two global motion tasks, which varied in their requirements for segregating signal-from-noise. Following our pre-registered analyses, we fitted hierarchical Bayesian diffusion models to the data, blinded to group membership. Unblinding revealed reduced evidence accumulation in children with dyslexia compared to typical children for both tasks. We also identified a response-locked EEG component which was maximal over centro-parietal electrodes which indicated a neural correlate of reduced drift-rate in dyslexia, thereby linking brain and behaviour. We suggest that children with dyslexia are slower to extract sensory evidence from global motion displays, regardless of whether they are required to segregate signal-from-noise, thus furthering our understanding of atypical perceptual decision-making processes in dyslexia.

Motion Segmentation in Artificial and Biological Systems

1998 ◽  
Vol 53 (7-8) ◽  
pp. 622-627
Author(s):  
Walter J. Gillner
Keyword(s):  
Visual Information ◽  
Visual Motion ◽  
Obstacle Detection ◽  
Object Motion ◽  
Motion Processing ◽  
Motion Field ◽  
Detection Systems ◽  
Visual Motion Processing ◽  
Retinal Motion ◽  
Technical Vision

Abstract In the early steps of visual information processing motion is one of the most important queues for the development of spatial representations. Obstacle detection and egomotion estimation are only two examples of the powerfulness of visual motion detection systems. The underlying process of information extraction has to be active due to the observer’s capabilities of egomotion. This means that the observer’s motion has an impact on the pro­jected retinal motion field. Therefore one of the challenging tasks for biological as well as for technical vision systems is to couple retinal motion and egomotion and to uncouple egomotion and object motion. The following sections describe a model that couples visual motion processing with the egomotion parameters of a moving observer. Beneath a theoreti­cal introduction of the model an application to traffic scene analysis is presented. A t last the paper relates the model to biological motion processing systems.

Pursuit and optokinetic deficits following chemical lesions of cortical areas MT and MST

1988 ◽  
Vol 60 (3) ◽  
pp. 940-965 ◽  
Author(s):  
M. R. Dursteler ◽  
R. H. Wurtz
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Visual Motion ◽  
Ibotenic Acid ◽  
Motion Processing ◽  
Temporal Area ◽  
Target Speed ◽  
Pursuit Eye Movements ◽  
Medial Superior Temporal ◽  
Visual Motion Processing

1. Previous experiments have shown that punctate chemical lesions within the middle temporal area (MT) of the superior temporal sulcus (STS) produce deficits in the initiation and maintenance of pursuit eye movements (10, 34). The present experiments were designed to test the effect of such chemical lesions in an area within the STS to which MT projects, the medial superior temporal area (MST). 2. We injected ibotenic acid into localized regions of MST, and we observed two deficits in pursuit eye movements, a retinotopic deficit and a directional deficit. 3. The retinotopic deficit in pursuit initiation was characterized by the monkey's inability to match eye speed to target speed or to adjust the amplitude of the saccade made to acquire the target to compensate for target motion. This deficit was related to the initiation of pursuit to targets moving in any direction in the visual field contralateral to the side of the brain with the lesion. This deficit was similar to the deficit we found following damage to extrafoveal MT except that the affected area of the visual field frequently extended throughout the entire contralateral visual field tested. 4. The directional deficit in pursuit maintenance was characterized by a failure to match eye speed to target speed once the fovea had been brought near the moving target. This deficit occurred only when the target was moving toward the side of the lesion, regardless of whether the target began to move in the ipsilateral or contralateral visual field. There was no deficit in the amplitude of saccades made to acquire the target, or in the amplitude of the catch-up saccades made to compensate for the slowed pursuit. The directional deficit is similar to the one we described previously following chemical lesions of the foveal representation in the STS. 5. Retinotopic deficits resulted from any of our injections in MST. Directional deficits resulted from lesions limited to subregions within MST, particularly lesions that invaded the floor of the STS and the posterior bank of the STS just lateral to MT. Extensive damage to the densely myelinated area of the anterior bank or to the posterior parietal area on the dorsal lip of the anterior bank produced minimal directional deficits. 6. We conclude that damage to visual motion processing in MST underlies the retinotopic pursuit deficit just as it does in MT. MST appears to be a sequential step in visual motion processing that occurs before all of the visual motion information is transmitted to the brainstem areas related to pursuit.(ABSTRACT TRUNCATED AT 400 WORDS)

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