Precision of working memory for visual motion sequences and transparent motion surfaces

We applied electrical stimulation to physiologically identified sites in macaque middle temporal area (MT) to examine its role in short-term storage of recently encoded information about stimulus motion. We used a behavioral task in which monkeys compared the directions of two moving random-dot stimuli, sample and test, separated by a 1.5-s delay. Four sample directions were used for each site, and the animals had to indicate whether the direction of motion in the sample was the same as or different to the direction of motion in the test. We found that the effect of stimulation of the same directional column in MT depended on the behavioral state of the animal. Although stimulation had strong effects when applied during the encoding and the storage components of the task, these effects were not equivalent. Stimulation applied during the presentation of the sample produced signals interpreted by the monkeys as directional motion. However, the same stimulation introduced during the period of storage no longer produced signals interpreted as unambiguous directional information. We conclude that the directional information used by the monkeys in the working memory task is likely to be provided by neurons in MT, and the use of this information appears to be dependent on the portion of the task during which stimulation was delivered. Finally, the disruptive effects of stimulation during the delay suggest that MT neurons not only participate in the encoding of visual motion information but also in its storage by either maintaining an active connection with the circuitry involved in storage or being an integral component of that circuitry.

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Combined effects of feature-based working memory and feature-based attention on the perception of visual motion direction

Journal of Vision ◽

10.1167/11.1.11 ◽

2011 ◽

Vol 11 (1) ◽

pp. 11-11 ◽

Cited By ~ 22

Author(s):

D. Mendoza ◽

M. Schneiderman ◽

C. Kaul ◽

J. Martinez-Trujillo

Keyword(s):

Working Memory ◽

Visual Motion ◽

Combined Effects ◽

Motion Direction ◽

Feature Based

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Visual motion integration of bidirectional transparent motion in mouse opto-locomotor reflexes

Scientific Reports ◽

10.1038/s41598-021-89974-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

L. A. M. H. Kirkels ◽

W. Zhang ◽

Z. Rezvani ◽

R. J. A. van Wezel ◽

M. M. van Wanrooij

Keyword(s):

Visual Motion ◽

Whole Body ◽

Neural Responses ◽

Visual Motion Perception ◽

Transparent Motion ◽

Integration Mechanisms ◽

Sensory Evidence ◽

Random Dot Patterns ◽

Winner Take All ◽

Unidirectional Motion

AbstractVisual motion perception depends on readout of direction selective sensors. We investigated in mice whether the response to bidirectional transparent motion, activating oppositely tuned sensors, reflects integration (averaging) or winner-take-all (mutual inhibition) mechanisms. We measured whole body opto-locomotor reflexes (OLRs) to bidirectional oppositely moving random dot patterns (leftward and rightward) and compared the response to predictions based on responses to unidirectional motion (leftward or rightward). In addition, responses were compared to stimulation with stationary patterns. When comparing OLRs to bidirectional and unidirectional conditions, we found that the OLR to bidirectional motion best fits an averaging model. These results reflect integration mechanisms in neural responses to contradicting sensory evidence as has been documented for other sensory and motor domains.

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Orientation Selectivity of Motion-Boundary Responses in Human Visual Cortex

Journal of Neurophysiology ◽

10.1152/jn.00400.2010 ◽

2010 ◽

Vol 104 (6) ◽

pp. 2940-2950 ◽

Cited By ~ 22

Author(s):

Jonas Larsson ◽

David J. Heeger ◽

Michael S. Landy

Keyword(s):

Visual Cortex ◽

Visual Motion ◽

Selective Adaptation ◽

Probe Stimulus ◽

Human Visual Cortex ◽

Boundary Orientation ◽

Transparent Motion ◽

Visual Areas ◽

Motion Boundaries ◽

Motion Boundary

Motion boundaries (local changes in visual motion direction) arise naturally when objects move relative to an observer. In human visual cortex, neuroimaging studies have identified a region (the kinetic occipital area [KO]) that responds more strongly to motion-boundary stimuli than to transparent-motion stimuli. However, some functional magnetic resonance imaging (fMRI) studies suggest that KO may encompass multiple visual areas and single-unit studies in macaque visual cortex have identified neurons selective for motion-boundary orientation in areas V2, V3, and V4, implying that motion-boundary selectivity may not be restricted to a single area. It is not known whether fMRI responses to motion boundaries are selective for motion-boundary orientation, as would be expected if these responses reflected the population activity of motion-boundary–selective neurons. We used an event-related fMRI adaptation protocol to measure orientation-selective responses to motion boundaries in human visual cortex. On each trial, we measured the response to a probe stimulus presented after an adapter stimulus (a vertical or horizontal motion-boundary grating). The probe stimulus was either a motion-boundary grating oriented parallel or orthogonal to the adapter stimulus or a transparent-motion stimulus. Orientation-selective adaptation for motion boundaries—smaller responses for trials in which test and adapter stimuli were parallel to each other—was observed in multiple extrastriate visual areas. The strongest adaptation, relative to the unadapted responses, was found in V3A, V3B, LO1, LO2, and V7. Most of the visual areas that exhibited orientation-selective adaptation in our data also showed response preference for motion boundaries over transparent motion, indicating that most of the human visual areas previously shown to respond to motion boundaries are also selective for motion-boundary orientation. These results suggest that neurons selective for motion-boundary orientation are distributed across multiple human visual cortical areas and argue against the existence of a single region or area specialized for motion-boundary processing.

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Neural Timing Deficits Prevalent in Developmental Disorders, Aging, and Concussions Remediated Rapidly By Movement Discrimination Exercises

10.20944/preprints202105.0659.v1 ◽

2021 ◽

Author(s):

Teri Lawton ◽

John Shelley-Tremblay ◽

Ming-Xiong Huang

Keyword(s):

Working Memory ◽

Processing Speed ◽

Cognitive Skills ◽

Developmental Disorders ◽

Visual Motion ◽

Source Imaging ◽

Low Level ◽

Before And After ◽

High Level ◽

Movement Discrimination

(1) Background: Substantial evidence that neural timing deficits are prevalent in developmental disorders, aging, and concussions resulting from a mild Traumatic Brain Injury (mTBI) is presented. We show that if timing deficits are remediated using low-level movement discrimination training, then high-level cognitive skills, including reading, attention, processing speed, and working memory improve substantially. (2) Methods: Two case studies are presented using MEG source imaging on an adult dyslexic, and a healthy older adult observed before and after training on movement discrimination two times/week for 8 weeks for adult dyslexic. (3) Results: We found improvements in reading, attention, processing speed, and working memory on neuropsychological tests. Substantial MEG signal increases in visual Motion Networks (V1, V3, MT, MST), Attention Networks (ACC, dlPFC, vlPFC and precuneous/ PCC areas) and Memory Networks (dlPFC). (4) Conclusions: Improving neural timing deficits before cognitive exercises to improve specific cognitive skills provides a rapid and effective method to improve cognitive skills. Improving the timing and sensitivity of low-level dorsal pathways, improving feedforward and feedback pathways, is essential to improve high-level cognitive skills. This adaptive training with substantial feedback shows cognitive transfer to tasks not trained on, significantly improving a person’s quality of life rapidly and effectively.

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Neural mechanisms of speed perception: transparent motion

Journal of Neurophysiology ◽

10.1152/jn.00333.2013 ◽

2013 ◽

Vol 110 (9) ◽

pp. 2007-2018 ◽

Cited By ~ 10

Author(s):

Bart Krekelberg ◽

Richard J. A. van Wezel

Keyword(s):

Visual Motion ◽

Human Subjects ◽

Temporal Cortex ◽

Motion Patterns ◽

Tuning Curves ◽

Mt Neurons ◽

Transparent Motion ◽

Single Pattern ◽

Speed Perception ◽

Unidirectional Motion

Visual motion on the macaque retina is processed by direction- and speed-selective neurons in extrastriate middle temporal cortex (MT). There is strong evidence for a link between the activity of these neurons and direction perception. However, there is conflicting evidence for a link between speed selectivity of MT neurons and speed perception. Here we study this relationship by using a strong perceptual illusion in speed perception: when two transparently superimposed dot patterns move in opposite directions, their apparent speed is much larger than the perceived speed of a single pattern moving at that physical speed. Moreover, the sensitivity for speed discrimination is reduced for such bidirectional patterns. We first confirmed these behavioral findings in human subjects and extended them to a monkey subject. Second, we determined speed tuning curves of MT neurons to bidirectional motion and compared these to speed tuning curves for unidirectional motion. Consistent with previous reports, the response to bidirectional motion was often reduced compared with unidirectional motion at the preferred speed. In addition, we found that tuning curves for bidirectional motion were shifted to lower preferred speeds. As a consequence, bidirectional motion of some speeds typically evoked larger responses than unidirectional motion. Third, we showed that these changes in neural responses could explain changes in speed perception with a simple labeled line decoder. These data provide new insight into the encoding of transparent motion patterns and provide support for the hypothesis that MT activity can be decoded for speed perception with a labeled line model.

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