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Full-Text Articles in Neurosciences
Human Parietal "Reach Region" Primarily Encodes Intrinsic Visual Direction, Not Extrinsic Movement Direction, In A Visual Motor Dissociation Task., Juan Fernandez-Ruiz, Herbert C Goltz, Joseph F X Desouza, Tutis Vilis, J Douglas Crawford
Human Parietal "Reach Region" Primarily Encodes Intrinsic Visual Direction, Not Extrinsic Movement Direction, In A Visual Motor Dissociation Task., Juan Fernandez-Ruiz, Herbert C Goltz, Joseph F X Desouza, Tutis Vilis, J Douglas Crawford
Brain and Mind Institute Researchers' Publications
Posterior parietal cortex (PPC) participates in the planning of visuospatial behaviors, including reach movements, in gaze-centered coordinates. It is not known if these representations encode the visual goal in retinal coordinates, or the movement direction relative to gaze. Here, by dissociating the intrinsic retinal stimulus from the extrinsic direction of movement, we show that PPC employs a visual code. Using delayed pointing and event-related functional magnetic resonance imaging, we identified a cluster of PPC regions whose activity was topographically (contralaterally) related to the direction of the planned movement. We then switched the normal visual-motor spatial relationship by adapting subjects to …
Alcohol Slows Interhemispheric Transmission, Increases The Flash-Lag Effect, And Prolongs Masking: Evidence For A Slowing Of Neural Processing And Transmission., Sarah A Khan, Brian Timney
Alcohol Slows Interhemispheric Transmission, Increases The Flash-Lag Effect, And Prolongs Masking: Evidence For A Slowing Of Neural Processing And Transmission., Sarah A Khan, Brian Timney
Brain and Mind Institute Researchers' Publications
While the alcohol literature is extensive, relatively little addresses the relationship between physiological effects and behavioural changes. Using the visual system as a model, we examined alcohol's influence on neural temporal processing as a potential means for alcohol's effects. We did this by using tasks that provided a measure of processing speed: Poffenberger paradigm, flash-lag, and backward masking. After moderate alcohol, participants showed longer interhemispheric transmission times, larger flash-lags, and prolonged masking. Our data are consistent with the view that alcohol slows neural processing, and provide support for a reduction in processing efficiency underlying alcohol-induced changes in temporal visual processing.
Perceptual Functions Of Perirhinal Cortex In Rats: Zero-Delay Object Recognition And Simultaneous Oddity Discriminations., Susan J Bartko, Boyer D Winters, Rosemary A Cowell, Lisa M Saksida, Timothy J Bussey
Perceptual Functions Of Perirhinal Cortex In Rats: Zero-Delay Object Recognition And Simultaneous Oddity Discriminations., Susan J Bartko, Boyer D Winters, Rosemary A Cowell, Lisa M Saksida, Timothy J Bussey
Brain and Mind Institute Researchers' Publications
The perirhinal cortex (PRh) is widely accepted as having an important role in object recognition memory in humans and animals. Contrary to claims that PRh mediates declarative memory exclusively, previous evidence suggests that PRh has a role in the perceptual processing of complex objects. In the present study, we conducted an examination of the possible role of PRh in perceptual function in rats. We examined whether bilateral excitotoxic lesions of PRh or PPRh (perirhinal plus postrhinal cortices) in the rat would cause deficits in a zero-delay object-recognition task and a simultaneous oddity discrimination task. Both of these tasks measured spontaneous …