The neural basis of visual short-term memory

 

A critical question in human cognition is how the brain maintains information across eye movements and distraction. Without this capacity, we would experience the outside world as a series of disconnected glimpses. Between the visual system and frontal cortex, activity in areas of the dorsal parietal cortex, also involved in visual attention, reflect the number of items held in visual short-term memory (VSTM). What can this brain activity tell us about the processes underlying visual short-term memory and attention? How do these areas interact with other brain areas to form durable VSTM representations?

 

Hemispheric asymmetries

From the earliest stages, visual information is separated into left and right visual hemifields, each processed by cortical areas in the opposite, or contralateral, hemisphere. Work in the Visual Perception and Memory Lab investigates how differences in visual field representations across cortical areas result in how we perceive a unified world. How does the right parietal cortex code information across the visual field? What can asymmetries in healthy individuals reveal about neuropsychological disorders such as hemispatial neglect, which occur predominantly after damage to the right hemisphere? What are the behavioral consequences of these asymmetries in healthy individuals?

 

 

Ventral parietal cortex in memory and attention

The angular gyrus, adjacent to topogaphically defined parietal cortex, is a part of an attention network that shows reduced activity when we hold visual items in memory. However, this area has also been implicated in a myriad of cognitive functions including binding of visual features in the right hemisphere and binding of visual and semantic information in the left hemisphere. How can we reconcile these functions of the angular gyrus? Can we localize areas of the ventral parietal cortex involved in specific cognitive processes?