Item Details

abstract

The dorsolateral prefrontal cortex and the posterior parietal cortex are parts of the cortical network involved in attention, working-memory and executive function. The two areas share a number of similarities, although functional differences between the two have also been identified. A widely believed functional difference posits that the posterior parietal cortex plays a critical role in orienting bottom-up attention, whereas the prefrontal cortex is responsible for shifting attention based on top-down factors. To test this idea, we trained monkeys with bottom-up visual attention tasks and recorded neural activity from the dorsolateral prefrontal cortex and areas LIP and 7a of the posterior parietal cortex, including in simultaneous recordings. The average time of salient target discrimination in the dorsolateral prefrontal cortex appeared no later than the posterior parietal areas although the initial visual response latencies were earlier in the posterior parietal cortex than in the dorsolateral prefrontal cortex. Contrary to established theories, the results suggest that the prefrontal cortex computes salient stimuli in parallel with the posterior parietal cortex and contributes to the guidance of bottom-up visual attention. Despite this similarity in function in the context of attention, differences between the prefrontal and posterior parietal cortex have been reported and replicated in the context of working-memory tasks. In order to understand further how the intrinsic organization of those two areas accounts for their functional properties, we examined the strength of intrinsic functional connectivity between neurons sampled in each area during working-memory tasks. We found that functional connections were more localized over short distances in the posterior parietal cortex and more widespread in the prefrontal cortex. Our results shed light on the functional organization between the prefrontal and posterior parietal cortex and provide mechanistic accounts for the functional roles of the two areas.

subject

Attention

Intraparietal sulcus

Monkey

Neurophysiology

Principal sulcus

Working-memory

contributor

Katsuki, Fumi (author)

Constantinidis, Christos (committee chair)

Nicolle, Michelle (committee member)

Ramachandran, Ramnarayan (committee member)

Salinas, Emilio (committee member)

Stanford, Terrence (committee member)

date

2012-06-12T08:35:52Z (accessioned)

2013-06-12T08:30:09Z (available)

2012 (issued)

degree

Neurobiology & Anatomy (discipline)

embargo

2013-06-12 (terms)

identifier

http://hdl.handle.net/10339/37267 (uri)

language

en (iso)

publisher

Wake Forest University

title

Unique and shared roles of the prefrontal and posterior parietal cortex in cognitive functions

type

Dissertation