PERSISTENT ACTIVITY DURING WORKING MEMORY: MATURATION AND CORTICAL SPECIALIZATION

Working memory is one of the most critical cognitive functions and dorsolateral prefrontal cortex (dlPFC) has generally been recognized as the seat of working memory. Development of working memory ability through adolescence, accompanied by structural changes has been reported in human studies, however, how neurophysiological changes in population prefrontal neurons mediate working memory ability has remained unclear. Moreover, recent studies have challenged the role of the prefrontal cortex (PFC) in cognitive functions. Activation of posterior parietal cortex (PPC) in working memory task has also been reported. Here, we address two primary questions: First, how do changes in prefrontal activity during adolescence mediate working memory ability? And second, what is the difference of neural activity between prefrontal and posterior parietal neurons in a working memory task? For the first project, we reported behavioral performance and neurophysiological activity during monkeys’ maturation. Increased activity during the delay period was revealed but no change in the representation of stimuli. Decreased evoked activity by a distractor was also been found. As for the second project, we analyzed a sample of neurons from the prefrontal and parietal cortex, which was matched for delay period activity. No significant difference of tuning bias and correlation of firing rate and behavior deviations were found in a working memory task. The results suggest that behavioral performance during working memory is influenced by a distributed network of cortical areas during working memory.

Grantor dc:publisher

Wake Forest University

Year dc:date.issued

2017

Author dc:creator

• Li, Sihai

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10339/82189

OAI identifier oai:identifier

oai:wakespace.lib.wfu.edu:10339/82189