Poster B54, Sunday, March 26, 8:00 – 10:00 am, Pacific Concourse
Selective Attention and Load Effects in Parietal Cortex: A complex picture of working memory
Brandee Feola1, Donald J. Bolger1,2, Toby Hamovitz3, Lesley Sand1, Amber M. Sprenger3, Sharona M. Atkins1,2, Michael R. Dougherty3; 1Human Development and Quantitative Methodology Deparment, University of Maryland, College Park, 2Department of Neuroscience and Cognitive Sciences Department, University of Maryland, College Park, 3Psychology Department, University of Maryland, College Park
Whereas traditional frameworks of working memory have argued for separate components for executive processes and storage/maintenance, more recent models have suggested that working memory is an emergent process from selective attention. Recent evidence from neuroimaging has supported the notion that selective attention and memory load rely on a shared rather than distinct neural networks. The current study aims to disentangle the neural basis of working memory and attention by examining neural activity related to increasing working memory load compared to increases in distracting information. Eight-five participants completed a modified delayed match-to-sample task (DMTS) in a 3T Siemens Trio scanner. Three different colored cues were presented indicating whether participants were to attend to all (red and blue) stimuli, only red stimuli (filter), or not respond (nogo). Array stimuli appeared in a 4x4 grid consisting of 2 red dots and between 0-4 blue dots. After a delay, participants indicated if a target was present in a specific location. Results revealed traditional prefrontal and parietal regions for the task for both attend-all and filter conditions (relative to nogo trials). The right inferior parietal region showed typical increases with load in the attend all condition, but did not increase with distractors in the filter condition. These load effects in the IPL positively correlated with alternative measures of working memory (n-back, corsi-blocks). Moreover, a response to distractors in the IPL positively correlated with incongruency effects on the Flanker task (ANT executive) suggesting that this region is sensitive to individual differences in maintenance and selective attention.
Topic Area: EXECUTIVE PROCESSES: Working memory