Dawei Li

Graduate student McAlester Annex dlmgf@mail.missouri.edu

My research focuses on working memory capacity limits for stimuli from various domains, such as simple visual, verbal, or non-verbal auditory items. I also use functional magnetic resonance imaging (fMRI) method to investigate the brain activities during working memory processes. Previous studies I've done included two fMRI studies that investigated the brain activities when people were instructed to remember different numbers of visual or auditory items. We found that only one specific region, the left intraparietal sulcus, showed increased activity with high versus low memory load contrasts, no matter visual or auditory inputs. This finding suggested that left intraparietal sulcus might be part of a neural network for "abstract" working memory storage.

My current research is to evaluate working memory capacity for non-verbal auditory items. It has been widely accepted that people are able to hold 3 to 4 items in working memory (Cowan, 2001). However, such capacity limit doesn't apply to all kinds of items, and might require restrictions on the input stimuli. In the current studies, we used the change detection task to study people's working memory capacity for various non-verbal auditory items. While people could only remember 2 or less simple tones, their performance improved when the simple tones had additional timbre information. Our results suggested that high working memory performance might require involvement of categorical information. To listen to the sounds, please refer to the following site:
http://psychology.missouri.edu/sites/psychology.missouri.edu/files/Sound...

2011, MA in Psychology, University of Missouri
2007, BS in Physics, Peking University

Cowan, N., Li, D., Moffit, A., Becker,T.M., Martin, E.A., Saults, J.S., & Christ, S.E. (2011) A neural region of abstract working memory. Journal of Cognitive Neuroscience, 28(10), 2852-2863.