Poster A36, Saturday, March 25, 5:00 – 7:00 pm, Pacific Concourse
Stress Interactions with Working Memory in Adolescence
Alana Campbell1,2, Mae Nicopolis1,2, Louis Murphy1, Aysenil Belger1,2; 1University of North Carolina at Chapel Hill, 2Carolina Institute for Developmental Disablities
Adolescence is a crucial developmental window for stress responses and transitions to higher order cognition. Stress plays a role in the etiology of psychological diseases, including psychosis, modulates working memory, and mediates cortical plasticity in development. Power and phase locking in the electroencephalography (EEG) theta frequency range (4-8Hz) has been linked to frontal-sub-cortical connectivity associated with working memory. The goal of the current study is to investigate the influence of stress on working memory, specifically the EEG measures of the theta range, in adolescents. Fifteen adolescents (aged 11-16) participated in an EEG session recorded with a 64-channel BioSemi Active2 system. The participants completed a fractal n-back task (n = 0,1,2) before and after the Trier Social Stress Test (TSST). The TSST reliably elicits a stress response, measured via hear-rate variability and cortisol. Results show that before stress there is typical theta modulation with working memory load, such that the 2-back elicits greater theta power than the 1-back (p < .025). There is an interaction between load and pre-/post- stress condition (p < .025). Post-stress, there is diminished theta power in both the low and higher load conditions, with the post-stress setting showing a smaller increase in theta power as load increases. Further, there is a marked decrease in inter-trial phase coherence (ITC) in the theta range following stress. These results suggest that stress could disrupt working memory by diminishing synchronous firing in neuronal assemblies and by reducing the strength of the signal.
Topic Area: EXECUTIVE PROCESSES: Working memory