Poster D54, Monday, March 27, 8:00 – 10:00 am, Pacific Concourse
Variability in attentional control explains working memory impairments in ADHD
Sarah L. Karalunas1, Brittany Alperin1, Christiana Smith1; 1Oregon Health & Science University
Decreased working memory capacity and increased performance variability are two of the most commonly observed cognitive impairments in Attention-deficit/hyperactivity disorder (ADHD), but it is fundamentally unclear whether they should be viewed as two distinct deficits or as manifestations of the same underlying problem. Put another way, differences in working memory may arise not from consistently low memory capacity per se, but from variability in engaging that capacity. Here, we propose that working memory impairments and increased performance variability in ADHD both reflect limitations on attentional control. Using a novel adaptation of the well-validated change detection task, we examine fluctuations in working memory performance in a sample of 111 adolescents (50 with ADHD) and directly compare neurophysiological responses on trials with and without lapses of attention. Lower working memory capacity in children with ADHD fit with a graded attentional control model. Within the ADHD group, lapse trials were associated with smaller amplitude P1/N1 responses to stimuli than non-lapse trials. Greater alpha suppression in the pre-stimulus fixation period predicted higher average working memory performance. Results add parsimony to cognitive theories of ADHD and suggest that variability in engaging attentional control can account for working memory impairments in the disorder. Identifying mechanisms of cognitive impairments and neurophysiological predictors of performance in ADHD will be critical for developing novel treatments for the disorder.
Topic Area: EXECUTIVE PROCESSES: Working memory