FMRI response during figural memory task performance in college drinkers

Abstract

Rationale: Eighteen- to twenty-five-year-olds show the highest rates of alcohol use disorders (AUD) and heavy drinking, which may have critical neurocognitive implications. Regions subserving memory may be particularly susceptible to alcohol-related impairments. Objective: We used blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to examine the neural correlates of visual encoding and recognition among heavy-drinking college students. We predicted that heavy drinkers would show worse memory performance, increased frontal/parietal activation, and decreased hippocampal response during encoding. Methods: Participants were 23 heavy drinkers and 33 demographically matched light drinkers, aged 18-20, characterized using quantity/frequency of drinking and AUD diagnosis. Participants performed a figural encoding and recognition task during fMRI. BOLD response during encoding was modeled based on whether each stimulus was subsequently recognized or forgotten (i.e., correct vs. incorrect encoding). Results: There were no group differences in behavioral performance. Compared to light drinkers, heavy drinkers showed (1) greater BOLD response during correct encoding in the right hippocampus/medial temporal, right dorsolateral prefrontal, left inferior frontal, and bilateral posterior parietal cortices; (2) less left inferior frontal activation and greater bilateral precuneus deactivation during incorrect encoding; and (3) less bilateral insula response during correct recognition (clusters >10,233 μl, p < 0.05 whole brain). Conclusions: This is the first investigation of the neural substrates of figural memory among heavy-drinking older adolescents. Heavy drinkers demonstrated compensatory hyperactivation of memory-related areas during correct encoding, greater deactivation of default mode regions during incorrect encoding, and reduced recognition-related response. Results could suggest use of different encoding and recognition strategies among heavy drinkers. © 2013 Springer-Verlag Berlin Heidelberg.