Frontal steady-state potential changes predict long-term recognition memory performance

Converging evidence from event-related potential and functional brain imagi ng studies suggests that the brain activity at posterior regions of the fro ntal cortex can predict the strength of long-term memory traces. This study examined the relationship between posterior frontal steady-state visually evoked potential (SSVEP) latency changes and recognition memory after a del ay of 7 days. Thirty-five female subjects viewed an 18-min television docum entary program interspersed with 12 unfamiliar television advertisements wh ile brain electrical activity was recorded from four pre-frontal, two poste rior frontal and two occipital scalp sites. After 7 days, the recognition m emory was tested for images coinciding with the 20 most prominent frontal S SVEP latency minima and maxima during the viewing of ten contiguous adverti sements (advertisements 2-11), We found that images coinciding with posteri or frontal latency minima were more likely to be recognized (58.7% recognit ion) than images coinciding with SSVEP latency maxima (45.3% recognition). Furthermore, the relationship between posterior frontal SSVEP latency and r ecognition performance after 7 days was only apparent at the left posterior frontal site. The correlation between the recognition performance and SSVE P latency evaluated at all eight sites reached significance only at the lef t posterior frontal site. These findings suggest that frontal SSVEP latency variations can be used to assess the strength of long-term memory encoding for naturalistic stimuli. (C) 2000 Elsevier Science B.V. All rights reserv ed.