Amygdala stimulation disrupts the magnitude of reinforcement contribution to long-term memory

Abstract

Rats were trained in a symbolic delayed spatial matching-to-sample task using an eight-arm radial maze. Providing the animals with differential cues predicting a small or large reward on a subsequent retention test resulted in significantly better long-term retention (23 h) for the expectation of the large than the small reward. Electrical stimulation of the amygdala applied during, but not after, 10 sec exposure to the appropriate food cue predicting a large reward resulted in a retention deficit at the 23-h test delay. Similar treatments had no effect at a 20-min retention test. It is proposed that the amygdala is involved in processing of positive emotional attributes of specific memories. © 1982, Psychonomic Society, Inc.. All rights reserved.