Neural activation during frequency-memory performance

Lesion studies have demonstrated that frequency memory, or memory for the f requency of occurrence. is associated with prefrontal and not temporal lobe lesions. This study examined neural activation during performance on a fre quency-memory-judgment task and a recognition-memory task, both using words . Relative to a control task, the authors observed peaks of activation duri ng frequency-memory performance in the left ventrolateral prefrontal cortex (BA 45) and other areas typically associated with working memory (dorsolat eral prefrontal cortex, posterior parietal cortex). Recognition performance was associated with activation in the same left ventrolateral prefrontal l ocation as was observed with frequency memory. When comparing activation du ring frequency memory with activation during recognition memory, the author s found a suppression of activation in the hippocampus bilaterally during f requency memory. This study supports a neuroanatomical distinction between frequency and recognition memory.