Recall of frequency of occurrence of self-generated and examiner-provided words after frontal or temporal lobectomy.

Patients with unilateral excisions from the frontal or temporal lobe and normal control subjects were given two tasks requiring the recall of the frequency of occurrence of words that differed in the number of times they occurred in study lists. In one task, subjects were required to generate words in response to cues, whilst in the other they merely had to read responses that satisfied the cues. All subject groups gave higher frequency estimates to words they had generated than to words they had read. Across both tasks, the frontal-lobe groups (left more so than right) underestimated frequency of occurrence.