The role of the frontal lobes in memory: evidence from unilateral frontal resections for relief of intractable epilepsy

The current investigation explored processes associated with memory deficits in patients with frontal lobe dysfunction. Specifically, we examined deficits associated with the encoding, consolidation, and retrieval of information in memory in 53 patients who underwent either a unilateral frontal (N=13) or temporal (N=40) lobe resection for relief of intractable epilepsy. Post-surgical memory scores indicated that the frontal group and the temporal group did not differ in consolidation of information, as defined by the information forgotten between immediate and delayed recall. Instead, the temporal group evidenced significantly poorer recall of verbal information at both immediate and delayed recall. This effect was especially strong in the left temporal group for the recall of verbal information. Although no group differences were observed in the degree to which patients semantically organized information or made recency discriminations, the frontal group exhibited significantly weaker release from proactive interference than the temporal group, suggesting some impairment in encoding and retrieval processes associated with frontal lobe dysfunction.