Semantic encoding deficits in frontal lobe disease and amnesia

The relationship between semantic encoding deficits and memory dysfunction was evaluated for the following groups: amnesic patients with bilateral frontal lobe lesions; nonamnesic patients with bilateral frontal lesions; and alcoholic Korsakoff patients. Semantic encoding was assessed using the Wickens' release from proactive interference (PI) paradigm. Korsakoff patients and the poor memory frontal lobe patients failed to show automatic PI release, while good memory frontal patients did show a release. These results support the view that an encoding disability is a contributor to amnesics' memory disorder and they suggest a possible neuroanatomical correlate for impaired semantic encoding.