Deficits on subject-ordered tasks after frontal- and temporal-lobe lesions in man.

Seventy-nine patients with unilateral frontal- or temporal-lobe excisions and 18 normal control subjects were tested on four self-ordered tasks requiring the organization of a sequence of pointing responses. There were two verbal and two nonverbal tasks. Patients wih excisions from the left frontal lobe exhibited significant impairments on all four tasks, whilst patients with excisions from the right frontal lobe showed deficits only on the two nonverbal tasks. Patients with temporal-love lesions not extending posteriorly, on the medial side, beyond the pes of the hippocampus were unimpaired on all tasks, whereas those with more radical hippocampal excisions exhibited material-specific deficits that varied with the side of the lesion.