Stylus-maze performance in patients with frontal-lobe lesions: effects of signal valency and relationship to verbal and spatial abilities.

In 1964-1965 Milner demonstrated that patients with frontal lobe lesions display deficits on a stylus-maze task, and suggested that this is due to a dysfunction of the ability to change responses-set readily in accordance with varying environmental signals. Patients with frontal lobe lesions were tested on either the traditional form of the task (which emphasizes errors), or on a form which emphasizes correctness. Both groups displayed deficits, but there were no significant differences between groups. Errors were negatively correlated with spatial IQ, while rule-breakages were negatively correlated with verbal IQ.