Response suppression, initiation and strategy use following frontal lobe lesions.

Ninety-one patients with cerebral lesions were tested on a task involving two conditions. In the first condition (response initiation) subjects were read a sentence from which the last word was omitted and were required to give a word which completed the sentence reasonably. In the second condition (response suppression) subjects were asked to produce a word unrelated to the sentence. Patients with frontal lobe involvement showed longer response latencies in the first condition and produced more words which were related to the sentence in the second, in comparison to patients with lesions elsewhere. Moreover, in the second condition patients with frontal lobe lesions produced fewer words which showed the use of a strategy during response preparation. Performance on the initiation and suppression conditions was unrelated at the group or single case level. The relationship between response initiation, suppression and strategy use are discussed.