Induction of errors in a delayed response task by repetitive transcranial magnetic stimulation of the dorsolateral...

We used repetitive transcranial magnetic stimulation to study the function of the dorsolateral frontal cortex in a delayed response task in 10 normal volunteers. Unilateral stimulation of right or left prefrontal cortex during the delay period between instruction and execution cues led to a significantly greater number of response errors than stimulation of motor cortex or in unstimulated trials. Repetitive transcranial stimulation of appropriate intensity and frequency seems to disrupt the function of mnemonic cells in the prefrontal cortex and is useful for the study of the role of the prefrontal cortex in short-term motor memory.