Effect of transcranial magnetic stimulation on cerebral function in a monkey model

The effect of transcranial magnetic stimulation on higher cerebral function was studied using 3 monkeys. They were trained in a delayed response task which required spatial short-term memory. The task was presented by a computer on a cathode-ray tube and results of the delayed response task, which consisted of the percentage of correct choices, reaction time and trial number, were analyzed. For stimulation, small and large round coils were used as well as a figure 8 configuration. Their maximal B-fields were 3.3 T, 1.9 T and 2.4 T, respectively. A total of more than 7000 stimuli were given to each monkey in various patterns. There was no deficit in the delayed response. Further complications such as epileptic seizures were not observed either. In conclusion, transcranial magnetic stimulation does not appear to have any effect on higher cerebral functions in monkeys.