Diurnal variation in mental activities of French pupils and influence of test protocol.

The aim of the study was to determine the influence of the test protocol (individual vs. group) on the diurnal variations in mental activity of 18 11-year-old pupils. Number cancellation, a spatial orientation test, and mathematical problems were tested four times on three successive Fridays at 08:45, 11:15, 13:45 and 16:45 h. On the first and third Fridays the tests were performed on the group of subjects, whereas individual subjects were tested on the second Friday. Results indicated a possible influence of the test protocol (individual vs. group) on intellectual rhythmicity. Only in the group protocol did we find the psychological profile which is normally observed, namely, a performance increase during the morning, a postlunch fall, and then an increase in the afternoon. We suggest the existence of some group effect in these performance tests.