Daily rhythmicity of attention in morning- vs. evening-type adolescents at boarding school under different psychosociological testing conditions.

This study used a single protocol to investigate the respective and related effects of the psychosocial conditions of testing (individual vs. group) and personality on the levels and daily variation of attentional performance of adolescents attending boarding school. From scores obtained on an adapted version of Horne and Ostberg's Morningness-Eveningness Questionnaire (MEQ), 17 male (9 morning-type and 8 evening-type) participants were selected from among 50 volunteers. Attention was measured using a number crossing-out test carried out at four times of the day (07:30, 12:00, 14:00, and 19:30). No main effect of testing mode and personality trait was found on the mean level of performance. Time-of-day had an effect on the level of performance, which differed depending on whether the test was administered in a group or individually and on the morningness and eveningness dimension. The difference between the daily profiles appears to be dependent on the interaction of the factors studied. This study investigated the concept of "group psychological rhythmicity" and highlights the importance of synchronizing social rhythms.