Diurnal variations of performance and information processing

Chronobiologia. 1986 Oct-Dec;13(4):319-26.


The aim of the study was to establish whether performance of a task in which controlled search is required fluctuates during the day or, on the other hand, performance of a task in which the automatic detection is required does not fluctuate during the day. The material and the procedure for setting the subject with an automatic detection set and for controlled search were determined as experimental paradigms and based on the results of the studies published by Shiffrin and Schneider. Eighteen volunteers from first and second year students of Psychology (9 boys and 9 girls) took part in the study. The study was done in January and February 1985 in the Laboratory of experimental psychology of Tours (France) on Tuesdays, Thursdays and Fridays. Each subject individually participated in 4 sessions on the same day, at 08(30); 11(45); 13(45) and 17(00). The results indicate that the performances (number of the targets correctly detected and the reaction time) only fluctuate in the course of the day when the controlled search is required. We suggest that the independence or the dependence of performance variation may be linked to the use of one or another of the two information processes described by Shiffrin and Schneider: controlled search and automatic detection.

MeSH terms

  • Adult
  • Circadian Rhythm*
  • Female
  • Humans
  • Male
  • Mental Processes*
  • Models, Psychological
  • Research Design