The effect of diurnal variability on anticipation and reaction time in adolescents

The aim of this study is to investigate the effect of diurnal variability on anticipation and reaction time in adolescents. In total 60 intermediatechrono-typedvolunteers consisting of 30 males and 30 females aged between 14-18 years (x ̅±Sd= 15,62±1,04yr) participated in this study. The measurements in this research have been carried out according to randomized crossover design at the hours 08:30, 12:30 and 16:30. In measurement hours, first resting heart rate and the body temperature, then reaction and anticipation time measures have been recorded. Absolute error and fixed error values of anticipation time were calculated by using the anticipation time measurements. According to variance analysis for repeated measurements, significant diurnal changes were indicated in body temperature values in creasing to wards later hours of the day in all individuals(F(2-118)= 35,888; p= 0,000) and both in males (F(2-58)= 44,570; p= 0,000) and females (F(2-58)= 34,099; p= 0,000). Moreover, significant diurnal changes were indicated in anticipation time fixed error values in all individuals (F(2-118)= 31,634; p= 0,000) and both in males (F(2-58) = 17,491; p= 0,000) and females (F(2-58)= 15,947; p= 0,000). This change in females and in all individuals were increasing towards later hours of the day, on the other hand; in males, the best score has been recorded at 12.30hr. Significant diurnal change in aural reaction time (F(2-58)= 6,272; p= 0,003) was recorded only in males, the best scores are at 12:30hr and the worst scores are at 16:30hr. No significant diurnal changes were observed in the other variables. In conclusion; body temperature and anticipation time fixed error values were found to have diurnal variation effect in all individuals and in both genders separately. There was also a variation in auditory reaction time scores in males alone. KeyWords: Biorhythm, chronotype, circadianrhythm