Phasic alertness indicated by simple motor reaction time in late childhood: The effect of age and sex

Abstract

Background: In contrast to strongly established views on the development of tonic, top-down controlled alertness, a small number of neurobehavioral and neurophysiological studies deal with the developmental trajectory of exogenously driven phasic alertness during childhood. Objective: The current study aimed to examine the age and sex effects on phasic alerting during late childhood, and to analyse the degree of association between tonic and phasic alertness at the behavioural level. Methods: Three age groups of typically developing children, aged 10, 11 and 12 years (N = 59, 27 boys, 32 girls) performed a computer-based simple hand-eye reaction test of alertness that involved 28 trials with and 28 trials without a warning signal. Results: The results showed a moderate decrease of mean reaction time in both the alert and non-alert conditions with age. However, the alert effect calculated as the difference in reaction times achieved in alert and non-alert conditions was not affected by age and sex. Conclusions: In contrast to previous suggestions on possible continuing improvement in phasic alertness during late childhood, the current study suggested that the neurocognitive function of transient enhancement in attentional alertness (phasic alertness) does not change and it is stabilized in this developmental period. In addition, this function does not differ between males and females in childhood.