Dual-task study of cognitive and postural interference in 7-year-olds and adults.

The study examined, in children aged 7 and adults, the postural control when a cognitive task (modified Stroop) of varying level of difficulty is executed simultaneously. Postural difficulty also varied (with or without vibrations of the ankle joint). We hypothesized that children's performance was more affected than adults', when the difficulty of the cognitive and postural tasks increased. Results (i) demonstrated that the presence of a concurrent cognitive task affected postural sway at all ages; (ii) confirmed that the interference between mental activity and postural control can be attributed mainly to general capacity limitations and (iii) showed a degradation of the postural criteria in children but not of the cognitive ones, when the postural condition was constraining.