Further evidence that the callosum is involved in sustaining attention.

This study is a follow-up to a previous study that found a correlation between callosal efficiency and sustained attention. Normal children were tested on a vigilance task in which the amount of time between target presentations (interstimulus interval; ISI) was varied. Efficiency of the anterior callosum was assessed by a task that required subjects to perform incongruent movements with the left and right hands simultaneously. Subjects who showed less interference between the two hands missed fewer signals on the vigilance task after the longer ISIs, suggesting callosal involvement in the ability to sustain attention over a long period of time in the absence of sensory input. Age differences in the sustained attention were also observed.