Authors:

Dodds, C.m., Van Belle, J., PEERS, P.V., Dove, A., CUSACK, R., DUNCAN, J. & MANLY, T.

Reference:

Year of publication:

2008

CBU number:

6754

Abstract:

Left spatial neglect is a common and debilitating neurological symptom. Research suggests that its severity can be modulated by changes in general alertness. Analogous effects in healthy volunteers now suggest that this may reflect an amplified form of a normal pattern. Recent neuropsychological studies also suggest that concurrent cognitive load may exacerbate rightward bias. Here, for the first time, we examine the effect of both factors on spatial attention in healthy volunteers. Participants performed a task in which as many letters as possible needed to be reported from a briefly presented symmetrical visual array. The task was performed under three conditions (alone, with a syllable-discrimination secondary task and with a pitch-discrimination secondary task). The results confirmed a significant rightward shift associated with time-on-task across all conditions – the first demonstration of such an effect within a fixation controlled, brief presentation task. While the secondary tasks influenced overall visual performance, there was no discernible effect on bias.