Attenuation of spatial attentional asymmetries with poor sustained attention.

The co-existence of deficits in sustained and spatial attention in patients with acquired damage to the right cerebral hemisphere has led to the proposition that sustained attention could be a marker for left spatial inattention, or neglect. We investigated the possibility that reductions in leftward spatial attentional asymmetries could arise from individual differences in the capacity for sustained attention even within healthy adult populations. We observed that healthy participants who performed poorly on a test of sustained attention had a significantly attenuated left spatial bias, relative to those with good sustained attention capacity, on a free-viewing spatial attention test. Our results provide further support for the notion that sustained attention may exert a modulatory influence on spatial attention.