Abstract
In neurotypical individuals, attention to the left visual field increases after prolonged attention to the right visual field. The visual field specific increase is likely a byproduct of homeostatic rebalancing of visual field attention following sustained imbalance in attention between the visual fields. Individuals who suffer right unilateral stroke can experience a spectrum of left visual field inattention, from mild to severe (hemispatial neglect). We aimed to cause a rebound in attention to the impaired left visual field of stroke patients, following an attention demanding task to the unimpaired right visual field. First, we characterized participants’ (n=11) contralesional inattention using four tests. Next, across two counterbalanced sessions, participants performed either the intervention: attention isolated to right visual field only using right unilateral multiple object tracking (MOT) for 30 minutes, or the control: attention maintained bilaterally using bilateral MOT. Fixation was monitored with an eye-tracker. We tested bilateral MOT before and after to determine visual field specific intervention impact. When participants were considered as one group, the intervention had no impact on attention in the impaired left visual field. However, when dividing participants between severe or mild inattention, we found participants with mild inattention (n=6) experienced a 13% increase in attention in the impaired left visual field. Attention was unchanged in the unimpaired right visual field across intervention, indicating benefit could not have transferred to the left visual field due to training. More likely homeostatic rebalancing, following the intervention-based exacerbation of the already existing visual field attention imbalance, caused a left visual field attention increase. The large increase in attention to the impaired visual field indicates this intervention could be a strong candidate for rehabilitation in mildly affected patients. Future studies will examine the longevity and generalizability of such an intervention to other attention demanding tasks.