Visual evoked potential are affected by trunk rotation in neglect patients

Steady-State visual evoked potentials (VEPs) were recorded in four patients with unilateral visuo-spatial neglect, stimulating either the left or the right hemifield. In the standard condition (head and body oriented straight ahead towards the stimulus) the left hemifield VEP was delayed. When the body was turned to the left, however, the two hemifield latencies were comparable. These results were confirmed with the transient VEP technique. No effect of trunk rotation was observed in a group of patients with left brain damage and without neglect. The results imply that the sensory afferents from neck muscles might restore the altered occipital activity and suggest that the same conditions which modulate neglect modulate VEPs latencies.