Perception of moving and stationary gratings in brain damaged patients with unilateral spatial neglect

Contrast sensitivity for stationary and drifting sinusoidal gratings of different spatial frequencies was measured in 17 brain damaged patients (five left-brain damaged and 12 right-brain damaged patients, six of whom showed symptoms of spatial hemi-neglect). Twenty-nine combinations of spatio-temporal stimuli were considered in the drifting condition. No specific deficit for the group of patients with neglect symptom in the perception of moving and stationary gratings was observed. Also, no systematic deficit for perceiving the direction of motion--toward the neglect hemispace or away from it--was apparent. A small, selective impairment in the detection of stationary or very slow drifting gratings of low spatial frequency was observed in the presence of unilateral cortical damage, independently from its side (left or right) and from the presence of neglect. Some difficulty to detect the direction of motion was observed in a few individual patients.