Ipsilateral extinction in the hemineglect syndrome
T. E. Feinberg, L. D. Haber and C. B. Stacy
Neurobehavior Center, Beth Israel Medical Center, New York, NY 10003.
Data suggest right-hemisphere dominance for attention. Right-hemisphere
lesions reduce attentional capacity that may manifest as neglect or
extinction. Attention can be assessed with the Face-Hand Test where touch
on the face may extinguish simultaneous touch on the hand. Extinction
ipsilateral to unilateral lesions suggests abnormal attention to
ipsilateral hemispace. We tested patients with left- and right-hemisphere
lesions without neglect and right-hemisphere lesions with neglect with
stimuli applied exclusively ipsilateral to lesions. In experiment 1,
stimuli were applied in face-hand combinations. In experiment 2, the
Face-Hand Test was ranked from 0 (no extinction) to 7 (marked extinction)
using progressively greater stimulation. In both experiments,
right-hemisphere patients with neglect made significantly more errors than
left-hemisphere patients without neglect. These data support models of
bidirectional right-hemisphere attentional dominance.
