Auditory inattention in right-hemisphere-damaged patients with and without visual neglect

Fifteen right-hemisphere-damaged patients, eight with- and seven without visual neglect (N+ and N-, respectively), were assessed for the presence of auditory neglect using free-field bilateral simultaneous stimulation (BSS) and pseudorandom unilateral stimulation. Eight healthy subjects served as controls. Both N+ and N- groups extinguished left-sided sound stimuli in the BSS condition. N+ (but not N-) patients showed a right-side advantage in sound localization and were inferior, compared to normal individuals, in their ability to localize unilaterally administered sounds on the left side. Blindfolding significantly improved the localization performance. In a task demanding stimulus identification, both N+ and N- groups performed abnormally when auditory stimuli came from the left. Free-field stimulation is thus an adequate technique for the detection of auditory neglect. The results are consistent with the notion that left-sided neglect reflects a pathologically exaggerated attentional bias towards the right in normal individuals.