Attention deficits: Is there a right hemisphere specialization for simple reaction time, sustained attention, and phasic alertness?

Impairments of attentional focus often are claimed to be associated with le sions of the right hemisphere. Although some studies comparing right- and l eft-brain-damaged patients have supported this idea, others have not found differences between these patients in various attention tasks. The present study was carried out in order to further investigate the putative role of the right hemisphere in a simple reaction time tusk, a sustained attention task, and a phasic alertness task. Subjects were 46 patients with light-hem isphere lesions and 37 patients with left-hemisphere lesions. Results showe d no difference between right- and left-brain-damaged patients in simple re action time, in speed of response over time (sustained attention), and in t he capacity to prepare to an uncoming stimulus (phasic alertness). Future s tudies will have to use a more precise categorization of lesions than only right-versus left-brain damage. (C) 2000 Academic Press.