Perceptual span deficits in adults with HIV.

Studies have found that infection with the Human Immunodeficiency Virus (HIV) leads to cognitive dysfunction. In fact, attention problems have been reported to be the most frequent cognitive symptom in HIV-infected adults. One question is how early in the course of information processing can attention impairment be detected? To address this issue, performance on a perceptual span task was examined in 54 HIV-infected adults and 19 seronegative controls. In this task a target had to be identified in a briefly presented (50 ms) array of 1, 4, or 12 letter-characters. Response accuracy was differentially worse in the HIV+ group relative to seronegative controls in the most difficult condition, the 12-item array, but not in the easier conditions. There was no evidence of a group difference in response strategy due to disinhibition or in psychomotor speed. These data suggest that HIV infection leads to a reduction in early visual processing capacity (or span of apprehension). The present results illustrate a new type of attentional deficit in HIV and show the impact of HIV on cognition at an earlier point in information processing than has been previously reported.