Thirteen asymptomatic HIV-infected (HIV+) and 13 healthy control (HIV-)
subjects were instructed to detect "oddball" target tones from among a
sequence of nontarget tones delivered rapidly (3 tones/second) in one ear
while ignoring a similar sequence delivered simultaneously in the opposite
ear. Event-related potentials (ERPs) to all stimuli were recorded from
midline scalp sites. Both groups produced ERP correlates, termed the
"mismatch negativity" (MMN), to the oddball tones during delivery. However,
the HIV+ group produced MMNs that differed in morphology from those of the
HIV-group, suggesting that HIV may alter attentional perceptual processing.
These results suggest that auditory ERPs elicited by rapid, dichotic
stimulus presentations may be useful in monitoring subclinical effects of
HIV-related neuropathology on perceptual processing.