Fig. 2.

Performance on the signal detection task. One-phase association regression analysis on the cumulative proportion of animals meeting the criterion over sessions revealed that a different curve was best fit to each group, illustrating the gap between groups in the number of sessions needed to reach criterion (a). Percent accuracy was not significantly different between groups (3-day average: HIV-1 Tg: 77.8 ± 0.43; Control: 77.8 ± 0.42) (b). However, the HIV-1 Tg animals responded significantly less than the control animals during the signal detection task, with fewer hits, misses, and correct rejections than the control group, consistent with a lapse of attention (c). There was no significant difference in the number of false alarms, a putatvive index of response inhibition.