Interestingly, the oscillatory (baseline-relative) visual gamma response also exhibited a pattern of marginal significance [ F (2,53) = 2.97, P = 0.060, BF 10 = 1.23], and exploratory post hoc tests revealed that participants with HAND exhibited significantly lower responses [ t (35) = −2.26, P = 0.030, BF 10 = 1.23], while HIV-infected participants exhibited a non-significant effect in the same direction [ t (39) = −1.80, P = 0.080, BF 10 = 0.828].
Post hoc testing revealed a HIV-related decrease in oscillatory theta, such that HIV-infected participants exhibited a decrease that approached significance compared to controls [ t (39) = −1.90, P = 0.065, BF 10 = 1.00], while participants with HAND had substantially decreased responses compared to controls [ t (35) = −3.26, P = 0.002, BF 10 = 23.93].
The omnibus MANOVA for oscillatory activity (across frequency-specific responses) was marginally significant [Wilks’ Lambda = 0.773, F (8,100) = 1.719, P = 0.103]; however, subsequent one-way ANOVAs for each response showed that the visual theta response differed between groups [ F (2,53) = 5.45, P = 0.007, BF 10 = 6.74; Fig. 3 ].