Figure 3. Group mean beamformer images (pseudo-t) for uninfected older adults (top) and demographically-matched HIV-infected patients (bottom) are displayed across all time bins spanning the encoding (red labels) and maintenance (blue labels) phases.

Across both groups, there was a strong sustained decrease in alpha/beta oscillatory activity in left fronto-temporal cortices throughout most of the encoding and maintenance phases. This decrease began in posterior regions early in the encoding phase, spread anterior and superior to include language-related areas in the left supramarginal and prefrontal cortices during the second half of encoding and early maintenance period, then dissipated slightly throughout the remainder of the maintenance phase.