Both animal intracranial recordings and human scalp electrophysiological recordings make clear that neural oscillatory mechanisms play a critical role in sensory-perceptual and cognitive functions, including selective attention, working memory, and feature binding, to name a few. A variety of cognitive effects that are associated with specific brain oscillations have been reported, which range in spectral, temporal, and spatial characteristics depending on the context. A major focus of our group’s work has been on investigating the role of alpha-band oscillatory activity (8-14 Hz) as a potential attentional suppression mechanism. Our work has shown that 1) phasic increases in alpha-band power are associated with suppression of visual inputs when individuals need to selectively attend to auditory inputs (i.e. cross-sensory suppression), 2) that topographically/retinotopically specific increases in alpha-power are associated with suppressing irrelevant visual inputs from specific parts of space when other parts of space contain the information to be acted upon (i.e. visuo-spatial suppression), and 3) that increases in alpha power within a given visual processing stream (i.e. dorsal versus ventral) results in feature-specific attentional deployments (i.e. feature-based suppression). In this presentation, we will discuss the evidence for a prominent role in attentional suppression for alpha-band oscillatory activity, and present evidence for deficits in this ability in certain clinical populations (e.g. Autism Spectrum Disorder) and enhancements of it in other populations (e.g. Deafness)