Television commercials include elements designed to engage the viewer's attention. Manipulations of the commercial's visual structure that result in rapid pacing or frequent scene changes can be engaging because they require a frequent redirection of visual attention. Manipulations of semantic content through such techniques as the inclusion of humorous or anomalous elements can elicit cognitive engagement. Structural manipulations in videos are known to attenuate the alpha (8 to 13 Hz) rhythm of the electroencephalogram (EEG) recorded over posterior cortical regions involved with visual processes. To examine whether other engaging elements also affect the alpha rhythm, EEG was recorded from 10 participants who viewed television commercials. Principal components analysis was used to decompose the alpha rhythm into underlying factors that varied in spatial topography over the head and in spectral composition. Across commercials, the power of a posterior-distributed alpha component was inversely correlated with the frequency of scene changes. In contrast, a frontal component in the lower frequency portion of the alpha band was attenuated during commercials that elicited high subjective interest, independent of scene change frequency. And, an upper-frequency frontal alpha component was attenuated during commercials for which the item being advertised had a high probability of being subsequently recalled, independent of other factors. These frontal patterns of alpha reactivity are consistent with other neuroimaging results concerning frontal lobe activation by executive processes and episodic memory encoding. With appropriate neurologically guided analysis, EEG signals can provide a unique means of monitoring both perceptual and higher order neurocognitive processes during television viewing.