The purpose of this thesis was to investigate a proposed neurophysiological model for Necker cube reversals by using electroencephalography. It is suggested that Necker cube reversals are mediated by sustained focused attention to the overall drawing with visual selective attention to vertices of the cube. The main hypotheses were that deliberate attention would increase Necker cube reversals over passive attention, there would be greater high theta power during the deliberate focusing of attention than during passive attentional processing, and there would be greater theta power in the right hemisphere. Thirty undergraduate psychology students had monopolar EEG recorded bilaterally from frontal and parietal electrode sites. The subjects viewed computer presentations of the Necker cube under two different experimental conditions: a passive condition in which they were not instructed to influence reversals, and an active condition in which subjects deliberately shifted their focus of attention. / Master of Science