Cognitive enhancement devices have been supported by positive anecdotal reports, but generally have not undergone rigorous testing. In the following report we tested one such device, the MC Square, which uses Audio-Visual Stimulation (AVS) (synchronised pulsed tones and flickering lights set at an alpha or theta frequency) to entrain neural activity. Its effect on three key cognitive functions (verbal learning, memory, and attention) was tested following a regimen of training with the device. A double blind, placebo controlled (sham device), and crossover design was utilised with pre- and post-testing on the cognitive measures occurring during each phase of the crossover. The primary hypothesis was that after training with the MC Square there would be improvement in verbal memory, associative learning, working memory and attention/concentration. Results showed a statistically reliable improvement on the measure of attention/concentration, the Digit Span Forwards test, following MC Square training. The data suggest the MC Square device provides modest enhancement in the ability to focus, attend, and report information over the short term.