text: The auditory cortex has distinct responses to sounds in the gamma band. When subjects are exposed to three or four cycles of a 40 hertz click, an abnormal spike appears in the EEG data, which is not present for other stimuli. The spike in neuronal activity correlating to this frequency is not restrained to the tonotopic organization of the auditory cortex. It has been theorized that gamma frequencies are resonant frequencies of certain areas of the brain and appear to affect the visual cortex as well. Gamma band activation (25 to 100 Hz) has been shown to be present during the perception of sensory events and the process of recognition. In a 2000 study by Kneif and colleagues, subjects were presented with eight musical notes to well-known tunes, such as Yankee Doodle and Frère Jacques. Randomly, the sixth and seventh notes were omitted and an electroencephalogram, as well as a magnetoencephalogram were each employed to measure the neural results. Specifically, the presence of gamma waves, induced by the auditory task at hand, were measured from the temples of the subjects. The omitted stimulus response (OSR) was located in a slightly different position; 7 mm more anterior, 13 mm more medial and 13 mm more superior in respect to the complete sets. The OSR recordings were also characteristically lower in gamma waves as compared to the complete musical set. The evoked responses during the sixth and seventh omitted notes are assumed to be imagined, and were characteristically different, especially in the right hemisphere. The right auditory cortex has long been shown to be more sensitive to tonality (high spectral resolution), while the left auditory cortex has been shown to be more sensitive to minute sequential differences (rapid temporal changes) in sound, such as in speech.