Oscillations in different frequency bands like theta, alpha, beta, gamma and high gamma are thought to underlie processing of cognitive and emotional information. For example, theta (3 - 7 Hz) and alpha (8 - 12 Hz) oscillations are known to underlie working memory as well as attentional processing. Theta oscillations are known to differentiate emotional and neutral stimuli while gamma oscillations (30 - 50 Hz) are known to underlie rapid integration of information. The fact that these oscillations are also disrupted in neuropsychiatric disorders underline the importance of these oscillations.