Topic: stimulus-free gamma

The electrophysiological signal recorded from the brain shows rhythmic activity (oscillations) at different frequencies. One such rhythm, called gamma (~30-80 Hz), is modulated by high-level cognitive processes such as attention, memory, and meditation and, therefore, could provide clues about mechanisms underlying high-level cognition. Interestingly, gamma oscillations can be “induced” in the brain by presenting certain stimuli such as bars, gratings, and color patches (especially red hues). Moreover, these stimulus-induced gamma oscillations weaken with age and the onset of Alzheimer’s Disea