Oscillatory activity in the human somatosensory cortex is modified by expectancy

Using magnetoencephalography (MEG), we examined region-specific alterations in oscillatory activity to investigate the neural basis of predictive responding in somatosensory processing when subjects were presented with simple patterns of tactile stimuli that varied in predictability. Here we showed event-related changes in beta rhythm in primary somatosensory cortex (SI) in response to a somatosensory stimulus accompanied by transient suppressions (desynchrony) followed by rebounds above baseline levels. We found that similar beta transient rebound occurred during a ‘gap period’, in the absence of a stimulus input, but only when the gap was part of a predictable pattern. Our results provide evidence that SI exhibits stimulus-driven and top–down oscillatory responses that can be modified by experience.