Beta Rebound as an Index of Temporal Integration of Somatosensory and Motor Signals

Abstract

Modulation of cortical beta rhythm (15–30 Hz) is present during preparation for and execution of voluntary movements as well as during somatosensory stimulation. A rebound in beta synchronization is observed after the end of voluntary movements as well as after somatosensory stimulation and is believed to describe the return to baseline of sensorimotor networks. However, the contribution of efferent and afferent signals to the beta rebound remains poorly understood. Here, we applied electrical median nerve stimulation (MNS) to the right side followed by transcranial magnetic stimulation (TMS) on the left primary motor cortex after either 15 or 25 ms. Because the afferent volley reaches the somatosensory cortex after about 20 ms, TMS on the motor cortex was either anticipating or following the cortical arrival of the peripheral stimulus. We show modulations in different beta sub-bands and in both hemispheres, following a pattern of greater resynchronization when motor signals are paired with a peripheral one. The beta rebound in the left hemisphere (stimulated) is modulated in its lower frequency range when TMS precedes the cortical arrival of the afferent volley. In the right hemisphere (unstimulated), instead, the increase is limited to higher beta frequencies when TMS is delivered after the arrival of the afferent signal. In general, we demonstrate that the temporal integration of afferent and efferent signals plays a key role in the genesis of the beta rebound and that these signals may be carried in parallel by different beta sub-bands.

Fourier SPoC: A customised machine-learning analysis pipeline for auditory beat-based entrainment in the MEG

“…Other authors promote even more explicitly the use of beta oscillations of the motor system for sensory predictions [44] in addition to their likely primary function of the modulation of neural excitability for in movement preparation. A related recent study combining somatosensory stimulation with TMS applied over the motor cortex strongly supports the role for sensorimotor interaction in the genesis of a beta rebound peak [64]. This is consistent with the proposed role for beta oscillations of the motor system for sensory predictions [44], in addition to its likely primary function in timed movement preparation [65,66] and further supported by the rebound peak latency scaling with the period in a rhythmic motor task [65].…”

Effect of long-term paired associative stimulation on the modulation of cortical sensorimotor oscillations after spinal cord injury

“…In patients with stroke, the rebound magnitude correlated positively with clinical outcome [ 25 ]. The oscillatory rebound has been suggested to reflect the excitability or active inhibition of the sensorimotor cortex and it could be involved in the control of voluntary movements [ 15 , 26 , 27 ]. We speculate that the increased rebound observed after the PAS intervention reflects restoration of excitation–inhibition balance in the sensorimotor cortex.…”

Spike-phase coupling of subthalamic neurons to posterior opercular cortex predicts speech sound accuracy

“…In contrast, beta desynchronization is thought to disrupt the idle state, with the subsequent rebound mediating the return-to-baseline following sensorimotor engagement 50 . Other research posits that the temporal integration of somatosensory afferent and motor efferent signals plays a key role in the genesis of the beta rebound signal 51 . Our findings support a similar interpretation, albeit focusing on beta SPC instead of beta oscillations.…”