Does sonification of action simulation training impact corticospinal excitability and audiomotor plasticity?

Abstract

Sonification is a sensory augmentation strategy whereby a sound is associated with, and modulated by, movement. Evidence suggests that sonification could be a viable strategy to maximize learning and rehabilitation. Recent studies investigated sonification of action observation, reporting beneficial effects, especially in Parkinson’s disease. However, research on simulation training—a training regime based on action observation and motor imagery, in which actions are internally simulated, without physical execution—suggest that action observation alone is suboptimal, compared to the combined use of action observation and motor imagery. In this study, we explored the effects of sonified action observation and motor imagery on corticospinal excitability, as well as to evaluate the extent of practice-dependent plasticity induced by this training. Nineteen participants were recruited to complete a practice session based on combined and congruent action observation and motor imagery (AOMI) and physical imitation of the same action. Prior to the beginning, participants were randomly assigned to one of two groups, one group (nine participants) completed the practice block with sonified AOMI, while the other group (ten participants) completed the practice without extrinsic auditory information and served as control group. To investigate practice-induced plasticity, participants completed two auditory paired associative stimulation (aPAS) protocols, one completed after the practice block, and another one completed alone, without additional interventions, at least 7 days before the practice. After the practice block, both groups significantly increased their corticospinal excitability, but sonification did not exert additional benefits, compared to non-sonified conditions. In addition, aPAS significantly increased corticospinal excitability when completed alone, but when it was primed by a practice block, no modulatory effects on corticospinal excitability were found. It is possible that sonification of combined action observation and motor imagery may not be a useful strategy to improve corticospinal, but further studies are needed to explore its relationship with performance improvements. We also confirm the neuromodulatory effect of aPAS, but its interaction with audiomotor practice remain unclear.

From rubber hands to neuroprosthetics: Neural correlates of embodiment

“…Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) have been used extensively to study the neural mechanisms underlying the RHI. Applying a single TMS pulse to primary motor cortex (M1), the resulting motor-evoked potentials (MEPs) recorded from a target muscle can be used as a readout of corticospinal excitability at rest ( Bestmann et al, 2015 , Rossini, 2015 ), during perceptual ( Castro et al, 2021 , Pellegrino et al, 2022 ) and motor tasks ( Castro et al, 2021 , Pascual-Leone et al, 1995 ). The involvement of corticospinal neurons is thought to be mostly indirect, via intracortical and cortico-cortical connections, depending on the coil orientation and stimulation intensity ( Di Lazzaro et al, 2012 ).…”

Impact of supplementary sensory feedback on the control and embodiment in human movement augmentation

“…force applied by a pencil on a surface) into a sound whose intensity or frequency can vary accordingly to the considered parameter 130 – 132 . Despite never being tested in a proper SRL protocol, sonification was shown to improve motor learning during a simple key pressing task 131 – 134 , and recalibrated perception of body size, such as height 135 and finger length 136 . In prosthetics, information about prosthesis configuration delivered though sound cues can improve control performance and reduce cognitive burden 137 , 138 .…”

Exploring crossmodal correspondences for future research in human movement augmentation

“…Sonification is a strategy of heteromodal sensory substitution which relays kinematic and dynamic features of a movement with sounds ( Castro et al, 2021a , b ); however, its effectiveness is dependent on the specific rules used for encoding. Sonification can also be exploited to relay feedback related to an SRL.…”