I can't reach it! Focus on theta sensorimotor rhythm toward a better understanding of impaired action-perception coupling.

It is known that anxiety (ANX) impairs action-perception coupling. This study tests whether this impairment could be associated with an alteration of the sensorimotor function. To this aim, the cortical activities underlying the sensorimotor function were recorded in twelve volunteers in a reach-to-grasp paradigm, in which the level of ANX and the position of a glass were manipulated. The experimental manipulation of the ANX-related somatosensory state was expected to prompt participants to underestimate their reaching-to-grasp capabilities while the sensorimotor-related oscillatory brain activities around the 6-Hz (θ) frequency over motor-related and parietal regions were expected to be modulated. We also investigated the oscillatory brain dynamics around the 11.5-Hz (fast-α) frequency as a neural hallmark of ANX manipulation induced by the breath-restriction. Results indeed showed that participants underestimated their reaching-to-grasp maximal performance. Concomittantly, θ-EEG synchronization over the motor cortex contralateral to the dominant hand was higher during glass presentation under breath-restriction condition (+20.1%; p<0.05), and when the glass was perceived as non-reachable (+20.0%; p<0.05). Fast-α-EEG desynchronization was reduced under breath-restriction (-37.7%; p<0.05). The results confirm that ANX-related impairment of action-perception coupling co-modulates with theta-sensorimotor rhythm. This finding is discussed as an altered "readiness state" in the reaching-related cortical network, while individuals are anxious.