University of Bath

A preprint proposes a two-stage CNN-LSTM-RL framework that uses reinforcement learning to apply residual kinematic corrections to the output of a CNN-LSTM continuous motor imagery decoder. The RL agent is trained offline, without direct EEG input, to optimize motion accuracy against a target trajectory. Compared with CNN-LSTM alone, CNN-LSTM-RL lifted the 2D mean correlation from 0.5076 to 0.7181 and the VR-scene correlation from 0.6420 to 0.7780, cutting RMSE by 40.2% and 38.2% respectively. The authors say correcting kinematic error through offline residual RL strengthens 3D BCI motor imagery decoding without additional neural data; the study has not been peer reviewed.

Intracranial recordings from ten epilepsy patients show that neural activity during cued limb motor imagery changes with the phase of the task: low-frequency (8-30 Hz) activity was mostly suppressed during preparation and switched to activation once imagery began, while high-frequency (60-115 Hz) responses were stronger, more widely distributed, and at some contacts followed an activation-then-suppression sequence. The stereoelectroencephalography (sEEG) data indicate that responses are not uniform but shift with task stage and brain region, which the authors tie to stage-aware feature design for BCIs and to neurorehabilitation.