Mental tasks induce common modulations of oscillations in cortex and spinal cord.

Fifteen healthy adults in a single laboratory doing a fixed, low-force foot contraction. No patients were studied and no clinical outcome was measured, so nothing here says whether any of this helps anyone. Producing the motor neuron signal requires the person to activate a muscle voluntarily, because the signal is derived from muscle recordings during the contraction. Correlating power cannot show which way information flows. The authors also cannot rule out that the brain and motor neuron signals are both driven by a third, possibly subcortical, source. The analysis that separates the task effect from force assumes the relationship between them is linear and additive. The task correlations were computed from only four data points per participant, which the authors acknowledge makes them noisy, and is why they tested across participants. Not every participant showed a clear EEG spatial pattern, which the authors attribute to noise in the EEG and imperfect transmission of the oscillations to motor neurons.

The funding and conflicts of interest section names only the University of Freiburg as funder. Nothing else about funding or competing interests appears in the text provided. The methods name several commercial devices (electrode grids, amplifiers, the dynamometer and analysis software).

Do not read this as evidence that motor imagery or a mind-controlled device changes anything for patients. The participants were 15 healthy adults and nothing was measured about pain, function or recovery. The mental tasks could be identified from spinal motor neuron activity at 30% against a 25% chance level, and the authors state that a substantial improvement is needed before this could be used as a control signal.