The applied currents were 6 µA ± 3 with fixed stimulus duration at 0.3 ms which was 50% larger than that required to activate both 1b and 1s boutons on recording muscles.
After mounting, the muscles were conditioned by stimulating with a pair of platinum wire electrodes (0.5 mm in diameter, 15 mm in length) with current pulses of suprathreshold voltage (2 ms duration) at 0.5 Hz for >10 min. In control recording, muscles were stimulated at 0.5 or 2 Hz in flowing Krebs solution.
However, even with clinical grade EEG sets it is difficult to avoid recording muscle movements (when concentrating on a mental activity, people tend to furrow their brows and make involuntarily facial movements – see box).
In response to the specific criticism that the Epoc was recording muscle artefacts, Fedele wrote: "Yes, EEG signal [sic] can capture facial movements and the headset can detect head rotation, but the BrainControl app uses one output only, and that is the EEG signals related to movement imaginations".
She also said that it was irrelevant whether the Epoc was also recording muscle artefacts, as even clinical grade EEGs could not eliminate all sources of cortical "noise" and what mattered was that the algorithm was able to train correct correlations.
Adrenergic activity was assessed by recording muscle sympathetic nerve traffic (MSNA) before and several months after device implantation and activation.
During work shift (8 hours) on the first day of physical activity measurement, participants in group B will in addition to physical activity measurements, carry equipment recording muscle activity, ground reaction force and postures.
Two-dimensional B-mode ultrasound will be used to examine MG muscle function during treadmill walking by attaching a flat ultrasound transducer (LV7.5/65/64D, Telemed Echo Blaster 64 EXT-1T, Vilnius, Lithuania) to the surface of the skin above the MG muscle, and recording muscle fascicle length changes as described previously.
This effect was equally present in the two experiments, for both the recorded muscles, and before and after each experiment, since no significant interaction between Intensity and the other factors was found (ps>.35).
We calculated multiple-input impulse responses between the neural signals and each of the recorded muscles using a Weiner cascade model (a dynamic linear system followed by a static nonlinearity) [36].
An increase in the electrical potential during swallowing goes along with the mandibular stabilization obtained with the isometric contraction of the recorded muscles.
