Gesture Decoding Using ECoG Signals from Human Sensorimotor Cortex: A Pilot Study

Figure 2

Time frequency plots of the ECoG signals and decoding performance obtained from all channels and selected channels. (a) Normalized power spectrum of ECoG signal from a representative channel 35 over sensorimotor cortex of P1 which was averaged and aligned with visual cue (time = 0). The frequency increases in log scale, and the color bar gives the scale of the spectrum amplitude values. The gestures from left to right are scissor, rock, and paper, respectively. Vertical magenta bars in the subplot indicate the frequency bands used in decoding (high gamma frequency band (70–135 Hz) and low-frequency band (4–12 Hz)). Black solid lines represent the averaged grasping onset across trials, and the grey dash lines represent the averaged end timing of grasping. (b) The decoding performance of different frequency bands (low-, high-, and hybrid frequency band, from left to right) using all channels (left column). The performances of hybrid frequency band are significantly higher than that of high frequency band in P1 and P2 ( value < 0.01), and both the hybrid and high frequency decoding results are higher than low frequency in all participants. The black dash line represent the chance level.

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