Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 2009, 586-9

Human Motor Cortical Activity Recorded With Micro-ECoG Electrodes, During Individual Finger Movements

Affiliations

Human Motor Cortical Activity Recorded With Micro-ECoG Electrodes, During Individual Finger Movements

W Wang et al. Conf Proc IEEE Eng Med Biol Soc.

Abstract

In this study human motor cortical activity was recorded with a customized micro-ECoG grid during individual finger movements. The quality of the recorded neural signals was characterized in the frequency domain from three different perspectives: (1) coherence between neural signals recorded from different electrodes, (2) modulation of neural signals by finger movement, and (3) accuracy of finger movement decoding. It was found that, for the high frequency band (60-120 Hz), coherence between neighboring micro-ECoG electrodes was 0.3. In addition, the high frequency band showed significant modulation by finger movement both temporally and spatially, and a classification accuracy of 73% (chance level: 20%) was achieved for individual finger movement using neural signals recorded from the micro-ECoG grid. These results suggest that the micro-ECoG grid presented here offers sufficient spatial and temporal resolution for the development of minimally-invasive brain-computer interface applications.

Figures

Fig. 1
Fig. 1
Head x-ray (lateral view) showing the locations and sizes of the implanted ECoG electrodes. One micro-ECoG grid (16 contacts), one regular ECoG grid (32 contacts), and two 6-contact regular ECoG strips were implanted. Inset: A side-by-side comparison of the regular ECoG grid and the micro-ECoG grid showing the center-to-center electrode spacing.
Fig. 2
Fig. 2
Coherence analysis for the micro-ECoG grid (red lines) and the regular grid (blue lines). 2A (left): Averaged coherence between neighboring electrodes. 2B (right): Coherence as a function of distance between electrodes. Error bars are standard deviations. Coherence values were calculated at all possible inter-electrode distances given the geometric configurations of the electrodes on the grids.
Fig. 3
Fig. 3
Modulation of neural signals recorded by the micro-ECoG grid during individual finger movements. The five columns from left to right correspond to instructed thumb, index, middle, ring, and little finger movement, respectively. Top row: Spatial pattern of 60–120 Hz band activity averaged over movement and across all trials for all 14 recording electrodes on the micro-ECoG grid. Numbers indicate electrode locations. Middle: Movements of five fingers (PIP joint angles) from nine repetitions. PIP joints exhibiting the most significant change during this task were chosen for analysis. All joint angle data has been normalized to the angle of thumb PIP joint during maximum thumb flexion. Vertical dotted lines represent onset of finger movement. Bottom row: Spectrograms (spectral power change from baseline as a function of both frequency and time) averaged across all trials for Electrode No. 11. Again, vertical dotted lines represent onset of finger movement.

Similar articles

See all similar articles

Cited by 39 PubMed Central articles

See all "Cited by" articles

Publication types

Feedback