Extended Data Fig. 7. Contribution of each array and microelectrode to decoding performance.

(a) Word error rates for a retrospective offline decoding analysis using just the ventral 6v array (left column), dorsal 6v array (middle column), or both arrays (right column). Each circle indicates the word error rate for one of 10 RNN seeds. Word error rates were aggregated across 400 trials. Horizontal lines depict the mean across all 10 seeds. (b) Heatmaps depicting the (offline) increase in phoneme error rate when removing each electrode from the decoder by setting the values of its corresponding features to zero. Results were averaged across 10 RNN seeds that were originally trained to use every electrode. Almost all electrodes seem to contribute to decoding performance, although the most informative electrodes are concentrated on the ventral array. The effect of removing any one electrode is small (<1% increase in phoneme error rate), owing to the redundancy across electrodes.