Fig. 1: The handwriting task and neural representation during attempted handwriting.
From: Human motor cortex encodes complex handwriting through a sequence of stable neural states
a, The participant has two 96-channel Utah intracortical microelectrode arrays implanted in the left MC. Both arrays (array A and array B) are positioned in the hand knob area, approximately 1 cm apart from each other. b, The participant is instructed to attempt handwriting under video guidance (Supplementary Video 1). c, Trial design schematic. Each trial consists of a single character displayed on the screen. A trial begins with the target character being displayed on the screen (prepare), followed by a go cue (green light), and acted writing of the character stroke by stroke (Methods). d, Writing of an example Chinese character in terms of strokes (top). e–g, Summary of the main findings. MC programmes character writing by sequencing a small set of stable states (f), each encoding a set of specific stroke fragments (e). A set of neurons exhibits directional tuning that is stable within each state but strongly variable across states (g). h, Writing movements were decoded using both state-dependent (first identifying the neural state and then performing state-dependent decoding for each fragment) and state-independent neural decoders Source data.
