Fig. 4. Directional tuning during bimanual versus unimanual movements.
(A) Fraction of neurons in each cortical area which had significant tuning to both arms during unimanual (red) and bimanual (blue) trials, determined from regression. (B) The absolute value of the difference between preferred direction of the contralateral arm computed from bimanual trials and unimanual trials. Data shown separately for each cortical area. (C) Same analysis as (B) but showing the difference in preferred direction for the ipsilateral arm. All data are mean ± standard error. Analysis compiled from activity of 492 M1 neurons, 203 SMA neurons, 90 S1 neurons, and 61 PPC neurons.