Figure caption 4. Model implementation details.

Firing rate model performance depends on the location of the projection field, the sampling rate of the sensor, and the size of the contact area (corresponding to the size of the projection field). A| Schematic of the hand used in the model with abbreviations of hand areas and locations of the centers of projection fields used for each area (black dots). B| Firing rate traces (FR_t) computed for three locations of the hand using the same time-varying noise stimulus. Responses from the distal digits (D1d and D2d) are similar to each other, but differ from responses from the palm (PW1). C| R2 between FR_t traces derived for different locations of the hand. D| Mean performance as a function of sampling frequency. Model performance improves as temporal resolution of the sensor input improves. E| Mean performance as a function of contact area size (radius of the pin). The model was trained with a contact area of 2, 4, and 6 mm, respectively, then was tested with different smaller/larger contact areas ranging from 0.1 to 7 mm. For all analyses, the model was trained using sustained indentations and pink noise filtered below 5Hz. Test set consisted of steps of varying length and amplitude, noise of random seed and sinusoids of varying frequencies (<5Hz). Model must be tailored to the size of the projection field.