, 2010). Nine sensors embedded in the glove sampled extension/flexion and ulnar/radial deviation (i.e., adduction/abduction) of the wrist (sensors eW and dW); carpometacarpal opposition/reposition of digit 5 (o5); flexion/extension at the metacarpophalangeal joints of digits 5, 3, 2, and 1 (f5, f3, f2, and f1); and trapeziometacarpal abduction/adduction and opposition/reposition UMI-77 mw of

digit 1 (a1 and o1). (The f3 channel was not available during stimulation at 3 of the 13 sites.) EMG data were recorded through 15 (G1) or 19 (G2) electrodes chronically implanted in left forelimb muscles. Proximal muscles acting on the shoulder and elbow included Del (deltoideus), Pec (pectoralis major), TriU and TriR (triceps brachii, ulnar and radial short heads), Bic (biceps brachii longus), and BR (brachioradialis). Wrist and extrinsic hand extensors included AbPL (abductor pollicis longus) and extensors ECRB (carpi radialis brevis), EDC (digitorum communis), ED23 (digiti secundi and tertii proprius), ED45 (digiti quarti and quinti proprius), and ECU (carpi ulnaris). Wrist and extrinsic hand flexors included FCR (carpi radialis), FDS (digitorum superficialis), FDPU and FDPR (digitorum profundus, ulnar and radial), and FCU (carpi ulnaris). Intrinsic hand muscles included AbPB (abductor pollicis brevis), AdP (adductor pollicis), OpP LY2835219 clinical trial (opponens pollicis), F5B (flexor digiti quinti brevis manus), and Op5 (opponens digiti quinti manus).

Both grasping-related and ICMS-evoked EMG data were band-pass filtered, notch filtered, amplified, and digitized by hardware, as described elsewhere (Overduin et al., 2008), and then further band-pass filtered and full-wave rectified. Grasp-related EMG data were integrated within 9 ms (G1) or 11 ms (G2) bins, depending on the relative speed of the animal’s

movements. ICMS-evoked EMG data were instead integrated between 25 and 150 ms from the onset of each ICMS train. For grasp-related data, trials were time-aligned on the moment of object removal from the first well, truncated to windows of 100 samples spanning Casein kinase 1 [–350:+550] ms (G1) or [–500:+600] ms (G2) around this moment, and averaged over the 40 trials in each of the 50 object conditions. Each channel was normalized to its maximum integrated EMG level observed over these averaged trials. The same normalization factors were applied to the ICMS-evoked data. These software preprocessing steps, as well as the subsequent analyses, were done in MATLAB (MathWorks). Kinematic “convergence” was defined as a reduction in joint distance from a mean posture observed across trials. Using Figure 1B as an example, absolute displacements between the nine black dots (defining hand posture at 25 ms into ICMS, over nine stimulation trials) and their mean were calculated for each joint dimension (e.g., a1). This was then repeated for the nine lightest gray dots defining hand posture at 150 ms into ICMS by taking these points’ absolute displacements from their mean.