Start training

Skill · Shadow Hand

Count fingers

Five pathways, one per finger. Each finger folds only while its own pathway is ON.

Train this skillThe Shadow Hand

Runs on the Shadow Hand · Dexterous hand

01 Pathways

How the neurons drive it.

A pathway is one cue: the electrode we pulse, the electrodes we read, and the rule that decides when it is ON. This skill has five.

“thumb”

Pulse electrode
11at 10 Hz
Read electrodes
2 3 10 12 18 19
ON at
0.6spikes per electrode per 100 ms

We pulse electrode 11 at 10 Hz. When electrodes 2, 3, 10, 12, 18 and 19 average at least 0.6 spikes per 100 ms, and twice the rate of the rest of the array, “thumb” is ON.

“index”

Pulse electrode
14at 10 Hz
Read electrodes
5 6 13 15 21 22 23
ON at
0.6spikes per electrode per 100 ms

We pulse electrode 14 at 10 Hz. When electrodes 5, 6, 13, 15, 21, 22 and 23 average at least 0.6 spikes per 100 ms, and twice the rate of the rest of the array, “index” is ON.

“middle”

Pulse electrode
33at 10 Hz
Read electrodes
24 25 32 40 41 42
ON at
0.6spikes per electrode per 100 ms

We pulse electrode 33 at 10 Hz. When electrodes 24, 25, 32, 40, 41 and 42 average at least 0.6 spikes per 100 ms, and twice the rate of the rest of the array, “middle” is ON.

“ring”

Pulse electrode
53at 10 Hz
Read electrodes
44 45 46 54 60 61 62
ON at
0.6spikes per electrode per 100 ms

We pulse electrode 53 at 10 Hz. When electrodes 44, 45, 46, 54, 60, 61 and 62 average at least 0.6 spikes per 100 ms, and twice the rate of the rest of the array, “ring” is ON.

“little”

Pulse electrode
58at 10 Hz
Read electrodes
49 50 51 57 59
ON at
0.6spikes per electrode per 100 ms

We pulse electrode 58 at 10 Hz. When electrodes 49, 50, 51, 57 and 59 average at least 0.6 spikes per 100 ms, and twice the rate of the rest of the array, “little” is ON.

These are the skill file’s starting electrodes, numbered column by column across the 8 × 8 array. Calibration moves each pathway onto electrodes your culture actually answers on and raises its ON threshold above resting noise.

02 Movement

What the Shadow Hand does.

Target pose “thumb”

thumb flex
1.2 rad
thumb bend
0.6 rad
thumb tip
0.8 rad

Target pose “index”

index flex
1.4 rad
index curl
2.6 rad

Target pose “middle”

middle flex
1.4 rad
middle curl
2.6 rad

Target pose “ring”

ring flex
1.4 rad
ring curl
2.6 rad

Target pose “little”

little flex
1.4 rad
little curl
2.6 rad

03 The test

Moves only while cued.

Pulse thumb, index, middle, ring, little in turn (1.5 s each): each finger folds only in its own window.

The test · 11 s · moves only while cued
thumb
thumb: pulsed 0.5–2 s
index
index: pulsed 2.5–4 s
middle
middle: pulsed 4.5–6 s
ring
ring: pulsed 6.5–8 s
little
little: pulsed 8.5–10 s

It passes when

  1. 01Thumb folds in its window
  2. 02Thumb open in other windows
  3. 03Index folds in its window
  4. 04Index open in other windows
  5. 05Middle folds in its window
  6. 06Middle open in other windows
  7. 07Ring folds in its window
  8. 08Ring open in other windows
  9. 09Little folds in its window
  10. 10Little open in other windows

04 Proof

Proof it is the neurons.

Validation replays this test three times on the same spontaneous activity. The skill counts only if it passes with stimulation and fails under both controls; if it also passes without the neurons, it is marked invalid.

With stimulationShould pass
No stimulationShould fail
Spikes blockedShould fail

How validation works

05 More skills

More for the Shadow Hand.

  1. 01Close fist1 pathway · 6 s testThe Shadow Hand closes into a fist only while the “fist” pathway is ON.
  2. 02Pinch1 pathway · 6 s testThumb and index fingertips meet in a pinch only while the “pinch” pathway is ON.

All skills

Shadow Hand

Train “Count fingers” on the Shadow Hand.

Choose a biocomputer, launch, and watch it calibrate, train and validate.

Start trainingBiocomputers How it works