Data Lab node
Inter-Brain Sync
Synchrony between people’s brains, live, from one Signal whose channels are named Person·Electrode (Signal Align makes it). The Band (alpha by default) is isolated without delay, mains hum notched out, and every pair of channels from DIFFERENT people is measured over the Window: PLV = how steady their phase difference is (1 = locked), or wPLI, which ignores zero-lag coupling such as shared noise. Pairing: the same electrode on both heads, all × all, or brain regions. Baseline measures the same data with one side shifted in time — Excess is the synchrony above that chance level. Pair picks which two people Synchrony, Excess, Phase Difference, Valid and Matrix show (the Person Matrix, Pairs and Timeline always hold all of them); Phase Difference is the mean lead of the first of the two, in degrees. Cable Signal Align’s Mask so gaps are left out; Valid says how much of the window had data from both — below 80 % a pair reads 0 (no data, no synchrony).
Inputs
| Port | Type | Default |
|---|---|---|
| SignalOne Signal with channels named Person·Electrode — the Signal output of Signal Align. Needs at least two people. | structure | — |
| MaskSignal Align’s Mask: which moments each person had data for. Gaps are then left out of the measurement instead of counted as a held, flat line; when less than 80 % of the window has data from both, the pair reads 0. | structure | — |
| BandThe rhythm to measure. Alpha 8–12 Hz by default. With internet clocks alpha and theta are reliable; beta and gamma need very tight timing (5 ms is 72° at 40 Hz). | int | — |
| LowCustom band: the lower edge in Hz. | float | 8 |
| HighCustom band: the upper edge in Hz (at most 45 % of the sample rate). | float | 12 |
| NotchRemoves mains hum and its 2nd harmonic. Riga and Sicily share one 50 Hz grid, so the hum is in step at both sites and would read as synchrony. | int | 0 |
| MeasurePLV: how steady the phase difference is, 0…1, any lag. wPLI: like PLV but ignores zero-lag coupling (shared noise, a common reference) — it can also miss true zero-lag synchrony. | int | 0 |
| PairingSame Electrode: Fp1 with Fp1, O2 with O2. All × All: every channel of one person with every channel of the other. Regions: frontal, central, temporal, parietal, occipital from the 10-20 names. | int | 0 |
| WindowSeconds measured each time, 0.5–30. Longer = steadier but slower to react; aim for 10+ cycles of the band’s low edge (alpha: 1–2 s, theta: 2–4 s). | float | 2 |
| Update RateNew values per second. 0 = every frame. | float | 10 |
| BaselineMeasures the same window with one person shifted in time to get the chance level for this band and window; Excess = Synchrony minus it. Does not remove synchrony caused by a shared stimulus. | bool | true |
| EnableOff stops the measurement and clears its history. | bool | true |
| PairWhich two people Synchrony, Excess, Phase Difference, Valid and Matrix show, e.g. Local ↔ Other. The Person Matrix, Pairs and Timeline always hold every pair. The list fills in once the node has measured. | int | 0 |
Outputs
| Port | Type |
|---|---|
| Synchrony | float |
| Excess | float |
| Phase Difference | float |
| Valid | float |
| Matrix | structure |
| Person Matrix | structure |
| Pairs | structure |
| Timeline | structure |
| Info | string |
Open Inter-Brain Sync in the interactive catalog →
Inter-Brain Sync is one of 381 nodes in Grafit Pro.
Free download. Every feature for 7 days, no card. Then €99.99 once — or keep playing your projects as a Player.