Dpli Connectivity

Module name: DpliConnectivity

Package: CEAMSModules 7.4.0

Version: 2.1.0

Overview

This node computes corrected Directed Phase Lag Index (dPLI) connectivity from EEG epochs.

Workflow

  1. Stack input epochs into a 3D array with shape (num_epochs, num_channels, num_samples).

  2. Treat non-finite values (NaN/Inf) as artifacts; convert to NaN so they can be dropped.

  3. Remove artifact windows by dropping any epoch that contains NaN or zeros (across any channel/sample).

  4. For each remaining epoch, compute dPLI between all channel pairs using Hilbert phase.

  5. Build a null distribution via per-channel time-shift surrogates and apply a Wilcoxon test: apply the “gap + 0.5” correction logic when p < p_value; otherwise leave at 0.5 baseline.

  6. Return the per-epoch corrected dPLI and the average across epochs, along with channel names.

Inputs

Input

Format

Default

Description

epochs

list[EpochModel]

—

Each EpochModel has .samples (2D array W×T: epochs × samples), .sample_rate, .channel.

events

pandas.DataFrame

—

Present for interface consistency; not used by the computation here.

num_surr

int

20

Number of time-shift surrogates for correction.

p_value

float

0.05

Significance threshold for the Wilcoxon signed-rank test.

Outputs

Output

Format

Description

dpli_results

dict
{
“final_dpli”: (num_epochs_kept, C, C) array of corrected dPLI per epoch,
“average_dpli”: (C, C) array = mean over kept epochs,
“channel_names”: list[str] of channel labels
}

Usage in a process

  1. Open Dev Tools -> New process in Snooz.

  2. In the Module Library, find Dpli Connectivity under the Connectivity Analysis category.

  3. Drag the module onto the process canvas.

  4. Connect the required inputs from upstream modules (or set values in the Settings tab).

  5. Connect outputs to downstream modules as needed.

  6. Double-click the module to configure parameters in the Settings tab.

  7. Run the process and inspect results in the Results tab.

Note

For general guidance on building processes with modules, see Explore examples.