Glossary#

Connectome-based neural mass model (CNMM)#

In this project, a neural mass model coupled by a structural connectivity matrix (sc), with optional distance-based delays (dist) and a measurement model.

Distance matrix#

Pairwise inter-regional distances (dist), used to compute integer delay indices in delayed coupling terms.

External input / stimulus#

The u or external input tensor supplied to forward simulation for resting-state (often zero) or evoked/stimulus-driven modeling.

Fitting paradigm#

A training workflow class (for example ModelFitting, FittingBatch, FittingFNGFPG) that defines simulation, optimization, and bookkeeping behavior.

FNG-FPG#

FittingFNGFPG (“Forward No Gradient, Forward Parallel Gradient”), a specialized approach for long simulations using a serial pass for initial conditions and a gradient-enabled blocked pass.

Lead field matrix#

A source-to-sensor projection matrix (lm) used to map simulated source activity to M/EEG channel space.

Neural mass model (NMM)#

A reduced biophysical model of population activity per region. In WhoBPyT, NMMs inherit from whobpyt.datatypes.AbstractNeuralModel.

Objective function / loss#

A differentiable criterion minimized during fitting, implemented via AbstractLoss and concrete classes such as CostsTS, CostsFC, and CostsMean.

Output variables#

Simulated observables exposed by a model for fitting. For the current Jansen-Rit implementation, output_names = ["eeg"].

Parameter object#

The whobpyt.datatypes.Parameter class storing a value, optional prior mean/precision, and flags controlling whether values and/or priors are trainable.

Prior loss#

A regularization term from AbstractLoss.prior_loss that penalizes deviation from parameter priors when hyperparameters are fit.

State variables#

Dynamical variables integrated by the model at each step. For JansenRitModel these are E, Ev, I, Iv, P, and Pv.

Structural connectivity (SC)#

The inter-regional coupling matrix used for long-range interactions (for example sc in JansenRitModel), often derived from diffusion MRI tractography.

Timeseries#

The whobpyt.datatypes.Timeseries container for empirical or simulated data, typically shaped as num_regions x ts_length.

Training statistics#

The TrainingStats record of losses, tracked parameters, and selected matrices (for example fitted connectivity/lead-field terms) across optimization.

Whole-brain model (WBM)#

A dynamical systems model that simulates activity across many brain regions at once, using region-to-region coupling and neural state equations.

Windowed fitting#

A training pattern where longer recordings are split into windows (Timeseries.windowedTensor), and gradients are backpropagated window-by-window.