directional-coordination-hierarchy-brain

name	directional-coordination-hierarchy-brain
version	1.0.0
description	Directional coordination hierarchy in large-scale brain dynamics — identifies three recurrent resting-state coordination regimes (feedback-dominated, feedforward-dominated, integrative), shows this framework is disrupted in schizophrenia, and links directional functional dynamics to symptom severity and cognition.
triggers	["directional brain coordination","large-scale brain dynamics hierarchy","resting-state directional coordination","cortical hierarchy dynamics","brain coordination regimes","feedforward feedback brain dynamics","integrative coordination brain","schizophrenia brain dynamics","directional functional connectivity","cortical information flow hierarchy"]
authors	["Wiafe, S.-L.","Soleimani, N.","Fu, Z.","Miller, R.","Calhoun, V."]
source	biorxiv:10.64898/2026.05.25.727703
published	2026-05-25

Directional Coordination Hierarchy in Large-Scale Brain Dynamics

Overview

This methodology reveals that resting-state brain dynamics are fundamentally organized along a directional coordination axis that recapitulates the classical cortical hierarchy. Using directed measures of interregional coordination on fMRI data, the work identifies three stable recurrent coordination regimes and demonstrates their disruption in schizophrenia.

Core Framework

Three Coordination Regimes

1. Feedback-dominated mode: Transmodal cortex (prefrontal, default mode) leads sensory systems — top-down information flow
2. Feedforward-dominated mode: Sensory systems lead transmodal cortex — bottom-up processing
3. Integrative mode: Balanced bidirectional exchange across all cortical areas

These three modes define a low-dimensional coordination landscape that:

• Replicates across four independent cohorts (high stability)
• Constitutes a fundamental property of the adult brain
• Tracks hierarchical information flow known from structural connectivity

Analytical Approach

Step 1: Extract directionality of interregional coordination
  - Use directed functional connectivity measures (e.g., Granger causality, transfer entropy)
  - Apply to resting-state fMRI time series
  - Focus on temporal dynamics of coupling direction

Step 2: Identify recurrent coordination regimes
  - Cluster directors of interregional coordination
  - Identify stable 3-mode solution across cohorts

Step 3: Characterize the coordination landscape
  - Compute persistence/dwell time per regime
  - Measure global convergence rate and entropy
  - Map regimes onto cortical hierarchy axis (unimodal → transmodal)

Step 4: Apply to clinical population
  - Compare coordination landscapes in schizophrenia vs controls
  - Correlate with symptom severity (PANSS), cognition, medication
  - Mediation analysis for medication effects

Key Findings

Schizophrenia Disrupts the Coordination Landscape

• Feedback-dominated coordination becomes less persistent → reduced top-down control
• Integrative coordination becomes more persistent → excessive integration
• Global dynamics shift: faster convergence, reduced entropy → loss of dynamical flexibility and directional constraint

Clinical Correlates

• Coordination landscape alterations track symptom severity (positive/negative symptoms)
• Predict cognitive performance independently