Graph measures in task-based fMRI: Functional integration during read-out of visual and auditory information

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Network Science

Background:

• Functional brain networks exhibit dynamic changes based on cognitive demands.
• Graph theory provides a framework for quantifying brain network integration and connectivity.

Purpose of the Study:

• To investigate how attention to auditory and visual information modulates graph theoretical measures of functional connectivity.
• To examine changes in integration between auditory, visual, and task-core network modules during audiovisual attention.

Main Methods:

• Functional magnetic resonance imaging (fMRI) BOLD activity was recorded in healthy volunteers.
• Network nodes were defined by BOLD contrasts in sensory and attention networks.
• Functional connectivity and graph theoretical measures were computed under different attentional conditions (color vs. pitch).

Main Results:

• Attending to color increased connection strength between the task and visual modules.
• Attending to pitch increased connection strength between the task and auditory modules.
• Attentional modulation led to stronger integration of sensory regions, evidenced by nodal graph measures.

Conclusions:

• Task demands dynamically adjust modality-specific and modality-independent functional brain networks.
• Graph theoretical measures effectively capture these attentional modulations in brain network organization.
• Findings support the role of dynamic network adjustments in cognitive processing and attention.