Functional Near-Infrared Spectroscopy for Recording Brain Activity During Social Interactions

Abstract

Source: Reindl, V., et al. Conducting Hyperscanning Experiments with Functional Near-Infrared Spectroscopy. J. Vis. Exp. (2019)

This video demonstrates the use of functional near-infrared spectroscopy (fNIRS) to measure brain activity during social interactions. Participants engage in a coordinated task that increases activity in the prefrontal cortex, a region critical for social behavior, while the system detects changes in light absorption due to blood oxygenation. By analyzing the synchrony of brain activity between participants, the study assesses neural dynamics underlying social interaction.

Protocol

All procedures involving human participants have been performed in compliance with the institutional, national, and international guidelines for human welfare and have been reviewed by the local institutional review board.

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
NIRS measurement system with probe sets and probe holder grids	Hitachi Medical Corporation, Tokyo, Japan	ETG-4000 Optical Topography System	The current study protocol requires an optional second adult probe set for 52 channels of measurement in total as well as two 3x5 probe holder grids.
raw EEG caps	EASYCAP GmbH, Herrsching, Germany	C-SCMS-56; C-SCMS-58	Caps must be provided with holes for NIRS probes by the experimenter. Choose cap size the same size or slightly larger than participant's head circumference.
Technical computing software	The MathWorks, Inc., Natick, MA	MATLAB R2014a (or later versions)	Serves as base for Psychophysics Toolbox extensions (stimulus presentation), SPM for fNIRS toolbox (fNIRS data analysis), and ASToolbox (WTC computation).