The authors thank Instituto do C&#233;rebro (InCe-IIEP) and Hospital Israelita Albert Einstein (HIAE) for this study support.&#160;Special thanks to Jos&#233; Bel&#233;m de Oliveira Neto for the English proofreading of this article.

Paulo Rodrigo Baz&#225;n has provided freelance scientific consulting to NIRx Medizintechnik GmbH and to Brain Support Corporation, which is a distributor of NIRx Medizintechnik GmbH. The other authors declare that there are no conflicts of interest with respect to the authorship or the publication of this article.

This study aimed to create a protocol using hyperscanning on four brains concurrently under naturalistic conditions. The experimental paradigm used different drawing tasks and the correlation of multiple outcome measures, drawing metrics, behaviors, and brain signals. The critical steps within this protocol are the consideration of the challenges arising from its high complexity and the maintenance of its ecological and naturalistic conditions.
Video observation was key to this study. It&#160;...

Interpersonal interaction behavior is an important component of the process of connecting and creating empathic bonds. Previous research indicates that this behavior can be expressed in the occurrence of synchronicity, when biological and behavioral signals align during social contact. Evidence shows that synchronicity can occur between people interacting for the first time1,2,3. Most studies on social interactions and their underlying neural mechanisms use a single person or second person approach2,4, and little is known about transposing this knowledge to group social dynamics. Evaluating interpersonal responses in groups of three or more individuals is still a challenge for scientific research. This leads to the necessity of bringing to the laboratory the complex environment of social interactions in everyday human beings under naturalistic conditions5.
In this context, the functional near-infrared spectroscopy (fNIRS) technique is a promising tool for assessing the relationships between interpersonal interaction in naturalistic contexts and its brain correlates. It presents fewer restrictions on participant mobility compared to functional magnetic resonance imaging (fMRI) and is resilient to motion artifacts6,7. The fNIRS technique works by assessing hemodynamic effects in response to brain activation (changes in blood concentration of oxygenated and deoxygenated hemoglobin). These variations can be measured by the amount of diffusion of infrared light through scalp tissue. Previous studies have demonstrated the flexibility and robustness of the technique in ecological hyperscanning experiments and the potential to expand knowledge in applied neuroscience6,8.
The choice of an experimental task for the naturalistic assessment of the neural correlates of social interaction processes in groups is a crucial step in approaching applied neuroscience studies9.&#160;Some examples already reported in the literature with the use of fNIRS in group paradigms include music performance10,11,12, classroom interaction8, and communication13,14,15,16,17.
One of the aspects not yet explored by previous studies is the use of drawing games that have as the main feature the manipulation of empathic components to assess social interaction. In this context, one of the games frequently used to induce social interaction in dynamics among strangers is the collaborative drawing game18,19. In this game, sheets of paper are divided into equal parts, and the group participants are challenged to draw shared self-portraits of all members. In the end, each member has their portrait drawn in a collaborative way by several hands.
The objective is to promote quick integration among strangers, provoked by directing visual attention to the faces of the group partners. It can be considered an &#34;ice-breaking&#34; activity due to its ability to support curiosity and consequent empathic processes among the members19.
One of the advantages of using drawing tasks is their simplicity and ease of reproduction20. They also do not require any specific technical training or skills, as seen in the studies using musical performance paradigms21,22,23,24. This simplicity also enables the choice of a more naturalistic stimulus within a social context4,9,25.
Besides being an instrument for inducing social behavior in groups, drawing is also considered a tool for psychological evaluation26. Some graphic-projective psychological tests, such as House-Tree-Person (HTP)27,28,29, Human Figure Drawing - Sisto Scale27, and Kinetic Family Drawing30&#160;are used in a complementary way for qualitative and quantitative diagnoses. Their results usually express unconscious processes, giving clues about the individual&#39;s symbolic system and, therefore, their interpretations of the world, experiences, affections, etc.
The practice of drawing makes one think and helps create meaning for experiences and things, adding sensations, feelings, thoughts, and actions31. It gives clues about how to perceive and process these life experiences26. Drawing uses visual codes to allow one to understand and communicate thoughts or feelings, making them accessible to manipulation and, thus, creating the possibility for new ideas and readings31.
In art therapy, drawing is a tool to work on attention, memory, and organization of thoughts and feelings32, and it can be used as means to produce social interaction33.
This study aimed to develop a naturalistic experimental protocol to assess vascular and behavioral brain responses during interpersonal interaction in quartets using a collaborative drawing dynamic. In this protocol, the evaluation of the brain responses of the quartet (individually and the synchronicity between partners) and the possible outcome measures, such as behavioral measures (drawing and gaze behavior)&#160;are proposed. The aim is to provide more information on social neuroscience.

<table><tbody><tr><td>2 NIRSport&amp;nbsp;</td><td>NIRx Medizintechnik GmbH, Germany</td><td>Nirsport 88</td><td>The equipment belong to InCe ( Instituto do C&amp;eacute;rebro - Hospital Israelita Albert Einstein). two continuous-wave systems (NIRSport8x8, NIRx Medical Technologies, Glen Head, NY, USA) with eight LED illumination sources emitting two wavelengths of near-infrared light (760 and 850 nm) and eight optical detectors each. 7.91 Hz. Data were acquired with the NIRStar software version 15.2&amp;nbsp; (NIRx Medical Technologies, Glen Head, New York) at a sampling rate of 3.472222.</td></tr><tr><td>4 fNIRS caps</td><td>NIRx Medizintechnik GmbH, Germany</td><td></td><td>The blackcaps used in the recordings had a configuration based on the international 10-20</td></tr><tr><td>C&amp;acirc;mera 360&amp;deg; - Kodak Pix Pro SP360</td><td>Kodak</td><td></td><td>Kodak PixPro:&amp;nbsp;https://kodakpixpro.com/cameras/360-vr/sp360</td></tr><tr><td>Cameras de suporte - Iphone 8</td><td>Apple</td><td>Iphone 8</td><td>Supporting Camera</td></tr><tr><td>fOLD toolbox (fNIRS Optodes&amp;rsquo; Location Decider)</td><td>Zimeo Morais, G.A., Balardin, J.B. &amp;amp; Sato, J.R. fNIRS Optodes&amp;rsquo; Location Decider (fOLD): a toolbox for probe arrangement guided by brain regions-of-interest.&amp;nbsp;&lt;em&gt;Scientific Reports.&lt;/em&gt;&amp;nbsp;&lt;strong&gt;8,&lt;/strong&gt;&amp;nbsp;3341 (2018). https://doi.org/10.1038/s41598-018-21716-z</td><td>Version 2.2 (https://github.com/nirx/fOLD-public)</td><td>Optodes placement was guided by the fOLD toolbox (fNIRS Optodes&amp;rsquo; Location Decider, which allows placement of sources and detectors in the international 10&amp;ndash;10 system to maximally cover anatomical regions of interest according to several parcellation atlases. The ICBM 152 head model&amp;nbsp; parcellation was used to generate the montage, which was designed to provide coverage of the most anterior portion of the bilateral prefrontal cortex</td></tr><tr><td>Notebook Microsoft Surface</td><td>Microsoft</td><td></td><td>Notebook receiver of the fNIRS signals</td></tr><tr><td>R platform for statistical computing&amp;nbsp;</td><td>https://www.r-project.org&amp;nbsp;</td><td>R version 4.2.0</td><td>R is a free software environment for statistical computing and graphics. It compiles and runs on a wide variety of UNIX platforms, Windows and MacOS</td></tr><tr><td>REDCap</td><td>REDCap is supported in part by the National Institutes of Health (NIH/NCATS UL1 TR000445)</td><td></td><td>REDCap is a secure web application for building and managing online surveys and databases.</td></tr><tr><td>software Mangold Interact</td><td>Mangold International GmbH, Ed.&amp;nbsp;</td><td>interact 5.0</td><td>Mangold:&amp;nbsp;https://www.mangold-international.com/en/products/software/behavior-research-with-mangold-interact.html. Allows analysis of videos for behavioral outcomes and of autonomic monitoring for emotionally driven physiological changes (may require additional software, such as DataView). Allow the use of different camera types simultaneously and hundreds of variations of coding methods.</td></tr><tr><td>software NIRSite</td><td>NIRx Medizintechnik GmbH, Germany</td><td>NIRSite 2.0</td><td>For creating the montage and help optode placement and location in the blackcaps.</td></tr><tr><td>software nirsLAB-2014</td><td>NIRx Medizintechnik GmbH, Germany</td><td>nirsLAB 2014</td><td>fNIRS Data Processing</td></tr><tr><td>software NIRStar</td><td>NIRx Medizintechnik GmbH, Germany</td><td>version 15.2</td><td>&amp;nbsp;for fNIRS data aquisition: NIRStar software version 15.2&amp;nbsp; at a sampling rate of 3.472222</td></tr><tr><td>software NIRStim</td><td>NIRx Medizintechnik GmbH, Germany</td><td></td><td>&amp;nbsp;For creation and organization of paradigm blocks</td></tr></tbody></table>

group synchronization during collaborative drawing using functional near-infrared spectroscopy

Functional near-infrared spectroscopy (fNIRS) is a noninvasive method particularly suitable for measuring cerebral cortex activation in multiple subjects, which is relevant for studying group interpersonal interactions in ecological settings. Although many fNIRS systems technically offer the possibility to monitor more than two individuals simultaneously, establishing easy-to-implement setup procedures and reliable paradigms to track hemodynamic and behavioral responses in group interaction is still required. The present protocol combines fNIRS and video-based observation to measure interpersonal synchronization in quartets during a cooperative task.This protocol provides practical recommendations for data acquisition and paradigm design, as well as guiding principles for an illustrative data analysis example. The procedure is designed to assess differences in brain and behavior interpersonal responses between social and non-social conditions inspired by a well-known ice-breaker activity, the Collaborative Face Drawing Task. The described procedures can guide future studies to adapt group naturalistic social interaction activities to the fNIRS environment.

The protocol was applied to a quartet composed of young women (24-27 years old), all of them students on postgraduate programs (Hospital Israelita Albert Einstein, S&#227;o Paulo, Brasil), with master&#39;s or doctorate level education. All participants were right-handed, and only one reported having previous drawing experience. No participants had a reported history of neurological disorders.
For the scales and psychological test results, two participants (2 and 4) showed high scores for anxi...

Watch this Scientific Journal Video about Group Synchronization During Collaborative Drawing Using Functional Near-Infrared Spectroscopy at JoVE.com

Group Synchronization During Collaborative Drawing Using Functional Near-Infrared Spectroscopy

The present protocol combines functional near-infrared spectroscopy (fNIRS) and video-based observationto measure interpersonal synchronization in quartets during a collaborative drawing task.

Functional near-infrared spectroscopy (fNIRS) is a noninvasive method particularly suitable for measuring cerebral cortex activation in multiple subjects, ...

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1.9K Views.  Hospital Israelita Albert Einstein (HIAE). The present protocol combines functional near-infrared spectroscopy (fNIRS) and video-based observationto measure interpersonal synchronization in quartets during a collaborative drawing task.

Video: Group Synchronization During Collaborative Drawing Using Functional Near-Infrared Spectroscopy

Functional Near Infrared Spectroscopy of the Sensory and Motor Brain Regions with Simultaneous Kinematic and EMG Monitoring During Motor Tasks

There are several advantages that functional near-infrared spectroscopy (fNIRS) presents in the study of the neural control of human movement. It is relatively flexible with respect to participant positioning and allows for some head movements during tasks. Additionally, it is inexpensive, light weight, and portable, with very few contraindications to its use. This presents a unique opportunity to study functional brain activity during motor tasks in individuals who are typically developing, as well as those with movement disorders, such as cerebral palsy. An additional consideration when studying movement disorders, however, is the quality of actual movements performed and the potential for additional, unintended movements. Therefore, concurrent monitoring of both blood flow changes in the brain and actual movements of the body during testing is required for appropriate interpretation of fNIRS results. Here, we show a protocol for the combination of fNIRS with muscle and kinematic monitoring during motor tasks. We explore gait, a unilateral multi-joint movement (cycling), and two unilateral single-joint movements (isolated ankle dorsiflexion, and isolated hand squeezing). The techniques presented can be useful in studying both typical and atypical motor control, and can be modified to investigate a broad range of tasks and scientific questions.

Monitoring brain activity during upright motor tasks is of great value when investigating the neural source of movement disorders. Here, we demonstrate a protocol that combines functional near infrared spectroscopy with continuous monitoring of muscle and kinematic activity during 4 types of motor tasks.

There are several advantages that functional near-infrared spectroscopy (fNIRS) presents in the study of the neural control of human movement. It is ...

Behavior

Using MazeSuite and Functional Near Infrared Spectroscopy to Study Learning in Spatial Navigation

MazeSuite is a complete toolset to prepare, present and analyze navigational and spatial experiments1. MazeSuite can be used to design and edit adapted virtual 3D environments, track a participants' behavioral performance within the virtual environment and synchronize with external devices for physiological and neuroimaging measures, including electroencephalogram and eye tracking.
Functional near-infrared spectroscopy (fNIR) is an optical brain imaging technique that enables continuous, noninvasive, and portable monitoring of changes in cerebral blood oxygenation related to human brain functions2-7. Over the last decade fNIR is used to effectively monitor cognitive tasks such as attention, working memory and problem solving7-11. fNIR can be implemented in the form of a wearable and minimally intrusive device; it has the capacity to monitor brain activity in ecologically valid environments. 
Cognitive functions assessed through task performance involve patterns of brain activation of the prefrontal cortex (PFC) that vary from the initial novel task performance, after practice and during retention12. Using positron emission tomography (PET), Van Horn and colleagues found that regional cerebral blood flow was activated in the right frontal lobe during the encoding (i.e., initial na&iuml;ve performance) of spatial navigation of virtual mazes while there was little to no activation of the frontal regions after practice and during retention tests. Furthermore, the effects of contextual interference, a learning phenomenon related to organization of practice, are evident when individuals acquire multiple tasks under different practice schedules13,14. High contextual interference (random practice schedule) is created when the tasks to be learned are presented in a non-sequential, unpredictable order. Low contextual interference (blocked practice schedule) is created when the tasks to be learned are presented in a predictable order.
Our goal here is twofold: first to illustrate the experimental protocol design process and the use of MazeSuite, and second, to demonstrate the setup and deployment of the fNIR brain activity monitoring system using Cognitive Optical Brain Imaging (COBI) Studio software15. To illustrate our goals, a subsample from a study is reported to show the use of both MazeSuite and COBI Studio in a single experiment. The study involves the assessment of cognitive activity of the PFC during the acquisition and learning of computer maze tasks for blocked and random orders. Two right-handed adults (one male, one female) performed 315 acquisition, 30 retention and 20 transfer trials across four days. Design, implementation, data acquisition and analysis phases of the study were explained with the intention to provide a guideline for future studies.

MazeSuite is a complete toolset to prepare, present and analyze navigational and spatial experiments. Functional near-infrared spectroscopy (fNIR) is an optical brain imaging technique that enables noninvasive and portable monitoring of cerebral blood oxygenation changes. This paper summarizes collective use of MazeSuite and fNIR within a cognitive processing learning paradigm.

MazeSuite is a complete toolset to prepare, present and analyze navigational and spatial experiments1. MazeSuite can be used to design and edit adapted ...

Neuroimaging Field Methods Using Functional Near Infrared Spectroscopy (NIRS) Neuroimaging to Study Global Child Development: Rural Sub-Saharan Africa

Portable neuroimaging approaches provide new advances to the study of brain function and brain development with previously inaccessible populations and in remote locations. This paper shows the development of field functional Near Infrared Spectroscopy (fNIRS) imaging to the study of child language, reading, and cognitive development in a rural village setting of C&#244;te d&#39;Ivoire. Innovation in methods and the development of culturally appropriate neuroimaging protocols allow&#160;a first-time look into the brain&#39;s development and children&#39;s learning outcomes in understudied environments. This paper demonstrates protocols for transporting and setting up a mobile laboratory, discusses considerations for field versus laboratory neuroimaging, and presents a guide for developing neuroimaging consent procedures and building meaningful long-term collaborations with local government and science partners. Portable neuroimaging methods can be used to study complex child development contexts, including the impact of significant poverty and adversity on brain development. The protocol presented here has been developed for use in C&#244;te d&#39;Ivoire, the world&#39;s primary source of cocoa, and where reports of child labor in the cocoa sector are common. Yet, little is known about the impact of child labor on brain development and learning. Field neuroimaging methods have the potential to yield new insights into such urgent issues, and the development of children globally.

Neuroimaging Field Methods Using Functional Near Infrared Spectroscopy NIRS Neuroimaging to Study Global Child Development: Rural Sub-Saharan Africa

Portable neuroimaging approaches (functional Near Infrared Spectroscopy) provide advances to the study of the brain in previously inaccessible regions; here, rural C&#244;te d&#39;Ivoire. Innovation in methods and development of culturally-appropriate neuroimaging protocols permits novel study of the brain&#39;s development and children&#39;s learning outcomes in environments with significant poverty and adversity.

Portable neuroimaging approaches provide new advances to the study of brain function and brain development with previously inaccessible populations and in ...

Conducting Hyperscanning Experiments with Functional Near-Infrared Spectroscopy

Concurrent brain recordings of two or more interacting persons, an approach termed hyperscanning, are gaining increasing importance for our understanding of the neurobiological underpinnings of social interactions, and possibly interpersonal relationships. Functional near-infrared spectroscopy (fNIRS) is well suited for conducting hyperscanning experiments because it measures local hemodynamic effects with a high sampling rate and, importantly, it can be applied in natural settings, not requiring strict motion restrictions. In this article, we present a protocol for conducting fNIRS hyperscanning experiments with parent-child dyads and for analyzing brain-to-brain synchrony. Furthermore, we discuss critical issues and future directions, regarding the experimental design, spatial registration of the fNIRS channels, physiological influences and data analysis methods. The described protocol is not specific to parent-child dyads, but can be applied to a variety of different dyadic constellations, such as adult strangers, romantic partners or siblings. To conclude, fNIRS hyperscanning has the potential to yield new insights into the dynamics of the ongoing social interaction, which possibly go beyond what can be studied by examining the activities of individual brains.

The present protocol describes how to conduct fNIRS hyperscanning experiments and analyze brain-to-brain synchrony. Further, we discuss challenges and possible solutions.

Concurrent brain recordings of two or more interacting persons, an approach termed hyperscanning, are gaining increasing importance for our understanding ...

Conducting Concurrent Electroencephalography and Functional Near-Infrared Spectroscopy Recordings with a Flanker Task

Concurrent EEG and fNIRS recordings offer an excellent opportunity to gain a full understanding of the neural mechanism of cognitive processing by inspecting the relationship between the neural and hemodynamic signals. EEG is an electrophysiological technology that can measure the rapid neuronal activity of the cortex, whereas fNIRS relies on the hemodynamic responses to infer brain activation. The combination of EEG and fNIRS neuroimaging techniques can identify more features and reveal more information associated with the functioning of the brain. In this protocol, fused EEG-fNIRS measurements were performed for concurrent recordings of evoked-electrical potentials and hemodynamic responses during a Flanker task. In addition, the critical steps for setting up the hardware and software system as well as the procedures for data acquisition and analysis were provided and discussed in detail. It is expected that the present protocol can pave a new avenue for improving the understanding of the neural mechanisms underlying various cognitive processes by using the EEG and fNIRS signals.

The present protocol describes how to perform concurrent EEG and fNIRS recordings and how to inspect the relationship between the EEG and fNIRS data.&#160;

Concurrent EEG and fNIRS recordings offer an excellent opportunity to gain a full understanding of the neural mechanism of cognitive processing by ...

Qualitative and Comparative Cortical Activity Data Analyses from a Functional Near-Infrared Spectroscopy Experiment Applying Block Design

Neuroimaging studies play a pivotal role in the evaluation of pre- vs. post-interventional neurological conditions such as in rehabilitation and surgical treatment. Among the many neuroimaging technologies used to measure brain activity, functional near-infrared spectroscopy (fNIRS) enables the evaluation of dynamic cortical activities by measuring the local hemoglobin levels similar to functional magnetic resonance imaging (fMRI). Also, due to lesser physical restriction in fNIRS, multiple variants of sensorimotor tasks can be evaluated. Many laboratories have developed several methods for fNIRS data analysis; however, despite the fact that the general principles are the same, there is no universally standardized method. Here, we present the qualitative and comparative analytic methods of data obtained from a multi-channel fNIRS experiment using a block design. For qualitative analysis, we used a software for NIRS as a mass-univariate approach based on the generalized linear model. The NIRS-SPM analysis shows qualitative results for each session by visualizing the activated area during the task. In addition, the non-invasive three-dimensional digitizer can be used to estimate the fNIRS channel locations relative to the brain. To corroborate the NIRS-SPM findings, the amplitude of the changes in hemoglobin levels induced by the sensorimotor task can be statistically analyzed by comparing the data obtained from two different sessions (before and after intervention) of the same study subject using a multi-channel hierarchical mixed model. Our methods can be used to measure the pre- vs. post-intervention analysis in a variety of neurological disorders such as movement disorders, cerebrovascular diseases, and neuropsychiatric disorders.

We describe the analysis of continuous-wave functional near-infrared spectroscopy experiment using a block design with a sensorimotor task. To increase the reliability of the data analysis, we used the qualitative general linear model-based statistical parametric mapping and the comparative hierarchical mixed models for multi-channels.

Neuroimaging studies play a pivotal role in the evaluation of pre- vs. post-interventional neurological conditions such as in rehabilitation and surgical ...

Inter-Brain Synchrony in Open-Ended Collaborative Learning: An fNIRS-Hyperscanning Study

fNIRS hyperscanning is widely used to detect the neurobiological underpinnings of social interaction. With this technique, researchers qualify the concurrent brain activity of two or more interactive individuals with a novel index called inter-brain synchrony (IBS) (i.e., phase and/or amplitude alignment of the neuronal or hemodynamic signals across time). A protocol for conducting fNIRS hyperscanning experiments on collaborative learning dyads in a naturalistic learning environment is presented here. Further, a pipeline of analyzing IBS of oxygenated hemoglobin (Oxy-Hb) signal is explained. Specifically, the experimental design, the process of NIRS data recording, data analysis methods, and future directions are all discussed. Overall, implementing a standardized fNIRS hyperscanning pipeline is a fundamental part of second-person neuroscience. Also, this is in line with the call for open-science to aid the reproducibility of research.

The protocol for conducting fNIRS hyperscanning experiments on collaborative learning dyads in a naturalistic learning environment is outlined. Further, a pipeline to analyze the Inter-Brain Synchrony (IBS) of oxygenated hemoglobin (Oxy-Hb) signals is presented.

fNIRS hyperscanning is widely used to detect the neurobiological underpinnings of social interaction. With this technique, researchers qualify the ...

Revolutionizing fNIRS Studies&#58; A Novel Approach to Neural Coupling

New Framework for Understanding Cross-Brain Coherence in Functional Near-Infrared Spectroscopy (fNIRS) Hyperscanning Studies

Despite the growing body of functional near-infrared spectroscopy (fNIRS) hyperscanning studies, the assessment of coupling between two neural signals using wavelet transform coherence (WTC) seems to ignore the directionality of the interaction. The field is currently lacking a framework that allows researchers to determine whether a high coherence value obtained using a WTC function reflects in-phase synchronization (i.e., neural activation is seen in both members of the dyad at the same time), lagged synchronization (i.e., neural activation is seen in one member of the dyad prior to the other member), or anti-phase synchronization (i.e., neural activation is increased in one member of the dyad and decreased in the other). To address this need, a complementary and more sensitive approach for analyzing the phase coherence of two neural signals is proposed in this work. The toolbox allows investigators to estimate the coupling directionality by classifying the phase angle values obtained using traditional WTC into in-phase synchronization, lagged synchronization, and anti-phase synchronization. The toolbox also allows researchers to assess how the dynamics of interactions develop and change throughout the task. Using this novel WTC approach and the toolbox will advance our understanding of complex social interactions through their uses in fNIRS hyperscanning studies.

Author Spotlight: Unlocking New Insights in fNIRS Studies -  A Novel Framework for Inter-Brain Synchrony Analysis 

Wavelet transform coherence (WTC) is a common methodology for assessing the coupling between signals that is used in functional near-infrared spectroscopy (fNIRS) hyperscanning studies. A toolbox for assessing the directionality of the signal interaction is presented in this work.

Despite the growing body of functional near-infrared spectroscopy (fNIRS) hyperscanning studies, the assessment of coupling between two neural signals ...

fNIRS Hyperscanning Protocol to Analyze Inter-Brain Synchrony in Counseling

Functional Near-Infrared Spectroscopy Hyperscanning Study in Psychological Counseling

Functional Near-Infrared Spectroscopy (fNIRS) hyperscanning is an innovative technique that enables real-time monitoring of brain activity among multiple individuals engaged in social interactions. Researchers in this field quantify concurrent brain activities through the index of inter-brain synchrony (IBS). In psychological counseling research, the use of fNIRS to measure IBS has garnered attention for its potential to illuminate the dynamics of counselor-client interactions. Nevertheless, the field currently lacks a standardized protocol for precisely measuring IBS between counselors and clients, which would facilitate the revelation of real-time interaction patterns during counseling sessions. To address this need, this paper proposes a detailed standardized protocol, outlining the procedural steps for conducting fNIRS hyperscanning in psychological counseling settings, focusing on the acquisition of brain signals, calculation of IBS between counselors and clients, and analysis of lead-lag patterns of IBS throughout counseling sessions. Implementing this standardized fNIRS hyperscanning pipeline not only enhances the reproducibility and reliability of IBS measurements in psychological counseling research but also facilitates deeper insights into the neural mechanisms underlying working alliance. By integrating fNIRS hyperscanning into naturalistic counseling environments, researchers can advance understanding of how IBS correlates with counseling outcomes, potentially informing personalized approaches to mental health treatment.

The protocol aims to provide a detailed description of the methodology for conducting an fNIRS hyperscanning study in psychological counseling. This includes the preparations for the experiment, the procedure for collecting data, and the subsequent data analysis process.

Functional Near-Infrared Spectroscopy (fNIRS) hyperscanning is an innovative technique that enables real-time monitoring of brain activity among multiple ...

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

Source:&#160;<a style='text-decoration:none;' href='https://dx.doi.org/10.3791/58807'><span style='-webkit-text-decoration-skip:none;font-family:Arial,sans-serif;font-size:12pt;font-style:normal;font-variant:normal;font-weight:400;text-decoration-skip-ink:none;vertical-align:baseline;white-space:pre-wrap;'>Reindl, V.,&#160;et al<span style='-webkit-text-decoration-skip:none;font-family:Arial,sans-serif;font-size:12pt;font-style:normal;font-variant:normal;font-weight:400;text-decoration-skip-ink:none;vertical-align:baseline;white-space:pre-wrap;'>. Conducting Hyperscanning Experiments with Functional Near-Infrared Spectroscopy. J. Vis. Exp. (2019)</a> &#160;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.

Source:&#160;Reindl, V.,&#160;et al. Conducting Hyperscanning Experiments with Functional Near-Infrared Spectroscopy. J. Vis. Exp. (2019)&#160;This video ...