A recent study by Naudszus, Moffat, and Cross introduces a state-based analysis framework that captures these temporal changes by jointly analysing within-brain and between-brain functional connectivity during collaborative drawing. Instead of focusing solely on average synchrony, the proposed approach identifies recurring connectivity patterns that evolve throughout the interaction, providing a more detailed view of collaborative neural dynamics.

Study Design and Methodology

The study involved 122 participants forming 61 dyads: 30 same-generation dyads consisting of two younger adults and 31 intergenerational dyads consisting of one younger and one older adult. All participants were previously unacquainted and completed six weekly sessions including one individual and two collaborative drawing tasks. Brain activity was recorded simultaneously using two Cortivision Photon Cap fNIRS systems positioned over the bilateral inferior frontal gyrus (IFG) and temporoparietal junction (TPJ), enabling synchronized hyperscanning recordings throughout the experiment.

To characterise neural interactions over time, the researchers analysed dynamic functional connectivity using overlapping 15-second sliding windows rather than averaging connectivity across the entire task. Kernel functions were used to estimate similarity between neural signals, while HbO and HbR connectivity matrices were combined into block-diagonal matrices and clustered using Riemannian geometry-based k-means. Following hyperparameter optimisation, each time window was assigned to one of the identified two-brain states, allowing the researchers to quantify their occurrence, duration and coverage throughout the interaction.

The clustering pipeline consisted of five key components
(Source: https://www.sciencedirect.com/science/article/pii/S000169182601053X?via%3Dihub#f0005)

Seven Recurring Two-Brain States

The analysis identified seven recurring connectivity states representing different configurations of within-brain and between-brain functional connectivity. Three of these states showed significant differences between real interacting dyads and pseudo dyads, indicating that they reflected genuine interaction-related neural dynamics rather than coincidental similarity between independently recorded participants.

Among these, State G showed the clearest relationship with collaborative interaction. During collaborative drawing, intergenerational dyads remained in this state significantly longer than same-generation dyads. The state was characterised by relatively low-to-medium between-brain connectivity together with prominent within-brain connectivity between the bilateral IFG of one member of the dyad. The authors suggest that this asymmetric connectivity pattern may be consistent with leader-follower dynamics, while emphasising that additional behavioural measures would be needed to directly verify this interpretation.

Relationship with Collaborative Behaviour

Behavioural analyses showed that intergenerational dyads engaged in more overt turn-taking than same-generation dyads, while longer durations of State G were associated with less turn-taking, corresponding to more simultaneous drawing. Neither turn-taking behaviour nor the occurrence, duration or coverage of any two-brain state changed significantly across the six-week study.

Conclusion

The proposed state-based framework provides a way to analyse how within-brain and between-brain functional connectivity evolve during social interaction. By identifying recurring two-brain states, the approach captures temporal changes that are not accessible through conventional average connectivity measures. According to the authors, this methodology may support future fNIRS hyperscanning studies investigating collaborative behaviour in more naturalistic settings.

Source

Based on: Naudszus, M., Moffat, D. C., & Cross, E. S. (2026). Two-brain states characterize within- and between-brain connectivity during intergenerational collaborative drawing. Acta Psychologica, 252, 107252:

Learn more about Photon Cap in hyperscanning research

The study utilized fNIRS technology to capture brain activity during naturalistic interaction. If you’re interested in how Photon Cap supports this type of research, check out our previous articles:

Cardiac synchrony in same-generation and intergenerational dyads: a longitudinal fNIRS study
or Hyperscanning with the Photon Cap: The Role of Neural Synchrony During Social Interactionu

Objectives

The study aimed to:

• Examine changes in cardiac synchrony across six sessions
• Assess relationships between collaboration, social closeness, and interpersonal distance
• Compare these measures between intergenerational and same-generation dyads

Study Design and Participants

The study included 122 participants, forming:

• 31 intergenerational dyads (older adults aged 69+ and younger adults aged 18–35)
• 30 same-generation dyads (younger adults only)

All participants were initially strangers and interacted with the same partner across six weekly sessions.

Methodology

Each session combined structured tasks, self-report measures, and multimodal recordings.

Tasks and Behavioral Measures

Participants completed:

• Individual and collaborative drawing tasks
• Weekly collaborative activities (including a jigsaw puzzle task)

Behavioral measures included:

• External ratings of drawing collaboration
• Puzzle task performance
• Interpersonal distance, estimated from motion tracking data

 

Self-Report Measures

Social closeness was assessed using the Inclusion of Other in Self (IOS) scale.

 

Measurement Tools

The study applied a multimodal hyperscanning approach using:

• Functional near-infrared spectroscopy (fNIRS) using Cortivision Photon Cap to record cortical hemodynamic activity
• fNIRS-derived signals to estimate inter-beat intervals (IBI) for cardiac synchrony analysis
• Video recordings and OpenPose-based motion tracking to quantify interpersonal distance

Cardiac synchrony was calculated using cross-correlation of IBI time series across time lags.

Results

Behavioral and Social Measures

• Intergenerational dyads showed higher levels of collaboration in drawing tasks compared to same-generation dyads
• Same-generation dyads performed better in the puzzle task
• Social closeness increased across sessions in both groups

Relationships between measures differed between groups:

• In intergenerational dyads, closer interpersonal distance was associated with higher collaboration and greater social closeness
• In same-generation dyads, interpersonal distance showed different patterns of association with these measures

Cardiac Synchrony

The analyses showed that:

• Cardiac synchrony did not differ substantially between intergenerational and same-generation dyads
• No substantial differences were observed between collaborative and individual tasks
• Cardiac synchrony did not show substantial relationships with collaboration, social closeness, or interpersonal distance

Additionally, no substantial differences were found between real and pseudo dyads.

A trend-level association between drawing collaboration and cardiac synchrony was observed in intergenerational dyads across most time lags.

Conclusion

The study indicates that collaborative behavior and self-reported social closeness provide more consistent information about relationship development than cardiac synchrony in this context.

Cardiac synchrony did not show substantial associations with behavioral or social measures across repeated interactions, although a trend-level relationship with collaboration was observed in intergenerational dyads.

Source

Based on: Moffat, R., Naudszus, L. A., & Cross, E. S. (2026). Cardiac Synchrony During Collaborative Drawing: A Longitudinal Comparison of Same Generation and Intergenerational Dyads. New York Academy of Sciences:

Learn more about Photon Cap in hyperscanning research

The study utilized fNIRS technology to capture brain activity during naturalistic interaction. If you’re interested in how Photon Cap supports this type of research, check out our previous article: Hyperscanning with the Photon Cap: The Role of Neural Synchrony During Social Interaction

Monitoring Brain Activity in Space

At the core of the MagyAR study was functional near-infrared spectroscopy (fNIRS), used to monitor changes in cerebral oxygenation and brain activity in orbit. The system deployed on the ISS was provided by Cortivision, enabling stable, non-invasive neuroimaging in microgravity conditions.
fNIRS proved particularly suitable for this environment due to its robustness against motion and external interference. Within the experiment, it was used to capture how fluid shifts and altered oxygen delivery-well-documented effects of microgravity-affect neural processes associated with cognition.
The study combined fNIRS with virtual reality (VR) and eye-tracking, forming a multimodal framework for assessing mental performance. Astronauts performed cognitive and motor tasks in a controlled VR setting while brain activity and physiological responses were recorded simultaneously.

Experimental Scope

Measurements were conducted at multiple stages of the mission, enabling observation of both immediate and progressive adaptations to space conditions. The experiment focused on:

• cerebral blood flow and changes in blood oxygenation,
• attention and executive functions,
• planning and executing movements.

Complementary biological data, including saliva samples, were collected to track metabolic changes.

Mission Status and Next Steps

The in-orbit phase of the MagyAR experiment has been successfully completed. Detailed scientific results are expected following full post-mission data analysis.

Broader Research Context

The MagyAR project was part of a wider set of experiments conducted by the University of Pécs, including:

• ESEL3D, examining the behavior of 3D-printed materials in space conditions,
• Step in Space (SiS), a virtual reality initiative presenting the mission and its experiments,
• additional biomedical and plant-based studies conducted within consortium projects.

See the MagyAR Experiment in Action

A short video prepared by the HUNOR team presents the MagyAR experiment, showcasing the integration of virtual reality and fNIRS to study cognitive and motor processes in microgravity.

Check out the video on LinkedIn

 

To explore how this technology is used toward brain-computer interface applications in space, read more about the PhotonGrav in our dedicated article: PhotonGrav: Pioneering BCI in Space

Source

This blog post is based on information from the official website the University of Pécs and official page of the Hungarian Astronaut Programme, HUNOR:

Based on original publication: Holla, B., Sharma, E., Venkataramanan, S. et al. The PAthways to Resilience And Mental health (PARAM) project: protocol for a multi-site developmental cohort in India. BMC Psychiatry 25, 1051 (2025). https://doi.org/10.1186/s12888-025-07492-x

Yang et al. (2025) acknowledge that in engineering design, decision-making tasks often require collaboration among multidisciplinary teams. Differences in the knowledge structures of various disciplines can lead to ambiguities or misunderstandings of specialized terminology and concepts – meaning discrepancy – leading to communication barriers that may ultimately affect the quality of final decisions.

The research team suggests that such communication failures occur due to cognitive conflict induced by increased cognitive load.

Previous studies of decision-making paradigms have explored managerial influence theories and behavioral analyses, however, the cognitive and neural mechanisms of interdisciplinary group decision-making were largely unexplored.

To fill in this gap, Yang et al. (2025) developed an experimental Multi-Attribute Decision-Making with Layered Group Dynamics (MADM-LGD) task – a decision path model that connects diversity of meaning interpretations with cognitive conflict, increased cognitive load, and reduced communication efficiency.

This study uses fNIRS to track prefrontal oxygenation, integrating semantic and linguistic analyses to explore how cognitive level and interdisciplinary communication shape the quality of group decision-making.

The study involved 54 participants, including 25 undergraduates, 21 master’s students, and 8 doctoral students from universities in Shanghai. Participants were organized into 18 groups of three members each. The final selection consisted of 34 males and 20 females, all of whom had recent experience working or interning in engineering companies.

To understand how different decision-making factors affect the quality of choices, Yang et al. (2025) used MADM-LGD task, designed to imitate a cruise ship cabin crew interaction, hence group decision-making dynamics.

The experiment lasted for a month in the summer of 2024, and was carried out in an independent, quiet laboratory environment, where the researchers were collecting and analyzing Oxy-Hb levels data using Photon Cap C20 fNIRS technology.

The procedure consisted of two decision-making phases (individual and group) and a total of seven stages with brief breaks, as illustrated in the overall flowchart (Yang et al., 2025) below.

The full sequence of procedural steps. (Figure 2 in Yang et al., 2025)

• an individual phase (I1–I2) – making the individual decisions independently in accordance with the previously briefed instructions within the three-minute periods (Individual phases P1 and P2).
• a group phase (G1–G5) – conducting several group discussion-making rounds to compare and select the most effective scheme among the provided ones, followed by individual scoring for all selected schemes afterwards (Group phases P1 to P5).

The fluctuations of Oxy-Hb levels were measured by Photon Cap across all seven stages divided into individual (I1 to I2) and group (G1–G5) stages accordingly. The duration of the test session was approximately 45 minutes in total, divided into alternating intervals of cognitive stimulation and rest.

As mentioned earlier, Yang et al. (2025) used Photon Cap C20 along with the Cortivision Pathfinder to measure cortical hemodynamic activity during both resting and decision-making conditions to monitor changes in Oxy-Hb levels, with participants sitting quietly with eyes closed during resting phases to allow Oxy-Hb levels to return to baseline. 

For greater precision, an enhanced “10–5 system” was used to place optodes over prefrontal  regions of interest (ROIs) such as frontopolar (FOA), pars triangularis Broca (PTBA), dorsolateral prefrontal cortex (DLPFC), and inferior prefrontal gyrus (IPFG).

Overall, the montage consisted of 22 channels with 8 light sources and 8 detectors.

Photon Cap channel layout over the frontal lobe during the procedure.

(Figure 4 in Yang et al., 2025)

Collected data included participants’ profile information (gender, age, handedness), dialogue texts from interdisciplinary group discussions, and cortical Oxy-Hb concentrations during the MADM-LGD task.

Using Photon Cap the researchers identified that activation was mainly concentrated in the frontopolar area (FOA), especially during transitions between individual and group decision-making. Significant differences in averaged Oxy-Hb levels were observed across all seven stages I1 to I2 and G1 to G5 accordingly. Brain activity increased from individual stage I1 to I2, then dropped as participants moved into the group stages (G1–G5), suggesting a shift in cognitive effort and strategy use. 

According to Yang et al. (2025) these findings indicate that individual decision-making demanded higher cognitive load, while group collaboration tended to reduce it – highlighting the neural basis of how collaboration can ease mental strain, relieve pressure, improve performance, promote clearer understanding and better overall decision quality.

The Photon Cap proved effective for examining cognitive load, and Yang et al. (2025) suggest that future studies combine fNIRS and eye-tracking to gain deeper insights into cognitive control and visual attention in interdisciplinary group decision-making.