Instructor-learner neural synchronization during elaborated feedback predicts learning transfer

The provision of feedback with complex information beyond the correct answer, i.e., elaborated feedback, can powerfully shape learning outcomes such as transfer, i.e., the ability to extend what has been learned in one context to new contexts. However, an understanding of neurocognitive processes of elaborated feedback during instructor-learner interactions remains elusive. Here, a two-person interactive design is used during simultaneous recording of functional near-infrared spectroscopy (fNIRS) signals from adult instructor-learner dyads. Instructors either provided elaborated feedback (i.e., correct answer and an example) or simple feedback (i.e., correct answer only) to learners during a concept learning task. Our results showed that elaborated feedback produced comparable levels of retention to simple feedback, however, transfer was significantly enhanced by elaboration. We also noted significant instructor-learner neural synchronization in frontoparietal regions during the provision of elaborated feedback, especially when examples were provided. Further, interpersonal neural synchronization in the parietal cortex successfully predicted transfer of knowledge to novel contexts. This prediction was retained for both learner-delayed and learner-preceding neural synchronization. These findings point toward transfer effects of elaborated feedback provided in a social context can be predictable through interpersonal neural synchronization, which may hold important implications for real-world learning and pedagogical efficacy.

Zhu Y, Leong V, Hou Y, Zhang D, Pan Y*, Hu Y*. Instructor-learner neural synchronization during elaborated feedback predicts learning transfer. Journal of Educational Psychology. forthcoming.   (Download)

The interpersonal neuroscience of social learning

The study of the brain mechanisms underpinning social behavior is currently undergoing a paradigm shift, moving its focus from single individuals to the real-time interaction among groups of individuals. Although this development opens unprecedented opportunities to study how interpersonal brain activity shapes behaviors through learning, there have been few direct connections to the rich field of learning science. Our paper examines how the rapidly developing field of interpersonal neuroscience is (and could be) contributing to our understanding of social learning. To this end, we first review recent research extracting indices of brain-to-brain coupling (BtBC) in the context of social behaviors, and in particular social learning. We then discuss how studying communicative behaviors during learning can aid the interpretation of BtBC, and how studying BtBC can inform our understanding of such behaviors. Importantly, we then discuss how BtBC and communicative behaviors collectively can predict learning outcomes, suggesting several causative and mechanistic models. Finally, we highlight key methodological and interpretational challenges, as well as exciting opportunities for integrating research in interpersonal neuroscience with social learning, and propose a multi-person framework for understanding how interpersonal transmission of information between individual brains shapes social learning.

Pan Y*, Novembre G, Olsson A*. The interpersonal neuroscience of social learning. Perspectives on Psychological Science. 2021.   (Download)

Interpersonal brain synchronization with instructor compensates for learner's sleep deprivation in interactive learning

Recent advances shifted the focus on single-brain functioning toward two-brain communication during learning interactions, following the demonstration that interpersonal brain synchronization (IBS) can track instructor-learner information exchange. Here, we investigated (i) whether sleep deprivation (SD) that potentially impacts both social interactions and learning abilities modulates IBS, and (ii) conversely whether and to what extent IBS might compensate for SD-related learning deficits. Instructors (always with regular sleep, RS) were asked to teach numerical reasoning strategies to learners (either SD or RS), during which the activity of both brains was simultaneously recorded using functional near-infrared spectroscopy (fNIRS). SD learners initially performed below their baseline level, worse than RS learners, but learning improvement was comparable between RS and SD conditions after learning with the instructor. IBS within the instructor-learner dyads was higher in the SD (vs. RS) condition in the left inferior frontal cortex. In addition, clustered IBS (estimated by nonnegative matrix factorization) was correlated with performance improvement. Finally, Granger Causality analyses revealed biased causality with higher instructor-to-learner than learner-to-instructor directionality in brain signal processing. Together, these results indicate that SD-related learning deficits can to some extent be compensated via interactions with an instructor, as reflected by increased IBS and preserved learning ability. It suggests an essential role of the instructor in driving synchrony between teaching and SD learning brains during interactions.

Pan Y*, Guyon C, Borragán G, Hu Y*, Peigneux, P*. Interpersonal brain synchronization with instructor compensates for learner's sleep deprivation in interactive learning. Biochemical Pharmacology. 2021. 191: 114111.   (Download)

Mortality threat mitigates interpersonal competition: An EEG-based hyperscanning study

Awareness of death has been shown to influence human cognition and behavior. Yet, how mortality threat impacts our daily social behavior remains elusive. To address this issue, we developed a dyadic experimental model and recruited 86 adults (43 dyads) to complete two computer-based tasks (i.e., competitive and cooperative button-pressing). We manipulated dyads’ awareness of death (mortality threat vs. neutral control, MT vs. NC) and simultaneously measured their neurophysiological activity using electroencephalography (EEG) during the task. Several fundamental observations were made. First, the MT group showed significantly attenuated competition and slightly promoted cooperation. Second, compared to NC, MT significantly decreased gamma-band inter-brain synchronization (IBS) in the competitive context, which was associated with increased subjective fear of death within dyads. Notably, those effects were context-specific: we did not observe comparable results in the cooperative context. Finally, a machine-learning approach was successfully used to discriminate between the MT and NC groups based on accumulated IBS. Together, these findings indicate that mortality threat to some extent mitigates interpersonal competition, and such mitigation might be associated with changes of gamma-band IBS.

Zhou X#, Pan Y#, Zhang R, Bei L, Li X*. Mortality threat mitigates interpersonal competition: An EEG-based hyperscanning study. Social Cognitive and Affective Neuroscience, 2021. 16: 621-631. (# = equal contributions)   (Download)

Social safety learning: Shared safety abolishes the recovery of learned threat

Humans, like other social animals, learn about threats and safety in the environment through social cues. Yet, the processes that contribute to the efficacy of social safety learning during threat transmission remain unknown. Here, we developed a novel dyadic model of associative threat and extinction learning. In three separate social groups, we manipulated whether safety information during extinction was acquired via direct exposure to the conditioned stimulus (CS) in the presence of another individual (Direct exposure), via observation of other's safety behavior (Vicarious exposure), or via the combination of both (Shared exposure).These groups were contrasted against a fourth group receiving direct CS exposure alone (Asocial exposure). Based on skin conductance responses, we observed that all social groups outperformed asocial learning in inhibiting the recovery of threat, but only Shared exposure abolished threat recovery. These results suggest that social safety learning is optimized by a combination of direct exposure and vicariously transmitted safety signals. This work might help develop exposure therapies used to treat symptoms of threat and anxiety-related disorders to counteract maladaptive fears in humans.

Pan Y, Olsson A, Golkar A*. Social safety learning: Shared safety abolishes the recovery of learned threat. Behaviour Research and Therapy. 2020. 135: 103733.   (Download)

Dual brain stimulation enhances interpersonal learning through spontaneous movement synchrony

Social interactive learning denotes the ability to acquire new information from a conspecific – a prerequisite for cultural evolution and survival. As inspired by recent neurophysiological research, here we tested whether social interactive learning can be augmented by exogenously synchronizing oscillatory brain activity across an instructor and a learner engaged in a naturalistic song-learning task. We used a dual brain stimulation protocol entailing the trans-cranial delivery of synchronized electric currents in two individuals simultaneously. When we stimulated inferior frontal brain regions, with 6 Hz alternating currents being in-phase between the instructor and the learner, the dyad exhibited spontaneous and synchronized body movement. Remarkably, this stimulation also led to enhanced learning performance. These effects were both phase- and frequency-specific: 6 Hzanti-phase stimulation, or 10 Hz in-phase stimulation, did not yield comparable results. Furthermore, a mediation analysis disclosed that interpersonal movement synchrony acted as a partial mediator of the effect of dual brain stimulation on learning performance, i.e. possibly facilitating the effect of dual brain stimulation on learning. Our results provide a causal demonstration that inter-brain synchronization is a sufficient condition to improve real-time information transfer between pairs of individuals.

Pan Y, Novembre G, Song B, Zhu Y, Hu Y*. Dual brain stimulation enhances interpersonal learning through spontaneous movement synchrony. Social Cognitive and Affective Neuroscience. 2021. 16, 210-221.   (Download)

Instructor-learner brain coupling discriminates between instructional approaches and predicts learning

The neural mechanisms that support naturalistic learning via effective pedagogical approaches remain elusive. Here we used functional near-infrared spectroscopy to measure brain activity from instructor-learner dyads simultaneously during dynamic conceptual learning. Results revealed that brain-to-brain coupling was correlated with learning outcomes, and, crucially, appeared to be driven by specific scaffolding behaviors on the part of the instructors (e.g., asking guiding questions or providing hints). Brain-to-brain coupling enhancement was absent when instructors used an explanation approach (e.g., providing definitions or clarifications). Finally, we found that machine-learning techniques were more successful when decoding instructional approaches (scaffolding vs. explanation) from brain-to-brain coupling data than when using a single-brain method. These findings suggest that brain-to-brain coupling as a pedagogically relevant measure tracks the naturalistic instructional process during instructor-learner interaction throughout constructive engagement, but not information clarification.

Pan Y, Dikker S, Goldstein P, Zhu Y, Yang C, Hu Y*. Instructor-learner brain coupling discriminates between instructional approaches and predicts learning. NeuroImage. 2020. 211, 116657 (Download)

The averaged inter-brain coherence between the audience and a violinist predicts the popularity of violin performance

Why is some music well-received whereas other music is not? Previous research has indicated the close temporal dependencies of neural activity among performers and among audiences. However, it is unknown whether similar neural contingencies exist between performers and audiences. Here, we used dual near-infrared spectroscopy (NIRS) to assess whether inter-brain synchronization between violinist and audience underlies the popularity of violin performance. In the experiment, individual audience members (16 females) watched pre-recorded videos, each lasting 100 s or so, in which a violinist performed 12 musical pieces. The results showed that the popularity of the performance correlated with the left-temporal inter-brain coherence (IBC) between the audience and the violinist. The 11 correlation was stronger at late watching (> 50 s) than at early watching (~ 50 s). The smaller the Granger causality from the audience to the violinist was, the higher was the popularity of the piece with the audience. Discriminant analysis showed that the IBC could distinguish high popularity from low popularity. Further analysis using support vector regression showed that the IBC could also predict the popularity. These findings reveal the association of IBC with the popularity of violin performance. Music appreciation involves the brains of music producers and perceivers in a temporally aligned network through which audiences perceive the intentions of the performer and show positive emotions related to the musical performance.

Hou Y, Song B, Hu Y, Pan Y*, Hu Y*. The averaged inter-brain coherence between the audience and a violinist predicts the popularity of violin performance. NeuroImage. 2020. 211, 116655

(Download)

Two-person approaches to studying social interaction in psychiatry: Uses and clinical relevance

Social interaction is ubiquitous in human society. The two-person approach—a new, powerful tool to study information exchange and social behaviors—aims to characterize the behavioral dynamics and neural mechanisms of real-time social interactions. In this review, we discuss the assets of two-person approaches compared to those for conventional, single-person approaches. We describe measures and paradigms that model social interaction in three dimensions (3-D), including eye-to-eye, body-to-body, and brain-to-brain relationships. We then discuss how these two-person measures and paradigms are used in psychiatric conditions (e.g., autism, mood disorders, schizophrenia, borderline personality disorder, and psychotherapy). Furthermore, the advantages of a two-person approach (e.g., dual brain stimulation, multiperson neurofeedback) in clinical interventions are described. Finally, we discuss the methodological and translational challenges surrounding the application of two-person approaches in psychiatry, as well as prospects for future two-/multi-person studies. We conclude that two-person approaches serve as useful additions to the range of behavioral and neuroscientific methods available to assess social interaction in psychiatric settings, for both diagnostic techniques and complementary interventions.

Pan Y, Cheng X*. Two-person approaches to studying social interaction in psychiatry: Uses and clinical relevance. Frontiers in Psychiatry. 2020. 11, 301 (Download)

Applications of functional near-infrared spectroscopy in fatigue, sleep deprivation, and social cognition

Functional near-infrared spectroscopy (fNIRS) is an optical diffusion technique that allows the non-invasive imaging of cortical activity. During the last two decades, rapid technical and methodological advances have made fNIRS a powerful tool to investigate the cerebral correlates of human performance and cognitive functions, including fatigue, sleep deprivation and social cognition. Despite intrinsic limitations such as restricted brain depth and spatial resolution, its applicability, low cost, ecological validity, and tolerance to movements make fNIRS advantageous for scientific research and clinical applications. It can be viewed as a valid and promising brain imaging approach to investigate applied societal problems (e.g., safety, children development, sport science) and complement other neuroimaging techniques. The intrinsic power of fNIRS measurements for the study of social cognition is magnified when applied to the hyperscanning paradigm (i.e., measuring activity in two or more brains simultaneously). Besides consolidating existing findings, future fNIRS research should focus on methodological advances (e.g., artefacts correction, connectivity approaches) and standardization of analysis pipelines, and expand currently used paradigms in more naturalistic but controlled settings.

Pan Y, Borragán G, Peigneux P*. Applications of functional near-infrared spectroscopy in fatigue, sleep deprivation, and social cognition. Brain Topography. 2019. 32, 998-1012 (Download)

Learning desire is predicted by similar neural processing of naturalistic educational materials

Naturalistic stimuli can elicit highly similar brain activity across viewers. How do naturalistic educational materials engage human brains and evoke learning desire? Here, we presented 15 audiovisual course clips (each lasting about 120 s) to university students and recorded their neural activity through electroencephalography (EEG). Upon finishing all the video viewings, subjects ranked 15 courses in order of learning desire and reported the reasons of high learning desire (i.e., “value” and “interest”). The brain activity during the video viewing was measured as the neural similarity via inter-subject correlation (ISC), that is, correlation between each subject’s neural responses and others’. Based on averaged learning desire rankings across subjects, course clips were classified with high vs. medium vs. low motivational effectiveness. We found that ISC of high effective course clips was larger than that of low effective ones. The ISC difference (high vs. low) was positively associated with subjects’ learning desire difference (high vs. low). Such an association occurred when viewing time accumulated to about 80 s. Moreover, ISC was correlated with “interest-based” rather than “value-based” learning desire. These findings advance our understanding of learning motivation via the neural similarity in the context of online education and provide potential neurophysiological suggestions for pedagogical practices.

Zhu Y, Pan Y*, Hu Y*, Learning desire is predicted by similar neural processing of naturalistic educational materials. eNeuro. 2019. 6, 0083-19.2019 (Download)

Coordination elicits synchronous brain activity between co-actors: Frequency ratio matters

People could behave in two different ways when engaging in interpersonal coordination activities: moving at the same frequency (isofrequency pattern, IP; the movement frequency ratio is 1:1) or at different frequencies (multifrequency pattern, MP; the movement frequency ratio is non 1:1). However, how the interpersonal coordination pattern modulates coordination outcome and the related brain-to-brain connectivity are not fully understood. Here, we adopted a continuous joint drawing task in which two participants co-drew shapes of parallelogram according to two coordination patterns (i.e., IP vs. MP) while their brain activities were simultaneously recorded by the functional near-infrared spectroscopy (fNIRS) based hyperscanning technique. Dyads showed better coordination performance, as well as relatively greater interpersonal brain synchronization (IBS) at the left frontopolar area, in the MP condition compared to the IP condition. Granger causality analyses further disclosed the bidirectional influences between the brains of the coordinating individuals. Such interpersonal influences were enhanced when individuals coordinated in the MP condition. Finally, the IBS during coordination was related to the dyadic self-control level. Taken together, our study revealed that interpersonal multifrequency coordination pattern facilitates the coordination efficiency, which was associated with the enhanced brain-to-brain connectivity. Our work also suggests the potentially positive role of self-control during the interpersonal coordination process.

Cheng X, Pan Y, Hu Y, Hu Y*. Coordination elicits synchronous brain activity between co-actors: Frequency ratio matters. Frontiers in Neuroscience. 2019. 13, 1071 (Download)

Interpersonal synchronization of inferior frontal cortices tracks social interactive learning of a song

Much of human learning emerges as a result of interaction with others. Yet, this interpersonal process has been poorly characterized from a neurophysiological perspective. This study investigated (i) whether Interpersonal Brain Synchronization (IBS) can reliably mark social interactive learning, and specifically (ii) during what kind of interactive behavior. We recorded brain activity from learner-instructor dyads using the functional Near-Infrared Spectroscopy (fNIRS) during the acquisition of a music song. We made four fundamental observations. First, during the interactive learning task, brain activity recorded from the bilateral Inferior Frontal Cortex (IFC) synchronized across the learner and the instructor. Second, such IBS was observed in particular when the learner was observing the instructor’s vocal behavior and when the learning experience entailed a turn-taking and more active mode of interaction. Third, this specific enhancement in IBS predicted learner’s behavioral performance. Fourth, Granger causality analyses further disclosed that the signal recorded from the instructor’s brain better predicted that recorded from the learner’s brain than vice versa. Together, these results indicate that social interactive learning can be neurophysiologically characterized in terms of IBS. Furthermore, they suggest that the learner’s involvement in the learning experience, alongside the instructor’s modeling, are key factors driving the alignment of neural processes across learner and instructor. Such alignment impacts upon the real-time acquisition of new information and eventually upon the learning (behavioral) performance. Hence, besides providing a biological characterization of social interactive learning, our results hold relevance for clinical and pedagogical practices.

Pan Y, Novembre G, Song B, Li X, Hu Y. Interpersonal synchronization of inferior frontal cortices tracks social interactive learning of a song. NeuroImage. 2018. 183, 280-290. (Download)

Inter-Brain Synchrony and Cooperation Context in Interactive Decision Making

People engaged in interactive decision making rely on prior decision behaviors by other persons to make new choices and they exhibit inter-brain synchrony between each other. The functional meanings of such inter-brain synchrony, however, remains obscure. In the present study, dyads (15 pairs, all female) played the Prisoner's Dilemma game while their brain activities were recorded simultaneously by electroencephalography (EEG)-based hyperscanning technique. We manipulated the context of the game with higher versus lower cooperation index (HCI vs. LCI) and to each participant, we depicted the interaction as involving either another human partner or a machine (H-H vs. H-M). The results showed a higher cooperation rate and larger theta/alpha-band inter-brain synchrony in condition H-H than in H-M. In the condition H-H, there were larger centrofrontal theta-band and centroparietal alpha-band inter-brain synchrony in tasks set for high cooperation (HCI vs. LCI). Enhanced inter-brain synchrony covaried with increased cooperative choices observed between LCI and HCI. Furthermore, a subjective measure of perceived cooperativeness mediated the relationship between game context and inter-brain synchrony. These findings provide evidence for a role of cooperation on inter-brain synchrony during interactive decision making, and suggest distinct underlying neural processes recruited by cooperation contexts to enable high-level social cognitive processing in decision making.

Hu Y*, Pan Y*, Shi X, Cai Q, Li X, Cheng X. Inter-brain synchrony and cooperation context in interactive decision making. Biological Psychology. 2018. 133, 54-62. (Download)

Cooperation in lovers: An fNIRS - based hyperscanning study

This study investigated interactive exchange in lovers and the associated interpersonal brain synchronization (IBS) using functional near-infrared spectroscopy (fNIRS)-based hyperscanning. Three types of female-male dyads, lovers, friends and strangers, performed a cooperation task during which brain activity was recorded in right frontoparietal regions. We measured better cooperative behavior in lover dyads compared with friend and stranger dyads. Lover dyads demonstrated increased IBS in right superior frontal cortex, which also covaried with their task performance. Granger causality analyses in lover dyads revealed stronger directional synchronization from females to males than from males to females, suggesting different roles for females and males during cooperation. Our study refines the theoretical explanation of romantic interaction between lovers.

Pan Y, Cheng X, Zhang Z,   Li X, Hu Y.   Cooperation in lovers: An fNIRS-based hyperscanning study. Human Brain Mapping. 2017. 38, 831-841. (Download)

Memory skills mediating superior memory in a world-class memorist

Laboratory studies have investigated how individuals with normal memory spans attained digit spans over 80 digits after hundreds of hours of practice. Experimental analyses of their memory skills suggested that their attained memory spans were constrained by the encoding time, for the time needed will increase if the length of digit sequences to be memorised becomes longer. These constraints seemed to be violated by a world-class memorist, Feng Wang (FW), who won the World Memory Championship by recalling 300 digits presented at 1 digit/s. In several studies we examined FW’s memory skills underlying his exceptional performance. First FW reproduced his superior memory span of 200 digits under laboratory condition, and we obtained his retrospective reports describing his encoding/retrieval processes (Experiment 1). Further experiments used self-paced memorisation to identify temporal characteristics of encoding of digits in 4-digit clusters (Experiment 2), and explored memory encoding at presentation speeds much faster than 1 digit/s (Experiment 3). FW’s superiority over previous digit span experts is explained by his acquisition of well-known mnemonic techniques and his training that focused on rapid memorisation. His memory performance supports the feasibility of acquiring memory skills for improved working memory based on storage in long-term memory.

Ericsson KA, Cheng X, Pan Y, Ku Y, Ge Y, Hu Y. Memory skills mediating superior memory in a world-class memorist, Memory. 2017. 25(9), 1294-1302 (Download)