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



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



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 Snipaste_2018-08-08_18-15-17.png(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 Snipaste_2018-08-08_18-15-17.png (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 Snipaste_2018-08-08_18-15-17.png(Download)

Recent Publications

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. Snipaste_2018-08-08_18-15-17.png(Download)

Recent Publications(1)

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. Snipaste_2018-08-08_18-15-17.png(Download)


Interpersonal brain synchronization associated with working alliance during psychological counseling

The mechanisms underlying behavioral synchrony during psychological counseling are not clear. Recent research has provided evidence that pervasive synchrony is associated with interpersonal brain synchronization (IBS) and possibly contributes to the positive working alliance—the degree to which the counseling dyads engage in collaborative and purposive work. Our study explored the IBS between the clients and the counselors using functional near-infrared spectroscopy (fNIRS)-based hyperscanning. Thirty-four participants (as clients) were randomly assigned either to the psychological counseling group or to the chatting group; three female professional counselors provided them with 40 minutes of psychological counseling or chatting. We found better working alliances and increased IBS in the right temporo-parietal junction (rTPJ) between clients and counselors during psychological counseling (versus chatting). Such IBS also correlated with the bond of working alliance. To our knowledge, our work represents the first demonstration of fNIRS-hyperscanning measurements for synchronous brain activity between the clients and counselors. This study refines the neural explanation of behavioral synchrony during psychological counseling.

Zhang Y, Meng T, Hou Y, Pan Y*, Hu Y*. Interpersonal brain synchronization associated with working alliance during psychological counseling. Psychiatry Research: Neuroimaging. 2018. 282, 103-109. Snipaste_2018-08-08_18-15-17.png(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. Snipaste_2018-08-08_18-15-17.png(Download)


ERPs and oscillations during encoding predict retrieval of digit memory in superior mnemonists

Previous studies have consistently demonstrated that superior mnemonists (SMs) outperform normal individuals in domain-specific memory tasks. However, the neural correlates of memory-related processes remain unclear. In the current EEG study, SMs and control participants performed a digit memory task during which their brain activity was recorded. Chinese SMs used a digit-image mnemonic for encoding digits, in which they associated 2-digit groups with images immediately after the presentation of each even-position digit in sequences. Behaviorally, SMs’ memory of digit sequences was better than the controls’. During encoding in the study phase, SMs showed an increased right central P2 (150–250 ms post onset) and a larger right posterior high-alpha (10–14 Hz, 500–1720 ms) oscillation on digits at even-positions compared with digits at odd-positions. Both P2 and high-alpha oscillations in the study phase co-varied with performance in the recall phase, but only in SMs, indicating that neural dynamics during encoding could predict successful retrieval of digit memory in SMs. Our findings suggest that representation of a digit sequence in SMs using mnemonics may recruit both the early-stage attention allocation process and the sustained information preservation process. This study provides evidence for the role of dynamic and efficient neural encoding processes in mnemonists.

Pan Y, Li X, Chen X, Ku Y, Dong Y, Dou Z, He L, Hu Y, Li W,   Zhou X. ERPs and oscillations during encoding predict retrieval of digit memory in superior mnemonists. Brain and Cognition. 2017. 117, 17-25. Snipaste_2018-08-08_18-15-17.png(Download)


Brain-to-brain synchronization across two persons predicts mutual prosociality

People tend to be more prosocial after synchronizing behaviors with others, yet the underlying neural mechanisms are rarely known. In the present study, participant dyads performed either a coordination task or an independence task, with their brain activations recorded via the funtional near-infrared spectoscopy (fNIRS) hyperscanning technique. Participant dyads in the coordination group showed higher synchronized behaviors and greater subsequent inclination to help each other thanthose in the independent group, indicating the prosocial effect of interpersonal synchrony. Importantly, the coordination group demonstrated the significant task-related brain coherence, namely the inter-brain synchronization (IBS), at the left middle frontal area. The detected IBS was sensitive to shared intentionality between participants and was correlated with the mutual prosocial inclination. Further, the task- related brain coherence played a mediation role in the prosocial effect of interpersonal synchrony. This study reveals the relevance of brain-to-brain synchronization among individuals with subsequent mutual prosocial inclination, and suggests the neural mechanism associating with shared cognition for the facilitation of interpersonal synchrony on prosociality.

Hu Y, Hu YY, Li X, Pan Y, Cheng X. Brain-to-brain synchronization across two persons predicts mutual prosociality. Social Cognitive & Affective Neuroscience. 2017. 12, 1835-1844. Snipaste_2018-08-08_18-15-17.png(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 Snipaste_2018-08-08_18-15-17.png(Download)


Examination of mechanisms underlying enhanced memory performance in action video game players: A pilot study

Previous studies have shown enhanced memory performance resulting from extensive action video game playing. The mechanisms underlying the cognitive benefit were investigated in the current study. We presented two types of retro-cues, with variable intervals to memory array (Task 1) or test array (Task 2), during the retention interval in a change detection task. In Task 1, action video game players (AVGPs) demonstrated steady performance while non-action video game players (NVGPs) showed decreased performance as cues occurred later, indicating their performance difference increased as the cue-to-memory-array intervals became longer. In Task 2, both participant groups increased their performance at similar rates as cues presented later, implying the performance difference in two groups were irrespective of the test-array-to-cue intervals. These findings suggested that memory benefit from game plays is not attributable to the higher ability of overcoming interference from the following stimuli. Implications for the future studies were discussed.

Li X, Cheng X, Li J, Pan Y, Hu Y, Ku Y. Examination of mechanisms underlying enhanced memory performance in action video game players: A pilot study. Frontiers in Psychology. 2015. 6, 843. Snipaste_2018-08-08_18-15-17.png(Download)


Neural patterns during memory encoding as a source for the effectiveness of mnemonic training

Memory has been demonstrated to be improved by the mnemonic training. The intentionally targeted cognitive processes, however are not fully understood, making the mechanisms for the effectiveness of training unclear. In the present study, a group of children was trained to use a mnemonic method of encoding 2-digit groups into images prestored in memory. These children demonstrated performance improvement in the short-term memory task after 22-day training. After training, they showed central-frontal P200 (170–220 ms) and left-frontal theta (200–1000 ms) in encoding of even- vs. odd-position digits. Furthermore, the mnemonic-induced P200 effect convaried with memory improvement. These findings suggest that the enhanced memory can be explained by the changed neural patterns. Extending former findings that memory training brings on neurological changes, we propose that neural patterns during encoding offer a window into the targeted cognitive processes with the mnemonic using and further into the source of the effectiveness of training.

Pan Y, Hao N, Liu N, Li X, Zhao Y, Cheng X, Ku Y, Hu Y. Neural patterns during encoding as a source for the effectiveness of mnemonic training.
Special issue of International Journal of Psychology
, 2016. 51, 881. (31st International Congress of Psychology, 24–29 July 2016, Yokohama, Japan)