11-month-olds recognize the teacher-student relationship.

Understanding how preverbal infants perceive and differentiate the roles of teachers and students can provide profound insights into the early stages of human learning and cognition. We thus developed a paradigm based on the task order and the interactive position to determine if infants understand teacher-student relationships. Five experiments (N = 104), reveal that, after watching the teacher agent instruct the student agent from failure to success, 11-month-old infants looked at the teacher for a longer time when they watched a new naïve agent seek information in a new ambiguous scenario. Three additional control experiments excluded alternative interpretations of infants' selective looking, suggesting that agents' order-related actions influenced infants' identification. Another control experiment demonstrated the importance of the position when the teacher and the student had interactive exchanges. These findings indicate that preverbal infants can recognize the teacher-student relationship, which is crucial to accessing effective information in early life.

Classification of Known and Unknown Study Items in a Memory Task Using Single-Trial Event-Related Potentials and Convolutional Neural Networks.

This study examines the feasibility of using event-related potentials (ERPs) obtained from electroencephalographic (EEG) recordings as biomarkers for long-term memory item classification. Previous studies have identified old/new effects in memory paradigms associated with explicit long-term memory and familiarity. Recent advancements in convolutional neural networks (CNNs) have enabled the classification of ERP trials under different conditions and the identification of features related to neural processes at the single-trial level. We employed this approach to compare three CNN models with distinct architectures using experimental data. Participants (N = 25) performed an association memory task while recording ERPs that were used for training and validation of the CNN models. The EEGNET-based model achieved the most reliable performance in terms of precision, recall, and specificity compared with the shallow and deep convolutional approaches. The classification accuracy of this model reached 62% for known items and 66% for unknown items. Good overall accuracy requires a trade-off between recall and specificity and depends on the architecture of the model and the dataset size. These results suggest the possibility of integrating ERP and CNN into online learning tools and identifying the underlying processes related to long-term memorization.

Future optimism group based on the chronological stress view is less likely to be severe procrastinators.

Previous studies have shown that procrastinators tend to disregard the future. However, the "time view" of procrastinators, including their impressions of the future, has not been sufficiently examined. Therefore, we introduced new indices, "chronological stress view" and "chronological well-being view," which treat impressions of the past, present, and future (= time view) as time-series data via stress and well-being, respectively. The results showed that the group that believed that stress did not increase as they moved into the future had a lower percentage of severe procrastinators. No relationship was found between the chronological well-being view and procrastination. This result suggests that people who are relatively optimistic about the future based on the chronological stress view are less likely to be severe procrastinators. This may suggest the importance of having a hopeful prospect in the future to avoid procrastinating on actions that should yield greater rewards in the future.

Social robots as effective language tutors for children: empirical evidence from neuroscience.

The aim of the current study was to investigate children's brain responses to robot-assisted language learning. EEG brain signals were collected from 41 Japanese children who learned French vocabularies in two groups; half of the children learned new words from a social robot that narrated a story in French using animations on a computer screen (Robot group) and the other half watched the same animated story on the screen but only with a voiceover narration and without the robot (Display group). To examine brain activation during the learning phase, we extracted EEG functional connectivity (FC) which is defined as the rhythmic synchronization of signals recorded from different brain areas. The results indicated significantly higher global synchronization of brain signals in the theta frequency band in the Robot group during the learning phase. Closer inspection of intra-hemispheric and inter-hemispheric connections revealed that children who learned a new language from the robot experienced a stronger theta-band EEG synchronization in inter-hemispheric connections, which has been previously associated with success in second language learning in the neuroscientific literature. Additionally, using a multiple linear regression analysis, it was found that theta-band FC and group assignment were significant predictors of children's language learning with the Robot group scoring higher in the post-interaction word recognition test. These findings provide novel neuroscientific evidence for the effectiveness of social robots as second language tutors for children.

Mother-child inter-brain synchrony during a mutual visual search task: A study of feedback valence and role.

Parent and child have been shown to synchronize their behaviors and physiology during social interactions. This synchrony is an important marker of their relationship quality and subsequently the child's social and emotional development. Therefore, understanding the factors that influence parent-child synchrony is an important undertaking. Using EEG hyperscanning, this study investigated brain-to-brain synchrony in mother-child dyads when they took turns performing a visual search task and received positive or negative feedback. In addition to the effect of feedback valence, we studied how their assigned role, i.e., observing or performing the task, influenced synchrony. Results revealed that mother-child synchrony was higher during positive feedback relative to negative feedback in delta and gamma frequency bands. Furthermore, a main effect was found for role in the alpha band with higher synchrony when a child observed their mother performing the task compared to when the mother observed their child. These findings reveal that a positive social context could lead a mother and child to synchronize more on a neural level, which could subsequently improve the quality of their relationship. This study provides insight into mechanisms that underlie mother-child brain-to-brain synchrony, and establishes a framework by which the impact of emotion and task demand on a dyad's synchrony can be investigated.

Infants' interoception is associated with eye contact in dyadic social interactions.

Interoception, that is, the perception of visceral stimuli, is the basis of socio-emotional development. However, no studies have demonstrated the relationship between the two in infants. This study aimed to elucidate the relationship between interoception and social behavior in infants and mothers. Visual preference for cardio-visual synchronous and asynchronous stimuli was assessed using a preferential-looking paradigm in 6-month infants and their mothers. The infant-mother interaction was also measured to assess social behavior, such as eye contact and positive facial expressions. The results showed that infants looked at asynchronous cardio-visual stimuli longer than synchronous cardio-visual stimuli, whereas mothers looked at synchronous cardio-visual stimuli longer than asynchronous cardio-visual stimuli. The proportion of looking time toward asynchronous cardio-visual stimuli in infants was positively correlated with infant-mother gaze and affect (positive facial expression) synchrony. Furthermore, mediation analyses showed that the relationship between infants' interoception and eye contact behavior is attributable to mother's positive facial expression. Our findings suggest that in infant-mother interactions, infants' interoception may play a role in eye contact behavior through the mother's positive facial expression, highlighting the importance of infants' interoception on social cognitive development.

Neural correlates of attentional orienting with neutral and fearful gaze cues in 12-month-olds.

Infants use information on gaze direction and facial expressions for social referencing when encountering various objects in their environment. However, it remains unclear how these social cues influence attentional orienting in infants. Using event-related potentials (ERPs), we investigated the neural correlates of attentional orienting cued by an averted gaze with neutral and fearful expressions in 12-month-olds. We focused on the ERPs in response to a face (N290, P400, and Nc) as well as a saccade toward the target (the presaccadic spike potential: SP) and found that the amplitudes of the face-sensitive ERPs (N290 and P400) were larger for directed than averted gaze direction irrespective of facial expression. Furthermore, the amplitude of the SP involved in overt orienting was larger for fearful expressions than for neutral expressions, irrespective of gaze congruency. These results suggest that information on gaze direction and facial expression, specifically neutral and fearful expressions, may be processed independently, and that fearful expressions dominantly influence the neural correlates of attentional orienting in infants around 12 months of age.

Synergistic effects of disgust and anger on amygdala activation while recalling memories of interpersonal stress: An fMRI study.

Occurrence of an unpleasant interpersonal event in daily life may cause an individual to experience unpleasant emotions and recall memories regarding it. These emotions, manifesting in daily social interactions, are often complex and mixed. In the laboratory, autobiographical recall is frequently used to induce emotions; however, it often involves recalling memories associated with a specific discrete emotion (e.g., sadness). To examine the neural activity of emotions similar to real-life experiences, we examined neural activity while recalling memories of stressful interpersonal events in daily life, without specifying a discrete emotion. Of the 23 university students recruited, 21 were analyzed and asked to freely recall memories and answer a series of questions on a monitor concerning their recalled memories while their neural activity was measured with functional magnetic resonance imaging. Amygdala activity increased while receiving the instructions, followed by a decrease in activity. This indicates that the participants' arousal and vigilance initially increased in response to a novel stimulus, and then decreased by habituation. Disgust and anger, which frequently occur as negative interpersonal feelings, were most prominently produced with strong associations with each other. More importantly, activation of the right amygdala while responding to questions regarding the recalled memories was positively correlated with disgust or anger only when not controlling for anger or disgust, respectively. These results indicate that responding to questions facilitated the generation of a mixed emotional response compared to during free recall alone. Furthermore, disgust and anger as a mixed emotion can synergistically activate amygdala.

Third-party punishment by preverbal infants.

Third-party punishment of antisocial others is unique to humans and seems to be universal across cultures. However, its emergence in ontogeny remains unknown. We developed a participatory cognitive paradigm using gaze-contingency techniques, in which infants can use their gaze to affect agents displayed on a monitor. In this paradigm, fixation on an agent triggers the event of a stone crushing the agent. Throughout five experiments (total N = 120), we show that eight-month-old infants punished antisocial others. Specifically, infants increased their selective looks at the aggressor after watching aggressive interactions. Additionally, three control experiments excluded alternative interpretations of their selective gaze, suggesting that punishment-related decision-making influenced looking behaviour. These findings indicate that a disposition for third-party punishment of antisocial others emerges in early infancy and emphasize the importance of third-party punishment for human cooperation. This behavioural tendency may be a human trait acquired over the course of evolution.

Manifesto for new directions in developmental science.

Although developmental science has always been evolving, these times of fast-paced and profound social and scientific changes easily lead to disorienting fragmentation rather than coherent scientific advances. What directions should developmental science pursue to meaningfully address real-world problems that impact human development throughout the lifespan? What conceptual or policy shifts are needed to steer the field in these directions? The present manifesto is proposed by a group of scholars from various disciplines and perspectives within developmental science to spark conversations and action plans in response to these questions. After highlighting four critical content domains that merit concentrated and often urgent research efforts, two issues regarding "how" we do developmental science and "what for" are outlined. This manifesto concludes with five proposals, calling for integrative, inclusive, transdisciplinary, transparent, and actionable developmental science. Specific recommendations, prospects, pitfalls, and challenges to reach this goal are discussed.

Timing of phase-amplitude coupling is essential for neuronal and functional maturation of audiovisual integration in adolescents.

OBJECTIVE: The ability to integrate audiovisual information matures late in adolescents, but its neuronal mechanism is still unknown. Recent studies showed that phase-amplitude coupling (PAC) of neuronal oscillations, which is defined as the modulation of high-frequency amplitude by low-frequency phase, is associated with audiovisual integration in adults. Thus, we investigated how PAC develops in adolescents and whether it is related to the functional maturation of audiovisual integration. In particular, we focused on the timing of PAC (or the coupling phase), which is defined as the low-frequency phase with maximum high-frequency amplitude. METHODS: Using magnetoencephalography (MEG) on 15 adults and 14 adolescents while they performed an audiovisual speech integration task, we examined PAC in association cortexes with a trial-by-trial analysis. RESULTS: Whereas delta-beta coupling was consistently observed in both adults and adolescents, we found that the timing of delta-beta PAC was delayed by 20-40 milliseconds in adolescents compared with adults. In addition, a logistic regression analysis revealed that the task performance improves as the timing of delta-beta PAC in the right temporal pole (TP) got closer to the trough position (180 degrees). CONCLUSION: These results suggest that the timing of PAC is essential for binding audiovisual information and underlies the developmental process in adolescents.

Higher hypnotic suggestibility is associated with the lower EEG signal variability in theta, alpha, and beta frequency bands.

Variation of information in the firing rate of neural population, as reflected in different frequency bands of electroencephalographic (EEG) time series, provides direct evidence for change in neural responses of the brain to hypnotic suggestibility. However, realization of an effective biomarker for spiking behaviour of neural population proves to be an elusive subject matter with its impact evident in highly contrasting results in the literature. In this article, we took an information-theoretic stance on analysis of the EEG time series of the brain activity during hypnotic suggestions, thereby capturing the variability in pattern of brain neural activity in terms of its information content. For this purpose, we utilized differential entropy (DE, i.e., the average information content in a continuous time series) of theta, alpha, and beta frequency bands of fourteen-channel EEG time series recordings that pertain to the brain neural responses of twelve carefully selected high and low hypnotically suggestible individuals. Our results show that the higher hypnotic suggestibility is associated with a significantly lower variability in information content of theta, alpha, and beta frequencies. Moreover, they indicate that such a lower variability is accompanied by a significantly higher functional connectivity (FC, a measure of spatiotemporal synchronization) in the parietal and the parieto-occipital regions in the case of theta and alpha frequency bands and a non-significantly lower FC in the central region's beta frequency band. Our results contribute to the field in two ways. First, they identify the applicability of DE as a unifying measure to reproduce the similar observations that are separately reported through adaptation of different hypnotic biomarkers in the literature. Second, they extend these previous findings that were based on neutral hypnosis (i.e., a hypnotic procedure that involves no specific suggestions other than those for becoming hypnotized) to the case of hypnotic suggestions, thereby identifying their presence as a potential signature of hypnotic experience.

Association between Behavioral Ambidexterity and Brain Health.

Appropriately handling and switching exploration of novel knowledge and exploitation of existing knowledge is a fundamental element of genuine innovation in society. Moreover, a mounting number of studies have suggested that such "ambidexterity" is associated not only with organizational performance but also with the human brain. Among these reports, however, there have not been any definitive MRI-based parameters that objectively and easily evaluate such ambidexterity. Therefore, an MRI-based index derived from gray matter volume, called the gray-matter brain healthcare quotient (GM-BHQ), was used to measure the association between ambidexterity and the entire human brain. For this purpose, 200 healthy adults were recruited as subjects to undergo structural T1-weighted imaging and to answer multiple psychological questionnaires. Ambidexterity was evaluated using two scales: the Curiosity and Exploration Inventory II and the Short Grit Scale, as exploration-exploitation indicators of curiosity and grit, respectively. Additionally, to enrich the understanding of these associations, three additional positive thinking scales were used-the General Self-Efficacy Scale, the Rosenberg Self-Esteem Scale, and the Life Orientation Test-to evaluate self-efficacy, self-esteem, and optimism, respectively. The authors discovered the GM-BHQ was weakly associated with curiosity, grit, and self-efficacy individually after controlling for age and sex. Furthermore, the GM-BHQ was directly associated with curiosity but indirectly associated with grit in the path model. However, no significant association was found between the GM-BHQ and the other outcome indicators (i.e., self-esteem and optimism). These results suggest that brain health is weakly associated with ambidexterity evaluated using psychological tests.

Passive Brain-Computer Interfaces for Enhanced Human-Robot Interaction.

Brain-computer interfaces (BCIs) have long been seen as control interfaces that translate changes in brain activity, produced either by means of a volitional modulation or in response to an external stimulation. However, recent trends in the BCI and neurofeedback research highlight passive monitoring of a user's brain activity in order to estimate cognitive load, attention level, perceived errors and emotions. Extraction of such higher order information from brain signals is seen as a gateway for facilitation of interaction between humans and intelligent systems. Particularly in the field of robotics, passive BCIs provide a promising channel for prediction of user's cognitive and affective state for development of a user-adaptive interaction. In this paper, we first illustrate the state of the art in passive BCI technology and then provide examples of BCI employment in human-robot interaction (HRI). We finally discuss the prospects and challenges in integration of passive BCIs in socially demanding HRI settings. This work intends to inform HRI community of the opportunities offered by passive BCI systems for enhancement of human-robot interaction while recognizing potential pitfalls.

Does watching Han Solo or C-3PO similarly influence our language processing?

Several studies have demonstrated that perceiving an action influences the subsequent processing of action verbs. However, which characteristics of the perceived action are truly determinant to enable this influence is still unknown. The current study investigated the role of the agent executing an action in this action-language relationship. Participants performed a semantic decision task after seeing a video of a human or a robot performing an action. The results of the first study showed that perceiving a human being executing an action as well as perceiving a robot facilitate subsequent language processing, suggesting that the humanness (The term "humanness" is used as meaning "belonging to human race" and not to refer to a personal quality) of the agent is not crucial in the link between action and language. However, this experiment was conducted with Japanese people who are very familiar with robots; thus, an alternative explanation could be that it is the unfamiliarity with the agent that could perturb the action-language relationship. To assess this hypothesis, we carried out two additional experiments with French participants. The results of the second study showed that, unlike the observation of a human agent, the observation of a robot did not influence language processing. Finally, the results of the third study showed that, after a familiarization phase, French participants too were influenced by the observation of a robot. Overall, the outcomes of these studies indicate that, more than the humanness of the agent, it is the familiarity which we have with this agent that is crucial in the action-language relationship.

Emotion-related cerebral blood flow changes in the ventral medial prefrontal cortex: An NIRS study.

The current study examined whether cerebral blood flow (CBF) changes in the anterior ventral medial prefrontal cortex (VMPFC) represent responses to emotional stimuli instead of cognitive control of emotion during distraction tasks, as suggested by our previous near-infrared spectroscopy (NIRS) study. The functional distinction of MPFC regions is occasionally difficult due to their multiple functions. Here, we addressed some remaining concerns from our previous distraction studies, and employed the distraction paradigm, in which negative or neutral images are presented as emotional stimuli; a rest period is included in one condition and working memory (distraction) tasks in the other. To extract the components of CBF changes associated with responses to negative emotional stimuli (defined as emotion-related CBF changes), we subtracted the CBF changes obtained in the neutral condition from those in the negative condition. We found that emotion-related CBF changes in the anterior left VMPFC were significantly greater in the rest condition than in the distraction task condition. These findings imply that the distraction task decreased unnecessary brain activities, resulting in decrease in the emotion-related CBF changes. They support our previous findings, indicating that CBF changes in anterior VMPFC regions, measured using NIRS, are specifically associated with responses to emotional stimuli.

Rapid saccadic response with fearful gaze cue.

It has been shown that an averted gaze with emotional expression guides our attention toward a gazed-at location, and the effect of a gaze with fearful expression has been well-investigated. However, the findings are not consistent, and most studies used the manual response measure. Recent studies suggest that examining eye movements is more suitable to capture the early stage of the effect of threat-related stimuli on attentional process. Therefore, in the present study, we investigated the effects of static neutral and fearful gaze on overt attention orienting by examining the saccadic responses in an unselected sample of people. Our results found the gaze congruency effects for both expressions, and importantly, enhanced attention orienting by fearful gaze at a short stimulus onset asynchrony (SOA): participants looked faster at the fearful gaze-cued target than the neutral gaze-cued one at the 300 ms SOA. These findings provide the first evidence that fearful averted gaze elicits rapid overt attention orienting toward the target, and suggest that the information of gaze direction and emotional expression are rapidly integrated and modulate the oculomotor system.

Parental presence with encouragement alters feedback processing in preschoolers: An ERP study.

External feedback plays an important role in adapting to the environment; however, feedback processing in preschoolers has not been fully understood. The present event-related brain potential (ERP) study sought to understand the influence of parental presence with encouragement on feedback processing by focusing on reward positivity (RewP: mean amplitude between 200-350 ms). Five-year-old children (N = 21) completed an animal search task both alone (the alone condition) and with a parent who offered words of encouragement (the with a parent condition). ERPs were recorded while they received negative and positive feedback. We found a larger RewP amplitude in response to positive feedback in the with a parent condition relative to in the alone condition. In addition, differences in RewP between positive and negative feedback were only observed in the with a parent condition. These findings suggest that everyday parental encouragement has the potential to promote differential positive and negative feedback processing possibly by enhancing the reward value of positive feedback.

Subtle temporal delays of mothers' responses affect imitation learning in children: Mother-child interaction study.

The relationship between temporal contiguity of mothers' teaching behaviors and children's imitation learning was investigated. Participants (2-year-old children) observed their mothers' demonstration of using novel toys over a double television system under live and delayed conditions. The dyads normally interacted in the live condition, whereas they interacted with a 1-s time delay inserted between the children's actions and mothers' responses in the delayed condition. Then, the children were tested with identical toys. Results indicated that children's smiling responses and imitation performances were significantly decreased in the delayed condition compared with the live condition, although mothers' teaching approach did not differ between conditions. These results suggest that a subtle temporal delay in mothers' responses could affect young children's imitation learning.

Distraction decreases prefrontal oxygenation: A NIRS study.

When near-infrared spectroscopy (NIRS) is used to measure emotion-related cerebral blood flow (CBF) changes in the prefrontal cortex regions, the functional distinction of CBF changes is often difficult because NIRS is unable to measure neural activity in deeper brain regions that play major roles in emotional processing. The CBF changes could represent cognitive control of emotion and emotional responses to emotional materials. Supposing that emotion-related CBF changes in the prefrontal cortex regions during distraction are emotional responses, we examined whether oxygenated hemoglobin (oxyHb) decreases. Attention-demanding tasks cause blood flow decreases, and we thus compared the effects of visually paced tapping with different tempos, on distraction. The results showed that the oxyHb level induced by emotional stimulation decreased with fast-tempo tapping significantly more than slow-tempo tapping in ventral medial prefrontal cortex regions. Moreover, a Global-Local task following tapping showed significantly greater local-minus-global response time (RT) difference scores in the fast- and mid-tempo condition compared with those in the slow-tempo, suggesting an increased attentional focus, and decreased negative emotion. The overall findings indicate that oxyHb changes in a relatively long distraction task, as measured by NIRS, are associated with emotional responses, and oxyHb can be decreased by successfully performing attention-demanding distraction tasks.