The future of real-world neuroscience: Imaging techniques to assess active brains in social environments

An Analytical Approach for Naturalistic Cooperative and Competitive EEG-Hyperscanning Data: A Proof-of-Concept Study

Investigating the neural mechanisms underlying both cooperative and competitive joint actions may have a wide impact in many social contexts of human daily life. An effective pipeline of analysis for hyperscanning data recorded in a naturalistic context with a cooperative and competitive motor task has been missing. We propose an analytical pipeline for this type of joint action data, which was validated on electroencephalographic (EEG) signals recorded in a proof-of-concept study on two dyads playing cooperative and competitive table tennis. Functional connectivity maps were reconstructed using the corrected imaginary part of the phase locking value (ciPLV), an algorithm suitable in case of EEG signals recorded during turn-based competitive joint actions. Hyperbrain, within-, and between-brain functional connectivity maps were calculated in three frequency bands (i.e., theta, alpha, and beta) relevant during complex motor task execution and were characterized with graph theoretical measures and a clustering approach. The results of the proof-of-concept study are in line with recent findings on the main features of the functional networks sustaining cooperation and competition, hence demonstrating that the proposed pipeline is promising tool for the analysis of joint action EEG data recorded during cooperation and competition using a turn-based motor task.

"World-Informed" Neuroscience for Diversity and Inclusion: An Organizational Change in Cognitive Sciences

By nature, humans are "tojisha (participating subjects/player-witnesses)" who encounter an unpredictable real world. An important characteristic of the relationship between the individual brain and the world is that it creates a loop of interaction and mutual formation. However, cognitive sciences have traditionally been based on a model that treats the world as a given constant. We propose incorporating the interaction loop into this model to create "world-informed neuroscience (WIN)". Based on co-productive research with people with minority characteristics that do not match the world, we hypothesize that the tojisha and the world interact in a two-dimensional way of rule-based and story-based. By defining the cognitive process of becoming tojisha in this way, it is possible to contribute to the various issues of the real world and diversity and inclusion through the integration of the humanities and sciences. The critical role of the brain dopamine system as a basis for brain-world interaction and the importance of research on urbanicity and adolescent development as examples of the application of WIN were discussed. The promotion of these studies will require bidirectional translation between human population science and animal cognitive neuroscience. We propose that the social model of disability should be incorporated into cognitive sciences, and that disability-informed innovation is needed to identify how social factors are involved in mismatches that are difficult to visualize. To promote WIN to ultimately contribute to a diverse and inclusive society, co-production of research from the initial stage of research design should be a baseline requirement.

Mobile cognition: imaging the human brain in the 'real world'

Cognitive neuroscience studies in humans have enabled decades of impactful discoveries but have primarily been limited to recording the brain activity of immobile participants in a laboratory setting. In recent years, advances in neuroimaging technologies have enabled recordings of human brain activity to be obtained during freely moving behaviours in the real world. Here, we propose that these mobile neuroimaging methods can provide unique insights into the neural mechanisms of human cognition and contribute to the development of novel treatments for neurological and psychiatric disorders. We further discuss the challenges associated with studying naturalistic human behaviours in complex real-world settings as well as strategies for overcoming them. We conclude that mobile neuroimaging methods have the potential to bring about a new era of cognitive neuroscience in which neural mechanisms can be studied with increased ecological validity and with the ability to address questions about natural behaviour and cognitive processes in humans engaged in dynamic real-world experiences.

Personalized values in life as point of interaction with the world: Developmental/neurobehavioral basis and implications for psychiatry

Behavioral neuroscience has dealt with short-term decision making but has not defined either daily or longer-term life actions. The individual brain interacts with the society/world, but where that point of action is and how it interacts has never been an explicit scientific question. Here, we redefine value as an intrapersonal driver of medium- and long-term life actions. Value has the following three aspects. The first is value as a driving force of action, a factor that commits people to take default-mode or intrinsic actions daily and longer term. It consists of value memories based on past experiences, and a sense of values, the source of choosing actions under uncertain circumstances. It is also a multilayered structure of unconscious/automatic and conscious/self-controlled. The second is personalized value, which focuses not only on the value of human beings in general, but on the aspect that is individualized and personalized, which is the foundation of diversity in society. Third, the value is developed through the life course. It is necessary to clarify how values are personalized through the internalization of parent-child, peer, and social experiences through adolescence, a life stage almost neglected in neuroscience. This viewpoint describes the brain and the behavioral basis of adolescence in which the value and its personalization occur, and the importance of this personalized value as a point of interaction between the individual brain and the world. Then the significance of personalized values in psychiatry is discussed, and the concept of values-informed psychiatry is proposed.

Inter-Brain Synchronization During Sandplay Therapy: Individual Analyses

Interactions between the client (Cl) and therapist (Th) evolve therapeutic relationships in psychotherapy. An interpersonal link or therapeutic space is implicitly developed, wherein certain important elements are expressed and shared. However, neural basis of psychotherapy, especially of non-verbal modalities, have scarcely been explored. Therefore, we examined the neural backgrounds of such therapeutic alliances during sandplay, a powerful art/play therapy technique. Real-time and simultaneous measurement of hemodynamics was conducted in the prefrontal cortex (PFC) of Cl-Th pairs participating in sandplay and subsequent interview sessions through multichannel near-infrared spectroscopy. As sandplay is highly individualized, and no two sessions and products (sandtrays) are the same, we expected variation in interactive patterns in the Cl–Th pairs. Nevertheless, we observed a statistically significant correlation between the spatio-temporal patterns in signals produced by the homologous regions of the brains. During the sandplay condition, significant correlations were obtained in the lateral PFC and frontopolar (FP) regions in the real Cl-Th pairs. Furthermore, a significant correlation was observed in the FP region for the interview condition. The correlations found in our study were explained as a “remote” synchronization (i.e., unconnected peripheral oscillators synchronizing through a hub maintaining free desynchronized dynamics) between two subjects in a pair, possibly representing the neural foundation of empathy, which arises commonly in sandplay therapy (ST).

Brain signatures predict communicative function of speech production in interaction

People normally know what they want to communicate before they start speaking. However, brain indicators of communication are typically observed only after speech act onset, and it is unclear when any anticipatory brain activity prior to speaking might first emerge, along with the communicative intentions it possibly reflects. Here, we investigated brain activity prior to the production of different speech act types, request and naming actions performed by uttering single words embedded into language games with a partner, similar to natural communication. Starting ca. 600 msec before speech onset, an event-related potential maximal at fronto-central electrodes, which resembled the Readiness Potential, was larger when preparing requests compared to naming actions. Analysis of the cortical sources of this anticipatory brain potential suggests a relatively stronger involvement of fronto-central motor regions for requests, which may reflect the speaker's expectation of the partner actions typically following requests, e.g., the handing over of a requested object. Our results indicate that different neuronal circuits underlying the processing of different speech act types activate already before speaking. Results are discussed in light of previous work addressing the neural basis of speech act understanding and predictive brain indexes of language comprehension.

Dissecting social interaction: dual-fMRI reveals patterns of interpersonal brain-behavior relationships that dissociate among dimensions of social exchange

During social interactions, each individual’s actions are simultaneously a consequence of and an antecedent to their interaction partner’s behavior. Capturing online the brain processes underlying such mutual dependency requires simultaneous measurements of all interactants’ brains during real-world exchange (‘hyperscanning’). This demands a precise characterization of the type of interaction under investigation, however, and analytical techniques capable of capturing interpersonal dependencies. We adapted an interactive task capable of dissociating between two dimensions of interdependent social exchange: goal structure (cooperation vs competition) and interaction structure [concurrent (CN) vs turn-based]. Performing dual-functional magnetic resonance imaging hyperscanning on pairs of individuals interacting on this task, and modeling brain responses in both interactants as systematic reactions to their partner’s behavior, we investigated interpersonal brain-behavior dependencies (iBBDs) during each dimension. This revealed patterns of iBBDs that differentiated among exchanges; in players supporting the actions of another, greater brain responses to the co-player’s actions were expressed in regions implicated in social cognition, such as the medial prefrontal cortex, precuneus and temporal cortices. Stronger iBBD during CN competitive exchanges was observed in brain systems involved in movement planning and updating, however, such as the supplementary motor area. This demonstrates the potential for hyperscanning to elucidate neural processes underlying different forms of social exchange.

Getting into sync: Data-driven analyses reveal patterns of neural coupling that distinguish among different social exchanges

In social interactions, each individual's brain drives an action that, in turn, elicits systematic neural responses in their partner that drive a reaction. Consequently, the brain responses of both interactants become temporally contingent upon one another through the actions they generate, and different interaction dynamics will be underpinned by distinct forms of between‐brain coupling. In this study, we investigated this by “performing functional magnetic resonance imaging on two individuals simultaneously (dual‐fMRI) while they competed or cooperated with one another in a turn‐based or concurrent fashion.” To assess whether distinct patterns of neural coupling were associated with these different interactions, we combined two data‐driven, model‐free analytical techniques: group‐independent component analysis and inter‐subject correlation. This revealed four distinct patterns of brain responses that were temporally aligned between interactants: one emerged during co‐operative exchanges and encompassed brain regions involved in social cognitive processing, such as the temporo‐parietal cortex. The other three were associated with competitive exchanges and comprised brain systems implicated in visuo‐motor processing and social decision‐making, including the cerebellum and anterior cingulate cortex. Interestingly, neural coupling was significantly stronger in concurrent relative to turn‐based exchanges. These results demonstrate the utility of data‐driven approaches applied to “dual‐fMRI” data in elucidating the interpersonal neural processes that give rise to the two‐in‐one dynamic characterizing social interaction.

Monitoring of fatigue in radiologists during prolonged image interpretation using fNIRS

PURPOSE

To determine whether functional near-infrared spectroscopy (fNIRS) allows monitoring fatigue in radiologists during prolonged image interpretation.

MATERIALS AND METHODS

Nine radiologists participated as subjects in the present study and continuously interpreted medical images and generated reports for cases for more than 4 h under real clinical work conditions. We measured changes in oxygenated hemoglobin concentrations [oxy-Hb] in the prefrontal cortex using 16-channel fNIRS (OEG16ME, Spectratech) every hour during the Stroop task to evaluate fatigue of radiologists and recorded fatigue scale (FS) as a behavior data.

RESULTS

Two subjects showed a subjective feeling of fatigue and an apparent decrease in brain activity after 4 h, so the experiment was completed in 4 h. The remaining seven subjects continued the experiment up to 5 h. FS decreased with time, and a significant reduction was observed between before and the end of image interpretation. Seven out of nine subjects showed a minimum [oxy-Hb] change at the end of prolonged image interpretation. The mean change of [oxy-Hb] at the end of all nine subjects was significantly less than the maximum during image interpretation.

CONCLUSION

fNIRS using the change of [oxy-Hb] may be useful for monitoring fatigue in radiologists during image interpretation.

fNIRS Assessment during an Emotional Stroop Task among Patients with Depression: Replication and Extension

OBJECTIVE

Accumulated evidence collected via functional near-infrared spectroscopy (fNIRS) has been reported with regard to mental disorders. A previous finding revealed that emotional words evoke left frontal cortex activity in patients with depression. The primary aim of the current study was to replicate this finding using an independent dataset and evaluate the brain region associated with the severity of depression using an emotional Stroop task.

METHODS

Oxygenized and deoxygenized hemoglobin recording in the brain by fNIRS on 14 MDD patients and 20 normal controls.

RESULTS

Hyperactivated oxygenized hemoglobin was observed in the left frontal cortex on exposure to unfavorable stimuli, but no significant difference was found among patients with depression compared with healthy controls on exposure to favorable stimuli. This result is consistent with previous findings. Moreover, an evoked wave associated with the left upper frontal cortex on favorable stimuli was inversely correlated with the severity of depression.

CONCLUSION

Our current work using fNIRS provides a potential clue regarding the location of depression symptom severity in the left upper frontal cortex. Future studies should verify our findings and expand them into a precise etiology of depression.

Sustained Attention in Real Classroom Settings: An EEG Study

Sustained attention is a process that enables the maintenance of response persistence and continuous effort over extended periods of time. Performing attention-related tasks in real life involves the need to ignore a variety of distractions and inhibit attention shifts to irrelevant activities. This study investigates electroencephalography (EEG) spectral changes during a sustained attention task within a real classroom environment. Eighteen healthy students were instructed to recognize as fast as possible special visual targets that were displayed during regular university lectures. Sorting their EEG spectra with respect to response times, which indicated the level of visual alertness to randomly introduced visual stimuli, revealed significant changes in the brain oscillation patterns. The results of power-frequency analysis demonstrated a relationship between variations in the EEG spectral dynamics and impaired performance in the sustained attention task. Across subjects and sessions, prolongation of the response time was preceded by an increase in the delta and theta EEG powers over the occipital region, and decrease in the beta power over the occipital and temporal regions. Meanwhile, implementation of the complex attention task paradigm into a real-world classroom setting makes it possible to investigate specific mutual links between brain activities and factors that cause impaired behavioral performance, such as development and manifestation of classroom mental fatigue. The findings of the study set a basis for developing a system capable of estimating the level of visual attention during real classroom activities by monitoring changes in the EEG spectra.

BLASST: Band Limited Atomic Sampling With Spectral Tuning With Applications to Utility Line Noise Filtering

OBJECTIVE

In this paper, we present and test a new method for the identification and removal of nonstationary utility line noise from biomedical signals.

METHODS

The method, band limited atomic sampling with spectral tuning (BLASST), is an iterative approach that is designed to 1) fit nonstationarities in line noise by searching for best-fit Gabor atoms at predetermined time points, 2) self-modulate its fit by leveraging information from frequencies surrounding the target frequency, and 3) terminate based on a convergence criterion obtained from the same surrounding frequencies. To evaluate the performance of the proposed algorithm, we generate several simulated and real instances of nonstationary line noise and test BLASST along with alternative filtering approaches.

RESULTS

We find that BLASST is capable of fitting line noise well and/or preserving local signal features relative to tested alternative filtering techniques.

CONCLUSION

BLASST may present a useful alternative to bandpass, notch, or other filtering methods when experimentally relevant features have significant power in a spectrum that is contaminated by utility line noise, or when the line noise in question is highly nonstationary.

SIGNIFICANCE

This is of particular significance in electroencephalography experiments, where line noise may be present in the frequency bands of neurological interest and measurements are typically of low enough strength that induced line noise can dominate the recorded signals. In conjunction with this paper, the authors have released a MATLAB toolbox that performs BLASST on real, vector-valued signals (available at https://github.com/VisLab/blasst).

Brain/MINDS: brain-mapping project in Japan

There is an emerging interest in brain-mapping projects in countries across the world, including the USA, Europe, Australia and China. In 2014, Japan started a brain-mapping project called Brain Mapping by Integrated Neurotechnologies for Disease Studies (Brain/MINDS). Brain/MINDS aims to map the structure and function of neuronal circuits to ultimately understand the vast complexity of the human brain, and takes advantage of a unique non-human primate animal model, the common marmoset (Callithrix jacchus). In Brain/MINDS, the RIKEN Brain Science Institute acts as a central institute. The objectives of Brain/MINDS can be categorized into the following three major subject areas: (i) structure and functional mapping of a non-human primate brain (the marmoset brain); (ii) development of innovative neurotechnologies for brain mapping; and (iii) human brain mapping; and clinical research. Brain/MINDS researchers are highly motivated to identify the neuronal circuits responsible for the phenotype of neurological and psychiatric disorders, and to understand the development of these devastating disorders through the integration of these three subject areas.

Wearable near-infrared spectroscopy neuroimaging and its applications

Wearable near-infrared spectroscopy (NIRS) systems are expected to be applied in various fields such as health care (medical use), education (teaching), and biofeedback. An investigation on hyperscanning by using NIRS is discussed first, where multiple brains were simultaneously measured for investigating and evaluating important social interactions, such as communication. The relationship between interacting brain activities and performance in cooperation has been demonstrated. An investigation on mood-state measurements in a return-to-work program is next discussed. It has been reported that a specified index calculated using NIRS signals obtained during performance of a working memory task correlated with a mood score. Using this index, the mood states of volunteers who participated in a return-to-work program after psychiatric clinical treatment were monitored. It has been suggested that the relationship between brain activities and subjective assessment of depression mood will be useful for evaluating the recovery stage for return-to-work programs. These techniques open new applications of wearable NIRS systems in mental health care.

Acceptability and feasibility of a visual working memory task in an ecological momentary assessment paradigm

Neuropsychological performance has historically been measured in laboratory settings using standardized assessments. However, these methods may be inherently limited in generalizability. This concern may be mitigated with paradigms such as ecological momentary assessment (EMA). We evaluated the initial feasibility and acceptability of administering a visual working memory (VWM) task on handheld computers across 1 EMA study week among adolescents/young adults (N = 39). Participants also completed standardized laboratory neurocognitive measures to determine the extent to which EMA VWM performance mapped onto scores obtained in traditional testing environments. Compliance with the EMA protocol was high as participants responded to 87% of random prompts across the study week. As expected, EMA VWM performance was positively associated with laboratory measures of auditory and VWM, and these relationships persisted after adjusting for predicted intelligence. Further, discriminant validity tests showed that EMA VWM was not linked with laboratory scores of verbal abilities and processing speed. These data provide initial evidence on the convergent and discriminant validity of interpretations from this novel, ecologically valid neurocognitive approach. Future studies will aim to further establish the psychometric properties of this (and similar) tasks and investigate how momentary fluctuations in VWM correspond with contextual influences (e.g., substance use, mood) and clinical outcomes.