Neural processes for live pro-social dialogue between dyads with socioeconomic disparity

An emerging theoretical framework suggests that neural functions associated with stereotyping and prejudice are associated with frontal lobe networks. Using a novel neuroimaging technique, functional near-infrared spectroscopy (fNIRS), during a face-to-face live communication paradigm, we explore an extension of this model to include live dynamic interactions. Neural activations were compared for dyads of similar and dissimilar socioeconomic backgrounds. The socioeconomic status of each participant was based on education and income levels. Both groups of dyads engaged in pro-social dialectic discourse during acquisition of hemodynamic signals. Post-scan questionnaires confirmed increased anxiety and effort for high-disparity dyads. Consistent with the frontal lobe hypothesis, left dorsolateral pre-frontal cortex (DLPFC), frontopolar area and pars triangularis were more active during speech dialogue in high than in low-disparity groups. Further, frontal lobe signals were more synchronous across brains for high- than low-disparity dyads. Convergence of these behavioral, neuroimaging and neural coupling findings associate left frontal lobe processes with natural pro-social dialogue under 'out-group' conditions and advance both theoretical and technical approaches for further investigation.

Joint Attention During Live Person-to-Person Contact Activates rTPJ, Including a Sub-Component Associated With Spontaneous Eye-to-Eye Contact

Eye-to-eye contact is a spontaneous behavior between interacting partners that occurs naturally during social interactions. However, individuals differ with respect to eye gaze behaviors such as frequency of eye-to-eye contacts, and these variations may reflect underlying differences in social behavior in the population. While the use of eye signaling to indicate a shared object of attention in joint attention tasks has been well-studied, the effects of the natural variation in establishing eye contact during joint attention have not been isolated. Here, we investigate this question using a novel two-person joint attention task. Participants were not instructed regarding the use of eye contacts; thus all mutual eye contact events between interacting partners that occurred during the joint attention task were spontaneous and varied with respect to frequency. We predicted that joint attention systems would be modulated by differences in the social behavior across participant pairs, which could be measured by the frequency of eye contact behavior. We used functional near-infrared spectroscopy (fNIRS) hyperscanning and eye-tracking to measure the neural signals associated with joint attention in interacting dyads and to record the number of eye contact events between them. Participants engaged in a social joint attention task in which real partners used eye gaze to direct each other's attention to specific targets. Findings were compared to a non-social joint attention task in which an LED cue directed both partners' attention to the same target. The social joint attention condition showed greater activity in right temporoparietal junction than the non-social condition, replicating prior joint attention results. Eye-contact frequency modulated the joint attention activity, revealing bilateral activity in social and high level visual areas associated with partners who made more eye contact. Additionally, when the number of mutual eye contact events was used to classify each pair as either "high eye contact" or "low eye contact" dyads, cross-brain coherence analysis revealed greater coherence between high eye contact dyads than low eye contact dyads in these same areas. Together, findings suggest that variation in social behavior as measured by eye contact modulates activity in a subunit of the network associated with joint attention.

Racial disparities in pre-operative pain, function and disease activity for patients with rheumatoid arthritis undergoing Total knee or Total hip Arthroplasty: a New York based study

Background

Black and Hispanic patients with osteoarthritis have more pain and worse function than Whites at the time of arthroplasty. Whether this is true for patients with rheumatoid arthritis (RA) is unknown.

Methods

This cross-sectional study used data on RA patients acquired between October 2013 and November 2018 prior to elective total knee (TKA) or hip arthroplasty (THA). Pain, function, and disease activity were assessed using the visual analogue scale (VAS), the Multidimensional Health Assessment Questionnaire (MDHAQ), and the Disease Activity Score (DAS28-ESR). We linked the cases to census tracts using geocoding to determine the community poverty level. Race, education, income, insurance and medications were collected via self-report. Using multivariable linear and logistic models we examined whether minority status predicted pain, function and RA disease activity at the time of arthroplasty.

Results

Thirty seven (23%) of the 164 patients were Black or Hispanic (minorities). The MDHAQ and DAS28-ESR were not significantly worse while VAS pain score was significantly worse in minority patients (p = 0.03). There was no significant difference in education between the groups. Insurance varied significantly; 29% of minority patients had Medicaid vs. 0% of Whites (p < 0.0001). In the multivariable analyses minority status was not significantly associated with DAS28-ESR [p = 0.66], MDHAQ [p = 0.26], or VAS pain [p = 0.18].

Conclusions

For Black and/or Hispanic patients with RA undergoing THA or TKA at a high-volume specialty hospital, unlike Black or Hispanic patients with osteoarthritis (OA), there was no association with worse pain, function, or RA disease activity at the time of elective arthroplasty.

The present and future use of functional near-infrared spectroscopy (fNIRS) for cognitive neuroscience

The past few decades have seen a rapid increase in the use of functional near-infrared spectroscopy (fNIRS) in cognitive neuroscience. This fast growth is due to the several advances that fNIRS offers over the other neuroimaging modalities such as functional magnetic resonance imaging and electroencephalography/magnetoencephalography. In particular, fNIRS is harmless, tolerant to bodily movements, and highly portable, being suitable for all possible participant populations, from newborns to the elderly and experimental settings, both inside and outside the laboratory. In this review we aim to provide a comprehensive and state-of-the-art review of fNIRS basics, technical developments, and applications. In particular, we discuss some of the open challenges and the potential of fNIRS for cognitive neuroscience research, with a particular focus on neuroimaging in naturalistic environments and social cognitive neuroscience.

Real-Time Eye-to-Eye Contact Is Associated With Cross-Brain Neural Coupling in Angular Gyrus

Direct eye contact between two individuals is a salient social behavior known to initiate and promote interpersonal interaction. However, the neural processes that underlie these live interactive behaviors and eye-to-eye contact are not well understood. The Dynamic Neural Coupling Hypothesis presents a general theoretical framework proposing that shared interactive behaviors are represented by cross-brain signal coherence. Using functional near-infrared spectroscopy (fNIRS) adapted for hyper scanning, we tested this hypothesis specifically for neural mechanisms associated with eye-to-eye gaze between human participants compared to similar direct eye-gaze at a dynamic video of a face and predicted that the coherence of neural signals between the two participants during reciprocal eye-to-eye contact would be greater than coherence observed during direct eye-gaze at a dynamic video for those signals originating in social and face processing systems. Consistent with this prediction cross-brain coherence was increased for signals within the angular gyrus (AG) during eye-to-eye contact relative to direct eye-gaze at a dynamic face video (p < 0.01). Further, activity in the right temporal-parietal junction (TPJ) was increased in the real eye-to-eye condition (p < 0.05, FDR corrected). Together, these findings advance a functional and mechanistic understanding of the AG and cross-brain neural coupling associated with real-time eye-to-eye contact.

Remote photonic sensing of cerebral hemodynamic changes via temporal spatial analysis of acoustic vibrations

A novel photonic method for remote monitoring of task-related hemodynamic changes in human brain activation is presented. Physiological processes associated with neural activity, such as nano-vibrations due to blood flow and tissue oxygenation in the brain, are detected by remote sensing of nano-acoustic vibrations using temporal spatial analysis of defocused self-interference random patterns. Temporal nanometric changes of the speckle pattern due to visual task-induced hemodynamic responses were tracked by this method. Reversing visual checkerboard stimulation alternated with rest epochs, and responsive signals were identified in occipital lobe using near-infrared spectroscopy. Temporal vibrations associated with these hemodynamic response functions were observed using three different approaches: (a) single spot illumination at active and control areas simultaneously, (b) subspots cross-correlation-based analysis, and (c) multiwavelength measurement using a magnitude-squared wavelet coherence function. Findings show remote sensing of task-specific neural activity in the human brain.

Optimization of wavelet coherence analysis as a measure of neural synchrony during hyperscanning using functional near-infrared spectroscopy

Significance: The expanding field of human social interaction is enabled by functional near-infrared spectroscopy (fNIRS) that acquires hemodynamic signals during live two-person interactions. These advances call for development of methods to quantify interactive processes. Aim: Wavelet coherence analysis has been applied to cross-brain neural coupling. However, fNIRS-specific computations have not been explored. This investigation determines the effects of global mean removal, wavelet equation, and choice of oxyhemoglobin versus deoxyhemoglobin signals. Approach: We compare signals with a known coherence with acquired signals to determine optimal computational approaches. The known coherence was calculated using three visual stimulation sequences of a contrast-reversing checkerboard convolved with the canonical hemodynamic response function. This standard was compared with acquired human fNIRS responses within visual cortex using the same sequences. Results: Observed coherence was consistent with known coherence with highest correlations within the wavelength range between 10 and 20 s. Removal of the global mean improved the correlation irrespective of the specific equation for wavelet coherence, and the oxyhemoglobin signal was associated with a marginal correlation advantage. Conclusions: These findings provide both methodological and computational guidance that enhances the validity and interpretability of wavelet coherence analysis for fNIRS signals acquired during live social interactions.

Co-localization of theta-band activity and hemodynamic responses during face perception: simultaneous electroencephalography and functional near-infrared spectroscopy recordings

Face-specific neural processes in the human brain have been localized to multiple anatomical structures and associated with diverse and dynamic social functions. The question of how various face-related systems and functions may be bound together remains an active area of investigation. We hypothesize that face processing may be associated with specific frequency band oscillations that serve to integrate distributed face processing systems. Using a multimodal imaging approach, including electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS), simultaneous signals were acquired during face and object picture viewing. As expected for face processing, hemodynamic activity in the right occipital face area (OFA) increased during face viewing compared to object viewing, and in a subset of participants, the expected N170 EEG response was observed for faces. Based on recently reported associations between the theta band and visual processing, we hypothesized that increased hemodynamic activity in a face processing area would also be associated with greater theta-band activity originating in the same area. Consistent with our hypothesis, theta-band oscillations were also localized to the right OFA for faces, whereas alpha- and beta-band oscillations were not. Together, these findings suggest that theta-band oscillations originating in the OFA may be part of the distributed face-specific processing mechanism.

Communication of emotion via drumming: dual-brain imaging with functional near-infrared spectroscopy

Nonverbal communication of emotion is essential to human interaction and relevant to many clinical applications, yet it is an understudied topic in social neuroscience. Drumming is an ancient nonverbal communication modality for expression of emotion that has not been previously investigated in this context. We investigate the neural response to live, natural communication of emotion via drumming using a novel dual-brain neuroimaging paradigm. Hemodynamic signals were acquired using whole-head functional near-infrared spectroscopy (fNIRS). Dyads of 36 subjects participated in two conditions, drumming and talking, alternating between 'sending' (drumming or talking to partner) and 'receiving' (listening to partner) in response to emotionally salient images from the International Affective Picture System. Increased frequency and amplitude of drum strikes was behaviorally correlated with higher arousal and lower valence measures and neurally correlated with temporoparietal junction (TPJ) activation in the listener. Contrast comparisons of drumming greater than talking also revealed neural activity in right TPJ. Together, findings suggest that emotional content communicated by drumming engages right TPJ mechanisms in an emotionally and behaviorally sensitive fashion. Drumming may provide novel, effective clinical approaches for treating social-emotional psychopathology.

Trustworthiness appraisal deficits in borderline personality disorder are associated with prefrontal cortex, not amygdala, impairment

Background

Borderline Personality Disorder (BPD) is associated with sensitivity to signals of interpersonal threats and misplaced trust in others. The amygdala, an integral part of the threat evaluation and response network, responds to both fear- and trust-related stimuli in non-clinical samples, and is more sensitive to emotional stimuli in BPD compared to controls. However, it is unknown whether the amygdalar response can account for deficits of trust and elevated sensitivity to interpersonal threat in BPD.

Methods

Facial stimuli were presented to 16 medication-free women with BPD and 17 demographically-matched healthy controls (total n = 33). Participants appraised fearfulness or trustworthiness of the stimuli while BOLD fMRI was obtained.

Results

Though BPD participants judged stimuli as less trustworthy compared to controls, trustworthiness did not correlate with amygdalar activity in either group. Trustworthiness correlated with prefrontal regional activity in the insula and lateral prefrontal cortex. Prefrontal BOLD activity while appraising trustworthiness was smaller in BPD compared to controls, and the size of the reduction was proportional to each participant's response bias.

Conclusions

Neural substrates of trustworthiness appraisal are associated with the lateral prefrontal cortex and insula, not amygdala, suggesting that untrustworthy stimuli do not elicit a subcortical threat response. Current models of BPD and its treatment may need to include a focus on improving impairments in frontally mediated trustworthiness appraisal in addition to amygdala- driven emotional hyper-reactivity.

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BPD is associated with sensitivity to signals of interpersonal betrayal and misplaced trust in others.

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BPD subjects judged faces to be less trustworthy than controls.

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Amygdala activity did not correlate with trustworthiness, but was modulated robustly by fearfulness of the stimulus.

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Prefrontal cortex, not amygdala, was modulated by trustworthiness.

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BPD was associated with reduced prefrontal activity, and the reduction was proportional to each individual’s response bias.

Functional connectivity of PAG with core limbic system and laryngeal cortico-motor structures during human phonation

Previous studies in animals and humans suggest the periaqueductal grey region (PAG) is a final integration station between the brain and laryngeal musculature during phonation. To date, a limited number of functional magnetic neuroimaging (fMRI) studies have examined the functional connectivity of the PAG during volitional human phonation. An event-related, stimulus-induced, volitional movement paradigm was used to examine neural activity during sustained vocalization in neurologically healthy adults and was compared to controlled exhalation through the nose. The contrast of vocalization greater than controlled expiration revealed activation of bilateral auditory cortex, dorsal and ventral laryngeal motor areas (dLMA and vLMA) (p < 0.05, corrected), and suggested activation of the cerbellum, insula, dorsomedial prefrontal cortex (dmPFC), amygdala, and PAG. The functionally defined PAG cluster was used as a seed region for psychophysiological interaction analysis (PPI) to identify regions with greater functional connectivity with PAG during volitional vocalization, while the above functionally defined amygdala cluster was used in an ROI PPI analysis. Whole-brain results revealed increased functional connectivity of the PAG with left vLMA during voicing, relative to controlled expiration, while trend-level evidence was observed for increased PAG/amygdala coupling during voicing (p = 0.07, uncorrected). Diffusion tensor imaging (DTI) analysis confirmed structural connectivity between PAG and vLMA. The present study sheds further light on neural mechanisms of volitional vocalization that include multiple inputs from both limbic and motor structures to PAG. Future studies should include investigation of how these neural mechanisms are affected in individuals with voice disorders during volitional vocalization.

A Review on the Use of Wearable Functional Near-Infrared Spectroscopy in Naturalistic Environments. JAPANESE PSYCHOLOGICAL RESEARCH 2018;60:347-373. [PMID: 30643322 PMCID: PMC6329605 DOI: 10.1111/jpr.12206]

The development of novel miniaturized wireless and wearable functional Near-Infrared Spectroscopy (fNIRS) devices have paved the way to new functional brain imaging that can revolutionize the cognitive research fields. Over the past few decades, several studies have been conducted with conventional fNIRS systems that have demonstrated the suitability of this technology for a wide variety of populations and applications, to investigate both the healthy brain and the diseased brain. However, what makes wearable fNIRS even more appealing is its capability to allow measurements in everyday life scenarios that are not possible with other gold-standard neuroimaging modalities, such as functional Magnetic Resonance Imaging. This can have a huge impact on the way we explore the neural bases and mechanisms underpinning human brain functioning. The aim of this review is to provide an overview of studies conducted with wearable fNIRS in naturalistic settings in the field of cognitive neuroscience. In addition, we present the challenges associated with the use of wearable fNIRS in unrestrained contexts, discussing solutions that will allow accurate inference of functional brain activity. Finally, we provide an overview of the future perspectives in cognitive neuroscience that we believe would benefit the most by using wearable fNIRS.

A cross-brain neural mechanism for human-to-human verbal communication

Neural mechanisms that mediate dynamic social interactions remain understudied despite their evolutionary significance. The interactive brain hypothesis proposes that interactive social cues are processed by dedicated brain substrates and provides a general theoretical framework for investigating the underlying neural mechanisms of social interaction. We test the specific case of this hypothesis proposing that canonical language areas are upregulated and dynamically coupled across brains during social interactions based on talking and listening. Functional near-infrared spectroscopy (fNIRS) was employed to acquire simultaneous deoxyhemoglobin (deOxyHb) signals of the brain on partners who alternated between speaking and listening while doing an Object Naming & Description task with and without interaction in a natural setting. Comparison of interactive and non-interactive conditions confirmed an increase in neural activity associated with Wernicke's area including the superior temporal gyrus (STG) during interaction (P = 0.04). However, the hypothesis was not supported for Broca's area. Cross-brain coherence determined by wavelet analyses of signals originating from the STG and the subcentral area was greater during interaction than non-interaction (P < 0.01). In support of the interactive brain hypothesis these findings suggest a dynamically coupled cross-brain neural mechanism dedicated to pathways that share interpersonal information.

A Perinatal Database Management System

Obstetric services have long recognized the need for ongoing evaluation of their experiences. Manual »departmental statistics« systems sufficed, but with the advent of more sophisticated care, perinatal re-gionalization and increased research activity, the potential usefulness of computer technology became obvious. At Cleveland Metropolitan General Hospital, a laboratory computer based patient information file system was designed and implemented beginning in 1974. Over the succeeding six years, data have been collected and stored for all delivered pregnancies. There are now over 61,000 files for more than 20,000 consecutively delivered patients. The system provides over 40,000 clinical reports per year. However, the use of a file-oriented system has limited our ability to respond to specific research queries. The application of a relational database management system, INGRES, for perinatal information is reported here. Examples of its use for efficiently »answering questions« are presented, as are guidelines for the development and implementation of computer-based perinatal record systems.

Comparison of oxyhemoglobin and deoxyhemoglobin signal reliability with and without global mean removal for digit manipulation motor tasks

Functional near-infrared spectroscopy (fNIRS) could be well suited for clinical use, such as measuring neural activity before and after treatment; however, reliability and specificity of fNIRS signals must be ensured so that differences can be attributed to the intervention. This study compared the test-retest and longitudinal reliability of oxyhemoglobin and deoxyhemoglobin signals before and after spatial filtering. In the test-retest experiment, 14 participants were scanned on 2 days while performing four right-handed digit-manipulation tasks. Group results revealed greater test-retest reliability for oxyhemoglobin than deoxyhemoglobin signals and greater spatial specificity for the deoxyhemoglobin signals. To further characterize reliability, a longitudinal experiment was conducted in which two participants repeated the same motor tasks for 10 days. Beta values from the two tasks with the lowest and highest test-retest reliability, respectively, in the spatially filtered deoxyhemoglobin signal are reported as representative findings. Both test-retest and longitudinal methods confirmed that task and signal type influence reliability. Oxyhemoglobin signals were more reliable overall than deoxyhemoglobin, and removal of the global mean reduced reliability of both signals. Findings are consistent with the suggestion that systemic components most prevalent in the oxyhemoglobin signal may inflate reliability relative to the deoxyhemoglobin signal, which is less influenced by systemic factors.

Distributed Neural Activity Patterns during Human-to-Human Competition

Interpersonal interaction is the essence of human social behavior. However, conventional neuroimaging techniques have tended to focus on social cognition in single individuals rather than on dyads or groups. As a result, relatively little is understood about the neural events that underlie face-to-face interaction. We resolved some of the technical obstacles inherent in studying interaction using a novel imaging modality and aimed to identify neural mechanisms engaged both within and across brains in an ecologically valid instance of interpersonal competition. Functional near-infrared spectroscopy was utilized to simultaneously measure hemodynamic signals representing neural activity in pairs of subjects playing poker against each other (human–human condition) or against computer opponents (human–computer condition). Previous fMRI findings concerning single subjects confirm that neural areas recruited during social cognition paradigms are individually sensitive to human–human and human–computer conditions. However, it is not known whether face-to-face interactions between opponents can extend these findings. We hypothesize distributed effects due to live processing and specific variations in across-brain coherence not observable in single-subject paradigms. Angular gyrus (AG), a component of the temporal-parietal junction (TPJ) previously found to be sensitive to socially relevant cues, was selected as a seed to measure within-brain functional connectivity. Increased connectivity was confirmed between AG and bilateral dorsolateral prefrontal cortex (dlPFC) as well as a complex including the left subcentral area (SCA) and somatosensory cortex (SS) during interaction with a human opponent. These distributed findings were supported by contrast measures that indicated increased activity at the left dlPFC and frontopolar area that partially overlapped with the region showing increased functional connectivity with AG. Across-brain analyses of neural coherence between the players revealed synchrony between dlPFC and supramarginal gyrus (SMG) and SS in addition to synchrony between AG and the fusiform gyrus (FG) and SMG. These findings present the first evidence of a frontal-parietal neural complex including the TPJ, dlPFC, SCA, SS, and FG that is more active during human-to-human social cognition both within brains (functional connectivity) and across brains (across-brain coherence), supporting a model of functional integration of socially and strategically relevant information during live face-to-face competitive behaviors.

Signal processing of functional NIRS data acquired during overt speaking

Functional near-infrared spectroscopy (fNIRS) offers an advantage over traditional functional imaging methods [such as functional magnetic resonance imaging (fMRI)] by allowing participants to move and speak relatively freely. However, neuroimaging while actively speaking has proven to be particularly challenging due to the systemic artifacts that tend to be located in the critical brain areas. To overcome these limitations and enhance the utility of fNIRS, we describe methods for investigating cortical activity during spoken language tasks through refinement of deoxyhemoglobin (deoxyHb) signals with principal component analysis (PCA) spatial filtering to remove global components. We studied overt picture naming and compared oxyhemoglobin (oxyHb) and deoxyHb signals with and without global component removal using general linear model approaches. Activity in Broca's region and supplementary motor cortex was observed only when the filter was applied to the deoxyHb signal and was shown to be spatially comparable to fMRI data acquired using a similar task and to meta-analysis data. oxyHb signals did not yield expected activity in Broca's region with or without global component removal. This study demonstrates the utility of a PCA spatial filter on the deoxyHb signal in revealing neural activity related to a spoken language task and extends applications of fNIRS to natural and ecologically valid conditions.