Abstract Neurofeedback (NF) is a promising method for helping individuals overcome choking under pressure. Identifying relevant neural biomarkers is crucial for developing effective NF. In this exploratory study, we aimed to investigate changes in prefrontal hemodynamic signals associated with golf-putting performance under psychological pressure using functional near-infrared spectroscopy. Participants engaged in a one-on-one golf-putting task against an experimenter, with monetary rewards introduced to induce psychological pressure. This manipulation successfully elicited psychological pressure, leading to impaired performance in some participants. Based on performance changes between the practice and competition sessions, participants were categorized into a non-choking group (performance improved) and a choking group (performance declined). Statistical analysis revealed significantly greater increases in prefrontal activation from practice to competition in the non-choking group than in the choking group, especially in the left superior frontal gyrus. Furthermore, moderate but statistically nonsignificant negative correlations were observed between changes in activation in this region and changes in putting error, indicating that greater activation increases tended to accompany less performance deterioration or greater performance improvement. These exploratory findings suggest that the left superior frontal gyrus warrants further investigation as a candidate biomarker for NF interventions aimed at mitigating choking under pressure.

Respiration is closely related to the parasympathetic nervous system (PSNS). This relation occurs within a single respiratory cycle, with PSNS activity reduced during inspiration and increased during expiration. Over a longer timescale, deep and slow breathing has been reported to enhance PSNS activity, indicating that not only the timing (phase) but also the respiratory depth and rate may influence autonomic nervous system activity. However, under spontaneous breathing, it remains unclear which of the following best reflects PSNS activity: (i) raw respiratory waveform, (ii) respiratory depth, or (iii) respiratory rate. Respiratory depth was defined as instantaneous amplitude and respiratory rate as instantaneous frequency, both derived from the Hilbert transform. Respiratory waveforms and electrocardiograms were recorded at rest in 37 healthy adults. PSNS activity was quantified using heart rate variability indices reflecting parasympathetic modulation, including HF power, RMSSD, and CVI. Within-participant correlations between each respiratory measure and PSNS indices were obtained, and repeated-measures ANOVA with respiratory measure as a factor was used to compare correlation strengths. Results showed a significant main effect, with instantaneous amplitude consistently exhibiting significantly stronger correlations than the instantaneous frequency across all PSNS indices. These findings suggest that Hilbert-derived amplitude serves as a useful indicator of respiratory depth during spontaneous breathing and that depth is more strongly associated with PSNS activity.

Fine motor tasks that involve precision grip depend on both motor control and cognitive processes. However, the neural mechanisms underlying individual differences in manual dexterity remain incompletely understood, particularly under ecologically valid task conditions. The present study aimed to establish a controlled functional near-infrared spectroscopy (fNIRS) paradigm capable of isolating cortical activation specifically elicited by precision grip, and to examine whether such activation is associated with individual differences in manual dexterity. Manual dexterity was assessed using the Purdue Pegboard test (PPT). Cortical activity was measured using 44-channel fNIRS while 40 young adult participants performed temporally controlled precision grip tasks derived from the PPT with either their right or left hand. Precision grip tasks elicited significant increases in oxyhemoglobin signal in bilateral prefrontal and sensorimotor regions compared with a control task. Furthermore, higher PPT assembly scores were associated with greater task-related activation in the lateral prefrontal cortex during right-hand precision grip task. In applied terms, greater task-evoked activation should be interpreted as increased cortical recruitment required to meet precision demands, rather than as inherently superior performance. Taken together, these preliminary findings provide a foundational reference for understanding precision grip–related cortical recruitment and its association with individual differences in manual dexterity, and demonstrate the feasibility of using fNIRS to study cognitive–motor integration under realistic task conditions.

Quantitative monitoring and measurement of hand motion in children are crucial to support healthy development. Electrical impedance tomography-based tactile sensors, also known as tomographic tactile sensors, provide a promising approach for grasp classification. Our previous study in adults and children demonstrated the feasibility of pinch classification using a cylindrical device equipped with the tomographic tactile sensor. In this study, we developed a new sensing device to classify the power grip and precision grip in children. In order to address concerns that children might lick or swing the device, a cylindrical sensing device was integrated sensor and measurement circuit, incorporated a protective layer for enhanced safety. Seventeen children participated in an experiment to evaluate the feasibility of the grasp classification. The classification features were voltage vectors and reconstructed images obtained from the sensor, and two machine learning methods were used as the classifiers. The average classification accuracy exceeded 85% for both feature types, surpassing the chance level of 50%. These results demonstrate that the basic grasp patterns in children can be accurately classified using a tomographic tactile sensor. This study provides new insights into the future application of grasp motion classification in children.

Online meetings have become increasingly prevalent, especially during the coronavirus disease 2019 pandemic. Although they offer convenience and effectiveness in various contexts, there is a pertinent question about whether they truly replicate the richness of in-person communication. This study delves into the distinctions between online and face-to-face interactions, with a particular focus on the synchronization of brain activity. Previous research has indicated a connection between synchronization and the quality of communication. Therefore, our hypothesis posits that face-to-face interactions lead to greater brain synchronization compared to online interactions, which often lack certain social cues. To investigate this, we conducted a study using functional near-infrared spectroscopy hyperscanning during an eye-contact task involving 28 male participants organized into 14 pairs. We assessed brain signal synchronization using wavelet coherence analysis. After comparing face-to-face and online conditions, our findings revealed significantly higher synchronization in face-to-face scenarios, particularly within the right temporoparietal region. These results align with the outcomes of other hyperscanning studies and suggest that face-to-face communication elicits a higher level of brain synchronization compared with online communication. In the future, this approach holds promise for evaluating the effectiveness of online meeting tools in achieving a more authentic virtual communication experience.

To advance the application of functional near-infrared spectroscopy (fNIRS) in brain-computer interface (BCI) technology, we investigated cortical activation patterns associated with auditory selective attention. Using a dichotic listening paradigm, participants were presented with simultaneous music and reading sounds to the left or right ear. During fNIRS recordings, they were instructed to selectively attend to the sound attribute (music vs. reading) or the spatial location (left vs. right ear). Cortical activity differences related to attentional targets were analyzed using a two-way analysis of variance (ANOVA), with sound attribute and spatial information as factors. Our results revealed a significant main effect of the sound attribute factor across multiple measurement channels. Notably, the right parietal region exhibited consistently greater activation when attention was directed toward music compared to reading sounds. Conversely, bilateral dorsolateral prefrontal cortex (DLPFC) channels showed higher activation when participants attended to reading sounds than to music. These findings indicate that cortical activation patterns are modulated by auditory attentional states based on sound attributes. Furthermore, preliminary classification analyses achieved an accuracy of 73.7% in discriminating attentional targets (music vs. reading sounds), demonstrating the feasibility of fNIRS-based BCI applications.

Functional near-infrared spectroscopy (fNIRS) is promising for neurofeedback (NF) applications and warrants further investigation. In this study, we developed an fNIRS-based NF system to modulate the hemodynamic asymmetry of the prefrontal cortex, which may help improve performance under pressure. The system was designed as a compact fNIRS system with two channels located in the prefrontal cortex and controlled using a smartphone. It calculates the dynamic laterality index (LI), indicating frontal asymmetry (a positive LI value when the left side is dominant), which is transformed into a white noise volume mixed with the music stimuli the participant listens to as feedback information. As the LI increases in the positive direction, the volume of the white noise reduces, making the music clearer. With this as the objective, the participants aimed to achieve a left-dominant state in the prefrontal cortex. We evaluated the NF system using a double-masked crossover design with eight participants. Analysis comparing the average LI in the NF and placebo conditions showed that the LI in the NF condition was significantly higher than that in the placebo condition. This finding demonstrates the feasibility of our NF system in modulating prefrontal asymmetry.

Fine motor skills have been suggested to be related to human cognitive abilities. To develop an objective method for evaluating fine motor skills, we applied a flexible tactile sensor based on electrical impedance tomography (EIT) and the contact resistance principle to a cylinder designed to mimic the peg used in the Functional Dexterity Test. Six pinching motions were classified to confirm the feasibility of the prototype system. Two types of classification were performed: classification using reconstructed images and classification using measured voltage vectors. The feasibility of the classification method was evaluated using adult participants, and it was demonstrated that the system can accurately classify various types of pinching motions. The results revealed that utilizing reconstructed images for classification achieved a classification accuracy of 79.4%, while employing measured voltage vectors for classification resulted in a classification accuracy of 91.4%. These findings underscore the potential for developing an automated finger motion analysis system using EIT-based tactile sensor.

Fine motor skills with the hands and fingers of children are useful for developmental assessment. To enable the sensing of subtle actions of the hand and fingers of children in a natural situation, we developed a cylindrical sensing device with a tomographic tactile sensor based on the concept of an object-based sensing system. U sing this device, we conducted an experiment to classify the number of fingers pinched and the pinching direction in children. The classification accuracy was calculated for each of the reconstructed images and the measured voltage signals based on the data collected during the experiment. Consequently, a maximum classification accuracy of 65.5% was achieved, which was above chance level (16.6 % ). Furthermore, the classification accuracy obtained using the measured voltage signal was demonstrated to be higher than that obtained using the reconstructed image. These accuracies were lower than those of adult participants in our previous study, which may have been influenced by the child's small hand and finger size and weak grip strength. Although there remains room for improvement, the results provide a basis for a new evaluation method for subtle actions of the hand and fingers, which will contribute to the development of novel methodologies for developmental research.

Previous studies have suggested a correlation between cognitive functions such as executive function and hand motor function, while there are few empirical studies on the direct relationship between these functions and brain activity. Therefore, this study aimed to investigate the relationship between hand motor function and brain activity by measuring and analyzing brain activity during hand motor and cognitive tasks. Twenty young men and 19 elderly men over the age of 65 participated in this experiment. The hand motor tasks included a grip strength test, a Purdue Pegboard Test, and a finger tapping task, while the cognitive tasks included the Mini-Addenbrooke's Cognitive Examination (M-ACE), a flanker task, and a working memory task. Brain activity in regions including the prefrontal cortex (PFC) during the cognitive tasks was measured using functional near-infrared spectroscopy (fNIRS). Correlation analysis between the hand motor scores and the cognitive task scores showed a significant positive correlation between the pegboard assembly score and the M- ACE score only in the elderly. In addition, we found a significant negative correlation between age and reaction time on the cognitive tasks. These results confirm that elderly people with high dexterity have higher cognitive function. Furthermore, the correlation analysis with brain activity showed a significant negative correlation between the mean activation of the left PFC during the working memory task and the assembly score in the elderly. This result suggests that brain activity was higher in elderly people with lower dexterity.

Finger movements are closely related to development disabilities such as autism spectrum disorder (ASD). These results suggest that a quantitative evaluation of finger movements may be applied to the early diagnosis of cognitive decline and autism in infants and young children. Therefore, we developed a novel automatic finger motion analysis system based on a tomographic tactile sensor by-using coupled conductors with a continuous sensing surface and conductive material with a high degree of freedom (DOF) of shape. Further, we developed two cylindrical sensors, with diameters of 25 and 50 mm, utilizing the high DOF of geometry. To evaluate the developed sensors, we conducted two validations-60-segment cross-validation and holdout validation–to identify the number of fingers engaged in grasping by adults. AlexNet was used for identification of the used reconstruction image; k-nearest neighbors (KNN) and Support vector machine (SVM) were used for the measurement of the voltage vector. According to the results, these accuracies exceeding the chance level was obtained for all participants of both validations. In addition, an average accuracy of approximately 90% was acquired using the measured voltage vector. In conclusion, the study findings indicate that the proposed device could be used for early diagnosis of ASD in infants and cognitive decline in older adults.

While music perception in infants has been studied through behavioral experiments, functional neuroimaging is now growing as a potential novel approach with which to elucidate this developmental process. This study used functional near-infrared spectroscopy (fNIRS) to measure the cortical hemodynamics of two- to five-month-old infants during music presentation to examine their perception of changes in tempo. We found that their hemoglobin signal increased after the music tempo changed in comparison with the no change condition (habituation). This suggests that infants can perceive music tempo changes and that the fNIRS technique is effective in studying their music perception.

To promote pro-environmental behavior (PEB), this study specifically assessed the feeling of a desire to make oneself look better, or to be concerned about one's own “reputation” when observed by an interactive virtual agent. For this study, a controlled experiment was conducted with an interactive agent and a non-interactive agent as experiment conditions to test whether interaction with an agent promotes concern about reputation and PEB. Specifically, this study was conducted to evaluate the following two hypotheses. (Hypothesis 1): A person tends to be more concerned about their own personal reputation when contacting an interactive agent as an observer than when contacting a non-interactive agent. (Hypothesis 2): A person is more likely to perform PEB when contacting an interactive agent than when contacting a non-interactive agent. Before contacting agents, experiment participants were assessed to ascertain their degree of PEB. After interacting with either agent for 5 min, the degree of PEB performed was measured again. The improvement was then evaluated. Then, a questionnaire was administered to assess reputational concern. The questionnaire results supported Hypotheses 1 and 2 (p < .01) and clarified that agent interaction induces concern for reputation in the judgment of an agent: even a non-human agent. Results also demonstrated the importance of interaction for PEB promotion.

Metabolic cage housing which is exposed to a number of environmental stressors is often used in pharmacokinetic studies. In this study, we compared the difference in stress response between single- and paired-housing in metabolic cages by evaluating the alteration of urinary stress hormones and behavior. Mice were randomly divided into single- or paired-housing groups and placed in a metabolic cage with wire mesh. Their urine was collected every 24 h for consecutive 4 days to determine excreted catecholamine and corticosterone. The change in body weight was significantly decreased at 3 and 4 days in the single-housing group compared with that before the experiment, but not paired-housing group. The level of urinary catecholamines, such as noradrenaline, adrenaline, and their metabolite vanillylmandelic acid, was significantly increased in the single-housing compared with paired housing group and urinary corticosterone increased as well. Next, for the two similarly housed groups, we observed spontaneous behavior on the fourth day and conducted an elevated plus-maze test on the fifth day. Spontaneous behavior was not different between experimental groups. In the elevated plus-maze test, the proportion of time spent in the open arms was significantly prolonged in the paired-housing group compared to that of the single-housing group. Short-term social isolation stress loading in metabolic cages was suggested to exhibit endocrinological and behavioral changes in mice. To reduce such interference due to stress exposure, it was suggested to keep two mice in a metabolic cage.

To further develop three-dimensional (3D) applications, it is important to elucidate the negative effects of 3D applications on the human body and mind. Thus, this study investigated differences in the effects of visual fatigue on cognition and brain activity using visual and auditory tasks induced by watching a 1-h movie in two dimensions (2D) and 3D. Eighteen young men participated in this study. Two conditions were randomly performed for each participant on different days, namely, watching the 1-h movie on television in 2D (control condition) and 3D (3D condition). Before and after watching the 1-h movie on television, critical flicker fusion frequency (CFF: an index of visual fatigue), and response accuracy and reaction time for the cognitive tasks were determined. Brain activity during the cognitive tasks was evaluated using a multi-channel near-infrared spectroscopy system. In contrast to the control condition, the decreased CFF, and the lengthened reaction time and the decreased activity around the right primary somatosensory cortex during Go/NoGo blocks in the visual task at post-viewing in the 3D condition were significant, with significant repeated measures correlations among them. Meanwhile, in the auditory task, the changes in cognitive performance and brain activity during the Go/NoGo blocks were not significant in the 3D condition. These results suggest that the failure or delay in the transmission of visual information to the primary somatosensory cortex due to visual fatigue induced by watching a 3D movie reduced the brain activity around the primary somatosensory cortex, resulting in poor cognitive performance for the visual task. This suggests that performing tasks that require visual information, such as running in the dark or driving a car, immediately after using a 3D application, may create unexpected risks in our lives. Thus, the findings of this study will help outlining precautions for the use of 3D applications.

Functional near-infrared spectroscopy (fNIRS) is a neuroimaging technique used to measure the relative changes in concentrations of oxygenated haemoglobin (oxy-Hb) and deoxygenated haemoglobin (deoxy-Hb) in the cerebral cortex. While most previous studies using fNIRS have relied only on a single oxy-Hb or deoxy-Hb parameter to infer about neural activation, the phase difference between the oxy- and deoxy-Hb signals (haemoglobin phase of oxygenation and deoxygenation: hPod) has been reported to be an important biomarker for analysing haemodynamic characteristics of the brain in infants. In this study, we examined the basic characteristics of adult hPod to develop a new analysis method to detect more sensitive signals that reflect neural activation in adults using fNIRS. We measured the hPod of 12 healthy adults in the frontal and occipital cortex during rest and upon exposure to visual stimuli and the verbal working memory (WM) task. We found that the average hPod values during the entire measurement period ranged between π and 1.5π rad in all conditions. This result indicates that the phase differences in adults were generally close to a stable antiphase pattern (hPod values around π), regardless of the presence or absence of tasks and stimuli. However, when dynamic changes in hPod values were analysed, significant differences between the resting state and WM tasks were observed during activation period in the frontal and occipital regions. These results suggest that the analysis of dynamic hPod change is useful for detecting a subtle activation for cognitive tasks.

Recent epidemiological and intervention studies have suggested that polyphenol-rich plant food consumption reduced the risk of cognitive decline. However, the findings were tentative and by no means definitive. In the present study, we examined the impact of short-term oral administration of cinnamtannin A2 (A2), an (-)-epicatechin tetramer, on adult hippocampal neurogenesis and cognitive function in mice. Mice received supplementation with vehicle (20% glycerol) or 100 mg/kg A2 for 10 days. Then, we conducted the open field test, the object location test, and the novel object test. In the open field test, the A2-treated group tended to spend more time in the center of the arena, compared to the vehicle-treated group. The A2-treated group spent significantly more time exploring objects placed in different locations, compared to the vehicle-treated group. There were no significant differences between groups in the object preference index or in the novel object test. In addition, A2 administration significantly increased the number of hippocampal bromodeoxyuridine-labeled cells in the dentate gyrus, but not in the CA1 or CA3 regions. These results suggested that short-term administration of A2 may impact spatial memory by enhancing neurogenesis in the dentate gyrus of adult mice. (C) 2021 Elsevier Inc. All rights reserved.

Rovers have been actively used for lunar and planetary exploration, as they can travel over a wide area in detail. The surface of the Moon and planets is soft ground covered with regolith, and slippage might be occurred while traveling through slanted craters and dunes, resulting in a discrepancy between the planned and actual routes. The information on the current position of the vehicle is very important. In addition, there is a risk of getting stuck due to the deviation from the route. In this study, we focus on skidding, and detect skidding at an early phase. The information detected during driving are utilized to suppress a skidding of the rover.

Creative problem solving has been important for the advent of new technologies. In this study, we hypothesized that subjective ratings of answers should be useful for evaluating the answer quality in creative problem solving. To test this hypothesis and extract objective indicators of the subjective ratings of answers, we evaluated the relationship between subjective ratings of task performance and behavioral and autonomic nervous activities during a creative problem-solving task performed via online conversation. The task involved an answerer and a supporter, and in the experiment, each pair performed 10 trials. The trials were categorized as highly or lowly rated according to the answerer’s confidence in the answer. The task performance and behavioral and autonomic nervous activities were then compared between these categories of trials. Behavioral activity was evaluated via movements and speech activities, while for autonomic nervous activity, sympathetic nervous activity (SNA) was evaluated via skin conductance. The task performance was significantly better in the highly rated trials, whereas there were no significant differences in the behavioral activities between the highly and lowly rated trials. Moreover, in the highly rated trials, the skin conductance of the answerer was significantly high, whereas that of the supporter was significantly low. The results support the hypothesis and suggest that contrasting differences in SNA between an answerer and a supporter are indicators of the subjective ratings of answers in creative problem solving.