Sustained decrease in oxygenated hemoglobin during video games in the dorsal prefrontal cortex: A NIRS study of children

Simultaneous measurement of electroencephalography and near-infrared spectroscopy during voluntary motor preparation

We investigated the relationship between electrophysiological activity and haemodynamic response during motor preparation by simultaneous recording of electroencephalography (EEG) and near-infrared spectroscopy (NIRS). It is still unknown how exactly EEG signals correlate with the haemodynamic response, although the activation in the premotor area during motor preparation has been captured by EEG and haemodynamic approaches separately. We conducted EEG-NIRS simultaneous recordings over the sensorimotor area with a self-paced button press task. Participants were instructed to press a button at their own pace after a cue was shown. The result showed that the readiness potential (RP), a negative slow potential shift occurring during motor preparation, on C3 in the extended 10–20 system occurred about 1000 ms before the movement onset. An increase in concentration of oxyhaemoglobin (oxyHb) in the premotor cortex during motor preparation was also confirmed by NIRS, which resulted in a significant correlation between the amplitude of the RP and the change in oxyHb concentration (Pearson’s correlation r² = 0.235, p = 0.03). We show that EEG-NIRS simultaneous recording can demonstrate the correlation between the RP and haemodynamic response in the premotor cortex contralateral to the performing hand.

The Influence of Music on Prefrontal Cortex during Episodic Encoding and Retrieval of Verbal Information: A Multichannel fNIRS Study

Music can be thought of as a complex stimulus able to enrich the encoding of an event thus boosting its subsequent retrieval. However, several findings suggest that music can also interfere with memory performance. A better understanding of the behavioral and neural processes involved can substantially improve knowledge and shed new light on the most efficient music-based interventions. Based on fNIRS studies on music, episodic encoding, and the dorsolateral prefrontal cortex (PFC), this work aims to extend previous findings by monitoring the entire lateral PFC during both encoding and retrieval of verbal material. Nineteen participants were asked to encode lists of words presented with either background music or silence and subsequently tested during a free recall task. Meanwhile, their PFC was monitored using a 48-channel fNIRS system. Behavioral results showed greater chunking of words under the music condition, suggesting the employment of associative strategies for items encoded with music. fNIRS results showed that music provided a less demanding way of modulating both episodic encoding and retrieval, with a general prefrontal decreased activity under the music versus silence condition. This suggests that music-related memory processes rely on specific neural mechanisms and that music can positively influence both episodic encoding and retrieval of verbal information.

Obstruction increases activation in the right inferior frontal gyrus

The right inferior frontal gyrus (IFG) is involved in intention understanding during interpersonal interactions. To examine how prior experience of cooperation and competition affects one's right IFG activation in the subsequent interaction, using near-infrared spectroscopy (NIRS) we simultaneously measured paired participants' bilateral IFG activations during a turn-taking game. Participant pairs were assigned to either one of two roles: a Builder taking the initial move to copy a target disk-pattern on monitor and the Partner taking the second move to aid in (cooperation) or to obstruct (competition) the Builder. The experiment consisted of two sessions. One participant (B-P) played as a Builder (B-) in session 1 and changed the role to the Partner (-P) in session 2, and vice versa for the paired participant (P-B). NIRS data in competition demonstrated that the Builder (B-) being obstructed in session 1 showed higher right IFG activation when (s)he took a role of obstructor (-P) in session 2 (the obstructed effect), whereas "the cooperated effect" was not revealed in cooperation. These results suggest that prior experience of being obstructed may facilitate understanding of the Builder and/or the obstructor's tactical move, thereby increasing his/her right IFG activation when one is meant to obstruct in subsequent competitions.

Temporal orienting of attention: An fNIRS study on the illusion of "a watched pot never boils"

The present study used a single-task paradigm in which participants received guidance to focus more attention (waiting for someone) on the temporal intervals in the "waiting" condition and to stay relaxed in the control condition. The reported time was longer in the waiting condition than in the control condition. Functional near-infrared spectroscopy was used to measure simultaneously the activation levels of the dorsolateral prefrontal cortex (DLPFC) for each condition. Greater oxyhemoglobin (oxy-Hb) activation in the waiting condition was observed compared with the control condition, whilst deoxyhemoglobin data showed no difference between the two conditions. The gradual changes in oxy-Hb in the DLPFC in increments of 100 ms yielded further insights into the role of this region in the "watched pot never boils" phenomenon.

Neuronal Correlates of Cognitive Control during Gaming Revealed by Near-Infrared Spectroscopy

In everyday life we quickly build and maintain associations between stimuli and behavioral responses. This is governed by rules of varying complexity and past studies have identified an underlying fronto-parietal network involved in cognitive control processes. However, there is only limited knowledge about the neuronal activations during more natural settings like game playing. We thus assessed whether near-infrared spectroscopy recordings can reflect different demands on cognitive control during a simple game playing task. Sixteen healthy participants had to catch falling objects by pressing computer keys. These objects either fell randomly (RANDOM task), according to a known stimulus-response mapping applied by players (APPLY task) or according to a stimulus-response mapping that had to be learned (LEARN task). We found an increased change of oxygenated and deoxygenated hemoglobin during LEARN covering broad areas over right frontal, central and parietal cortex. Opposed to this, hemoglobin changes were less pronounced for RANDOM and APPLY. Along with the findings that fewer objects were caught during LEARN but stimulus-response mappings were successfully identified, we attribute the higher activations to an increased cognitive load when extracting an unknown mapping. This study therefore demonstrates a neuronal marker of cognitive control during gaming revealed by near-infrared spectroscopy recordings.

Role of the right inferior frontal gyrus in turn-based cooperation and competition: A near-infrared spectroscopy study

Interpersonal interaction can be classified into two types: concurrent and turn-based interaction, requiring synchronized body-movement and complementary behaviors across persons, respectively. To examine the neural mechanism of turn-based interaction, we simultaneously measured paired participants activations in their bilateral inferior frontal gyrus (IFG) and the bilateral inferior parietal lobule (IPL) in a turn-taking game using near-infrared spectroscopy (NIRS). Pairs of participants were assigned to either one of two roles (game builder and the partner) in the game. The builder's task was to make a copy of a target disk-pattern by placing disks on a monitor, while the partner's task was to aid the builder in his/her goal (cooperation condition) or to obstruct it (competition condition). The builder always took the initial move and the partner followed. The NIRS data demonstrated an interaction of role (builder vs. partner) by task-type (cooperation vs. competition) in the right IFG. The builder in the cooperation condition showed higher activation than the cooperator, but the same builder in the competition condition showed lower activation than in the cooperation condition. The activations in the competitor-builder pairs showed positive correlation between their right IFG, but the activations in the cooperator-builder pairs did not. These results suggest that the builder's activation in the right IFG is reduced/increased in the context of interacting with a cooperative/competitive partner. Also, the competitor may actively trace the builder's disk manipulation, leading to deeper mind-set synchronization in the competition condition, while the cooperator may passively follow the builder's move, leading to shallower mind-set synchronization in the cooperation condition.

Differences in the Pattern of Hemodynamic Response to Self-Face and Stranger-Face Images in Adolescents with Anorexia Nervosa: A Near-Infrared Spectroscopic Study

There have been no reports concerning the self-face perception in patients with anorexia nervosa (AN). The purpose of this study was to compare the neuronal correlates of viewing self-face images (i.e. images of familiar face) and stranger-face images (i.e. images of an unfamiliar face) in female adolescents with and without AN. We used near-infrared spectroscopy (NIRS) to measure hemodynamic responses while the participants viewed full-color photographs of self-face and stranger-face. Fifteen females with AN (mean age, 13.8 years) and 15 age- and intelligence quotient (IQ)-matched female controls without AN (mean age, 13.1 years) participated in the study. The responses to photographs were compared with the baseline activation (response to white uniform blank). In the AN group, the concentration of oxygenated hemoglobin (oxy-Hb) significantly increased in the right temporal area during the presentation of both the self-face and stranger-face images compared with the baseline level. In contrast, in the control group, the concentration of oxy-Hb significantly increased in the right temporal area only during the presentation of the self-face image. To our knowledge the present study is the first report to assess brain activities during self-face and stranger-face perception among female adolescents with AN. There were different patterns of brain activation in response to the sight of the self-face and stranger-face images in female adolescents with AN and controls.

fMRI Validation of fNIRS Measurements During a Naturalistic Task

We present a method to compare brain activity recorded with near-infrared spectroscopy (fNIRS) in a dance video game task to that recorded in a reduced version of the task using fMRI (functional magnetic resonance imaging). Recently, it has been shown that fNIRS can accurately record functional brain activities equivalent to those concurrently recorded with functional magnetic resonance imaging for classic psychophysical tasks and simple finger tapping paradigms. However, an often quoted benefit of fNIRS is that the technique allows for studying neural mechanisms of complex, naturalistic behaviors that are not possible using the constrained environment of fMRI. Our goal was to extend the findings of previous studies that have shown high correlation between concurrently recorded fNIRS and fMRI signals to compare neural recordings obtained in fMRI procedures to those separately obtained in naturalistic fNIRS experiments. Specifically, we developed a modified version of the dance video game Dance Dance Revolution (DDR) to be compatible with both fMRI and fNIRS imaging procedures. In this methodology we explain the modifications to the software and hardware for compatibility with each technique as well as the scanning and calibration procedures used to obtain representative results. The results of the study show a task-related increase in oxyhemoglobin in both modalities and demonstrate that it is possible to replicate the findings of fMRI using fNIRS in a naturalistic task. This technique represents a methodology to compare fMRI imaging paradigms which utilize a reduced-world environment to fNIRS in closer approximation to naturalistic, full-body activities and behaviors. Further development of this technique may apply to neurodegenerative diseases, such as Parkinson’s disease, late states of dementia, or those with magnetic susceptibility which are contraindicated for fMRI scanning.

What hemodynamic (fNIRS), electrophysiological (EEG) and autonomic integrated measures can tell us about emotional processing

Due to its fast temporal evolution and its representation and integration among complex and widespread neural networks, the emotion perception process should preferably be examined by means of multimethodological approach. Indeed the indubitable vantage of acquiring both the autonomic (arousal-related) and the central (cortical-related) activities stands in the possibility to better elucidate the reciprocal interplay of the two compartments. In the present study EEG (frequency band analysis), systemic SCR and heart rate (HR) were all recorded simultaneously with hemodynamic (NIRS, Near-Infrared Spectroscopy) measurements as potential biological markers of emotions, related to both central and peripheral systems. These multiple measures were then related to the self-report correlates, that is the subjective appraisal in term of valence (positive vs. negative) and arousal (high vs. low) by using SAM rating. Twenty subjects were submitted to emotional cues processing (IAPS) when fNIRS, frequency bands (alpha, beta, delta, theta), SCR and HR were recorded. As shown by O2Hb increasing within the right hemisphere, the contribution of prefrontal cortex was elucidated, by pointing out a relevant lateralization effect (more right-PFC activity) induced by the specific valence (negative) of the emotional patterns. Secondly, EEG activity (mainly low-frequency theta and delta bands) was intrinsically associated with the cortical hemodynamic responsiveness to the negative emotional patterns, within the right side. Finally SCR increased mainly in response to negative patterns, and the autonomic behavior was related to explicit (SAM) and cortical (NIRS; EEG) activity. The intrinsic relationships between these three different levels are discussed.

Assessment of cerebral blood flow in patients with multiple chemical sensitivity using near-infrared spectroscopy--recovery after olfactory stimulation: a case-control study

OBJECTIVES

Multiple chemical sensitivity (MCS) is a chronic acquired disorder characterized by non-specific symptoms in multiple organ systems associated with exposure to odorous chemicals. We previously observed significant activations in the prefrontal cortex (PFC) during olfactory stimulation using several different odorants in patients with MCS by near-infrared spectroscopy (NIRS) imaging. We also observed that the patients with MCS did not adequately distinguish non-odorant in the late stage of the repeated olfactory stimulation test. The sensory recovery of the olfactory system in the patients with MCS may process odors differently from healthy subjects after olfactory stimulation.

METHODS

We examined the recovery process of regional cerebral blood flow (rCBF) after olfactory stimulation in patients with MCS. NIRS imaging was performed in 6 patients with MCS and in 6 controls. The olfactory stimulation test was continuously repeated 10 times. The study also included a subjective assessment of the physical and psychological status and of the perception of irritating and hedonic odors.

RESULTS

After olfactory stimulation, significant activations were observed in the PFC of patients with MCS on both the right and left sides compared with controls. The activations were specifically strong in the orbitofrontal cortex (OFC). Compared with controls, autonomic perception and feelings identification were poorer in patients with MCS. OFC is associated with stimuli response and the representation of preferences.

CONCLUSIONS

These results suggest that a past strong exposure to hazardous chemicals activates the PFC during olfactory stimuli in patients with MCS, and a strong activation in the OFC remains after the stimuli.

Hemodynamic response of children with attention-deficit and hyperactive disorder (ADHD) to emotional facial expressions

Children with attention-deficit/hyperactivity disorder (ADHD) have difficulty recognizing facial expressions. They identify angry expressions less accurately than typically developing (TD) children, yet little is known about their atypical neural basis for the recognition of facial expressions. Here, we used near-infrared spectroscopy (NIRS) to examine the distinctive cerebral hemodynamics of ADHD and TD children while they viewed happy and angry expressions. We measured the hemodynamic responses of 13 ADHD boys and 13 TD boys to happy and angry expressions at their bilateral temporal areas, which are sensitive to face processing. The ADHD children showed an increased concentration of oxy-Hb for happy faces but not for angry faces, while TD children showed increased oxy-Hb for both faces. Moreover, the individual peak latency of hemodynamic response in the right temporal area showed significantly greater variance in the ADHD group than in the TD group. Such atypical brain activity observed in ADHD boys may relate to their preserved ability to recognize a happy expression and their difficulty recognizing an angry expression. We firstly demonstrated that NIRS can be used to detect atypical hemodynamic response to facial expressions in ADHD children.

Sex differences in addictive disorders

Gender-dependent differences in the rate of initiation and frequency of misuse of addicting drugs have been widely described. Yet, men and women also differ in their propensity to become addicted to other rewarding stimuli (e.g., sex, food) or activities (e.g., gambling, exercising). The goal of the present review is to summarize current evidence for gender differences not only in drug addiction, but also in other forms of addictive behaviours. Thus, we first reviewed studies showing gender-dependent differences in drug addiction, food addiction, compulsive sexual activity, pathological gambling, Internet addiction and physical exercise addiction. Potential risk factors and underlying brain mechanisms are also examined, with particular emphasis given to the role of sex hormones in modulating addictive behaviours. Investigations on factors allowing the pursuit of non-drug rewards to become pathological in men and women are crucial for designing gender-appropriate treatments of both substance and non-substance addictions.

The processing of faces across non-rigid facial transformation develops at 7 month of age: a fNIRS-adaptation study

BACKGROUND

Using near-infrared spectroscopy (NIRS), our previous neural adaptation studies found that infants' bilateral temporal regions process facial identity (FiHN 5:153, 2011). In addition, we revealed that size-invariant processing of facial identity develops by 5 months of age (NR 23:984-988, 2012), while view-invariant processing develops around 7 months of age (FiHN 5:153, 2011). The aim in the current study was to examine whether infants' brains process facial identity across the non-rigid transformation of facial features by using the neural adaptation paradigm. We used NIRS to compare hemodynamic changes in the bilateral temporal areas of 5- to 6-month-olds and 7- to 8-month-olds during presentations of an identical face and of different faces.

RESULTS

We found that (1) the oxyhemoglobin concentration around the T5 and T6 positions increased significantly during the presentation of different faces only in 7- to 8-month-olds and (2) 7- to 8-month-olds, but not 5- to 6-month-olds, showed attenuation in these channels to the presentation of the same face rather than to the presentation of different faces, regardless of non-rigid changes in facial features.

CONCLUSIONS

Our results suggest that the processing of facial identity with non-rigid facial transformation develops around 7 months after birth.

Less Effort, Better Results: How Does Music Act on Prefrontal Cortex in Older Adults during Verbal Encoding? An fNIRS Study

Several neuroimaging studies of cognitive aging revealed deficits in episodic memory abilities as a result of prefrontal cortex (PFC) limitations. Improving episodic memory performance despite PFC deficits is thus a critical issue in aging research. Listening to music stimulates cognitive performance in several non-purely musical activities (e.g., language and memory). Thus, music could represent a rich and helpful source during verbal encoding and therefore help subsequent retrieval. Furthermore, such benefit could be reflected in less demand of PFC, which is known to be crucial for encoding processes. This study aimed to investigate whether music may improve episodic memory in older adults while decreasing the PFC activity. Sixteen healthy older adults (μ = 64.5 years) encoded lists of words presented with or without a musical background while their dorsolateral prefrontal cortex (DLPFC) activity was monitored using a eight-channel continuous-wave near-infrared spectroscopy (NIRS) system (Oxymon Mk III, Artinis, The Netherlands). Behavioral results indicated a better source-memory performance for words encoded with music compared to words encoded with silence (p < 0.05). Functional NIRS data revealed bilateral decrease of oxyhemoglobin values in the music encoding condition compared to the silence condition (p < 0.05), suggesting that music modulates the activity of the DLPFC during encoding in a less-demanding direction. Taken together, our results indicate that music can help older adults in memory performances by decreasing their PFC activity. These findings open new perspectives about music as tool for episodic memory rehabilitation on special populations with memory deficits due to frontal lobe damage such as Alzheimer’s patients.

Investigation of frontal lobe activation with fNIRS and systemic changes during video gaming

Frontal lobe activation caused by tasks such as videogames can be investigated using multichannel near-infrared spectroscopy (fNIRS), sometimes called optical topography. The aims of this study are to investigate the effects of video gaming (fighting and puzzle games) in the brain and the systemic physiology and to determine whether systemic responses during the gaming task are associated with the measurement of localised cerebral haemodynamic changes as measured by fNIRS. We used a continuous-wave 8-channel fNIRS system to measure the changes in concentration of oxy-haemoglobin (HbO2) and deoxy-haemoglobin (HHb) and changes in total haemoglobin (ΔtHb = ΔHbO2 + ΔHHb) over the frontal lobe in 30 healthy volunteers. The Portapres system was used to measure mean blood pressure (MBP) and heart rate (HR), and a laser Doppler was employed to measure the changes in scalp blood flow (or flux). Even though we observed significant changes in systemic variables during gaming, in particular in scalp flow, we also managed to see localised activation patterns over the frontal polar (FP1) region. However, in some channels over the frontal lobe, we also observed significant correlations between the HbO2 and systemic variables.

Oxyhemoglobin changes during cognitive rehabilitation after traumatic brain injury using near infrared spectroscopy

To investigate cerebral reactions to cognitive rehabilitation tasks, oxyhemoglobin changes were compared in 9 patients with cognitive impairments after traumatic brain injury (TBI) and 47 healthy controls using functional near infrared spectroscopy (fNIRS) during nine cognitive rehabilitation tasks employed at Nagoya City Rehabilitation Center. Forty-seven measurement channels were placed on the frontal to temporal cortices, and organized into seven channel regions. Oxyhemoglobin changes were normalized based on the mean oxyhemoglobin value at the resting state, and integrated throughout a task. Statistical analyses of the differences between the TBI patients and controls were performed with the two-sided Mann-Whitney U test. Oxyhemoglobin changes were high for both controls and TBI patients in the lateral frontal regions. Oxyhemoglobin changes in TBI patients tended to be higher than controls in the medial frontal regions for most training tasks, and significant differences (p < 0.05) were seen for two tasks in the medial frontal regions. Different regions were activated during the tasks in TBI patients compared to controls. fNIRS measurement is useful in the evaluation of changes of neuronal activities during rehabilitation tasks in TBI patients.

Relationship between Neural Activity and Executive Function: An NIRS Study

Objective. This study examined the relationship between neural activity and executive function (EF) by near-infrared spectroscopy (NIRS). In addition, an oral reading span test (RST) was used to explore this association. Methods. Fifteen adults participated in the study. We used the RST and simple reading as the two tasks. Results. The RST score and cortical hemodynamic response in the left inferior frontal gyrus were significantly correlated. Conclusion. Based on the oral RST performance assessment and NIRS examination, the present findings suggest a relationship between EF and cortical activation.

Negative emotion modulates prefrontal cortex activity during a working memory task: a NIRS study

This study investigated the neural processing underlying the cognitive control of emotions induced by the presentation of task-irrelevant emotional pictures before a working memory task. Previous studies have suggested that the cognitive control of emotion involves the prefrontal regions. Therefore, we measured the hemodynamic responses that occurred in the prefrontal region with a 16-channel near-infrared spectroscopy (NIRS) system. In our experiment, participants observed two negative or two neutral pictures in succession immediately before a 1-back or 3-back task. Pictures were selected from the International Affective Picture System (IAPS). We measured the changes in the concentration of oxygenated hemoglobin (oxyHb) during picture presentation and during the n-back task. The emotional valence of the picture affected the oxyHb changes in anterior parts of the medial prefrontal cortex (MPFC) (located in the left and right superior frontal gyrus) and left inferior frontal gyrus during the n-back task; the oxyHb changes during the task were significantly greater following negative rather than neutral stimulation. As indicated in a number of previous studies, and the time courses of the oxyHb changes in our study, activation in these locations is possibly led by cognitive control of emotion, though we cannot deny it may simply be emotional responses. There were no effects of emotion on oxyHb changes during picture presentation or on n-back task performance. Although further studies are necessary to confirm this interpretation, our findings suggest that NIRS can be used to investigate neural processing during emotional control.

Neurobehavioral and hemodynamic evaluation of Stroop and reverse Stroop interference in children with attention-deficit/hyperactivity disorder

Failure of executive function (EF) is a core symptom of attention-deficit/hyperactivity disorder (ADHD). However, various results have been reported and sufficient evidence is lacking. In the present study, we evaluated the characteristics of children with ADHD using the Stroop task (ST) and reverse Stroop task (RST) that reflects the inhibition function of EF. We compared children with ADHD, typically developing children (TDC), and children with autism spectrum disorder (ASD), which is more difficult to discriminate from ADHD. A total of 10 children diagnosed with ADHD, 15 TDC, and 11 children diagnosed with ASD, all matched by age, sex, language ability, and intelligence quotient, participated in this study. While each subject performed computer-based ST and RST with a touch panel, changes in oxygenated hemoglobin (oxy-Hb) were measured in the prefrontal cortex (PFC) by near-infrared spectroscopy (NIRS) to correlate test performance with neural activity. Behavioral performance significantly differed among 3 groups during RST but not during ST. The ADHD group showed greater color interference than the TDC group. In addition, there was a negative correlation between right lateral PFC (LPFC) activity and the severity of attention deficit. Children with ADHD exhibit several problems associated with inhibition of color, and this symptom is affected by low activities of the right LPFC. In addition, it is suggested that low hemodynamic activities in this area are correlated with ADHD.

Music improves verbal memory encoding while decreasing prefrontal cortex activity: an fNIRS study

Listening to music engages the whole brain, thus stimulating cognitive performance in a range of non-purely musical activities such as language and memory tasks. This article addresses an ongoing debate on the link between music and memory for words. While evidence on healthy and clinical populations suggests that music listening can improve verbal memory in a variety of situations, it is still unclear what specific memory process is affected and how. This study was designed to explore the hypothesis that music specifically benefits the encoding part of verbal memory tasks, by providing a richer context for encoding and therefore less demand on the dorsolateral prefrontal cortex (DLPFC). Twenty-two healthy young adults were subjected to functional near-infrared spectroscopy (fNIRS) imaging of their bilateral DLPFC while encoding words in the presence of either a music or a silent background. Behavioral data confirmed the facilitating effect of music background during encoding on subsequent item recognition. fNIRS results revealed significantly greater activation of the left hemisphere during encoding (in line with the HERA model of memory lateralization) and a sustained, bilateral decrease of activity in the DLPFC in the music condition compared to silence. These findings suggest that music modulates the role played by the DLPFC during verbal encoding, and open perspectives for applications to clinical populations with prefrontal impairments, such as elderly adults or Alzheimer's patients.

Changes in cerebral blood flow during olfactory stimulation in patients with multiple chemical sensitivity: a multi-channel near-infrared spectroscopic study

Multiple chemical sensitivity (MCS) is characterized by somatic distress upon exposure to odors. Patients with MCS process odors differently from controls. This odor-processing may be associated with activation in the prefrontal area connecting to the anterior cingulate cortex, which has been suggested as an area of odorant-related activation in MCS patients. In this study, activation was defined as a significant increase in regional cerebral blood flow (rCBF) because of odorant stimulation. Using the well-designed card-type olfactory test kit, changes in rCBF in the prefrontal cortex (PFC) were investigated after olfactory stimulation with several different odorants. Near-infrared spectroscopic (NIRS) imaging was performed in 12 MCS patients and 11 controls. The olfactory stimulation test was continuously repeated 10 times. The study also included subjective assessment of physical and psychological status and the perception of irritating and hedonic odors. Significant changes in rCBF were observed in the PFC of MCS patients on both the right and left sides, as distinct from the center of the PFC, compared with controls. MCS patients adequately distinguished the non-odorant in 10 odor repetitions during the early stage of the olfactory stimulation test, but not in the late stage. In comparison to controls, autonomic perception and negative affectivity were poorer in MCS patients. These results suggest that prefrontal information processing associated with odor-processing neuronal circuits and memory and cognition processes from past experience of chemical exposure play significant roles in the pathology of this disorder.

Implicit emotion regulation in the presence of threat: neural and autonomic correlates

Efficient emotion regulation is essential for social interaction and functioning in human society and often happens without direct intention and conscious awareness. Cognitive labeling of stimuli based on certain characteristics has been assumed to represent an effective strategy of implicit emotional regulation whereas processing based on simple perceptual characteristics (e.g., matching) has not. Evidence exists that the ventrolateral prefrontal cortex (VLPFC) might be of functional relevance during labeling by down-regulating limbic activity in the presence of threatening stimuli. However, it remained unclear whether this VLPFC activation was particularly specific to threat because previous studies focused exclusively on threatening stimuli. In the current study, 35 healthy participants labeled or matched both threatening and neutral pictures while undergoing 52-channel functional near-infrared spectroscopy. Results showed increased VLPFC activation during labeling of threatening but not neutral pictures. No increase in prefrontal activation was detected during matching. Moreover, skin conductance increased equally for both valence conditions during initial phases of labeling whereas during matching stronger increases were found for threatening stimuli. Although a general inverse relationship between VLPFC function and skin conductance was not confirmed, both were negatively correlated during matching of threatening pictures in subjects with high state anxiety. It was concluded that the VLPFC plays an essential role during implicit emotion regulation. Further, even simple perceptual processing seems to engage regulatory top-down activation in anxious individuals.

Increased prefrontal oxygenation related to distractor-resistant working memory in children with attention-deficit/hyperactivity disorder (ADHD)

This study aimed at investigating the effect of distraction on working memory and its underlying neural mechanisms in children with attention-deficit/hyperactivity disorder (ADHD). To this end, we studied hemodynamic activity in the prefrontal cortex using near-infrared spectroscopy while 16 children with ADHD and 10 typically developing (TD) children performed a working memory task. This task had two conditions: one involved a distraction during the memory delay interval, whereas the other had no systematic distraction. The ADHD patients showed significantly poorer behavioral performance compared with the TD group, particularly under the distraction. The ADHD group exhibited significantly higher level of prefrontal activation than did TD children. The activity level was positively correlated with the severity of ADHD symptoms. These results suggest that the impairment in the inhibition of distraction is responsible for the working memory deficits observed in ADHD children. Inefficient processing in the prefrontal cortex appears to underlie such deficits.

Contrast reversal of the eyes impairs infants' face processing: a near-infrared spectroscopic study

Human can easily detect other's eyes and gaze from early in life. Such sensitivity is supported by the contrast polarity of human eyes, which have a white sclera contrasting with the darker colored iris (Kobayashi & Kohshima, (1997). Nature, 387, 767-768; Kobayashi & Kohshima, (2001). Journal of Human Evolution, 40, 419-435). Recent studies suggest that the contrast polarity around the eyes plays an important role in infants' face processing. Newborns preferred upright face images to inverted ones in contrast-preserved faces, but not in contrast-reversed faces (Farroni et al., (2005). Proceedings of National Academy of Sciences of the United States of America, 102, p. 17245-17250). Seven- to 8-month-old infants failed to discriminate between faces when the contrast polarity of eyes was reversed (Otsuka et al., (2013). Journal of Experimental Child Psychology, 115, 598-606). Neuroimaging study with adults revealed that full-negative faces induced less activation in the right fusiform gyrus than either full-positive faces or negative faces with contrast-preserved eyes (Gilad et al., (2009). Proceedings of National Academy of Sciences of the United States of America, 106, p. 5353-5358). In the present study, we investigated whether contrast-reversed eyes diminish infants' brain activity related to face processing. We measured hemodynamic responses in the bilateral temporal area of 5- to 6-month-old infants. Their hemodynamic responses to faces with positive eyes and those with negative eyes were compared against the baseline activation during the presentation of object images. We found that the presentation of faces with positive eyes increased the concentration of oxy-Hb in the right temporal area and those of total-Hb in the bilateral temporal areas. No such change occurred for faces with negative eyes. Our results suggest the importance of contrast polarity of the eyes in the face-selective neural responses from early development.

A near-infrared brain function study of Chinese dyslexic children

Recently, two findings using functional magnetic resonance imaging of dyslexic in Chinese show the left middle frontal gyrus is a crucial area associated with reading disability. The purpose of present study was to replicate the previous findings using near-infrared spectroscopy and a consonant-vowel task which engaged finer-grained phonological processing. Compared to the control group, our study showed the dyslexic children had decreased amounts of oxy-hemoglobin and total-hemoglobin in the left dorsolateral prefrontal cortex. These results supported the previous findings and indicated that phonological deficit was also the cause of dyslexia in Chinese and it might be explained by decreased activity in left dorsolateral prefrontal cortex. Our study suggests that dyslexic children have an abnormal hemodynamic pattern in the left inferior frontal gyrus and the left middle frontal gyrus, which can provide a new target for diagnosing or treating the condition with the near-infrared spectroscopy.

Behavioral and neural differences during two versions of cognitive shifting tasks in young children and adults

The present study examined how young children and adult participants activated inferior prefrontal regions when they were given different cognitive shifting tasks. Children and adults were given two versions of the Dimensional Change Card Sort task (the standard and advanced versions), and brain activations during the tasks were examined using near infrared spectroscopy. On the behavioral level, the performance of both children and adults deteriorated during the advanced version as compared to the standard version. On the neural level, adults exhibited similar bilateral inferior prefrontal activations during the advanced version and the standard version. On the other hand, children showed the significant differences of the activations between the regions during the advanced version, but not during the standard version. The results indicated that children recruited different inferior prefrontal areas depending on the demands of cognitive shifting.

Disentangling Fun and Enjoyment in Exergames Using an Expanded Design, Play, Experience Framework: A Narrative Review

With exergames (as with physical activity in general), more intense and longer-duration game play should accrue more health benefits. Exergames, however, appear to be played for relatively short durations, often at medium or lower intensities. Ostensibly games are played for fun or enjoyment. Enhancing the fun or enjoyment experienced during exergame play should enhance the intensity and duration of physical activity, and thereby the health benefits. Research, reviewed herein, indicates fun and/or enjoyment in games are inherently laden with psychosocial, physiological, and embodiment substrates. Physical activity may also have separate or closely related psychosocial, physiological, and embodiment enjoyment substrates. Research is needed to integrate these levels of experience and to identify the game mechanics that enhance, and even maximize, the fun or enjoyment experienced in exergames, to thereby increase the health benefit.

Effects of video game playing on cerebral blood flow in young adults: a SPECT study

To study the impact of video game playing on the human brain, the effects of two video games playing on cerebral blood flow (CBF) in young adults were determined. Thirty healthy subjects comprising 18 males and 12 females who were familiar with video game playing were recruited. Each subject underwent three sessions of single photon emission computed tomography (SPECT) with a bolus injection of 20 mCi (99m)Tc ECD IV to measure their CBF. The first measurement was performed as baseline, the second and third measurements were performed after playing two different video games for 30 min, respectively. Statistic parametric mapping (SPM2) with Matlab 6.5 implemented on a personal computer was used for image analysis. CBF was significantly decreased in the prefrontal cortex and significantly increased in the temporal and occipital cortices after both video games playing. Furthermore, decreased CBF in the anterior cingulate cortex (ACC) which was significantly correlated with the number of killed characters was found after the violent game playing. The major finding of hypo-perfusion in prefrontal regions after video game playing is consistent with a previous study showing reduced or abnormal prefrontal cortex functions after video game playing. The second finding of decreased CBF in the ACC after playing the violent video game provides support for a previous hypothesis that the ACC might play a role in regulating violent behavior.

Size-invariant representation of face in infant brain: an fNIRS-adaptation study

We studied whether 5-month-old to 8-month-old infants process faces in a size-invariant manner by applying the fNIRS-adaptation paradigm used in our previous study. We used near-infrared spectroscopy to measure hemodynamic responses in the temporal regions of infants' brains during the repeated presentation of an identical face and different faces while changing the size of the faces. As a result, we found that (a) the hemodynamic responses in the channels around the T5 and T6 positions increased significantly during the presentation of different faces and (b) the hemodynamic responses in these channels showed attenuation to the presentation of the same face compared with the presentation of different faces even when the size of the faces altered. Our findings indicated that infants could show adaptation to the same face despite size alterations and that this processing occurred in the bilateral temporal areas.

Co-speech gesture production in an animation-narration task by bilinguals: a near-infrared spectroscopy study

To examine the neural mechanism of co-speech gesture production, we measured brain activity of bilinguals during an animation-narration task using near-infrared spectroscopy. The task of the participants was to watch two stories via an animated cartoon, and then narrate the contents in their first language (Ll) and second language (L2), respectively. The participants showed significantly more gestures in L2 than in L1. The number of gestures lowered at the ending part of the narration in L1, but not in L2. Analyses of concentration changes of oxygenated hemoglobin revealed that activation of the left inferior frontal gyrus (IFG) significantly increased during gesture production, while activation of the left posterior superior temporal sulcus (pSTS) significantly decreased in line with an increase in the left IFG. These brain activation patterns suggest that the left IFG is involved in the gesture production, and the left pSTS is modulated by the speech load.

Effects of aging on cerebral oxygenation during working-memory performance: a functional near-infrared spectroscopy study

Working memory is sensitive to aging-related decline. Evidence exists that aging is accompanied by a reorganization of the working-memory circuitry, but the underlying neurocognitive mechanisms are unclear. In this study, we examined aging-related changes in prefrontal activation during working-memory performance using functional Near-Infrared Spectroscopy (fNIRS), a noninvasive neuroimaging technique. Seventeen healthy young (21–32 years) and 17 healthy older adults (64–81 years) performed a verbal working-memory task (n-back). Oxygenated and deoxygenated hemoglobin concentration changes were registered by two fNIRS channels located over the left and right prefrontal cortex. Increased working-memory load resulted in worse performance compared to the control condition in older adults, but not in young participants. In both young and older adults, prefrontal activation increased with rising working-memory load. Young adults showed slight right-hemispheric dominance at low levels of working-memory load, while no hemispheric differences were apparent in older adults. Analysis of the time-activation curve during the high working-memory load condition revealed a continuous increase of the hemodynamic response in the young. In contrast to that, a quadratic pattern of activation was found in the older participants. Based on these results it could be hypothesized that young adults were better able to keep the prefrontal cortex recruited over a prolonged period of time. To conclude, already at low levels of working-memory load do older adults recruit both hemispheres, possibly in an attempt to compensate for the observed aging-related decline in performance. Also, our study shows that aging effects on the time course of the hemodynamic response must be taken into account in the interpretation of the results of neuroimaging studies that rely on blood oxygen levels, such as fMRI.

The effect of family therapy on the changes in the severity of on-line game play and brain activity in adolescents with on-line game addiction

We evaluated whether a brief 3-week family therapy intervention would change patterns of brain activation in response to affection and gaming cues in adolescents from dysfunctional families who met criteria for on-line game addiction. Fifteen adolescents with on-line game addiction and fifteen adolescents without problematic on-line game play and an intact family structure were recruited. Over 3 weeks, families were asked to carry out homework assignments focused on increasing family cohesion for more than 1 hour/day and 4 days/week. Before therapy, adolescents with on-line game addiction demonstrated decreased activity as measured by functional magnetic resonance imaging (fMRI) within the caudate, middle temporal gyrus, and occipital lobe in response to images depicting parental affection and increased activity of the middle frontal and inferior parietal in response scenes from on-line games, relative to healthy comparison subjects. Improvement in perceived family cohesion following 3 weeks of treatment was associated with an increase in the activity of the caudate nucleus in response to affection stimuli and was inversely correlated with changes in on-line game playing time. With evidence of brain activation changes in response to on-line game playing cues and images depicting parental love, the present findings suggest that family cohesion may be an important factor in the treatment of problematic on-line game playing.

Functional near-infrared spectroscopy studies in children

Psychosomatic and developmental behavioral medicine in pediatrics has been the subject of significant recent attention, with infants, school-age children, and adolescents frequently presenting with psychosomatic, behavioral, and psychiatric symptoms. These may be a consequence of insecurity of attachment, reduced self-confidence, and peer -relationship conflicts during their developmental stages. Developmental cognitive neuroscience has revealed significant associations between specific brain lesions and particular cognitive dysfunctions. Thus, identifying the biological deficits underlying such cognitive dysfunction may provide new insights into therapeutic prospects for the management of those symptoms in children. Recent advances in noninvasive neuroimaging techniques, and especially functional near-infrared spectroscopy (NIRS), have contributed significant findings to the field of developmental cognitive neuroscience in pediatrics. We present here a comprehensive review of functional NIRS studies of children who have developed normally and of children with psychosomatic and behavioral disorders.

Cortical activation during attention to sound in autism spectrum disorders

Individuals with autism spectrum disorders (ASDs) can demonstrate hypersensitivity to sounds as well as a lack of awareness of them. Several functional imaging studies have suggested an abnormal response in the auditory cortex of such subjects, but it is not known whether these subjects have dysfunction in the auditory cortex or are simply not listening. We measured changes in blood oxygenated hemoglobin (OxyHb) in the prefrontal and temporal cortices using near-infrared spectroscopy during various listening and ignoring tasks in 11 ASD and 12 control subjects. Here we show that the auditory cortex in ASD subjects responds to sounds fully during attention. OxyHb in the auditory cortex increased with intentional listening but not with ignoring of the same auditory stimulus in a similar fashion in both groups. Cortical responses differed not in the auditory but in the prefrontal region between the ASD and control groups. Thus, unawareness to sounds in ASD could be interpreted as due to inattention rather than dysfunction of the auditory cortex. Difficulties in attention control may account for the contrary behaviors of hypersensitivity and unawareness to sound in ASD.

Intensity dependent repetitive transcranial magnetic stimulation modulation of blood oxygenation

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is increasingly being investigated in clinical settings for the treatment of neurological and psychiatric disorders such as dystonia, schizophrenia, and major depressive disorder (MDD). Using near infra-red spectroscopy (NIRS), very short trains of rTMS have previously been shown to modulate cortical blood oxygenation.

METHODS

In order to investigate the effect of longer, clinically relevant trains of 1 Hz rTMS on oxy-hemoglobin (HbO) at prefrontal cortex, the current study applied ten minute trains of rTMS at both subthreshold and suprathreshold intensities.

RESULTS

A similar profile of oxygenation change was observed during the beginning 30-40 s of the trains, however for the remainder, subthreshold rTMS returned to baseline while the suprathreshold TMS resulted in a long period of reduced oxygenation.

LIMITATIONS

Small sample size.

CONCLUSIONS

The differences observed may be a product of changes in HbO requirements by inhibitory/excitatory neural circuits, either by reduced HbO demand or by increased HbO consumption, while sustained HbO reduction may be a consequence of a modulation of vaso-motor reactivity. This study has implications for understanding the mechanisms involved in the physiological changes evoked by rTMS and efficacious clinical application of rTMS in disorders such as MDD.

Do infants represent the face in a viewpoint-invariant manner? Neural adaptation study as measured by near-infrared spectroscopy

Recent adult functional magnetic resonance imaging (fMRI) studies reported that face-sensitive cortical areas showed attenuated responses to the repeated presentation of an identical facial image compared to the presentation of different facial images (fMRI-adaptation effects: e.g., Andrews and Ewbank, 2004). Building upon this finding, the current study, employing the adaptation paradigm, used near-infrared spectroscopy (NIRS) to explore the neural basis of face processing in infants. In Experiment 1, we compared hemodynamic responses in the bilateral temporal regions during the repeated presentation of the same face (the same-face condition) and the sequential presentation of different faces (the different-face condition). We found that (1) hemodynamic responses in the channels around the T5 and T6 regions increased during the presentation of different faces compared to those during the presentation of different objects; and that (2) these channels showed significantly lower response in the same-face condition than in the different-face condition, demonstrating the neural adaptation effect in 5- to 8-month-olds as measured by NIRS. In Experiment 2, when faces in both the same-face and different-face conditions were changed in viewpoint, lower hemodynamic responses in the same-face condition were found in 7- to 8-month-olds but not in 5- to 6-month-olds. Our results suggest that faces are represented in a viewpoint-invariant manner in 7- and 8-month-old infants.