Modulation effects of the intact motor skills on the relationship between social skills and motion perceptions in children with autism spectrum disorder: A pilot study.

BACKGROUND: An individual with autism spectrum disorder (ASD) has social skill, motor skill, and motion perception deficits. However, the relationship among them was not clarified. Therefore, this study aimed to evaluate the effects of motor skills on social skills and motion perception. METHODS: Five typically developed children and fourteen children with ASD participated in our study. The N200 component, a brain activity indicating motion perception, was induced in mid-temporal (MT/V5) brain area by watching a random dot kinematograph, and was recorded using a scalp electroencephalogram. Furthermore, the social responsiveness scale (SRS) indicating the social skill deficit, the developmental coordination disorder questionnaire (DCDQ) estimating the developmental coordination disorder (DCD), and the movement assessment battery for children second edition (MABC-2) indicating motor skills were recorded in the children with ASD. A hierarchical multiple regression analysis was conducted to examine the modulation effects of motor skills on the relationship between social skills and motion perception. The dependent variable was the N200 latency, and the independent variables were SRS, MABC-2, and combined MABC-2 and SRS. RESULTS: The N200 latency was more delayed in children with ASD relative that in typically developed children. Intact balance ability modulated the relationship between social skills and N200 latency in children with ASD. Within the high balance ability, when the social skills worsened, the N200 latency was shortened. CONCLUSIONS: This is the first report that intact motor skills could modulate the relationship between social skills and motion perception.

Uniqueness of action monitoring in children with autism spectrum disorder: Response types and temporal aspects.

BACKGROUND: Action monitoring, the process for evaluating the appropriateness of one's own actions, is reported to be atypical in individuals with autism spectrum disorder (ASD). METHOD: We examined the characteristics of action monitoring in 11 children with ASD and 12 children with typical development (TD), analyzing stimulus-locked and response-locked event-related potential components (i.e., N2; error-related negativity, ERN; and error positivity, Pe) related to execution of a flanker task. RESULTS: We found a smaller N2 amplitude in children with ASD than in those with TD. Children with ASD also had a larger amplitude of ERN for partial error responses (electromyographic activity corresponding to the inappropriate hand side before response execution) than did children with TD. Additionally, the ERN amplitude for the partial error response was correlated with the Autistic Mannerisms of the Social Responsiveness Scale. There were no significant differences in Pe amplitudes between children with ASD and those with TD. CONCLUSION: The results suggest that action monitoring in children with ASD is significantly different both before and after response execution. We hypothesized that the detail-focused processing style of ASD reduces the demands of action monitoring before response execution; however, autistic mannerisms evoke excessive concern regarding trivial mistakes after response execution.

Applicability of the Movement Assessment Battery for Children-Second Edition to Japanese children: A study of the Age Band 2.

BACKGROUND: The diagnosis of Developmental Coordination Disorder (DCD) requires a precise assessment of motor skills via a standardized tool such as the Movement Assessment Battery for Children-Second Edition (MABC-2). Although the MABC-2 has been widely used in English-speaking countries, to the best of our knowledge, no studies have examined its applicability to Japanese children. Thus, it has been difficult to diagnose DCD in Japan. AIMS: As a preliminary investigation preceding its formal standardization in Japan, we examined the applicability of the MABC-2. METHODS AND PROCEDURES: Participants comprised 132 typically developing Japanese children who completed a test set of the MABC-2 for Age Band 2. We analyzed both internal consistency and factorial validity for our Japanese sample. We also included a comparison between our sample of Japanese children and the normative sample of the MABC-2, as well as an examination of gender differences. OUTCOMES AND RESULTS: Our results indicated acceptable internal consistency and scale homogeneity. High factorial validity, which has not been examined in other populations, was also confirmed for the test set. Moreover, we found differences in component scores between the Japanese and normative children with respect to Manual Dexterity and Balance. We also found that girls obtained superior Manual Dexterity and Balance scores compared with boys. CONCLUSIONS AND IMPLICATIONS: The present findings represent the first step towards the standardization of the MABC-2 in a Japanese population.

Mu rhythm desynchronization by tongue thrust observation.

We aimed to investigate the mu rhythm in the sensorimotor area during tongue thrust observation and to obtain an answer to the question as to how subtle non-verbal orofacial movement observation activates the sensorimotor area. Ten healthy volunteers performed finger tap execution, tongue thrust execution, and tongue thrust observation. The electroencephalogram (EEG) was recorded from 128 electrodes placed on the scalp, and regions of interest were set at sensorimotor areas. The event-related desynchronization (ERD) and event-related synchronization (ERS) for the mu rhythm (8-13 Hz) and beta (13-25 Hz) bands were measured. Tongue thrust observation induced mu rhythm ERD, and the ERD was detected at the left hemisphere regardless whether the observed tongue thrust was toward the left or right. Mu rhythm ERD was also recorded during tongue thrust execution. However, temporal analysis revealed that the ERD associated with tongue thrust observation preceded that associated with execution by approximately 2 s. Tongue thrust observation induces mu rhythm ERD in sensorimotor cortex with left hemispheric dominance.

Cerebral oscillatory activity during simulated driving using MEG.

We aimed to examine cerebral oscillatory differences associated with psychological processes during simulated car driving. We recorded neuromagnetic signals in 14 healthy volunteers using magnetoencephalography (MEG) during simulated driving. MEG data were analyzed using synthetic aperture magnetometry to detect the spatial distribution of cerebral oscillations. Group effects between subjects were analyzed statistically using a non-parametric permutation test. Oscillatory differences were calculated by comparison between "passive viewing" and "active driving." "Passive viewing" was the baseline, and oscillatory differences during "active driving" showed an increase or decrease in comparison with a baseline. Power increase in the theta band was detected in the superior frontal gyrus (SFG) during active driving. Power decreases in the alpha, beta, and low gamma bands were detected in the right inferior parietal lobe (IPL), left postcentral gyrus (PoCG), middle temporal gyrus (MTG), and posterior cingulate gyrus (PCiG) during active driving. Power increase in the theta band in the SFG may play a role in attention. Power decrease in the right IPL may reflect selectively divided attention and visuospatial processing, whereas that in the left PoCG reflects sensorimotor activation related to driving manipulation. Power decreases in the MTG and PCiG may be associated with object recognition.

Facial identity recognition in children with autism spectrum disorders revealed by P300 analysis: a preliminary study.

BACKGROUND: To reveal the neural substrate of communication difficulties in children with autism spectrum disorders (ASDs), we investigated the P300 component of event-related potentials (ERPs) as represented by the average of electroencephalography findings time-locked to events and behavior. Because the P300 amplitude influences attentional resource allocation during discrimination, the component elicited during perception of known and unknown faces should indicate familiarity processing. METHODS AND RESULTS: Nine typically developing children (TD) and nine children with ASDs participated in this study (Experiment 1). The P300 amplitude in TD children was significantly larger during familiar face perception than during unfamiliar face perception (p<0.01). However, there was no evidence of familiarity effect in children with ASDs. In three children with ASDs, we also assessed the P300 amplitude during perception of a therapist's face one month before (baseline), a few days before and after social skills training (SST) sessions (Experiment 2). To evaluate the effect of familiarity on facial identity processing, we analyzed the therapist/unknown ratio of P300 amplitudes related to the face discrimination task as an index. The ratio was larger after SST sessions than before, but there was no difference in the ratio between baseline and before SST assessments. CONCLUSION: The P300 might be influenced by attentional resource allocation depending on the stage of learning face identification in children with ASDs. We speculate that this approach to evaluating brain responses during facial identity recognition could be used as a tool to clarify children's communication difficulties.

Event-related oscillations in structural and semantic encoding of faces.

OBJECTIVE: The ability to perceive faces is acquired through an interaction between species-specific biological mechanisms and social experience. To elucidate the mechanisms of the cognitive system underlying face recognition, we investigated cerebral oscillations related to encoding in 'person identity nodes'. METHODS: EEG was measured in nine healthy adults during perception of their own face, familiar face and unfamiliar face images. RESULTS: Event-related synchronization (ERS) in theta, alpha and beta bands was initially induced in occipito-temporal areas within 0-200 ms of the presentation of facial stimuli. In addition, delta ERS over parietal and left temporal areas was greater in response to familiar faces around 0-800 ms compared with unfamiliar faces. Beta ERS over the right prefrontal area was significantly greater in response to a participant's own face compared with a familiar face at 400-800 ms post-stimulus. CONCLUSIONS: ERS within 0-200 ms reflects structural encoding of faces (i.e., N170 of the event related potential). Delta ERS within 0-800 ms suggests an association with memory retrieval. Beta ERS within 400-800 ms is consistent with the cortical areas reported to be strongly related to self-face perception in previous fMRI studies. SIGNIFICANCE: The delta and beta bands ERS might provide an index of familiarity and self-recognition, respectively.

Reduced prefrontal hemodynamic response in children with ADHD during the Go/NoGo task: a NIRS study.

The current study examined the hemodynamic response during the Go/NoGo task in children with/without attention deficit/hyperactivity disorder (ADHD). Using near-infrared spectroscopy, oxy-Hb and deoxy-Hb concentration changes in the frontal areas were compared during the conditions with/without inhibitory demand. Compared with typically developing children, children with ADHD showed significantly reduced activation during the conditions with inhibitory demand (NoGo-condition) in the frontal areas. However, no significant differences in activation during the conditions without inhibitory demand (Go-condition) were found between the two groups. The current findings revealed that children with ADHD exhibit an altered hemodynamic response specifically during response inhibition, but not during response execution, and suggested the clinical usefulness of near-infrared spectroscopy for the evaluation of response inhibition deficits in children with ADHD.

Multiple band frequency analysis in a child of medial temporal lobe ganglioglioma.

We report a 1-year 6-month-old girl with ganglioglioma in the right medial temporal lobe who showed epileptic spasms in clusters. Spasms occasionally followed a dazed and fearful gaze. Interictal electroencephalography (EEG) showed diffuse bursts of slightly irregular high-voltage spikes and slow waves without hypsarrhythmia. The findings on ictal EEG, single-photon emission computed tomography, and F-18 fluorodeoxyglucose positron emission tomography indicated focus on the right medial temporal lobe. Ictal fast rhythmic activity analysis of scalp EEG by multiple band frequency analysis showed gamma rhythms at 65-80 Hz with a high spectral power around the tumor area. Epileptic spasms completely disappeared after tumor resection. These findings suggest that the cerebral cortex may be a source of epileptic spasms and indicate the possibility of usefulness of fast activity analysis in this condition.

Self-face recognition in children with autism spectrum disorders: a near-infrared spectroscopy study.

It is assumed that children with autism spectrum disorders (ASD) have specificities for self-face recognition, which is known to be a basic cognitive ability for social development. In the present study, we investigated neurological substrates and potentially influential factors for self-face recognition of ASD patients using near-infrared spectroscopy (NIRS). The subjects were 11 healthy adult men, 13 normally developing boys, and 10 boys with ASD. Their hemodynamic activities in the frontal area and their scanning strategies (eye-movement) were examined during self-face recognition. Other factors such as ASD severities and self-consciousness were also evaluated by parents and patients, respectively. Oxygenated hemoglobin levels were higher in the regions corresponding to the right inferior frontal gyrus than in those corresponding to the left inferior frontal gyrus. In two groups of children these activities reflected ASD severities, such that the more serious ASD characteristics corresponded with lower activity levels. Moreover, higher levels of public self-consciousness intensified the activities, which were not influenced by the scanning strategies. These findings suggest that dysfunction in the right inferior frontal gyrus areas responsible for self-face recognition is one of the crucial neural substrates underlying ASD characteristics, which could potentially be used to evaluate psychological aspects such as public self-consciousness.

Scanning strategies do not modulate face identification: eye-tracking and near-infrared spectroscopy study.

BACKGROUND: During face identification in humans, facial information is sampled (seeing) and handled (processing) in ways that are influenced by the kind of facial image type, such as a self-image or an image of another face. However, the relationship between seeing and information processing is seldom considered. In this study, we aimed to reveal this relationship using simultaneous eye-tracking measurements and near-infrared spectroscopy (NIRS) in face identification tasks. METHODOLOGY/PRINCIPAL FINDINGS: 22 healthy adult subjects (8 males and 14 females) were shown facial morphing movies in which an initial facial image gradually changed into another facial image (that is, the subject's own face was changed to a familiar face). The fixation patterns on facial features were recorded, along with changes in oxyhemoglobin (oxyHb) levels in the frontal lobe, while the subjects identified several faces. In the self-face condition (self-face as the initial image), hemodynamic activity around the right inferior frontal gyrus (IFG) was significantly greater than in the familiar-face condition. On the other hand, the scanning strategy was similar in almost all conditions with more fixations on the eyes and nose than on other areas. Fixation time on the eye area did not correlate with changes in oxyHb levels, and none of the scanning strategy indices could estimate the hemodynamic changes. CONCLUSIONS/SIGNIFICANCE: We conclude that hemodynamic activity, i.e., the means of processing facial information, is not always modulated by the face-scanning strategy, i.e., the way of seeing, and that the right IFG plays important roles in both self-other facial discrimination and self-evaluation.

Late response evoked by cerebellar stimuli: effect of optokinetic stimulation.

We previously demonstrated that late electromyographic responses with a latency of 100 ms were evoked bilaterally in soleus muscles following transcranial magnetic stimulation over the left cerebellum. Efferent fibers from the left cerebellum modulate vestibulospinal tract influences on the extensor muscles of the left hindlimb. Here, we investigated whether the vestibulospinal tract mediates this late response. We activated the vestibulospinal tract by optokinetic stimulation. Our results show that the latency of the soleus electromyographic response is shortened by optokinetic stimulation, but the latency of the motor response evoked by the corticospinal tract is unchanged. These findings support our hypothesis that vestibulospinal tracts mediate late electromyographic responses, and allow the development of techniques to assess the human vestibulospinal system function.

Effects of the emotional connotations in words on the frontal areas--a spatially filtered MEG study.

The objective of this study was to elucidate how and where emotional connotations in words influenced linguistic processing in the language-related areas. We recorded neuromagnetic signals in nine right-handed and one left-handed healthy volunteers while they silently read emotional and emotionless words written in Japanese kanji characters, and investigated the distribution of the cerebral oscillatory changes using synthetic aperture magnetometry. Event-related desynchronizations (ERDs) in the beta-low gamma bands were observed in the anterior cingulate cortex (ACC) that were specific to the reading of emotional words in seven of nine right-handers. Beta-low gamma band ERDs were also detected in the left inferior or middle frontal gyrus (IFG or MFG) in nine right-handers regardless of the tasks. The magnitude of the ERDs in the IFG or MFG was significantly greater during emotional-word reading than during emotionless-word reading in nine right-handers. Left-dominant ERDs in the beta and gamma bands were observed in the prefrontal cortex (PFC) when negative emotional words were read (i.e. sadness), while right-dominant ERDs were observed for positive emotional words (i.e. happiness) in seven of nine right-handers (p=0.012, corrected). In one left-hander, the ERD in the ACC and the greater ERD that occurred in the IFG that was specific to emotional-word reading were also observed, but their lateralities in the IFG and PFC were reversed. These results suggest that emotional connotations in words facilitated the ERDs in the frontal language-related areas, and that these facilitations might be modulated by emotional processing in the ACC. Furthermore, negative and positive emotional words may be processed by different mechanisms.

Gamma-band desynchronization in language areas reflects syntactic process of words.

The aim of this study was to verify the relation between gamma-band activity and process of function words. We recorded the neuromagnetic signals in six healthy volunteers during silent reading of verbs (verb task) and forming of the past tenses (past-tense task) and investigated the spatio-temporal distribution of event-related desynchronization (ERD) and synchronization using synthetic aperture magnetometry. In both tasks, ERDs were observed simultaneously at multiple language-related areas. The left junctional area of inferior frontal sulcus and precentral sulcus and the left supramarginal gyrus showed stronger and/or longer-lasting ERDs in past-tense task than in verb task. This result suggests that the gamma-activities reflect the syntactic process of words.

Neuromagnetic gamma-band activity in the primary and secondary somatosensory areas.

To evaluate the gamma-band activity related to somatosensory processing, we recorded neuromagnetic signals from seven healthy subjects. The source power changes evoked by electrical stimulation of the median nerve were estimated with synthetic aperture magnetometry (SAM). Source power in the low gamma band (40 Hz) decreased in the contralateral primary somatosensory cortex (SI) for a few hundred milliseconds (i.e. middle and long latency) and then increased inversely. Source power in the high gamma band (70-90 Hz) increased simultaneously both in the contralateral SI and contra/ipsilateral secondary somatosensory cortex (SII) in 80-180 ms. These results suggest that low and high gamma oscillations work under independent mechanisms during somatosensory processing. In particular, high gamma oscillations may play an essential role in making a functional connection between SI and SII.