Sayaka Yoshimura

Development of a multi-dimensional scale for PDD and ADHD.

A novel assessment scale, the multi-dimensional scale for pervasive developmental disorder (PDD) and attention-deficit/hyperactivity disorder (ADHD) (MSPA), is reported. Existing assessment scales are intended to establish each diagnosis. However, the diagnosis by itself does not always capture individual characteristics or indicate the level of support required, since inter-individual differences are substantial and co-morbidity is common. The MSPA consists of 14 domains and each domain is rated by a nine-point quantitative scale. The clinical and behavioral features are projected onto a radar-chart, which facilitates understanding of the disorders both by the patients themselves and by those in their surroundings. We assessed 179 patients and analyzed features by six diagnostic subgroups, which showed relationships between features and diagnoses. The inter-rater reliability was satisfactory.

Impaired Overt Facial Mimicry in Response to Dynamic Facial Expressions in High-Functioning Autism Spectrum Disorders

Previous electromyographic studies have reported that individuals with autism spectrum disorders (ASD) exhibited atypical patterns of facial muscle activity in response to facial expression stimuli. However, whether such activity is expressed in visible facial mimicry remains unknown. To investigate this issue, we videotaped facial responses in high-functioning individuals with ASD and controls to dynamic and static facial expressions of anger and happiness. Visual coding of facial muscle activity and the subjective impression ratings showed reduced congruent responses to dynamic expressions in the ASD group. Additionally, this decline was related to social dysfunction. These results suggest that impairment in overt facial mimicry in response to others’ dynamic facial expressions may underlie difficulties in reciprocal social interaction among individuals with ASD.

Sex differences in the rapid detection of emotional facial expressions.

Background Previous studies have shown that females and males differ in the processing of emotional facial expressions including the recognition of emotion, and that emotional facial expressions are detected more rapidly than are neutral expressions. However, whether the sexes differ in the rapid detection of emotional facial expressions remains unclear. Methodology/Principal Findings We measured reaction times (RTs) during a visual search task in which 44 females and 46 males detected normal facial expressions of anger and happiness or their anti-expressions within crowds of neutral expressions. Anti-expressions expressed neutral emotions with visual changes quantitatively comparable to normal expressions. We also obtained subjective emotional ratings in response to the facial expression stimuli. RT results showed that both females and males detected normal expressions more rapidly than anti-expressions and normal-angry expressions more rapidly than normal-happy expressions. However, females and males showed different patterns in their subjective ratings in response to the facial expressions. Furthermore, sex differences were found in the relationships between subjective ratings and RTs. High arousal was more strongly associated with rapid detection of facial expressions in females, whereas negatively valenced feelings were more clearly associated with the rapid detection of facial expressions in males. Conclusion Our data suggest that females and males differ in their subjective emotional reactions to facial expressions and in the emotional processes that modulate the detection of facial expressions.

The structural neural substrate of subjective happiness

Happiness is a subjective experience that is an ultimate goal for humans. Psychological studies have shown that subjective happiness can be measured reliably and consists of emotional and cognitive components. However, the neural substrates of subjective happiness remain unclear. To investigate this issue, we used structural magnetic resonance imaging and questionnaires that assessed subjective happiness, the intensity of positive and negative emotional experiences, and purpose in life. We found a positive relationship between the subjective happiness score and gray matter volume in the right precuneus. Moreover, the same region showed an association with the combined positive and negative emotional intensity and purpose in life scores. Our findings suggest that the precuneus mediates subjective happiness by integrating the emotional and cognitive components of happiness.

Increased Putamen Volume in Adults with Autism Spectrum Disorder

Basal ganglia (BG) abnormalities are implicated in the pathophysiology of autism spectrum disorder (ASD). However, studies measuring the volume of the entire BG in individuals with ASD have reported discrepant findings, and no study conducted volume measurement of the entire substructures of the BG (the caudate, putamen, nucleus accumbens, and globus pallidus) in individuals with ASD. We delineated the BG substructures and measured their volumes in 29 adults with ASD without intellectual disabilities and 29 age- and gender-matched typically developed adult controls. We acquired T1-weighted anatomical images and performed semiautomated delineation and volume measurements of the above-mentioned subregions. Total cerebral volumes, sex, and ages were partialed out. Compared with controls, the putamen was significantly larger in the ASD group. The increased volume of the putamen found in high-functioning adults with ASD suggests that structural or histological abnormalities of the putamen may underlie the pathologies of ASD, such as repetitive and stereotyped behaviors and impaired social interactions.

Is impaired joint attention present in non-clinical individuals with high autistic traits?

BackgroundJoint attention skills are impaired in individuals with autism spectrum disorder (ASD). Recently, varying degrees of autistic social attention deficit have been detected in the general population. We investigated gaze-triggered attention in individuals with high and low levels of autistic traits under visual–auditory cross-modal conditions, which are more sensitive to social attention deficits than unimodal paradigms.MethodsSixty-six typically developing adults were divided into low- and high-autistic-trait groups according to scores on the autism-spectrum quotient (AQ) questionnaire. We examined gaze-triggered attention under visual–auditory cross-modal conditions. Two sounds (a social voice and a non-social tone) were manipulated as targets to infer the relationship between the cue and the target. Two types of stimulus onset asynchrony (SOA) conditions (a shorter 200-ms SOA and a longer 800-ms SOA) were used to directly test the effect of gaze cues on the detection of a sound target across different temporal intervals.ResultsIndividuals with high autistic traits (high-AQ group) did not differ from those with low autistic traits (low-AQ group) with respect to gaze-triggered attention when voices or tones were used as targets under the shorter SOA condition. In contrast, under the longer SOA condition, gaze-triggered attention was not observed in response to tonal targets among individuals in the high-AQ group, whereas it was observed among individuals in the low-AQ group. The results demonstrated that cross-modal gaze-triggered attention is short-lived in individuals with high autistic traits.ConclusionsThis finding provides insight into the cross-modal joint attention function among individuals along the autism spectrum from low autistic traits to ASD and may further our understanding of social behaviours among individuals at different places along the autistic trait continuum.

Structural Neural Substrates of Reading the Mind in the Eyes.

The ability to read the minds of others in their eyes plays an important role in human adaptation to social environments. Behavioral studies have resulted in the development of a test to measure this ability (Reading the Mind in the Eyes Test, revised version; Eyes Test), and have demonstrated that this ability is consistent over time. Although functional neuroimaging studies revealed brain activation while performing the Eyes Test, the structural neural substrates supporting consistent performance on the Eyes Test remain unclear. In this study, we assessed the Eyes Test and analyzed structural magnetic resonance images using voxel-based morphometry (VBM) in healthy participants. Test performance was positively associated with the gray matter volumes of the dorsomedial prefrontal cortex, inferior parietal lobule (temporoparietal junction), and precuneus in the left hemisphere. These results suggest that the fronto-temporoparietal network structures support the consistent ability to read the mind in the eyes.

Attention orienting by eye gaze and arrows reveals flexibility to environmental changes

This study aimed to evaluate the difference in non-predictive cues between gaze and arrows in attention orienting. Attention orienting was investigated with gaze or arrows as separate cues in a simple condition (i.e., block design) in Experiment 1 and in an unpredictable condition (i.e., randomized design) in Experiment 2. Two kinds of sound (voice and tone) stimuli were used as targets. Results showed that gaze and arrow cues induced enhanced attention orienting to a voice versus tone target in the block condition. However, in the randomized condition, enhanced attention orienting to a voice versus tone target was found in gaze but not arrow cues. The congruency of the meaning between a social cue (i.e., gaze) and a social target (i.e., voice) was clear in the randomized but not blocked design, because social gaze and non-social arrow cues were implemented in the same block. Thus, attention orienting might be mediated by the associated relationship of cue-target in a randomized condition, as an enhanced orienting effect was found when the associated relationship of cue-target was strong (i.e., social cue and target). The present study suggests that the difference in attention orienting between gaze and arrows is apparent in a randomized design (the unpredictable condition), and people employ a flexibly strategy of orienting to better respond to environmental changes.

Putamen volume correlates with obsessive compulsive characteristics in healthy population.

Obsessions and compulsions (OCs) are frequent in healthy subjects; however neural backgrounds of the subclinical OCs were largely unknown. Results from recent studies suggested involvement of the putamen in the OC traits. To investigate this issue, 49 healthy subjects were assessed using structural magnetic resonance imaging (MRI) and the Maudsley Obsessive Compulsive Inventory (MOCI). Anatomical delineation on MRI yielded the global volume and local shape of the putamen. Other striatal structures (the caudate nucleus and globus pallidus) were also examined for exploratory purpose. The relationship between volume/shape of each structures and MOCI measure was analyzed, with sex, age, state anxiety, trait anxiety, and full-scale Intelligence Quotient regressed out. The volume analysis revealed a positive relationship between the MOCI total score and the bilateral putamen volumes. The shape analysis demonstrated associations between the higher MOCI total score and hypertrophy of the anterior putamen in both hemispheres. The present study firstly revealed that the volume changes of the putamen correlated with the manifestation of subclinical OC traits. The dysfunctional cortico-anterior striatum networks seemed to be one of the neuronal subsystems underlying the subclinical OC traits.

Time course of gamma-band oscillation associated with face processing in the inferior occipital gyrus and fusiform gyrus: A combined fMRI and MEG study.

Debate continues over whether the inferior occipital gyrus (IOG) or the fusiform gyrus (FG) represents the first stage of face processing and what role these brain regions play. We investigated this issue by combining functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) in normal adults. Participants passively observed upright and inverted faces and houses. First, we identified the IOG and FG as face‐specific regions using fMRI. We applied beamforming source reconstruction and time–frequency analysis to MEG source signals to reveal the time course of gamma‐band activations in these regions. The results revealed that the right IOG showed higher gamma‐band activation in response to upright faces than to upright houses at 100 ms from the stimulus onset. Subsequently, the right FG showed greater gamma‐band response to upright faces versus upright houses at around 170 ms. The gamma‐band activation in the right IOG and right FG was larger in response to inverted faces than to upright faces at the later time window. These results suggest that (1) the gamma‐band activities occurs rapidly first in the IOG and next in the FG and (2) the gamma‐band activity in the right IOG at later time stages is involved in configuration processing for faces. Hum Brain Mapp 38:2067–2079, 2017.