Hirokazu Kumazaki
Kanazawa University
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Publication
Featured researches published by Hirokazu Kumazaki.
Molecular Autism | 2016
Hirokazu Kumazaki; Taro Muramatsu; Takashi X. Fujisawa; Masutomo Miyao; Eri Matsuura; Ken Ichi Okada; Hirotaka Kosaka; Akemi Tomoda; Masaru Mimura
BackgroundAtypical responsiveness to olfactory stimuli has been reported as the strongest predictor of social impairment in children with autism spectrum disorders (ASD). However, previous laboratory-based sensory psychophysical studies that have aimed to investigate olfactory sensitivity in children with ASD have produced inconsistent results. The methodology of these studies is limited by several factors, and more sophisticated approaches are required to produce consistent results.MethodsWe measured olfactory detection thresholds in children with ASD and typical development (TD) using a pulse ejection system—a newly developed methodology designed to resolve problems encountered in previous studies. The two odorants used as stimuli were isoamyl acetate and allyl caproate.ResultsForty-three participants took part in this study: 23 (6 females, 17 males) children with ASD and 20 with TD (6 females, 14 males). Olfactory detection thresholds of children with ASD were significantly higher than those of TD children with both isoamyl acetate (2.85 ± 0.28 vs 1.57 ± 0.15; p < 0.001) and allyl caproate ( 3.30 ± 0.23 vs 1.17 ± 0.08; p < 0.001).ConclusionsWe found impaired olfactory detection thresholds in children with ASD. Our results contribute to a better understanding of the olfactory abnormalities that children with ASD experience. Considering the role and effect that odors play in our daily lives, insensitivity to some odorants might have a tremendous impact on children with ASD. Future studies of olfactory processing in ASD may reveal important links between brain function, clinically relevant behavior, and treatment.
British Journal of Psychiatry Open | 2015
Shinichiro Takiguchi; Takashi X. Fujisawa; Sakae Mizushima; Daisuke N. Saito; Yuko Okamoto; Koji Shimada; Michiko Koizumi; Hirokazu Kumazaki; Minyoung Jung; Hirotaka Kosaka; Michio Hiratani; Yusei Ohshima; Martin H. Teicher; Akemi Tomoda
Background Child maltreatment is a major risk factor for psychopathology, including reactive attachment disorder (RAD). Aims To examine whether neural activity during reward processing was altered in children and adolescents with RAD. Method Sixteen children and adolescents with RAD and 20 typically developing (TD) individuals performed tasks with high and low monetary rewards while undergoing functional magnetic resonance imaging. Results Significantly reduced activity in the caudate and nucleus accumbens was observed during the high monetary reward condition in the RAD group compared with the TD group (P=0.015, family-wise error-corrected cluster level). Significant negative correlations between bilateral striatal activity and avoidant attachment were observed in the RAD and TD groups. Conclusions Striatal neural reward activity in the RAD group was markedly decreased. The present results suggest that dopaminergic dysfunction occurs in the striatum of children and adolescents with RAD, leading towards potential future risks for psychopathology. Declaration of interest None. Copyright and usage
robot and human interactive communication | 2016
Jiro Shimaya; Yuichiro Yoshikawa; Yoshio Matsumoto; Hirokazu Kumazaki; Hiroshi Ishiguro; Masaru Mimura; Masutomo Miyao
We conducted a pilot experiment to examine the potential of a communication robot for supporting verbal interaction among adolescents with autism spectrum disorders (ASD) and their caregivers. Three teenagers with ASD indirectly conversed with their teacher via a desktop humanoid robot for around 40 min on average per day. In this situation, they showed some positive tendencies such as non-echolalic responses and talk about problems related to human relationships; they had not shown such tendencies before when they directly talked with their teacher in their daily life. During the trials, they also showed changes in their attitudes toward their teachers and friends; this implies that individuals with ASD could use their experience of communication with a robot for communication with a human. A quantitative analysis of the utterances in the trials suggested that reduced utterances from a caregiver might positively influence individuals with ASD toward sharing more information.
Frontiers in Psychiatry | 2017
Hirokazu Kumazaki; Zachary Warren; Blythe A. Corbett; Yuichiro Yoshikawa; Yoshio Matsumoto; Haruhiro Higashida; Teruko Yuhi; Takashi Ikeda; Hiroshi Ishiguro; Mitsuru Kikuchi
The feasibility and preliminary efficacy of an android robot-mediated mock job interview training in terms of both bolstering self-confidence and reducing biological levels of stress in comparison to a psycho-educational approach human interview was assessed in a randomized study. Young adults (ages 18–25 years) with autism spectrum disorder (ASD) were randomized to participate either in a mock job interview training with our android robot system (n = 7) or a self-paced review of materials about job-interviewing skills (n = 8). Baseline and outcome measurements of self-reported performance/efficacy and salivary cortisol were obtained after a mock job interview with a human interviewer. After training sessions, individuals with ASD participating in the android robot-mediated sessions reported marginally improved self-confidence and demonstrated significantly lower levels of salivary cortisol as compared to the control condition. These results provide preliminary support for the feasibility and efficacy of android robot-mediated learning.
Frontiers in Psychiatry | 2015
Sakae Mizushima; Takashi X. Fujisawa; Shinichiro Takiguchi; Hirokazu Kumazaki; Shiho Tanaka; Akemi Tomoda
Childhood maltreatment (CM), including abuse and neglect, is a crucial factor that distorts child development. CM is associated with alterations in numerous brain regions, and may be associated with hormonal dysregulation. This study aimed to investigate differences in secretion patterns of cortisol (CT) and oxytocin (OT) among children who experienced CM, children living in residential care facilities and in unstable environments. Among 38 maltreated children, 23 (mean age = 12.2 years, SD = 3.0) were categorized as “Settled” and 15 (mean age = 13.1 years, SD = 2.2) as “Unsettled.” Twenty-six age- and gender-matched (mean age = 12.6 years, SD = 2.1), typically developing (TD) children were also included. Clinical and psychological assessments, including IQ and trauma evaluations, were conducted for all participants. Age, gender, and full-scale IQ were used as covariates in hormone analysis. Two saliva samples were collected, one on awakening and the other at bedtime. There were significant differences in the awakening CT levels of the “Unsettled” group, and in bedtime OT levels in the “Settled” group as compared with TD children, and between CM groups. Furthermore, there was a significant difference in trauma-symptomatic depression scores between the “Settled” and “Unsettled” CM group. These results suggest that CT diurnal secretions tend to be reactive to current stress rather than previous experience. OT diurnal secretions are presumably hyper-regulated for coping with the environment to survive and thrive. By measuring salivary CT/OT diurnal patterns, hormonal dysregulation of CM children living in “Settled” environments and “Unsettled” environments was indicated.
Journal of Clinical Psychopharmacology | 2014
Hirokazu Kumazaki; Koichiro Watanabe; Yasushi Imasaka; Kazuhiko Iwata; Akemi Tomoda; Masaru Mimura
Abstract We report several cases in which patients with autistic disorder with mental retardation who received risperidone experienced urinary incontinence. We retrospectively investigated the medical records of patients housed in facilities for patients with autistic disorder with mental retardation. Those who had undergone a medical examination at a hospital in Tokyo from April 1999 to March 2009 were included in the study. Retrospective data were gathered including age, sex, IQ, birth weight, dosage of risperidone, urinary density, as well as existence of urinary and fecal incontinence. We divided the participants into those who did and did not experience urinary incontinence after taking risperidone and compared the 2 groups. Risperidone had been prescribed to 35 patients. In spite of the fact that no patient had a history of urinary incontinence, 14 patients experienced urinary incontinence after receiving risperidone. Moreover, 4 of these 14 patients also had fecal incontinence. Among the variables we examined, the only significant difference between groups was in sex, with significantly more women experiencing incontinence compared with men. When the dose of risperidone was reduced or the patients switched to other drugs, urinary incontinence of the patients improved. Hence, risperidone may have a casual relationship with urinary incontinence. Further research is needed to understand the pathophysiology of possible effect.
American Journal of Psychiatry | 2017
Hirokazu Kumazaki; Taro Muramatsu; Yuichiro Yoshikawa; Yoshio Matsumoto; Masutomo Miyao; Hiroshi Ishiguro; Masaru Mimura; Yoshio Minabe; Mitsuru Kikuchi
TO THE EDITOR: Facial expression is crucial for conveying emotions and communicating. Altered facial expressivity could contribute to social isolation and difficulties in emotional regulation (1). Individualswithautismspectrumdisorder (ASD) exhibit little facial expressivity (2). However, few studies have investigated interventions for improving facial expressivity in such patients. This letter documents the case of a patient with ASD who received intervention using an android robot. The patient provided informed consent, and the study design was approved by the appropriate ethics review boards.
Frontiers in Psychiatry | 2018
Hirokazu Kumazaki; Zachary Warren; Amy Swanson; Yuichiro Yoshikawa; Yoshio Matsumoto; Hideyuki Takahashi; Nilanjan Sarkar; Hiroshi Ishiguro; Masaru Mimura; Yoshio Minabe; Mitsuru Kikuchi
Research suggests that many individuals with autism spectrum disorder (ASD) often demonstrate challenges providing appropriate levels of information during conversational interchanges. Considering the preference of individuals with ASD, and recent rapid technological advances, robotic systems may yield promise in promoting certain aspects of conversation and interaction such as self-disclosure of appropriate personal information. In the current work, we evaluated personal disclosures of events with specific emotional content across two differing robotic systems (android and simplistic humanoid) and human interactions. Nineteen participants were enrolled in this study: 11 (2 women and 9 men) adolescents with ASD and 8 (4 women and 4 men) adolescents with TD. Each participant completed a sequence of three interactions in a random order. Results indicated differences regarding comfort level and length of disclosures between adolescents with ASD and typically developing (TD) controls in relation to system interactions. Specifically, adolescents with ASD showed a preference for interacting with the robotic systems compared to TD controls and demonstrated lengthier disclosures when interacting with the visually simple humanoid robot compared to interacting with human interviewer. The findings suggest that robotic systems may be useful in eliciting and promoting aspects of social communication such as self-disclosure for some individuals with ASD.
Scientific Reports | 2017
Yuko Yoshimura; Mitsuru Kikuchi; Norio Hayashi; Hirotoshi Hiraishi; Chiaki Hasegawa; Tetsuya Takahashi; Manabu Oi; Gerard B. Remijn; Takashi Ikeda; Daisuke N. Saito; Hirokazu Kumazaki; Yoshio Minabe
The inferior frontal and superior temporal areas in the left hemisphere are crucial for human language processing. In the present study, we investigated the magnetic mismatch field (MMF) evoked by voice stimuli in 3- to 5-year-old typically developing (TD) children and children with autism spectrum disorder (ASD) using child-customized magnetoencephalography (MEG). The children with ASD exhibited significantly decreased activation in the left superior temporal gyrus compared with the TD children for the MMF amplitude. If we classified the children with ASD according to the presence of a speech onset delay (ASD - SOD and ASD - NoSOD, respectively) and compared them with the TD children, both ASD groups exhibited decreased activation in the left superior temporal gyrus compared with the TD children. In contrast, the ASD - SOD group exhibited increased activity in the left frontal cortex (i.e., pars orbitalis) compared with the other groups. For all children with ASD, there was a significant negative correlation between the MMF amplitude in the left pars orbitalis and language performance. This investigation is the first to show a significant difference in two distinct MMF regions in ASD – SOD children compared with TD children.
Scientific Reports | 2016
Hidetsugu Komeda; Hidekazu Osanai; Kaichi Yanaoka; Yuko Okamoto; Toru Fujioka; Sumiyoshi Arai; Keisuke Inohara; Masuo Koyasu; Takashi Kusumi; Shinichiro Takiguchi; Masao Kawatani; Hirokazu Kumazaki; Michio Hiratani; Akemi Tomoda; Hirotaka Kosaka
Autism spectrum disorder (ASD) is characterized by problems with reciprocal social interaction, repetitive behaviours/narrow interests, and impairments in the social cognition and emotional processing necessary for intention-based moral judgements. The aim of this study was to examine the information used by early adolescents with and without ASD when they judge story protagonists as good or bad. We predicted that adolescents with ASD would use protagonists’ behaviour, while typically developing (TD) adolescents would use protagonists’ characteristics when making the judgements. In Experiment 1, we measured sentence by sentence reading times and percentages for good or bad judgements. In Experiment 2, two story protagonists were presented and the participants determined which protagonist was better or worse. Experiment 1 results showed that the adolescents with ASD used protagonist behaviours and outcomes, whereas the TD adolescents used protagonist characteristics, behaviours, and outcomes. In Experiment 2, TD adolescents used characteristics information when making “bad” judgements. Taken together, in situations in which participants cannot go back and assess (Experiment 1), and in comparable situations in which all information is available (Experiment 2), adolescents with ASD do not rely on information about individual characteristics when making moral judgements.
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National Institute of Advanced Industrial Science and Technology
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