Motofumi Sumiya | National Institute for Physiological Sciences (NIPS) (original) (raw)

Papers by Motofumi Sumiya

Research paper thumbnail of Surprise acts as a reducer of outcome value

Research paper thumbnail of Emotions surrounding friendships of adolescents with autism spectrum disorder in Japan: A qualitative interview study

Emotions are embedded in culture and play a pivotal role in making friends and interacting with p... more Emotions are embedded in culture and play a pivotal role in making friends and interacting with peers. To support the social participation of students with autism spectrum disorders (ASD) it is essential to understand their emotional life in the context of ethnic and school cultures. We are particularly interested in how anxiety and loneliness are experienced in developing and maintaining friendships in the daily encounters of adolescents with ASD in the specific context of Japanese schools, because these emotions could serve either as facilita-tors or barriers to social interaction, depending on how individuals manage them. The present qualitative study investigated perceptions of emotions related to friendship in the everyday school life of 11 adolescents with ASD in Japan. Data were collected by means of semi-structured individual interviews, which revealed a wide range of motivations for socialization , limited future prospects to deepen friendships, robust self-awareness of one's own social challenges, and conscious efforts to cope with these challenges. An inductive approach to data analysis resulted in four themes: social motivation, loneliness, anxiety, and distress. To our knowledge this is the first study to uncover the rich emotional life of adolescents with ASD in the context of their friendships in an Asian culture.

Research paper thumbnail of Brain networks of social action-outcome contingency: The role of the ventral striatum in integrating signals from the sensory cortex and medial prefrontal cortex

Social interactions can be facilitated by action-outcome contingency, in which self-actions resul... more Social interactions can be facilitated by action-outcome contingency, in which self-actions result in relevant responses from others. Research has indicated that the striatal reward system plays a role in generating action-outcome contingency signals. However, the neural mechanisms wherein signals regarding self-action and others' responses are integrated to generate the contingency signal remain poorly understood. We conducted a functional MRI study to test the hypothesis that brain activity representing the self modulates connectivity between the striatal reward system and sensory regions involved in the processing of others' responses. We employed a contingency task in which participants made the listener laugh by telling jokes. Participants reported more pleasure when greater laughter followed their own jokes than those of another. Self-relevant listener's responses produced stronger activation in the medial prefrontal cortex (mPFC). Laughter was associated with activity in the auditory cortex. The ventral striatum exhibited stronger activation when participants made listeners laugh than when another did. In physio-physiological interaction analyses, the ventral striatum showed interaction effects for signals extracted from the mPFC and auditory cortex. These results support the hypothesis that the mPFC, which is implicated in self-related processing, gates sensory input associated with others' responses during value processing in the ventral striatum.

Research paper thumbnail of Temporal reward discounting and ADHD: task and symptom specific effects

This study investigated a new aspect of the association between ADHD symptoms and delay aversion.... more This study investigated a new aspect of the association between ADHD symptoms and delay aversion. Participants were 55 undergraduate Psychology students with varying levels of self-reported ADHD symptoms. Various delay aversion tasks were used, including real and hypothetical temporal discounting tasks previously used in the field of ADHD. ADHD symptoms, specifically hyperactivity/impulsivity, were associated with steep discounting, but only when rewards and delays were real. These data suggest that (1) real temporal discounting tasks are more sensitive to ADHD-related delay aversion than hypothetical ones; (2) delay aversion may be a causal mechanism specifically associated with ADHD-Combined and Hyperactive/Impulsive Types but not Inattentive Type. These findings may help refine behavioral treatment approaches and models of ADHD.

Research paper thumbnail of Studying the relation between temporal reward discounting tasks used in populations with ADHD: A factor analysis

International journal of …, 2010

Background: This study aimed at investigating the relationship between tasks that have been used ... more Background: This study aimed at investigating the relationship between tasks that have been used in attention deficit hyperactivity disorder (ADHD) to measure choices between smaller immediate and larger delayed rewards: real and hypothetical temporal discounting tasks, and single-choice paradigms.Methods: Participants were 55 undergraduate psychology students. Tasks included a real and hypothetical version of a temporal discounting (TD) task with choices between a large reward (10 cents) after delays up to 60 seconds, and smaller immediate rewards (2–8 cents); two versions of a hypothetical temporal discounting task with choices between a large reward ($100) after delays up to 120 months, and smaller immediate rewards ($1–$95); a Choice Delay Task with choices between one point now and two points after 30 seconds (one point is worth five cents).Results: Correlation analyses showed that the real and the hypothetical TD tasks with 10 cents were very strongly associated. However, the hypothetical TD tasks with $100 did not correlate with either the real or the hypothetical TD task with 10 cents. Principal component analysis extracted two components: one for small amounts and short delays, and a second one for large rewards and long delays.Conclusions: Temporal reward discounting is not a uniform construct. Functional brain imaging research could shed more light on unique brain activation patterns associated with different forms of temporal reward discounting. Copyright © 2010 John Wiley & Sons, Ltd.

Research paper thumbnail of Surprise acts as a reducer of outcome value

Research paper thumbnail of Emotions surrounding friendships of adolescents with autism spectrum disorder in Japan: A qualitative interview study

Emotions are embedded in culture and play a pivotal role in making friends and interacting with p... more Emotions are embedded in culture and play a pivotal role in making friends and interacting with peers. To support the social participation of students with autism spectrum disorders (ASD) it is essential to understand their emotional life in the context of ethnic and school cultures. We are particularly interested in how anxiety and loneliness are experienced in developing and maintaining friendships in the daily encounters of adolescents with ASD in the specific context of Japanese schools, because these emotions could serve either as facilita-tors or barriers to social interaction, depending on how individuals manage them. The present qualitative study investigated perceptions of emotions related to friendship in the everyday school life of 11 adolescents with ASD in Japan. Data were collected by means of semi-structured individual interviews, which revealed a wide range of motivations for socialization , limited future prospects to deepen friendships, robust self-awareness of one's own social challenges, and conscious efforts to cope with these challenges. An inductive approach to data analysis resulted in four themes: social motivation, loneliness, anxiety, and distress. To our knowledge this is the first study to uncover the rich emotional life of adolescents with ASD in the context of their friendships in an Asian culture.

Research paper thumbnail of Brain networks of social action-outcome contingency: The role of the ventral striatum in integrating signals from the sensory cortex and medial prefrontal cortex

Social interactions can be facilitated by action-outcome contingency, in which self-actions resul... more Social interactions can be facilitated by action-outcome contingency, in which self-actions result in relevant responses from others. Research has indicated that the striatal reward system plays a role in generating action-outcome contingency signals. However, the neural mechanisms wherein signals regarding self-action and others' responses are integrated to generate the contingency signal remain poorly understood. We conducted a functional MRI study to test the hypothesis that brain activity representing the self modulates connectivity between the striatal reward system and sensory regions involved in the processing of others' responses. We employed a contingency task in which participants made the listener laugh by telling jokes. Participants reported more pleasure when greater laughter followed their own jokes than those of another. Self-relevant listener's responses produced stronger activation in the medial prefrontal cortex (mPFC). Laughter was associated with activity in the auditory cortex. The ventral striatum exhibited stronger activation when participants made listeners laugh than when another did. In physio-physiological interaction analyses, the ventral striatum showed interaction effects for signals extracted from the mPFC and auditory cortex. These results support the hypothesis that the mPFC, which is implicated in self-related processing, gates sensory input associated with others' responses during value processing in the ventral striatum.

Research paper thumbnail of Temporal reward discounting and ADHD: task and symptom specific effects

This study investigated a new aspect of the association between ADHD symptoms and delay aversion.... more This study investigated a new aspect of the association between ADHD symptoms and delay aversion. Participants were 55 undergraduate Psychology students with varying levels of self-reported ADHD symptoms. Various delay aversion tasks were used, including real and hypothetical temporal discounting tasks previously used in the field of ADHD. ADHD symptoms, specifically hyperactivity/impulsivity, were associated with steep discounting, but only when rewards and delays were real. These data suggest that (1) real temporal discounting tasks are more sensitive to ADHD-related delay aversion than hypothetical ones; (2) delay aversion may be a causal mechanism specifically associated with ADHD-Combined and Hyperactive/Impulsive Types but not Inattentive Type. These findings may help refine behavioral treatment approaches and models of ADHD.

Research paper thumbnail of Studying the relation between temporal reward discounting tasks used in populations with ADHD: A factor analysis

International journal of …, 2010

Background: This study aimed at investigating the relationship between tasks that have been used ... more Background: This study aimed at investigating the relationship between tasks that have been used in attention deficit hyperactivity disorder (ADHD) to measure choices between smaller immediate and larger delayed rewards: real and hypothetical temporal discounting tasks, and single-choice paradigms.Methods: Participants were 55 undergraduate psychology students. Tasks included a real and hypothetical version of a temporal discounting (TD) task with choices between a large reward (10 cents) after delays up to 60 seconds, and smaller immediate rewards (2–8 cents); two versions of a hypothetical temporal discounting task with choices between a large reward ($100) after delays up to 120 months, and smaller immediate rewards ($1–$95); a Choice Delay Task with choices between one point now and two points after 30 seconds (one point is worth five cents).Results: Correlation analyses showed that the real and the hypothetical TD tasks with 10 cents were very strongly associated. However, the hypothetical TD tasks with $100 did not correlate with either the real or the hypothetical TD task with 10 cents. Principal component analysis extracted two components: one for small amounts and short delays, and a second one for large rewards and long delays.Conclusions: Temporal reward discounting is not a uniform construct. Functional brain imaging research could shed more light on unique brain activation patterns associated with different forms of temporal reward discounting. Copyright © 2010 John Wiley & Sons, Ltd.