Research Activities

Research participants: Please contact the Principal Investigator if you have any questions about the research you participated in or if you would like to have your data withdrawn from further analysis of the collected data.

  • Unit Principal Investigator: Gail Tripp
  • Phone: 098-966-8812
  • E-mail: tripp@oist.jp
  • Address: OIST Lab 4 Level C, 1919-1 Tancha, Onna, Kunigami, Okinawa, Japan 904-0495

1. Role of Reinforcement in ADHD

1.1 Reinforcement sensitivity, working memory, and attention deficit hyperactivity disorder: Changing reinforcement contingencies and response cost (HSR-2008-001)

Research period: 12/1/2008- 3/31/2021 (may be extended)

Summary: The research aims to further clarify the nature and extent of altered reinforcement sensitivity in children displaying symptoms consistent with a diagnosis of DSM-IV/DSM-5 ADHD (referred to as children with ADHD). More specifically, we plan to (a) compare the extent to which different schedules of reinforcement (e.g., reinforcement frequency) and changes in reinforcement contingencies influence the behavior of children with and without ADHD, (b) assess the effect of discontinuing reinforcement on the behavior of the two groups of children, (c) compare the influence of response cost (loss of points) on how children with and without ADHD allocate their behavior, and (d) assess how well the children condition to cues that predict reward (i.e., how strongly they associate cues and reward). We will also assess the children’s performance on tests of working memory (retrieving and manipulating information) and whether this is linked to their sensitivity to reinforcement. The studies will extend our previous research and contribute new fundamental knowledge about reinforcement mechanisms in children whose behavior is consistent with a diagnosis of ADHD.

The experimental tasks include the following:

  • Signal detection task examining sensitivity to changing reinforcement contingencies (Completed)
    • Collaborator: Prof. Brent Alsop, University of Otago, NZ. Developer of the signal detection task. Initial processing of data generated by the computer task. No access to personal information.
  • Matching law task examining response cost
    • Collaborator: Prof. Brent Alsop, University of Otago, NZ. Developer of the matching law detection task. Initial processing of data generated by the computer task. No access to personal information. 
    • Collaborators: Prof. Egas Caparelli-Daquer, Federal University of State of Rio de Janeiro/University of Rio de Janeiro, Brazil; Prof. Erasmo Barbante Casella, University of Sao Paulo, Brazil; Prof. Paulo Mattos, D’Or Institute Research and Education, Brazil. Responsible for data collection in Rio de Janeiro and Sao Paulo, Brazil.  No access to any data collected in Okinawa. 
  • Sequence learning task examining the effects of delayed reward on learning
    • Collaborator: Prof. Brent Alsop, University of Otago. Developer of the sequence learning task. Initial processing of data generated by the computer task. No access to personal information.
  • Conditioning task examining the effects of a reward-predicting cue on choice responses
    • Collaborator: Prof. Brent Alsop, University of Otago. Developer of the conditioning task. Initial processing of data generated by the computer task. No access to personal information.
    • Collaborator: Dr. Heloisa Alves, University of Massachusetts Dartmouth, US. Responsible for data collection from typically develop children in US. No access to any data collected in Okinawa.
  • Pavlovian-to-Instrumental Transfer task examining the effects of classically conditioned cues on instrumental behavior
    • Collaborator: Prof. Jeff Wickens, OIST, Japan. Task development. No access to any data collected at the Unit
  • Operant behavior task examining the effects of partial vs. continuous reinforcement on behavior acquisition and extinction
    • Collaborator: Associate Prof. Saskia Van der Oord and Prof. Tom Beckers, Ms. An-Katrien Hulsbosch, KU Leuven, Belgium, Dr. Hasse de Meyer, HELP University, Malaysia. No access to personal information.​

1.2 Effects of extinction on the behavior of children with and without ADHD (HSR-2020-022, under review)

Research period: Upon approval - 3/31/2023 (may be extended)

Summary: This research aims to clarify the nature and extent of altered reinforcement sensitivity in children displaying symptoms consistent with a diagnosis of DSM-5 Attention Deficit and Hyperactivity Disorder (ADHD). Specifically, we plan to examine how the discontinuation of positive reinforcement (i.e., extinction) affects the behavior of children with and without ADHD. Children with ADHD have been observed to have difficulty maintaining desirable behavior when reinforcements are not provided. However, experimental research evidence assessing behavioral responses under extinction among children with ADHD is limited. The study will extend our previous research and contribute new fundamental knowledge about reinforcement mechanisms in children whose behavior is consistent with a diagnosis of ADHD.

  • Collaborator: Prof. Brent Alsop, University of Otago. Developer of the extinction task. Initial processing of data generated by the computer task. No access to personal information.

1.3 Functional imaging of altered reward sensitivity and its relation to human behavior (HSR-2010-002)

Research Period: 11/1/2010 – 3/31/2021 (may be extended)

Summary: The purpose of the research is to assess sensitivity to reward and cues that predict reward in young adults with and without ADHD using data obtained from functional magnetic resonance imaging (fMRI). University students and adults meeting the diagnostic criteria for ADHD and an age and gender matched control sample will complete an assessment of their neuropsychological functioning and then participate in a single fMRI session in which their BOLD responses to stimuli indicating reward, non-reward and signals predicting reward are recorded. The study findings will contribute to our understanding of the neurobiological causes of ADHD, in particular, whether individuals with ADHD differ from controls in their sensitivity to reward and cues predicting reward. The study is being carried out at the Cognitive and Behavioral Neuroscience Unit, D'Or Institute for Research and Education (IDOR) in Rio de Janeiro, Brazil. IDOR conducts comprehensive research to assess a variety of aspects of human motivation and emotion including reinforcement sensitivity (“Marcadores endofenotipiocos subjacentes aos mecanismos motivacionais humanos: neuroimagem e polimorfismos geneticos” – “Endophenotype markers underlying human motivation mechanisms: neuroimaging and genetic polymorphisms”). Some anonymous data from the research (fMRI data related to reward sensitivity, diagnostic information and neuropsychological assessment findings) will be shared with the Human Developmental Neurobiology Unit at OIST. No personal information will be shared. We will analyze the data from different perspectives together with the researchers at IDOR.

  • Collaborators: Dr. Jorge Moll, Prof. Paulo Mattos, D’Or Institute for Research and Education, Brazil. Responsible for data collection and data processing in Brazil.
  • Collaborator: Prof. Jeff Wickens, OIST, Japan. Protocol development. 

1.4 Involvement in other research activities examining the role of reinforcement in ADHD

  • Provide consultation to research by Ms. An-Katrien Hulsbosch supervised by Associate Prof. Saskia Van de Oord at University of Luven, Belgium, examining frustration responses to partial reinforcement and punishment in ADHD. Professor Tripp is recognized by KU Leuven as a promotor of Ms. Hulsbosch’s PhD research.
  • Provide consultation to research by Ms. Alessandra Sayao supervised by Prof. Egas Caparelli-Daquer at Federal University of Rio de Janeiro, Brazil, examining heart rate responses to reward stimuli. 

2. Language and Social Problem Solving in ADHD

2.1 Relationship of Language and Social Problem Solving in ADHD (HSR-2015-002)

Research Period: 9/20/2015 – 3/31/2022

Summary: Children with attention deficit hyperactivity disorder (ADHD) are at increased risk for social difficulties with many studies reporting up to 50% of children experience difficulties in their social interactions with peers and adults. The underlying cause of these difficulties is uncertain and to date treatment programs show limited success. In this study we focus on the contribution of general and pragmatic (social use of language) language skills, theory of mind (i.e. understanding that others have a different perspective from our own), and executive function skills to the social problem solving and social skills of children demonstrating high rates of inattention, hyperactivity and impulsivity. Participating children are shown video clips illustrating social dilemmas and are asked about the nature of the social conflicts, emotions of the characters involved, and provide possible solutions to the conflicts. In addition to completing a comprehensive assessment of their cognitive and behavioral functioning to characterize their strengths and difficulties the children will complete assessments of their language skills, theory of mind, and social problem solving skills. The children’s parents will rate the children’s communication skills, social skills and executive function skills. The children’s teachers will complete measures of their executive functioning and social skills. These data will be used to evaluate the extent to which these different factors are able to explain variability in the social behaviors and social problem-solving skills of children with ADHD. 

2.2 Relationship of Language and Social Problem Solving in ADHD (HSR-2015-002)

Research Period: 12/11/2011 – 3/31/2023

Summary: Children with ADHD frequently experience difficulties in their social interactions with peers and adults which persist over time. The current study extended existing research through examining relationships between pragmatic language use, general language skills, IQ and social problem-solving skills, and reported social difficulties. This is seen as an important step towards the development of more effective interventions for children with ADHD. 

  • Collaborator: Ms. Jaclyn Meredith, University of Otago, New Zealand. Access to data collected in Okinawa while she was a special research student at OIST supervised by Prof. Gail Tripp. Data was collected for Ms. Meredith’s PhD thesis.