Mapping autonomic signals and their contributions to emotional and cognitive features of ADHD

There is increasing recognition of the importance of emotion reactivity and emotion regulation in attention deficit/hyperactivity disorder (ADHD). Adolescents with ADHD have altered autonomic responses to rewards and reduced adaptability of autonomic responses to changing emotional demands (Musser et al., 2011; van Hulst et al., 2016). The differences in "bottom-up" emotional reactivity and "top-down" regulation may cosegregate with specific cognitive features of ADHD (Martel et al., 2009). It is unknown whether the relationships between specific emotion processes and ADHD features are reflected in distinct physiological indices of emotion. Moreover, emotion has strong implications for attention and impulse control, however little research has characterised how individual differences in autonomic emotional reactivity and regulation drive the cognitive features of ADHD. Lastly, the ADHD drug methylphenidate effectively improves self-report measures of emotion regulation; however, its effects on autonomic reactivity to changing emotions are largely untested. The proposed project addresses these three gaps in our understanding. In study 1, I will characterise individual differences in autonomic signatures of "top-down" and "bottom-up" emotions at multiple levels (heartrate, heartrate variability, beat-to-beat blood pressure, heartbeat-evoked potentials, and subjective affect) and test their hypothesised relationships with specific ADHD traits. In study 2, I will investigate how altered autonomic reactivity interacts with ADHD traits to inform risk taking and impulsivity. Lastly, study 3 will test the effects of methylphenidate on autonomic responses under changing emotional demands using an adapted version of the task from study 1 or a novel task.