Electrophysiological correlates of reinforcement learning in young people with Tourette syndrome with and without co-occurring ADHD symptoms.
Altered reinforcement learning is implicated in the causes of Tourette syndrome (TS) and attention-deficit/hyperactivity disorder (ADHD). TS and ADHD frequently co-occur but how this affects reinforcement learning has not been investigated. We examined the ability of young people with TS (n=18), TS+ADHD (N=17), ADHD (n=13) and typically developing controls (n=20) to learn and reverse stimulus-response (S-R) associations based on positive and negative reinforcement feedback. We used a 2 (TS-yes, TS-no)×2 (ADHD-yes, ADHD-no) factorial design to assess the effects of TS, ADHD, and their interaction on behavioural (accuracy, RT) and event-related potential (stimulus-locked P3, feedback-locked P2, feedback-related negativity, FRN) indices of learning and reversing the S-R associations. TS was associated with intact learning and reversal performance and largely typical ERP amplitudes. ADHD was associated with lower accuracy during S-R learning and impaired reversal learning (significantly reduced accuracy and a trend for smaller P3 amplitude). The results indicate that co-occurring ADHD symptoms impair reversal learning in TS+ADHD. The implications of these findings for behavioural tic therapies are discussed.
MRC Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, & Neuroscience (IoPPN), King's College London, 16 De Crespigny Park, Denmark Hill, London, SE5 8AF, UK. Electronic address: elizabeth.1.shephard@kcl.ac.uk.
Elizabeth
E
Shephard
Division of Psychiatry and Applied Psychology, Institute of Mental Health, University of Nottingham, Jubilee Campus, Triumph Road, Nottingham, NG7 2TU, UK. Electronic address: georgina.jackson@nottingham.ac.uk.
Georgina M
GM
Jackson
Division of Psychiatry and Applied Psychology, Institute of Mental Health, University of Nottingham, Jubilee Campus, Triumph Road, Nottingham, NG7 2TU, UK. Electronic address: maddie.groom@nottingham.ac.uk.
Madeleine J
MJ
Groom
D000293:Adolescent; D000704:Analysis of Variance; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications*; D002648:Child; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D058765:Neurofeedback / Q000502:physiology*; D025341:Principal Component Analysis; D011930:Reaction Time / Q000502:physiology; D012054:Reinforcement, Psychology; D005879:Tourette Syndrome / Q000150:complications*
ADHD; Comorbidity; Electrophysiology; Event-related potentials; Reinforcement learning; Tourette syndrome