Implicit sequence learning in young people with Tourette syndrome with and without co-occurring attention-deficit/hyperactivity disorder (ADHD)

Shephard, Elizabeth; Groom, Madeleine J.; Jackson, Georgina M.

Abstract

Impaired habit-learning has been proposed to underlie the tic symptoms of Tourette syndrome (TS). However, accounts differ in terms of how habit-learning is altered in TS, with some authors proposing habit-formation is impaired due to a deficient “chunking” mechanism, and others proposing habit-learning is over-active and tics reflect hyper-learned behaviours. Attention-deficit/hyperactivity disorder (ADHD) frequently co-occurs with TS and is known to affect cognitive function in young people with co-occurring TS and ADHD (TS+ADHD). It is unclear, however, how co-occurring ADHD symptoms affect habit-learning in TS. In this study, we investigated whether young people with TS would show deficient or hyper-active habit-learning, and assessed the effects of co-occurring ADHD symptoms on habit-learning in TS. Participants aged 9-17 years with TS (n = 18), TS+ADHD (n = 17), ADHD (n = 13) and typical development (n = 20) completed a motor sequence-learning task to assess habit-learning. We used a 2 (TS-yes, TS-no) x 2 (ADHD-yes, ADHD-no) factorial analysis to test the effects of TS, ADHD, and their interaction on accuracy and reaction time indices of sequence-learning. TS was associated with intact sequence-learning, but a tendency for difficulty transitioning from sequenced to non-sequenced performance was suggestive of hyper-learning. ADHD was associated with significantly poorer accuracy during acquisition of the sequence, indicative of impaired habit-learning. There were no interactions between the TS and ADHD factors, indicating young people with TS+ADHD showed both TS- and ADHD-related atypicalities in habit-learning.

Citation

Shephard, E., Groom, M. J., & Jackson, G. M. (2019). Implicit sequence learning in young people with Tourette syndrome with and without co-occurring attention-deficit/hyperactivity disorder (ADHD). Journal of Neuropsychology, 13(3), 529-549. https://doi.org/10.1111/jnp.12167

• Journal Article Type: Article
• Acceptance Date: Jun 18, 2018
• Online Publication Date: Jul 4, 2018
• Publication Date: 2019-09
• Deposit Date: Jun 26, 2018
• Publicly Available Date: Jul 5, 2019
• Journal: Journal of Neuropsychology
• Print ISSN: 1748-6645
• Electronic ISSN: 1748-6653
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Issue: 3
• Pages: 529-549
• DOI: https://doi.org/10.1111/jnp.12167
• Keywords: habit-learning, Tourette syndrome, ADHD, sequence learning, tics, comorbidity
• Public URL: https://nottingham-repository.worktribe.com/output/945323
• Publisher URL: https://onlinelibrary.wiley.com/doi/abs/10.1111/jnp.12167
• Additional Information: This is the peer reviewed version of the following article,, which has been published in final form at https://onlinelibrary.wiley.com/doi/abs/10.1111/jnp.12167. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.