Time perception deficit in ADHD and its correlation with early ADHD symptoms and early academic abilities

Abstract

Children with ADHD are often observed to have neuropsychological deficits such as executive dysfunction, delay aversion (DAv), and a recently proposed deficit, time perception (TP) deficit. This study investigates the role of TP in ADHD and academic skills in young children. The first study was conducted using a meta-analytic approach to explore whether timing deficit exists in children with ADHD. The results from 27 empirical studies with a total of 1,620 participants with ADHD and 1,249 paired typically developing peers showed substantial timing deficiencies in those with ADHD. Compared to their typically developing peers, children with ADHD demonstrated lower accuracy (g > 0.40) and precision in perceiving time (g = 0.66) and a greater propensity to overestimate time. Study 2 consisted of a three-year longitudinal study that explored the relationship between TP deficit, other neuropsychological deficits, and the roles of these neuropsychological deficits in ADHD symptoms and early academic skills in 131 preschoolers (M = 5.31 years) in Hong Kong. Factor analysis revealed three dissociable components in preschool ADHD, namely, inhibitory and attentional control deficit (IAC), DAv, and time perception/working memory (TP/WM) deficit. Regression analyses showed that all neuropsychological deficits predicted concurrent and future ADHD symptoms. TP deficit significantly predicted both ADHD symptoms and academic skills over three years. A close and significant correlation between time perception (TP) and working memory (WM) across time was also found. Based on the findings of Study 2, Study 3 explored the efficacy of a short, self-paced, online WM training program for preschoolers with ADHD symptoms. Fifty preschoolers aged four-to-six years (M = 4.93 years) were recruited and randomly allocated into three groups: an online WM training group (WM; n = 14), an online social-emotional (SE) skills training group (n = 15), and a waitlist control group (n = 21). Both the WM and SE groups received a 10-minute self-paced online training three times a week for five consecutive weeks. The results showed that online WM training and online SE training were effective in enhancing children’s verbal working memory and social situational knowledge, respectively. In pairwise comparisons, no significant transferrable effects of WM training on ADHD symptoms were observed across groups. However, a significant improvement in numeration at the post-test was observed in the WM group. Furthermore, insignificant results of changes in TP were found in the WM group, implying a non-causal link between these two constructs. In conclusion, the current thesis highlights the important role of TP in early ADHD and its relation to academic abilities. Results from the intervention study provided support for the efficacy of an online self-paced WM training for preschoolers with ADHD and suggest the potential utility of similar training in future intervention designs.