Citation

Machida K, Johnson KA. Brain Connect. 2019; ePub(ePub): ePub.

Affiliation

University of Melbourne, 2281, Melbourne School of Psychological Sciences, Parkville, Victoria, Australia; kajo@unimelb.edu.au.

Copyright

(Copyright © 2019, Mary Ann Liebert Publishers)

DOI

10.1089/brain.2019.0671

PMID

31441317

Abstract

It is common to find that individuals with Attention Deficit Hyperactivity Disorder (ADHD) produce more variable responses when performing cognitive tasks. The neural mechanism associated with heightened Response Time Variability (RTV) is not well understood in ADHD, nor in typically developing individuals. One potential mechanism that might be associated with increased RTV is functional connectivity of the brain, and specifically inefficient connections. This study examined the relations between functional connectivity of the brain, RTV, and levels of ADHD symptoms, using a cross-sectional developmental design. Twenty children aged 9 to 12 and 49 adolescents aged 15 to 18 completed the Sustained Attention to Response Task with flanker interference whilst EEG was recorded. The Conners 3 questionnaire was used to measure the participants' levels of ADHD symptoms. Parameters reflecting different aspects of RTV were computed using ex-Gaussian and Fast Fourier Transform (FFT) techniques. Functional connectivity between 64 electrodes was computed for the task period, and global efficiency reflecting functional integration, and modularity reflecting strength of functional segregation, were computed. Greater global efficiency in the theta band was associated with decreased RTV. Increased integration during the task may help to combine information more efficiently and produce stable responses. When congruent flankers were present, children with greater modularity in the beta band showed greater tau, which is thought to reflect attentional lapses. This association was not observed when incongruent flankers were present. Brains with increased strength of segregated activity might be more prone to attentional lapses, especially during simpler tasks.

Language: en

Keywords

Attention deficit hyperactivity disorder (ADHD); Cognitive control; Electroencephalography (EEG); Functional connectivity; Graph theory