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Response variability in Attention Deficit Hyperactivity Disorder: Evidence for neuropsychological heterogeneity
- Source :
-
Neuropsychologia . Mar2007, Vol. 45 Issue 4, p630-638. 9p. - Publication Year :
- 2007
-
Abstract
- Abstract: Response time (RT) variability is a common finding in ADHD research. RT variability may reflect frontal cortex function and may be related to deficits in sustained attention. The existence of a sustained attention deficit in ADHD has been debated, largely because of inconsistent evidence of time-on-task effects. A fixed-sequence Sustained Attention to Response Task (SART) was given to 29 control, 39 unimpaired and 24 impaired-ADHD children (impairment defined by the number of commission errors). The response time data were analysed using the Fast Fourier Transform, to define the fast-frequency and slow-frequency contributions to overall response variability. The impaired-ADHD group progressively slowed in RT over the course of the 5.5min task, as reflected in this group''s greater slow-frequency variability. The fast-frequency trial-to-trial variability was also significantly greater, but did not differentially worsen over the course of the task. The higher error rates of the impaired-ADHD group did not become differentially greater over the length of the task. The progressive slowing in mean RT over the course of the task may relate to a deficit in arousal in the impaired-ADHD group. The consistently poor performance in fast-frequency variability and error rates may be due to difficulties in sustained attention that fluctuate on a trial-to-trial basis. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 00283932
- Volume :
- 45
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- Neuropsychologia
- Publication Type :
- Academic Journal
- Accession number :
- 23557935
- Full Text :
- https://doi.org/10.1016/j.neuropsychologia.2006.03.034