Does response variability predict distractibility among adults with attention-deficit/hyperactivity disorder?
Zachary W Adams1, Walter M Roberts, Richard Milich
1Department of Psychology, University of Kentucky, Lexington, Kentucky 40506-0044, USA. zack.adams@uky.edu
Psychological Assessment
|March 30, 2011
Summary
Response time variability (RTSD) is a valid measure of inattention in adults with attention-deficit/hyperactivity disorder (ADHD). Increased RTSD in ADHD is linked to greater distractibility, supporting its use in clinical assessments.
Area of Science:
- Neuroscience
- Psychology
Background:
- Increased intraindividual response time variability (RTSD) is a known characteristic of attention-deficit/hyperactivity disorder (ADHD).
- RTSD is often used as a measure of inattention, but its direct link to distractibility requires further validation.
Purpose of the Study:
- To investigate whether RTSD is a valid indicator of inattention in adults with ADHD.
- To compare RTSD on the stop-signal task (SST) with performance on the delayed oculomotor response (DOR) task, a measure of distractibility.
Main Methods:
- Adults with ADHD (n=30) and controls (n=28) completed the SST and DOR task.
- The SST assessed inhibitory control, while the DOR task measured distractibility by assessing the ability to inhibit reflexive saccades.
Main Results:
- The ADHD group exhibited poorer inhibitory control, slower reaction times (RTs), greater RTSD, and more errors on the SST compared to controls.
- The ADHD group also showed greater distractibility on the DOR task.
- A significant association was found between greater RT variability and increased distractibility, specifically in participants with ADHD.
Conclusions:
- RTSD is linked to distractibility in adults with ADHD.
- These findings support the use of RTSD as a valid measure of inattention in ADHD assessments.
