All ETDs from UAB

Advisory Committee Chair

Despina Stavrinos

Advisory Committee Members

Rajesh Kana

Kristina Visscher

Document Type


Date of Award


Degree Name by School

Master of Arts (MA) College of Arts and Sciences


Motor vehicle collisions (MVC) are the leading cause of death for young drivers. MVC risk is higher among drivers with developmental disabilities, particularly individuals with Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD). Difficulties in time perception may negatively impact driving, such as with time-to-collision (TTC) estimations (i.e., an estimation of how long it will take to collide with another vehicle). The goal of this study was to determine whether individuals with ADHD and ASD displayed decrements in TTC estimations and whether perception of time in a general context was related to TTC estimations in a driving-specific context. A total of sixty participants (nADHD =20, nASD =20, nTD =20) completed a time reproduction task and a TTC estimation task. In the computerized time reproduction task, participants reproduced a set of Short Intervals (3, 4.5, and 6 seconds) and Long Intervals (9, 12, and 17 seconds). In the TTC estimation task, participants judged intervals of 3, 4.5, and 6 seconds while in a driving simulator. Mixed linear models examined whether individuals with ADHD or ASD significantly differed from typically developing (TD) controls in time reproduction and TTC estimation performance. Results indicated that individuals with ASD were less precise in time reproduction at Short and Long Interval sets and over-reproduced at Short Intervals. The presence of ADHD was not found to be related to time reproduction. The precision of iv time reproduction positively predicted the precision of TTC estimates. As the accuracy coefficient of time reproduction increased, the TTC accuracy coefficient decreased. While time perception ability seems related to TTC estimations, neither the ASD or ADHD group significantly differed from the TD group in their TTC estimations. Findings support prior notions that a clocking mechanism influences human TTC estimations. However, performance on a time reproduction task did not fully explain TTC estimation performance, suggesting other factors may also contribute to TTC estimations. This is further corroborated by the lack of significant group differences. That is, the ASD group displayed temporal processing abnormalities but did not produce differential TTC estimations.



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