Measuring Reaction Time: A Methodological Question

Wednesday, March 14, 2012
Poster Area 1 (Foyer Outside Exhibit Hall C) (Convention Center)
Melanie A. Hart, Texas Tech University, Lubbock, TX

Background/Purpose Reaction time (RT) is important in a number of activities, and is often used to measure the effectiveness of interventions. There are a number of tasks to measure RTs. With different tasks, the comparison of intervention effectiveness may be difficult. The purpose of this study was to examine two measures of RT, the Nelson timer (NT) and computer-controlled (CC).

Method College-age adults (N=36) completed two simple RT tasks. For both tasks, the participants completed 20 trials using their dominant hand. CC used a common computer workstation and commercial software. NT required the participant to sit in a chair with the right arm resting on a table with index finger and thumb extended approximately one inch apart. The NT was placed between and parallel with the index finger and thumb with the zero line even with the top of the thumb. Upon release of the timer, the participant was grasped the timer with the finger and thumb. RT was recorded at the top of the thumb. The participants completed both tasks one week later.

Analysis/Results Mean RTs were calculated and analyzed using a repeated measures ANOVA. The results indicated a significant difference between tasks and a significant interaction. The RTs for the CC task did not change across the tests, but decreased for the NT task.

Conclusions Results indicate a possible learning effect for the NT, but not the CC. Caution should be taken when making comparisons of interventions using different RT tasks, and when using the Nelson timer to measure RTs across time.