Simple and Choice Reaction Time Tasks

This demonstration compares simple reaction time (SRT) tasks, where there is one stimulus and one response, with choice reaction time (CRT) tasks, where multiple stimuli each require different responses. It shows how reaction time increases with task complexity, illustrating Hick’s law and the speed-accuracy trade-off.

1. Present a single stimulus (e.g., a light or cross on the screen).
2. Instruct participants to respond as quickly as possible with one action (e.g., pressing the space bar).
3. Repeat across several trials to collect average response times (Simple Reaction Time Task).
4. Present multiple possible stimuli (e.g., a cross appearing in one of four positions).
5. Assign each stimulus a unique response key (e.g., z, x, b, n).
6. Have participants respond according to the stimulus shown (Choice Reaction Time Task).
7. Record and compare the average response times for both tasks.

📄 Simple and choice reaction time tasks - Psytoolkit: https://www.psytoolkit.org/lessons/simple_choice_rts.html

• Increase the number of stimuli in the choice task to see how reaction time changes.
• Compare results across different age groups.
• Test performance under different conditions (e.g., tired vs. rested, hungry vs. full).
• Introduce time pressure to emphasize the speed-accuracy trade-off.

• Ensure participants have no medical conditions (such as epilepsy) that could be triggered by screen flashes.
• Encourage breaks if participants experience eye strain or fatigue.

• Why are reaction times faster in simple tasks compared to choice tasks? (Because fewer stimulus-response associations reduce processing time.)
• How does Hick’s law explain the relationship between number of choices and response time? (Response time increases as the number of choices grows.)
• What is the speed-accuracy trade-off, and how does it affect performance in these tasks? (Trying to be more accurate usually slows responses, while trying to be faster may increase errors.)
• How do factors like age, attention, or fatigue influence reaction times? (Younger and more alert participants tend to respond faster, while fatigue and distractions slow responses.)