PEBL Hub — IRB Fact Sheet — 2026-08-23
Choice Reaction Time
Category:Processing Speed
Duration:~4 minutes
Parameters:14 configurable parameters available
Version:1.0
Input:Keyboard
Description
A simple choice reaction time task where participants type the letter displayed on screen as quickly as possible. Measures basic processing speed and response selection.
Key Parameters
| reps | How many reps of the stimuli (default: 5) |
| soa | how long between stimili? (default: 2000) |
| numstim | Number of stimuli of set stim1..stim10 to use. Must be <= 10 (default: 6) |
| stim1 | Stimulus (default: a) |
| stim2 | Stimulus (default: d) |
| stim3 | Stimulus (default: c) |
| stim4 | Stimulus (default: e) |
| stim5 | Stimulus (default: o) |
| stim6 | Stimulus (default: n) |
| stim7 | Stimulus (default: b) |
| stim8 | Stimulus (default: g) |
| stim9 | Stimulus (default: s) |
| stim10 | Stimulus (default: q) |
| timeout | Time given for a response (default: 1500) |
| responsemode | Response method: auto (platform-aware), keyboardShift (L/R shift), keyboardSafe (Z/slash for web), mousetarget (click targets), mousebutton (L/R mouse buttons), userselect (custom key) (default: auto) |
Example Data Output (5 sample rows)
| subnum | trial | targ | foil | time | delay | resp | corr | mask | presstart | respend | prestime | rt |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ouehtaou | 1 | g | d | 6433 | 245 | <rshift> | 1 | /#$ | 6633 | 7412 | 246 | 430 |
| ouehtaou | 2 | o | d | 8433 | 127 | <rshift> | 1 | |$/ | 8634 | 9408 | 127 | 541 |
| ouehtaou | 3 | d | g | 10433 | 287 | <lshift> | 0 | &|\ | 10634 | 11305 | 288 | 280 |
| ouehtaou | 4 | o | e | 12433 | 154 | <rshift> | 1 | \|* | 12634 | 13368 | 154 | 477 |
| ouehtaou | 5 | g | e | 14433 | 281 | <rshift> | 1 | @%/ | 14634 | 15749 | 281 | 733 |