Color Stroop Task
A classic executive function task measuring inhibitory control by requiring participants to name the ink color of color words while ignoring the semantic meaning of the word itself.
Participants see color words (red, blue, green, yellow) printed in colored ink and must respond with the ink color using keyboard keys 1-4, ignoring the word meaning. The task includes three conditions: (1) congruent trials where word and color match (e.g., 'red' in red ink), (2) incongruent trials where they mismatch (e.g., 'red' in blue ink), and (3) neutral trials with non-color words. The task consists of practice trials with feedback, followed by two test blocks with no feedback. Optional vocal response mode is available but requires manual scoring.
Measures: Executive function, inhibitory control, selective attention, processing speed, and the ability to suppress prepotent reading responses in favor of color naming.
- Classic Stroop task implementing color-word interference paradigm
- Two test blocks of 72 trials each (24 congruent, 24 incongruent, 24 neutral)
- Practice block with accuracy threshold requirement (default 85%)
- Feedback provided during practice trials only
- Includes 8 language translations: English, German, Spanish, French, Italian, Korean, Dutch, Portuguese
- Updated to PEBL 2.3 with Layout system, block counters, and version 1.0 (2026)
- Audio response mode available but requires manual post-hoc scoring
- Uses adaptive label sizing for multilingual support
| stimsize | Stimulus size of font in pixels. (default: 60) |
| responsetype | Response method: 'keyboard', 'audio', or 'ask' (ask participant at start). (default: keyboard) |
| scorerealtime | For audio responses: set to 1 to score responses with keyboard in real-time. Otherwise responses must be coded afterward. (default: 0) |
| usepreset | If 1, use same sequence of stimuli every time. If 0, regenerate randomly on each run. (default: 1) |
| custompractrials | Number of practice trials if usepreset=0. (default: 8) |
| customtrials | Number of trials per block if usepreset=0. (default: 28) |
| fixationTime | Time for the fixation cross in milliseconds. (default: 1000) |
| responseTimeout | Time limit given for responding in milliseconds. (default: 3000) |
| practicethreshold | Whether to require practice round to threshold. 0=no threshold, 1=practice requires 100% accuracy. .85=85% (default: 0.85) |
| maxpracticerounds | Maximum number of practice rounds allowed. (default: 10) |
| GiveFeedback | Should feedback be given? Reset to 0 for test trials, 1 for practice trials. (default: 1) |
| voicekeythreshold | Voice key threshold for audio responses (may need adjustment based on microphone). (default: 0.35) |
| voiceKeyDuration | Voice key duration in milliseconds. (default: 200) |
| saveAudio | Should the audio buffer be saved for audio responses? (default: 1) |
| compressAudio | Command to compress audio files. (default: 0) |
| compressor | Compressor command for audio compression. (default: oggenc ) |
| Validation | validated |
| Psychometric data | Available |
| Normative data | Available |
| subnum | responsecond | code | block | trial | stimword | stimcolorid | stimcolorname | cond | responded | response | correct | abstime | rt | randomerror | incong | speechduration | recordtime |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| test | keyboard | data/test/trial--10000- | Practice1 | -10000 | green | 4 | yellow | I | 1 | 4 | 1 | 9685 | 951 | 0 | 0 | 0 | 951 |
| test | keyboard | data/test/trial--9999- | Practice1 | -9999 | yellow | 4 | yellow | C | 1 | 4 | 1 | 12648 | 605 | 0 | 0 | 0 | 605 |
| test | keyboard | data/test/trial--9998- | Practice1 | -9998 | green | 3 | green | C | 1 | 1 | 0 | 15261 | 759 | 1 | 0 | 0 | 759 |
| test | keyboard | data/test/trial--9997- | Practice1 | -9997 | yellow | 3 | green | I | 1 | 3 | 1 | 18026 | 706 | 0 | 0 | 0 | 706 |
| test | keyboard | data/test/trial--9996- | Practice1 | -9996 | blue | 3 | green | I | 1 | 3 | 1 | 20738 | 645 | 0 | 0 | 0 | 645 |