Replication of the stimulus stream from Dehaene et al. (2001), investigating visual masking: a four-letter word flashed for a few tens of milliseconds remains readable in isolation, but becomes invisible when surrounded by visual masks — even though it can still influence subsequent processing.
This experiment requires a commercial font that cannot be redistributed:
octin_college_rg.ttf in assets/font/| Condition | Context frames | Target |
|---|---|---|
visible_word |
Blank frames (71 ms each) | Word |
visible_blank |
Blank frames | Blank |
masked_word |
Mask frames (71 ms each) | Word |
masked_blank |
Mask frames | Blank |
Each 2400 ms trial embeds target sequences at 500 ms intervals within a continuous filler stream (72 % masks, 28 % blanks, each 43, 57, or 71 ms).
go run main.go # fullscreen
go run main.go -d # windowed (development)
go run main.go -d -s 1 # windowed, subject ID 1
go run main.go -targets 4 # 4 target sequences per trial (default 1)
| Flag | Default | Description |
|---|---|---|
-d |
off | Development mode: windowed 1024×768 |
-s |
0 |
Participant ID |
-targets |
1 |
Number of target sequences per trial |
| Key | Meaning |
|---|---|
| Any key | Report whether a word was seen (as instructed) |
| Escape | Quit |
Data are saved to goxpy_data/ as a .xpd file. One row per trial:
| Column | Description |
|---|---|
subject_id |
Participant ID |
trial_num |
Trial number |
condition |
Trial type (visible_word, etc.) |
word |
The embedded word (or empty for blank conditions) |
word_duration_ms |
Target presentation duration |
response |
Participant’s key press |
rt_ms |
Reaction time in milliseconds |
reported_word |
Word reported by participant |
Dehaene, S., Changeux, J.-P., Naccache, L., Sackur, J., & Sergent, C. (2006). Conscious, preconscious, and subliminal processing: A testable taxonomy. Trends in Cognitive Sciences, 10(5), 204–211.
Dehaene, S., Naccache, L., Cohen, L., Bihan, D. L., Mangin, J.-F., Poline, J.-B., & Rivière, D. (2001). Cerebral mechanisms of word masking and unconscious repetition priming. Nature Neuroscience, 4(7), 752–758.