Demonstrates change blindness: large changes to a visual scene are surprisingly hard to detect when the change is hidden by a brief blank interval between alternating images. Participants press Space as soon as they spot the change.
A 5×5 grid of coloured squares flickers between two versions (A and A′) with blank screens in between. Exactly one cell differs in colour between A and A′. The flicker cycle repeats until the participant responds or a 10-second timeout occurs.
| Phase | Duration |
|---|---|
| Image A | 240 ms |
| Blank | 80 ms |
| Image A′ | 240 ms |
| Blank | 80 ms |
go run main.go # fullscreen
go run main.go -d # windowed (development)
go run main.go -d -s 1 # windowed, subject ID 1
| Flag | Default | Description |
|---|---|---|
-d |
off | Development mode: windowed 1024×768 |
-s |
0 |
Participant ID |
| Key | Meaning |
|---|---|
| Space | Change detected |
If no response is given within 10 seconds the trial is recorded as a miss.
Data are saved to goxpy_data/ as a .xpd file. One row per trial:
| Column | Description |
|---|---|
trial |
Trial number |
change_row |
Row index of the changed cell (0-based) |
change_col |
Column index of the changed cell (0-based) |
color_before |
Cell colour in image A |
color_after |
Cell colour in image A′ |
rt_ms |
Reaction time in milliseconds (−1 if timed out) |
detected |
true if participant responded within the timeout |
Rensink, R. A., O’Regan, J. K., & Clark, J. J. (1997). To see or not to see: The need for attention to perceive changes in scenes. Psychological Science, 8(5), 368–373.