Replication of the paradigm introduced by Pylyshyn & Storm (1988), which demonstrates that humans can simultaneously track several independently moving objects without any visible distinguishing mark — evidence for a parallel, pre-attentive tracking mechanism.
| Phase | Duration | Description |
|---|---|---|
| Highlight | 4 s | 10 stationary circles; N targets flash red |
| Motion | variable | All circles turn blue and move in random directions, bouncing off the playfield boundary and each other |
| Response | — | Motion stops; click the N circles you believe were the targets |
| Feedback | brief | Correct = green, wrong = red, missed target = orange |
Eight trials are run: two for each target count N ∈ {4, 5, 6, 7}, in random order.
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 -speed 80 # custom dot speed (px/s)
| Flag | Default | Description |
|---|---|---|
-d |
off | Development mode: windowed 1024×768 |
-s |
0 |
Participant ID |
-speed |
50 |
Dot speed in pixels per second |
-disksize |
20 |
Radius of each circle in pixels |
-trialduration |
8000 |
Motion phase duration in milliseconds |
| Action | Meaning |
|---|---|
| Left click | Select / deselect a circle (response phase only) |
| Escape | Quit at any time |
Data are saved to goxpy_data/ as a .xpd file. One row per click, recording trial number, target count, whether the clicked circle was a target, and the running score.
Pylyshyn, Z. W., & Storm, R. W. (1988). Tracking multiple independent targets: Evidence for a parallel tracking mechanism. Spatial Vision, 3(3), 179–197.