Duration Perception in Radial Optic Flow

This short web demo recreates the structure of Gergely Gerstmayer and Jason Clarke’s ECVP experiment: a radial optic-flow stimulus appears, a word or non-word is briefly shown during the motion, and you estimate how long the motion lasted.

For the website version, the original spacebar reproduction response is replaced with a 0–5000 ms duration slider.

Your task: watch the motion display. A six-letter item will appear briefly during the motion. After the motion ends, use the slider to estimate the motion duration, then decide whether the item was a real U.K. English word.

The demonstration contains 24 trials: 2 motion types × 3 magnitudes × 4 durations, with lexical items varying in difficulty.

Website note: this is an illustrative demo, not the full 480-trial PsychoPy experiment. It preserves the critical timing structure and visual logic while remaining short enough for visitors to try.
Trial timing: fixation 750/950/1150 ms; motion 500/1000/2000/3000 ms; lexical item onset 100–200 ms after motion onset; lexical item shown for 300 ms; 1000 ms inter-trial interval.