A letter appears in the periphery of your vision. When flanking letters crowd around it, identification becomes harder — the crowding effect. Identify the target letter as fast as you can. Based on Bouma (1970), Whitney & Levi (2011).
Very Easy
20 trials, 3.0s limit, no flankers, near eccentricity
Easy
24 trials, 2.5s limit, flankers (wide spacing), near eccentricity
Medium
28 trials, 2.0s limit, flankers (medium spacing), medium eccentricity
Hard
32 trials, 1.5s limit, flankers (close spacing), medium eccentricity
Expert
36 trials, 1.2s limit, flankers (close spacing), far eccentricity
Scientific Background
Based on: Peripheral Letter Identification / Visual Crowding Paradigm (Bouma, 1970; Whitney & Levi, 2011) (Bouma & undefined, 1970)