Vibe Psychophysics

Do arrow fins make lines look longer or shorter? Adjust a comparison line to match a standard and measure your susceptibility to this classic size illusion.

Surrounding circles distort perceived size. Adjust a central circle to match a standard and see how context shapes perception.

Can you spot the change? Scenes flicker between two versions with a brief blank. Find the changing object — it's harder than you think.

Name the ink color of color words. When word and color conflict, your brain's automatic reading interferes — the most replicated effect in psychology.

Identify the center letter while ignoring surrounding flankers. Incongruent flankers slow you down, revealing involuntary processing of nearby stimuli.

Respond to the color of a circle appearing left or right. Even though position is irrelevant, spatial congruency speeds your response.

An arrow cue directs your attention. Detect targets faster at cued locations and measure the cost of invalid cues on covert attention.

Find a red vertical bar among distractors. Feature search is instant (pop-out!), but conjunction search requires slow, serial inspection.

Spot two targets in a rapid letter stream. The second target is often “blinked” — missed for 200–500 ms after the first, revealing a bottleneck in temporal attention.

Can you identify an arrow you cannot consciously see? Briefly masked arrows test whether visual processing occurs below the threshold of awareness.

Judge whether two shapes are the same or mirror-images. Response time increases linearly with rotation angle, revealing analog mental rotation.

Memorize a set of digits, then judge whether a probe was in the set. RT increases linearly with set size, revealing serial exhaustive memory scanning.

Listen to pairs of Shepard tones — layered octaves that create the illusion of endlessly ascending pitch. The tritone paradox reveals your personal pitch template.

Rate the perceived length of lines relative to a standard. Your data reveals whether perception follows Stevens' power law: ψ = k · Iⁿ.

Detect a faint signal hidden in visual noise. Your hit rate and false alarm rate reveal your sensitivity (d′) and response bias (criterion), the core of SDT.

Compare two lines and judge which is longer. The just-noticeable difference scales with stimulus magnitude — Weber's fundamental law of psychophysics.

Two squares flash briefly on either side of the screen. Judge which flashed first. Estimates your temporal resolution and any spatial bias in time perception.

The most fundamental measure in experimental psychology. Compare simple (one response) vs. choice (two responses) reaction time and see Hick's Law in action.