Subliminal Perception

Background

Can visual information influence behavior without conscious awareness? Subliminal perception research investigates whether stimuli presented below the threshold of awareness can still be processed by the visual system.

Masked Priming

In the masked priming paradigm, a brief target stimulus is sandwiched between forward and backward pattern masks. At very short durations (under ~50 ms), participants often report not seeing the target, yet their forced-choice responses reveal that the stimulus was processed.

Key Concepts

Objective threshold: The duration at which forced-choice accuracy exceeds chance (50%)

Subjective threshold: The duration at which participants report conscious awareness

Dissociation: When objective performance exceeds chance despite subjective reports of no awareness — evidence for unconscious processing

This Experiment

A brief arrow (left or right) appears between two pattern masks. You make a forced-choice direction judgment, then rate whether you saw the arrow. The arrow appears for 1–6 display frames (~17–100 ms at 60 Hz).

References

Marcel, A.J. (1983). Conscious and unconscious perception. Cognitive Psychology, 15, 238–300.

Dehaene, S. et al. (1998). Imaging unconscious semantic priming. Nature, 395, 597–600.

Greenwald, A.G., Draine, S.C. & Abrams, R.L. (1996). Three cognitive markers of unconscious semantic activation. Science, 273, 1699–1702.

On each trial, a brief arrow (pointing left or right) will flash between two pattern masks.

After each trial, you answer two questions:

Direction: Press ← or → to indicate the arrow direction. Guess if unsure!
Awareness: Press Y if you saw the arrow, or N if you did not.

The arrow may be extremely brief — sometimes just one display frame. Always guess a direction even if you saw nothing.

There are 4 practice trials with feedback, then 120 main trials (~7 minutes).

Subliminal Perception

Your Results