Subliminal stimuli - Wikipedia
Subliminal stimuli (; the prefix sub- literally means "below" or "less than") are any sensory stimuli below an individual's threshold for conscious perception, in contrast to supraliminal stimuli (above threshold). A 2012 review of functional magnetic resonance imaging (fMRI) studies showed that subliminal stimuli activate specific regions of the brain despite participants' unawareness.
https://en.wikipedia.org/wiki/Subliminal_stimuli
