noun, plural: subliminal stimuli
(psychology) A stimulus below the threshold-line for conscious perception but can evoke affective reactions without awareness
(Physiology) A stimulus with an adequate intensity can generate an action potential. But stimulus having intensity below the threshold will not be able to. The stimulus below threshold is referred to as subliminal. There should be a change in an action potential in order to evoke a response. In evoking a contraction of a skeletal muscle, for instance, the stimulus has to be liminal (i.e. adequate in strength and duration) to cause a depolarization and produce an action potential. When an action potential is reached, it will lead to cascading events resulting in the contraction of skeletal muscle fibers in a motor unit.
(Psychology) In psychological research, a subliminal stimulus is a kind of stimulus wherein it may be perceived and processed in the brain but does not elicit awareness of perception. For instance, a recipient of a subliminal stimulus may be able to perceive it but may not be consciously aware of it. This precept is used in advertising or marketing where a subliminal stimulus (e.g. music or image flashing) is incorporated to an ad but not enough to elicit conscious threshold and yet affect the consumer's brand choice.