1 In a task involving recall, recognition, or some other form of cognitive performance, the provision of a contextual cue (3), prime (1), or prompt that provides information about either the identity or the time of appearance of a target stimulus and that may facilitate a response (in facilitative priming) or inhibit it (in inhibitory priming). When primes provide information that influences expectancies of targets, as in associative priming in which primes are meaningfully related to targets, expectation-dependent or strategic priming may occur, whereas when primes are unrelated to targets only automatic priming can occur, though it occurs more quickly. Associative priming that is dependent on verbal meaning, as when the prime bread is provided for the target butter, is called semantic priming; and a common type of associative priming that is not dependent on verbal meaning is initial letter priming, when the first letter of the word to be remembered is provided as a cue. Associative priming based on the sounds of words is called phonological priming: see yolk phenomenon.
2 Reduced reaction time (quicker responding) resulting from a signal warning of the imminent presentation of the stimulus. Compare negative priming.
3 In research involving animals self-stimulating their pleasure centres, the provision of an initial stimulatory impulse at the start of the session to encourage the animal to provide further impulses on its own. [From Latin primus first]