Specificity of priming: a cognitive neuroscience perspective

• Published in: Nature reviews. Neuroscience Vol. 5; no. 11; pp. 853 - 862
• Main Authors: Schacter, Daniel L., Dobbins, Ian G., Schnyer, David M.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.11.2004; Nature Publishing Group
• Subjects: Amnesia; Animal Genetics and Genomics; Association; Behavioral Sciences; Biological and medical sciences; Biological Techniques; Biomedical and Life Sciences; Biomedicine; Brain research; Cognition; Cues; Fundamental and applied biological sciences. Psychology; General aspects; General aspects. Models. Methods; Humans; Medical imaging; Memory; Memory - physiology; Neurobiology; Neuroimaging; Neurosciences; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; review-article; Vertebrates: nervous system and sense organs; United States > US; Massachusetts; Ability; Specificity; Priming effect; Memory; Cognition; Representation; Review
• ISSN: 1471-003X; 1471-0048; 1471-0048; 1469-3178
• DOI: 10.1038/nrn1534

Key Points When subjects are shown words or objects during a training phase, and are then asked to perform a task that involves, for example, generating words from word stems or making a judgement about objects, their responses are quicker or more accurate for those words or objects to which they have previously been exposed. This effect is known as priming, and is accompanied by reductions in cortical activity that can be observed using functional imaging techniques. An important question relates to the specificity of priming: does priming reflect the influence of abstract representations of stimuli, or does it depend on their specific features? Three types of specificity can be considered: stimulus specificity, associative specificity and response specificity. Stimulus specificity relates to the effects on priming of changing the perceptual features of stimuli. For example, modality-specific priming refers to the fact that subjects show greater priming when both initial exposure and subsequent testing are done in the same modality (for example, visual) rather than in different modalities (visual and auditory). Results from patients with amnesia, and from neuroimaging studies, indicate that there are two routes to cross-modality priming: one involving changes in phonological processing and the other involving explicit retrieval. Stimulus specificity also refers to the effects of changing the typeface or case of a word between the study session and the test, or changing the view or examplar of an object. There is some evidence that medial temporal and diencephalic structures contribute to font- and voice-specific priming, but they are not essential for stimulus specificity in object priming. Associative specificity reflects the effects of changes in associations between pairs of stimuli. Priming is greater when associations (for example between pairs of words) are maintained. Associative priming seems to reflect some aspect of explicit memory, and to involve medial temporal structures. Response specificity refers to the effects of a change in the required response to a stimulus between the study phase and the test. Although priming occurs even when different responses are required (as in most studies of priming), the required response influences the degree of priming. It is possible that, with repetition, subjects begin to bypass semantic analysis of stimuli in favour of directly retrieving previous stimulus–response associations. This process could reduce demands on the prefrontal cortex, relying instead on the medial temporal lobe. Priming is a nonconscious form of memory that involves a change in a person's ability to identify, produce or classify an item as a result of a previous encounter with that item or a related item. One important question relates to the specificity of priming — the extent to which priming reflects the influence of abstract representations or the retention of specific features of a previous episode. Cognitive neuroscience analyses provide evidence for three types of specificity: stimulus, associative and response. We consider empirical, methodological and conceptual issues that relate to each type of specificity, and suggest a theoretical perspective to help in guiding future research.