The relationship between fMRI adaptation and repetition priming

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  • Tzvi Ganel
    University of Western Ontario, Canada
  • Claudia L R Gonzalez
    University of Western Ontario, Canada
  • Kenneth F Valyear
    University of Western Ontario, Canada
  • Jody C Culham
    University of Western Ontario, Canada
  • Melvyn A Goodale
    University of Western Ontario, Canada
  • Stefan Köhler
    University of Western Ontario, Canada

Neuroimaging investigations of the cortically defined fMRI adaptation effect and of the behaviorally defined repetition priming effect have provided useful insights into how visual information is perceived and stored in the brain. Yet, although both phenomena are typically associated with reduced activation in visually responsive brain regions as a result of stimulus repetition, it is presently unknown whether they rely on common or dissociable neural mechanisms. In an event-related fMRI experiment, we manipulated fMRI adaptation and repetition priming orthogonally. Subjects made comparative size judgments for pairs of stimuli that depicted either the same or different objects; some of the pairs presented during scanning had been shown previously and others were new. This design allowed us to examine whether object-selective regions in occipital and temporal cortex were sensitive to adaptation, priming, or both. Critically, it also allowed us to test whether any region showing sensitivity to both manipulations displayed interactive or additive effects. Only a partial overlap was found between areas that were sensitive to fMRI adaptation and those sensitive to repetition priming. Moreover, in most of the object-selective regions that showed both effects, the reduced activation associated with the two phenomena were additive rather than interactive. Together, these findings suggest that fMRI adaptation and repetition priming can be dissociated from one another in terms of their neural mechanisms.

Keywords

  • Adaptation, Physiological, Adult, Cerebral Cortex, Cues, Evoked Potentials, Female, Functional Laterality, Humans, Magnetic Resonance Imaging, Male, Occipital Lobe, Oxygen, Reaction Time, Temporal Lobe, Visual Pathways, Visual Perception, Clinical Trial, Journal Article, Research Support, Non-U.S. Gov't
Original languageEnglish
Pages (from-to)1432-1440
Number of pages9
JournalNeuroimage
Volume32
Issue number3
DOIs
Publication statusPublished - Sep 2006
Externally publishedYes
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