TY - JOUR

T1 - The relationship between fMRI adaptation and repetition priming

AU - Ganel, Tzvi

AU - Gonzalez, Claudia L R

AU - Valyear, Kenneth F

AU - Culham, Jody C

AU - Goodale, Melvyn A

AU - Köhler, Stefan

PY - 2006/9

Y1 - 2006/9

N2 - 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.

AB - 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.

KW - Adaptation, Physiological

KW - Adult

KW - Cerebral Cortex

KW - Cues

KW - Evoked Potentials

KW - Female

KW - Functional Laterality

KW - Humans

KW - Magnetic Resonance Imaging

KW - Male

KW - Occipital Lobe

KW - Oxygen

KW - Reaction Time

KW - Temporal Lobe

KW - Visual Pathways

KW - Visual Perception

KW - Clinical Trial

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

U2 - 10.1016/j.neuroimage.2006.05.039

DO - 10.1016/j.neuroimage.2006.05.039

M3 - Article

C2 - 16854597

VL - 32

SP - 1432

EP - 1440

JO - Neuroimage

JF - Neuroimage

SN - 1053-8119

IS - 3

ER -