Anthony Stigliani

Repetition of a stimulus typically leads to a reduction in neural response. This adaptation effect, sometimes known as repetition suppression or neural priming, can be observed both in individual neurons (as illustrated by a reduction in firing rate) and fMRI voxels containing hundreds of thousands of neurons (as illustrated by a reduction in BOLD response). When measured with fMRI, this repetition-related reduction in neural activity is known as fMRI-Adaptation (fMRI-A) and can be used to make inferences about the nature of neuron representations and their sensitivity to various stimulus transformations (e.g., Grill-Spector et al. 1999). While fMRI-A has proven to be a powerful and flexible tool for studying a variety of topics, some experimental designs are more optimal for studying particular phenomena than others. The purpose of this wiki page is to outline the critical components of fMRI-A methods and describe different types of experimental designs that may be used.

Background

Response of an example IT neuron to first the presentation of stimulus A (left), the first presentation of stimulus B (center), and repeated presentation of stimulus A (Grill-Spector et al. 2006).

Reductions in neural firing related to stimulus repetition were

References

Grill-Spector, K., Henson, R., & Martin, A. (2006). Repetition and the brain: neural models of stimulus-specific effects. Trends in Cognitive Science, 10(1), 14-23.