title: The relationship between stimulus repetitions and fulfilled expectations.
abstract: Several neuroimaging studies showed that fulfilled expectations increase the magnitude of repetition suppression (RS) in the face-selective visual cortex. However, previous fMRI studies did not allow a distinction between the reductions of the response due to stimulus repetitions and fulfilled expectations (expectation suppression, ES). In most prior studies repetitions and expectations were not independent from each other as repetitions occurred more often when they were expected and less often when they were not expected, thereby confounding RS with ES. To overcome this confound, we presented pairs of female and male faces that were either repeating or alternating with an overall probability of 50-50%. Orthogonally to this, the gender of the first face in each pair signaled with 75% accuracy whether repetitions or alternations were more likely to occur. We found significant RS in the FFA, the OFA and the LO. In addition, these areas showed a reduction of the response for expected when compared to surprising trials. Moreover, the effects of RS and ES were always additive rather than interactive in our ROIs. This implies that stimulus repetition and fulfilled expectations can be dissociated from one another in terms of their effects on the neural responses.
authors.affiliation: Department of Cognitive Neuroscience, Institute of Psychology, Friedrich Schiller University Jena, 07743 Jena, Germany; DFG Research Unit Person Perception, Friedrich Schiller University Jena, 07743 Jena, Germany.
authors.forename: Mareike
authors.initials: M
authors.lastname: Grotheer
authors.affiliation: Department of Cognitive Neuroscience, Institute of Psychology, Friedrich Schiller University Jena, 07743 Jena, Germany; DFG Research Unit Person Perception, Friedrich Schiller University Jena, 07743 Jena, Germany; Department of Cognitive Science, Budapest University of Technology and Economics, 1111 Budapest, Hungary. Electronic address: gyula.kovacs@uni-jena.de.
authors.forename: Gyula
authors.initials: G
authors.lastname: Kovács
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011336:Probability; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Expectation; Prediction; Repetition Suppression; Vision; fMRI adaptation