When does repetition suppression depend on repetition probability?

Gyula Kovã¡Cs,Rufin Vogels

doi:10.3389/fnhum.2014.00685

Abstract

When does repetition suppression depend on repetition probability?

Highlights

It has been shown recently that the probability of stimulus repetitions (Prep) determines the degree of repetition suppression (RS): the repetition-related decrease of the fMRI signal was larger for faces in the fusiform face area (FFA) in blocks with high when compared to low repetition probabilities (Summerfield et al, 2008)
This suggests that higher-order contextual expectations, via top-down connections, modulate fMRIa and the results were interpreted in the frame of predictive coding models (Rao and Ballard, 1999; Friston, 2005)
Contrary to Kovács et al (2013), they found Prep modulations of RS for line-drawings in the left LO. They argued that the reason of the discrepancy between the studies is the “diverging extent of repetition probability,” claiming that expectations were manipulated in the Kovács et al (2013) study using 60/20% of repetition trials in repetition/alternation blocks, respectively, while in their and prior investigations using faces, Prep varied between 75/25%

Summary

Introduction

Mayrhauser et al (2014) employed line-drawings of objects to test Prep effects in LO. They argued that the reason of the discrepancy between the studies is the “diverging extent of repetition probability,” claiming that expectations were manipulated in the Kovács et al (2013) study using 60/20% of repetition trials in repetition/alternation blocks, respectively, while in their and prior investigations using faces, Prep varied between 75/25%.

Results

Conclusion