Invariance of Functional Characteristics to Task Difference at Low-Level and High-Level Areas in the Ventral Visual Pathway

Abstract

Tasks with stimuli are often used for the examination of stimulus-related functional characteristics of brain areas. However, the task can affect the response to a stimulus. Repetition suppression is a phenomenon that can be used to probe neuronal properties using macroscale functional magnetic resonance imaging (fMRI). The use of repetition suppression as an investigative tool to assess functional characteristics warrants the investigation of the invariance of repetition suppression to a given task. In this study, we examined repetition suppression using images of faces during different tasks. We found that the task difference did not change the response patterns related to repetition suppression in high-level areas and the primary visual area while it changed amplitudes of fMRI response to the visual stimuli. The result suggests that the repetition-suppression phenomenon is robust compared with the amplitude of fMRI response, and functional characteristics can be examined using the repetition-suppression phenomenon even under the condition that fMRI response is varied by task difference.