Cortical Mechanisms for Cognition of Photograph and Painting : an fMRI Study

Abstract

Although recent advances in the computer graphics technique allow us to generate photo-like images (ex. painting), we can distinguish them from real photos. This suggests that an ability to detect the differences between real photo and photo-like images, that is an ability to detect the differences of realistic appearances, may be embedded in our cognitive system. In this study, we investigated the cortical mechanisms underlying this ability by means of fMRI. We found several brain regions, including middle occipital gyrus, middle temporal gyrus, temporo-parieto-occipital junction, parieto occipital sulcus (POS), fusiform gyrus (FG), and middle frontal gyrus (MFG), were activated during the photo-painting evaluation task. The detailed analysis showed that the activity in the POS and MFG was specifically enhanced when participants evaluate the presented images as more painting-like, while activation in the other regions was correlated with the physical properties of images, such as chromaticity, luminance or high spatial frequency component of images. These results suggest that the POS-MFG network may play a crucial role in the detection of differences between real photos and photo-like images.