We tested for differential brain response to distinct spatial frequency (SF) components in faces. During a functional magnetic resonance imaging experiment, participants were presented with "hybrid" faces containing superimposed low and high SF information from different identities. We used a repetition paradigm where faces at either SF range were independently repeated or changed across consecutive trials. In addition, we manipulated which SF band was attended. Our results suggest that repetition and attention affected partly overlapping occipitotemporal regions but did not interact. Changes of high SF faces increased responses of the right inferior occipital gyrus (IOG) and left inferior temporal gyrus (ITG), with the latter response being also modulated additively by attention. In contrast, the bilateral middle occipital gyrus (MOG) responded to repetition and attention manipulations of low SF. A common effect of high and low SF repetition was observed in the right fusiform gyrus (FFG). Follow-up connectivity analyses suggested direct influence of the MOG (low SF), IOG, and ITG (high SF) on the FFG responses. Our results reveal that different regions within occipitotemporal cortex extract distinct visual cues at different SF ranges in faces and that the outputs from these separate processes project forward to the right FFG, where the different visual cues may converge.
Bibliographical noteFunding Information:
We would like to thank C. Hutton, J. Ashburner, O. Joseph, and S. Dakin on useful advice regarding the stimuli preparation; U. Nopenney and A. Michelli for helping with the connectivity analysis; and Z. Israeli for giving overall useful comments on the manuscript. This study was supported by Wellcome Program Grants to R.D. and J.D., P.R. was supported by Wellcome scholarship and now is supported by Economic & Social Research Council/Medical Research Council fellowship, and finally P.V. is supported by the Swiss National Science Foundation. Conflict of Interest: None declared.
- Occipitotemporal cortex
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience
- Cognitive Neuroscience