An early category-specific neural response for the perception of both places and faces

Abstract

Rapid and accurate recognition of faces and places is crucial in everyday life. Magnetoencephalography (MEG) studies have demonstrated that the human visual system can categorize an incoming visual stimulus as a face within 100 ms, as reflected by the M100. No similar, early, place-specific MEG component has been described, somewhat surprisingly, as there is behavioral evidence for rapid visual categorization of places. The current study aimed to explore the existence, as well as the spatio-temporal dynamics, of a place-selective MEG component. MEG activity was recorded while 10 participants were presented with pairs of face and place stimuli. Our results show that the perception of places generates a category-specific MEG component (M100p), which occurs just as early as that seen for faces. Our findings suggest that early visual categorization within cortical areas does not occur exclusively for faces, but instead may be a more general phenomenon.

Keywords:

• Face perception
• M100
• MEG
• Place perception
• Visual perception

Acknowledgments

We wish to thank members of the Kanwisher Laboratory, Anina Rich and Matthew Finkbeiner, for their insightful comments on this work. We wish to thank Loes Koelewijn for her help with MEG data processing. We also wish to thank Graciela Tesan, Melanie Reid, and Christopher Sewell for the support provided in the MEG data acquisition. This work was supported by the Macquarie University Research Excellence Scholarship (iMQRES) to D. Rivolta. M. A. Williams is supported by the Australian Research Council Fellowship Schemes (grant number DP0984919). L. Schmalzl is supported by the European Research Council.

Notes

¹As indicated in the text, for each subject, we used the first category-specific dSPM map generated by S1 as ROI. The time course of dSPM maps was, on average, 115 ms (SD = 13.46) on the left and 115.2 ms (SD = 13.37) on the right hemisphere for place processing, whereas it was 122 ms (SD = 17.24) on the left and 126 ms (SD = 14.38) on the right hemisphere for face processing.

²We are not comfortable reporting the specific anatomical source of the M100s as the spatial resolution of MEG is poorer than fMRI.

³The difference in luminosity between familiar and unfamiliar faces is similar to the difference in luminance between familiar and unfamiliar places, t(118) = –1.28, p = .206.