Elsevier

NeuroImage

Volume 186, 1 February 2019, Pages 817-824
NeuroImage

A longitudinal study of infant view-invariant face processing during the first 3–8 months of life

https://doi.org/10.1016/j.neuroimage.2018.11.031Get rights and content
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open access

Highlights

  • The development of view-invariant face processing in infancy was investigated.

  • We longitudinally measured hemodynamic responses to frontal and profile images.

  • Each infant's hemodynamic data were individually analyzed using linear regression.

  • Processing of profile faces emerged later and faster than that of frontal faces.

  • Individual differences in development were explained by a linear function.

Abstract

View-invariant face processing emerges early in life. A previous study (Nakato et al., 2009) measured infant hemodynamic responses to faces from the frontal and profile views in the bilateral temporal areas, which have been reported to be involved in face processing using near-infrared spectroscopy. It was reported that 5-month-old infants showed increased oxyhemoglobin (oxy-Hb) responses to frontal faces, but not to profile faces. In contrast, 8-month-old infants displayed increased oxy-Hb responses to profile faces as well as to frontal faces. In this study, we used the experimental method developed in the previous study to investigate the development of view-invariant face processing, every month for 5 months (from the first 3–8 months of life). We longitudinally measured hemodynamic responses to faces from the frontal and profile views in 14 infants. The longitudinal measurements allowed us to investigate individual differences in each participant. We modeled each infant's hemodynamic oxy-Hb responses to frontal and profile faces using linear regression analysis. Processing of profile faces emerged later and underwent larger improvements than that of frontal faces. We also found an anticorrelation between the speed of improvement in face processing and the hemodynamic response to faces at the age of 3- months. Group analysis of the averaged hemodynamic data from the 14 infants using linear regression revealed that the processing of profile faces emerged between 5 and 6 months of age. Infant view-invariant face processing developed first for frontal faces. This was followed by the emergence of processing of profile faces.

Keywords

Infants
Longitudinal study
Face processing
View-dependent
Near-infrared spectroscopy
NIRS
Linear regression analysis

Cited by (0)

1

These authors contributed equally to the work.

2

Hiroko Ichikawa is now at Faculty of Science and Technology, Tokyo University of Science.

3

Emi Nakato is now at Department of Nursing, Ehime Prefectural University of Health Sciences.

4

Yasuhiko Igarashi is now at PRESTO, JST and Research and Service Division of Materials Data and Integrated System, National Institute for Materials Science.