Negative affect is related to reduced differential neural responses to social and non-social stimuli in 5-to-8-month-old infants: A functional near-infrared spectroscopy-study

Abstract

Both social perception and temperament in young infants have been related to social functioning later in life. Previous functional Near-Infrared Spectroscopy (fNIRS) data (Lloyd-Fox et al., 2009) showed larger blood-oxygenation changes for social compared to non-social stimuli in the posterior temporal cortex of five-month-old infants. We sought to replicate and extend these findings by using fNIRS to study the neural basis of social perception in relation to infant temperament (Negative Affect) in 37 five-to-eight-month-old infants. Infants watched short videos displaying either hand and facial movements of female actors (social dynamic condition) or moving toys and machinery (non-social dynamic condition), while fNIRS data were collected over temporal brain regions. Negative Affect was measured using the Infant Behavior Questionnaire. Results showed significantly larger blood-oxygenation changes in the right posterior-temporal region in the social compared to the non-social condition. Furthermore, this differential activation was smaller in infants showing higher Negative Affect. Our results replicate those of Lloyd-Fox et al. and confirmed that five-to-eight-month-old infants show cortical specialization for social perception. Furthermore, the decreased cortical sensitivity to social stimuli in infants showing high Negative Affect may be an early biomarker for later difficulties in social interaction.

Keywords: Functional near-infrared spectroscopy; Infants; Negative affect; Social perception; Temperament; fNIRS.

Fig. 1

Location of the NIRS channels over the left and right hemisphere, relative to 10–20 positions T7 and T8. Channels within the Region of Interest are marked green.

Fig. 2

Grand mean average time courses with Standard Error of HbO and HbR changes in millimolar (mM) as a function of time (stimulus block starts at 0) for each of the experimental conditions in the posterior temporal channels.

Fig. 3

Correlations between Negative Affect scores and differential HbO and HbR concentration changes (in mM) in the social dynamic compared to the non-social dynamic condition in the right posterior temporal region.