Maternal Sensitivity and Infant Neural Response to Touch: an fNIRS Study.

The mother's attunement to her infant's emotional needs influences her use of touching behaviors during mother-infant interactions. Moreover, maternal touch appears to modulate infants' physiological responses to affective touch. However, little is known about the impact of maternal sensitivity on infants' touch processing at a brain level. This study explored the association between maternal sensitivity when infants (N = 24) were 7 months old and their patterns of cortical activation to touch at 12 months. Brain activation was measured using functional near-infrared spectroscopy (fNIRS). Changes in oxy (HbO2)- and deoxy (HHb)-hemoglobin concentrations were measured in the left somatosensory cortex and right temporal cortex while infants received two types of tactile stimulation - affective and discriminative touch. Results showed that lower maternal sensitivity was associated with a higher HbO2 response for discriminative touch over the temporal region. Additionally, infants of less sensitive mothers tended to present a higher response in HbO2 for affective touch over the somatosensory region. These findings suggest that less sensitive interactions might result in lower exposure to maternal touch, which can be further related to infant's neural processing of touch.