Maternal touch and infant affect in the Still Face Paradigm: A cross-cultural examination.

Touch between mother and infant plays an important role in development starting from birth. Cross-cultural differences surrounding rearing practices have an influence on parent-infant interaction, including types of touch used and the development of emotional regulation. This study was designed to investigate maternal touch and infant emotional regulation in infant-mother dyads from Ecuador (n=25) and Hispanic dyads from the United States (US) (n=26). Mothers and their 4-month-old full-term infants participated in the Still Face Paradigm. Second-by-second coding of maternal touch and infant affect was completed. Overall the analyses showed that Ecuadorian mothers used more nurturing and accompaniment touch and less attention seeking touch than US Hispanic mothers during the pre-stressor (baseline) episode. Lagged multilevel models were used to investigate the effect of the different types of touch on infant emotional regulation in the groups for the episodes. The data suggest that playful touch had a significant increase in infant affect, whereas accompaniment and attention-seeking touch had a significant decrease in infant affect. Overall, this study provides support for the role of touch in mother-infant synchronicity in relation to infant's emotional regulation. Identifying touch that is more calming is important to foster emotional regulation in infancy, which can have important implications for development.

Enhanced tethered-flight duration and locomotor activity by overexpression of the human gene SOD1 in Drosophila motorneurons.

Mutation of the human gene superoxide dismutase (hSOD1) is associated with the fatal neurodegenerative disease familial amyotrophic lateral sclerosis (Lou Gehrig's disease). Selective overexpression of hSOD1 in Drosophila motorneurons increases lifespan to 140% of normal. The current study was designed to determine resistance to lifespan decline and failure of sensorimotor functions by overexpressing hSOD1 in Drosophila's motorneurons. First, we measured the ability to maintain continuous flight and wingbeat frequency (WBF) as a function of age (5 to 50 days). Flies overexpressing hSOD1 under the D42-GAL4 activator were able to sustain flight significantly longer than controls, with the largest effect observed in the middle stages of life. The hSOD1-expressed line also had, on average, slower wingbeat frequencies in late, but not early life relative to age-matched controls. Second, we examined locomotor (exploratory walking) behavior in late life when flies had lost the ability to fly (age ≥ 60 d). hSOD1-expressed flies showed significantly more robust walking activity relative to controls. Findings show patterns of functional decline dissimilar to those reported for other life-extended lines, and suggest that the hSOD1 gene not only delays death but enhances sensorimotor abilities critical to survival even in late life.