Posts Tagged ‘ neuroscience ’

Infants Can Sense Pleasant Touch

Friday, April 4th, 2014

Newborns and infants are sensitive to what German researchers term “pleasant touch,” and they display specific physiological and behavioral response to this style of touching.  The findings are yet more confirmation of what parents have known for years, that physical contact is an important part of forging the parent-child bond.  More from the journal Psychological Science:

Previous studies with adults have shown that when the skin is stroked, a specific type of touch receptor is activated in response to a particular stroking velocity, leading to the sensation of “pleasant” touch. Cognitive neuroscientist Merle Fairhurst of the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, and colleagues hypothesized that this type of response might emerge as early as infancy.

For the study, Fairhurst and colleagues had infants sit in their parents’ laps while the experimenter stroked the back of the infant’s arm with a paintbrush. The experimenter varied the rate of the brushstrokes among three defined velocities (0.3, 3, or 30 cm per second). The experimenters gauged the infants’ responses through physiological and behavioral measures.

The results showed that the infants’ heart rate slowed in response to the brushstrokes but only when the strokes were of medium velocity; in other words, the touch of the medium-velocity brush helped to decrease their physiological arousal.

The infants also showed more engagement with the paintbrush during the medium-velocity brushstrokes, as measured by how long and how often they looked at the brush while they were being stroked.

Interestingly, infants’ slower heart rate during medium-velocity brushstrokes was uniquely correlated with the primary caregivers’ own self-reported sensitivity to touch. That is, the more sensitive the caregiver was to touch, the more the infant’s heart rate slowed in response to medium-velocity touch.

The researchers note that this link between caregiver and infant could be supported by both “nurture” and “nature” explanations:

“One possibility is that infants’ sensitivity to pleasant touch stems from direct or vicarious experience of differing levels of social touch as a function of their caregiver’s sensitivity to social touch,” explains Fairhurst. “Another possibility is that social touch is genetically heritable and therefore correlated between caregivers and infants.”

According to the researchers, the findings “support the notion that pleasant touch plays a vital role in human social interactions by demonstrating that the sensitivity to pleasant touch emerges early in human development.”

Image: Mother hugging baby, via Shutterstock

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Researchers Examine Whether Mother’s Voice Can Help Preemies Thrive

Friday, March 16th, 2012

An innovative research study is under way at Brigham and Women’s Hospital in Boston to test whether the sounds of a mother’s heartbeat and voice can help premature infants better grow and thrive while they remain in hospital care.  The study, which was recently published in the Journal of Maternal-Fetal and Neonatal Medicine, involved a professional recording studio at the hospital’s neonatal intensive care unit (NICU) to allow neuroscientist Amir Lahav–who himself became the parent of premature twins five years ago–to measure whether the soothing sounds of their mothers can help premature babies develop.

Time magazine has a full report:

“The majority of babies born before 32 weeks’ gestation, even without a diagnosed brain injury, are likely to have learning, cognitive, social or sensory problems down the road,” says Lahav, who is now a pediatric researcher specializing in neonatal medicine and director of the Neonatal Research Lab at Brigham and Women’s. “That tells us that something we do is still not perfect.”

Could the lack of exposure to maternal sounds at a critical time period account at least in part for subsequent problems with language, attention deficit, learning disabilities, even autism? Lahav doesn’t think it’s far-fetched. “If a baby is in an isolated environment with only the sounds of machines and noise, it could possibly translate into problems with social behavior,” he says.

In the small study, Lahav and colleagues played recordings of moms who spoke, read or sang, to a group of 14 babies born between 26 to 32 weeks, for 45 minutes, four times a day. They found a significant reduction in  problems such as apnea, in which breathing stops occasionally for more than 20 seconds, and bradycardia, in which the heart beat slows down significantly, when babies listened to their personalized MSS, or maternal sound stimulation. Think of it like iTunes for babies.

All babies had fewer adverse episodes when exposed to maternal sounds, but the measurement was only statistically significant in babies 33 weeks or older, according to the study. That might be because by 32 weeks, the auditory brain system is more developed, and the babies are able to process the sounds better. In general, Lahav hypothesizes, babies who hear their mothers may have reduced cortisol levels, which correlate with less stress.

Image: Recording studio, via Shutterstock.

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