Extra Prenatal Testosterone Makes a Genius?

Extra Prenatal Testosterone Makes a Genius?

  7:01:00 PM    Science Lover

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A longstanding debate as to whether genius is a byproduct of good genes or good environment has an upstart challenger that may take the discussion in an entirely new direction. University of Alberta researcher Marty Mrazik says being bright may be due to an excess level of a natural hormone.

A longstanding debate as to whether genius is a 
byproduct of good genes or good environment has an 
upstart challenger that may take the discussion in an 
entirely new direction. University of Alberta researcher 
Marty Mrazik says being bright may be due to an 
excess level of a natural hormone. 
(Credit: iStockphoto/Vasiliy Yakobchuk)

 

Mrazik, a professor in the Faculty of Education's educational psychology department, and a colleague from Rider University in the U.S., have published a paper in Roeper Review linking giftedness (having an IQ score of 130 or higher) to prenatal exposure of higher levels of testosterone. Mrazik hypothesizes that, in the same way that physical and cognitive deficiencies can be developed in utero, so, too, could similar exposure to this naturally occurring chemical result in giftedness.

"There seems to be some evidence that excessive prenatal exposure to testosterone facilitates increased connections in the brain, especially in the right prefrontal cortex," said Mrazik. "That's why we see some intellectually gifted people with distinct personality characteristics that you don't see in the normal population."

Mrazik's notion came from observations made during clinical assessments of gifted individuals. He and his fellow researcher observed some specific traits among the subjects. This finding stimulated a conversation on the role of early development in setting the foundation for giftedness.

"It gave us some interesting ideas that there could be more to this notion of genius being predetermined from a biological perspective than maybe people gave it credit for," said Mrazik. "It seemed that the bulk of evidence from new technologies (such as Functional MRI scans) tell us that there's a little bit more going on than a genetic versus environmental interaction."

Based on their observations, the researchers made the hypothesis that this hormonal "glitch" in the in-utero neurobiological development means that gifted children are born with an affinity for certain areas such as the arts, math or science. Mrazik cautions that more research is needed to determine what exact processes may cause the development of the gifted brain.

He notes that more is known about what derails the brain's normal development, thus charting what makes gifted people gifted is very much a new frontier. Mrazik hopes that devices such as the Functional MRI scanner will give them a deeper understanding of the role of neurobiology in the development of the gifted brain.

"It's really hard to say what does put the brain in a pathway where it's going to be much more precocious," he said. "The next steps in this research lay in finding out what exact stimuli causes this atypical brain development."

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Babies, Even When Premature, 'See' With Their Hands

Babies, Even When Premature, 'See' With Their Hands

  9:56:00 PM    Science Lover

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Even premature babies at 33 weeks post-conceptional age, about 2 months before term (40 gestational weeks), are capable of recognizing and distinguishing two objects of different shapes (a prism and a cylinder) with their right or left hands. This is the first demonstration of fully efficient manual perception in preterm human infants.

A premature baby holding a cylinder. (Credit: Copyright Frédérique Berne-Audéoud)

The phenomenon was discovered by researchers at two laboratories: the Laboratoire de psychologie et neurocognition (CNRS / University of Grenoble 2 / University of Chambéry) and the Laboratoire de psychologie de la perception (CNRS / University of Paris Descartes) in cooperation with a team from the Neonatology Department of the Grenoble University Hospitals. The findings have been published on the PLoS One website.

The source of all perceptual knowledge, the sense organs and sensory systems of premature babies are less efficient than those of full-term babies, even though the latter are also not yet fully developed. Starting in the very first minutes after birth, a full-term infant is subjected to extensive tactile stimulation: it is washed, held on its mother's stomach, nursed, diapered, etc. Its body almost immediately experiences contact with skin other than its own, with towels, sheets, nipples -- in short, with objects of different textures, shapes and consistencies. It is common knowledge that a baby will flex its fingers tightly if its palm is touched by a finger, but this grasping reaction is not just a simple reflex. Even in the first hours of its life, a full-term newborn already has effective manual perception, a tactile capacity that enables it to make sense of its environment. But what about the premature infant, whose neurological functions are even less developed due to its early birth?

To find out, the researchers conducted an experiment with 24 premature babies aged 33 to 34+6 gestational weeks (GW), approximately 2 weeks after their birth. Their average gestational age (age at birth) was 31 GW (which corresponds to about 7 months of pregnancy) and their average weight at birth was 1500 g. The research team adopted an experimental method based on habituation (first phase) and reaction to novelty (second phase), similar to that used for full-term newborns. This method relies on a simple universal principle: the gradual loss of interest that all humans experience in relation to a familiar object and the renewed attention elicited by a new, unfamiliar object. In the first phase, the researcher places a small object (a prism for half of the babies and a cylinder for the other half) in one of the baby's hands (the right hand for half of the group and the left for the other half). As soon as the infant lets go of the object, the experimenter places it back in the same hand and measures how long the baby holds the object each time. The researchers observed that the holding time decreased over the course of the trials, indicating that the baby had become "habituated" to the shape of the object.

In the second phase, once the babies are habituated to their first objects, the researchers present an object with a new shape to half of the group and a familiar object (the same as in the habituation phase) to the other half. The result: the holding time is longer for the new object (reaction to novelty) than for the familiar object. This proves that the decrease in holding time (observed in the first phase) is not due to the babies' simply growing tired, because otherwise they would not be more interested in something new.

This experiment reveals for the first time that preterm infants are capable of recognizing an object with their hands (tactile habituation) and that they show a preference for a novel object, reflecting their capacity to differentiate between two objects of different shapes (tactile discrimination). In other words, each time they hold an object, premature babies, like those born at term, are capable of extracting information tactilely on its shape, temporarily storing this information in their memory and comparing it with new tactile input. If the object is the same they soon stop holding it, but if it is different they show greater interest. Therefore, preterm infants, like full-term newborns, are receptive to tactile information and are already learning.

These findings improve our understanding of the perceptual capacities of premature babies and should help neonatology professionals optimize the handling and treatment of their preterm charges, in particular for the purpose of reducing their stress and offering them optimal conditions for their development.

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