Tuesday, November 14, 2006

Infant Reflexes

When I think about ways to spice up my intro psych class, I am reminded of a video clip I overheard while returning to my office one day. My colleague was showing his class the home movie he made of his daughter failing to demonstrate "conservation," an understanding that the number of items (M&Ms, coins) doesn't increase simply because they are spaced out more or that the amount of juice in a cup doesn't increase because it has been poured into a narrower cup. It's considered to be a major cognitive milestone that kids achieve around 5-6 years of age. (Adult apes demonstrate conservation too, but monkeys don't.)

Anyhow, the class really enjoyed seeing an abstract concept realized; I think, or they just like watching videos that show young children can't grasp the most elementary of concepts that they all take for granted. One of the great advantages of having kids as a psych prof is that you can actually make a repository of videos of your own kid's infant reflexes, Piagetian tasks and oh, I don't know, various Freudian things that kids are bound to do, like saying they want to marry daddy when they grow up.

My SIL just had a baby, and my sister is expecting one in March, so I suppose I could enlist their help in making footage for my class until I have a subject of my own to work with. (Hint! hint! ) My furry monster canines just won't cut it for the infant reflexes and Freudian departments, but they do a decent job of demonstrating Piaget's "object permanance." Out of sight is nowhere out of mind for Max when it comes to a treat, let me tell you!

One of the reflexes that I find particularly fascinating from an evolutionary standpoint is the "Moro reflex." When an infant is startled or loses head support, the baby's arms fling straight out to the side, fists close, and then come back to the chest as you'd expect to happen if a primate needed to quickly grasp mom's hair in case of emergency. This happens for the first 3-5 months after birth and is one of the most convincing examples that we are primates whose ancestors were hairy.

Infant reflexes can be used to gauge whether the infant has a normal central nervous system. Besides the Moro (no connection to the delicious blood "moro" oranges I love), there's also the Babinski, rooting, stepping, and one I'd nver heard before looking into it today: the swimmer's or "Gallant" reflex. Hold the baby prone supported by your hand on its belly. Stroke one side of the baby's spine. The baby should flex its body toward the stroked side.

The video below (found on YouTube) isn't a perfectly textbook example of the Moro reflex, but I think it comes pretty close. I also think this baby looks too thin!!

3 comments:

ScienceWoman said...

Thanks for posting this - it's a particular interest for me right now. :)

By the way, do you have a reccomendation for a general book on evolutionary psychology for a little light reading? I've become fascinated by the subject since I started reading your blog.

Holly said...

Given that you're expecting your first child, I would highly recommend "Mother Nature" by Sarah Hrdy. She's a feminist sociobiologist who studies primates and tells stories well. Her book comes closest to what I think you'd enjoy given that you enjoy this blog. She's scientifically rigorous and covers multiple areas of evolutionary inquiry with a focus on parenting and infant attachment. It is one of my very favorite books :=)

Charlie said...

interesting topic! and yesthat baby does look quite thin!