What Can Your Baby Remember?

    First of all, a rant and confession- I missed last Science Friday, but it was not for lack of trying. I wanted to write a post about infant hair growth as I constantly get comments about Q-ball being a boy, despite the pink, heart-covered onesies, but after hours of research, the most I could conclude was, "babies' hair will grow in time..."  Pathetic. There appears to be one article that contains the information I was seeking, but none of the databases to which I have access had a copy. So, if you have access to databases of medical journals, let me know, and maybe we can work together!

   And, now to this Science Friday- For about a week, Q-ball's favorite toy was her pink monkey; another week it was her wooden spoon, and another week it was a cloth book.  Few items have remained favorites.  So, what changes?  As we could have imagined, a lot is going on inside Q-ball's growing brain that is affecting her memory and, likely, explains why those toys just aren't so great anymore.

   To explore this topic I'll have to give a VERY brief and basic overview of the development of the brain in regards to memory.  As has been mentioned in nearly all of my Science Friday posts, babies have an underdeveloped central nervous system.  This explains their lack of motor skills, inability to maintain visual focus, rhythmical motions like head-banging, and their poor memory.  Neurons are nerve cells which transmit (via an electrical impulse of known as a synapse) and store all of the information in our brains. Our experiences shape neural activity- the concept of learning to roll a ball, for example, literally re-shapes and strengthens synapses within our brains. When babies don't use certain synapses, they will actually disappear! But, do not worry, humans overproduce neurons and are meant to lose many throughout childhood. In fact, synapses in the visual and auditory regions of the brain of babies 4 to 12 months are 150% of that of an adults! This proves how much information babies are able to absorb throughout the day. I know that Q-ball's everyday explorations and observations are quite literally directly influencing her brain development.

     Many, many parts of our brain are involved in memory. Each of these sections of the brain develops at different times, and, subsequently, a human baby's ability to use each section for memory develops over time.  The first memories humans have are composed of habits and conditioned responses and are stored in the spinal cord and brain stem. In fact, fetuses in their third trimester have been able to demonstrate basic memory through reflex movements. When a loud sound is played close to Mama's belly, the fetus will likely jump at first.  But, eventually, he habituates (a term psychologists use for just getting use to something, and thus, no longer responding) to this noise and responds less and less.  After birth, conditioning simple reflexes continues to be the primary method of memory for young babies. When she was between 2 to 3 months, Q-ball loved laying under her mobile. When I placed her under it, it was clear that she remembered that if she moved in certain ways, she'd be able to get those little animals above her to move!  Research has shown that a 2-month old can remember how to move a mobile for just a day or so, but by 6-months, babies can remember how to move the same mobile, even if they have not seen it for up to 2 weeks!

        Next, the cerebral cortex further matures, which includes the hypothalamus. The hypothalamus is responsible for many of our actions on a daily basis, but in regards to our discussion on memory, it helps us identify new information.  By 6 to 9 months, babies seem to have an especially acute sense of what is new. This explains why Q-ball is no longer impressed with the spatula that was yesterday's coolest-thing-ever. She has habituated it, and she is craving more novel objects.  In one experiment, two groups of 6-month old infants were shown pictures of monkeys' faces.  Parents of babies in one group continued to regularly show them pictures of these monkeys until the two groups were again shown pictures of monkeys at 9-months. At this time, babies in the group who were regularly shown pictures were actually able to identify monkeys they had never seen before just by seeing their faces in pictures. Even people that work with the monkeys regularly cannot necessarily do that.

     So, how am I supposed to keep Q-ball engaged at home? First of all, I am careful to not play all my cards at once. So, many of the Christmas gifts are still in the closet to be slowly introduced, allowing me to regularly introduce new items. Not only does this keep her out of my hair focused for a short period, but it also helps build new synapses or at least ensure she's not losing them all. Secondly, it's important to not garnish the idea of "novel" to an infant. It does not need to involve expensive, electronic, noisy, "toy of the year" toys. When Q-ball found one of Daddy's paintbrushes, it was the best, most awesome paintbrush she had ever seen!  Mainly because it was the only paintbrush she had ever seen!  We've realized that basic household items- kitchen tools, crafting items, and containers- also make amazing baby (and cat) toys.  Finally, some evidence exists that babies are very particular about where they have seen certain items or had specific experiences.  As such, sometimes just moving some objects to a different room or a different shelf might make them seem novel.  

      Constantly rotating and introducing new objects is not easy. Especially when you only have a few extra minutes during naps or after baby falls asleep.  But, realizing that you are helping give your little one new experiences and shaping her brain makes it worth the effort.  

Sources:

Eliot, L. (1999). What's going on in there? How the brain and mind develop in the first five years of life. Bantam Books: NY.

Gredler, M. E. (2009). Learning and instruction: Theory into practice. Pearson: New Jersey.

Mayell, H. (2005, May 22). Babies recognize faces better than adults, study says. National geographic news. Retrieved from http://news.nationalgeographic.com/news/2005/03/0321_050321_babies.html