So after you saw the A-not-B error, you might have thought to yourself, “WOAH! What’s going on? Why do babies do that?”
Good question! That’s exactly what Jean Piaget asked as well. His theory was that these infants do not fully understand the concept of object permanence, that objects continue to exist even when they are unseen.
Much time has passed since the 1920-30s (Piagets’ heyday). And some people started supposing that the A-not-B error was not about concepts of objects’ existence at all.
But let me tell you the crazy punchline. BABIES MAKE THE A-NOT-B ERROR EVEN WITH TRANSPARENT HIDING LOCATIONS. CRAZY, eh? How do you explain dem apples Piaget? Your “object permanence” ain’t gonna help you now.
(Note about video: Now cogscibaby is too savvy for the regular old Piagetian search task now. I had to make it a little harder for him. But notice that even though he can clearly see the keys, he is still making a reaching error.)
Enter Linda Smith and Esther Thelen, cognitive scientists at Indiana University (full disclosure: my alma mater and Linda Smith is a beloved mentor). They noticed that babies are pretty terrible at moving/reaching in general. Babies are terrible motor planners! It takes a lot of cognitive resources for them to make even simple plans (like: 1. pull on string, 2. grab toy). Not only that but we know that babies’ brains also have all these extra neuronal connections (synapses) that we don’t actually need. The consequence of this super-connected brain is that many of their bodily systems interfere with one another. The motor system interferes with the visual system which then interferes with memory, etc. Finally, babies are not that great at thinking: they have super limited memories and are highly distractible.
So just to recap what 8-9 month life is like: (1) Motor planning is hard, (2) Motor system interferes with other cognitive systems, and (3) Limited attention/memory.
Smith and Thelen proposed that perhaps the A-not-B error was the result of the reach to location A, having taken a lot of resources to accomplish, now interfering with a new motor plan to reach to B! The A-not-B error is basically the overwhelming echo of that first reach to A. This theory is called the dynamic systems approach because there are these component systems (like motor, perception, memory) that are competing with each other.
And you can see that overwhelming echo in cogscibaby’s reach! Watch the video again and you’ll see his arm arc over the B location briefly before heading on over to A! Particularly because I had made him reach to A before and his posture is poised to go towards A anyway, he has a really hard time reaching to the new location. Hey cogscibaby — nice job demonstrating the dynamic systems explanation of the A-not-B error!!!