Jonah Lehrer has an excellent piece in today’s Boston Globe about how babies’ brains develop and what psychologists are starting to understand about the infant mind.
It’s largely riffing on the work of Alison Gopnik, one of the world’s leading developmental psychologists, who has long argued that babies might be more conscious than adults and that we learn to filter the world and mentally manage its initial chaos.
While this less focused form of attention makes it more difficult to stay on task – preschoolers are easily distracted – it also comes with certain advantages. In many circumstances, the lantern mode of attention can actually lead to improvements in memory, especially when it comes to recalling information that seemed incidental at the time.
Consider this memory task designed by John Hagen, a developmental psychologist at the University of Michigan. A child is given a deck of cards and shown two cards at a time. The child is told to remember the card on the right and to ignore the card on the left. Not surprisingly, older children and adults are much better at remembering the cards they were told to focus on, since they’re able to direct their attention. However, young children are often better at remembering the cards on the left, which they were supposed to ignore. The lantern casts its light everywhere.
I’m a bit sceptical of one bit of the article though, where it claims that babies have more neurons than adults, as researchers have only very recently attempted to make this estimate and, in fact, found that babies and adults have about the same in the cortex, which makes up the vast majority of the brain.
In terms of synapses, connections between neurons, this varies on the age of the infant. For example, have a look at this graph of synapse density as we grow, taken from a study of the human cortex.
Newborns start with fewer synapses than adults but this number rockets, so by six months of age we have approximately twice as many connections. This tails off as the brain prunes connections on a ‘use it or lose it’ basis.
I’m always slightly awestruck whenever I view that graph as it is a vivid illustration of the incredibly rapid changes changes that take place as we grow and learn to make sense of the world.
It’s this same sense of awe that the Boston Globe manages to capture as it explains how understanding the baby’s brain can help us make sense of the adult mind.
Link to Boston Globe article ‘Inside the baby mind’.
Mind Hacks 
That graph is interesting and to me surprising at first because the biggest drop in synapses is between around age 3 1/2 and 10. On 2nd thought it makes a kind of sense, in thinking of my own children, as during that time there is an increasing focus on learning specific concrete skills.