The Telegraph has an article and video on the Harvard ‘baby brain lab’ and some of its recent discoveries which are helping us understand how the mind and brain develops through the earliest months of life.
You would think babies are difficult to test with behavioural experiments because they are can’t even stick to simple procedures, so developmental psychologists have created a task that takes advantage of the fact that infants stare at things when they’re new or interesting, but get bored and stop looking at the things they’ve seen before.
Let’s say you wanted to test whether newborn babies can tell the difference between familiar and unfamiliar people when they see their faces from different angles.
You show a picture of a person’s face, facing directly forward, until the infant becomes bored and starts looking away.
Then you flash up two new pictures both taken at the same angle, one of the original person and one of a new person. You then measure how long the infant looks at each face.
Because infants look at new or different things for longer, they would spend more time looking at the unfamiliar face if they can genuinely tell the difference. If they both seem the same to the infant, they should look at both equally, on average.
In fact, this was a recent study done on 1 and 2-day old babies, and it turns out they can tell the difference between a familiar face and a new face when the change in viewing angle isn’t too great.
Variations on this simple procedure have taught us a great deal about what babies can perceive, understand or expect, as well as how their brains function when they’re doing these tasks.
What is often most surprising is what babies can do within their first few days or birth – such as recognise faces, as in the study above – but the debate about how much these sorts of skills are due to innate knowledge, or innate rapid learning mechanisms, are still raging:
Newborns have no idea what they look like, yet they enter the world equipped with a basic understand of what a face is. They know that the pink blob in the middle of a face is a tongue, and that they can poke out their own tiny tongue in just the same way. This was crucial ammunition for an intellectual war that still rages over whether we emerge from the womb as general-purpose learning machines that soak up details of our environments, or, as Spelke believes, born ‘precocious’, so we can immediately do things that are key to survival (just as newly-hatched chicks and fish can immediately do things such as navigate, or find and recognise food).
Spelke has crossed swords with Professor Mark Johnson of Birkbeck’s Centre for Brain and Cognitive Development in London, whose studies of infant brains stretch back nearly two decades. He points out that the four and six month olds at Spelkeland have hundreds of hours of experience in categorising the world, which challenges Spelke’s ‘core knowledge’ theory. He believes that we enter the world with ‘soft biases to attend to different aspects of the environment, and to learn about the world in particular ways’.
His colleague, Prof Annette Karmiloff-Smith, who once worked with Piaget, praises some of the Spelkeland work (‘Liz has done some great behavioural experiments’) but adds, ‘Paradoxically, although she studies babies, in my view she doesn’t raise questions about infants’ capacity for learning, which may account for their extraordinary abilities without the need for them to be born with pre-specified knowledge.’