National Geographic : 2005 Mar
What goes on inside a baby's head? Infants cannot communicate their thoughts directly, of course, nor are they likely to lie still in the ear splitting confinement of an MRI machine long enough for researchers to map activity in their brains. At Babylab, part of the Centre for Brain and Cognitive Development at Birkbeck, Univer sity of London, researcher Jordy Kaufman takes a direct route to reading a baby's mind. Kaufman outfits six-month-olds with hel mets of electrodes to record electrical activity in their brains while they watch a video car toon of a train disappearing into a tunnel. Traditional behavioral studies have implied that infants lack a sense of object permanence: When an object they've been looking at is suddenly hidden from view, they behave as if the object no longer exists. But Babylab's high-tech hairnet records a burst of activity in babies' right temporal lobes as they watch the train disappear, sim ilar to activity measured in adults who are asked to keep an unseen object in mind. And when the tunnel is lifted to reveal no train inside-a violation of object permanence the electrical activity spikes upward, sug gesting that the babies are trying to main tain a mental representation of the train in the face of visual evidence to the contrary. Does this mean that object permanence is prewired in the brain? Perhaps. But Kaufman prefers to see the development of mind as a fecund interaction between nature and nurture, as an infant's innate predispositions guide it to seek out experience that in turn nourishes and tunes specialized neural networks. A predisposition to look at faces, for in stance, seems to be innate, involving primi tive brain regions. But Babylab's Hanife Halit has demonstrated that regions in the higher level temporal cortex become more special ized in facial recognition through the first year of life, at first responding to upright and upside-down monkey and human faces, and finally just to upright human faces. Normal babies also prefer faces that are looking back at them, while autistic children do not. Halit speculates that without an initial predisposi tion for engaging faces, a baby's brain might fail to be enriched by the social interactions that guide normal development-leading to the wholesale indif ference to social stimuli that is one of the hall marks of autism.