Nimitha’s Reviews > Inventing Ourselves: The Secret Life of the Teenage Brain > Status Update

By day two, they can detect the difference between a foreign language and their own – sucking longer when they’re exposed to foreign-language sounds than when they hear sounds from their native language, to which they were exposed in the womb. By day three, a baby can recognize his or her mother’s voice, preferring to listen to her speech than to that of strangers.

The idea is that the baby will produce longer sucks for sounds that are not familiar, and shorter sucks for sounds he or she recognizes. Using this clever method, scientists have discovered that, by day one of life, babies can distinguish between male and female voices.

Early face recognition has been found to rely on subcortical structures. These structures, most of which develop early in life, contribute to a pathway in the brain that enables us to make fast, automatic movements in response to what we see or hear.

The main proposal of the mind-blindness theory is that the intuitive understanding that other people have minds is lacking or diminished in people with autism. If people with autism cannot automatically mentalize, then this would explain why they find communication and social interaction, especially understanding the nuances of social interaction, so challenging.

The part of the brain that processes sound (the auditory cortex) in highly skilled musicians is about 25 per cent larger than it is in people who have never played an instrument. The degree of enlargement is correlated with the age at which musicians began to practise, suggesting that the expansion of the auditory cortex is dependent on how much it is used.

Myelination is a very gradual process, beginning in the second trimester of foetal life and continuing during the rest of pregnancy and infancy, and throughout childhood, adolescence and early adulthood.

Introspection ability is associated with the size of the right rostrolateral prefrontal cortex: the better you are at introspecting, the larger this part of the brain is.

Synapses that are required to process the particular stimuli in one’s environment are maintained and strengthened, whereas those that are not needed are pruned away. The implication of this was that an adolescent’s environment – culture, education, home and social life, hobbies, nutrition and exercise – might contribute to shaping their brain.

Certain parts of the brain don’t stop developing in childhood,but instead continue to develop throughout childhood and adolescence. Furthermore, environmental experience might play an important role in shaping the human prefrontal cortex in adolescence. Synapses in this region of the brain are still being pruned away in adolescence, and we know that synaptic pruning depends partly on the individual’s environment.

We are all influenced by other people. What I would argue is that adolescents are especially susceptible to social influence. In terms of the decision see-saw, this means that social factors weigh in particularly heavily for adolescents; adolescent decision-making is more driven by the need for peer acceptance and the desire to avoid being socially excluded.