Some influences on cognition in early life: a short review of recent opinions.

Many factors can affect a child's ability to learn, and these may operate before, during, and after birth. Some of these are considered, and are hopefully important, but not necessarily the most obvious. The intrauterine environment may not be so influential as the infant's genetic endowment, but nevertheless is of considerable importance. For example, malnutrition resulting from placental insufficiency leading to small-for-date babies can impair brain development. Also a relationship between birth weight and cognitive function in early adult life has been demonstrated; and the babies' condition at birth can be a risk factor for various disabilities. Lack of stimulation in infancy, for example if postnatal depression interferes with the mother's interaction with her baby, can significantly affect the infant's learning capacity. A good paradigm is the development of language, which starts with the way mothers 'talk' to their babies; and this continues into childhood. The importance of nutrition also continues, and is one of the factors which favours breast feeding against formula foods. The whole subject has to be viewed against the background of normal development, and the great loss of neurons and synapses that occur in early life. If neural circuits are formed at this time, and these neurons and synapses are not lost, the easier it will be to exploit them. This emphasizes the importance of early education, which is not always sufficiently acknowledged.