Norman Doidge

Language development, for instance, has a critical period that begins in infancy and ends between eight years and puberty. After this critical period closes, a person’s ability to learn a second language without an accent is limited. In fact, second languages learned after the critical period are not processed in the same part of the brain as is the native tongue.

goslings, if exposed to a human being for a brief period of time, between fifteen hours and three days after birth, bonded with that person, instead of with their mother, for life

Competitive plasticity also explains why our bad habits are so difficult to break or “unlearn.” Most of us think of the brain as a container and learning as putting something in it. When we try to break a bad habit, we think the solution is to put something new into the container. But when we learn a bad habit, it takes over a brain map, and each time we repeat it, it claims more control of that map and prevents the use of that space for “good” habits. That is why “unlearning” is often a lot harder than learning, and why early childhood education is so important—it’s best to get it right early, before the “bad habit” gets a competitive advantage.

ost autistic children have an IQ of less than 70. They have major problems connecting socially to others and may, in severe cases, treat people like inanimate objects, neither greeting them nor acknowledging them as human beings. At times it seems that autistics don’t have a sense that “other minds” exist in the world.

Human beings exhibit an extraordinary degree of sexual plasticity compared with other creatures. We vary in what we like to do with our partners in a sexual act.

romantic love began to gain social approval in the aristocracies and courts of Europe only in the twelfth century—originally between an unmarried man and a married woman, either adulterous or unconsummated, usually ending badly. Only with the spread of democratic ideals of individualism did the idea that lovers ought to be able to choose spouses for themselves take firmer hold and gradually begin to seem completely natural and inalienable.

In Elizabethan times lovers were so enamored of each other’s body odors that it was common for a woman to keep a peeled apple in her armpit until it had absorbed her sweat and smell. She would give this “love apple” to her lover to sniff at in her absence.

we have two separate pleasure systems in our brains, one that has to do with exciting pleasure and one with satisfying pleasure. The exciting system relates to the “appetitive” pleasure that we get imagining something we desire, such as sex or a good meal. Its neurochemistry is largely dopamine-related, and it raises our tension level.
The second pleasure system has to do with the satisfaction, or consummatory pleasure, that attends actually having sex or having that meal, a calming, fulfilling pleasure. Its neurochemistry is based on the release of endorphins, which are related to opiates and give a peaceful, euphoric bliss.

We love being in love not only because it makes it easy for us to be happy but also because it makes it harder for us to be unhappy.

Evidence suggests that unlearning existing memories is necessary to make room for new memories in our networks.