Читать книгу Overcoming Internet Addiction For Dummies - David N. Greenfield - Страница 56

Many theories have been proposed to explain reduced access to the frontal lobes when people are engaged in addictive behaviors, but it’s likely due in part to the evolutionary and biological origins of addiction. The powerful dopamine pleasure center in the brain evolved because it helped ensure survival of the species. Think about it; food and sex are associated with some of the biggest releases of dopamine in the body, and they are two factors that are essential to human survival.

That food and sex become addictions for many people is no surprise. In fact, if you look at the overall negative health impact, food addiction alone likely dwarfs all other addictions combined.

Eating and sex are pleasurable because both are essential for the survival. They’re pleasurable, and hence dopaminergic, because our brains want to make sure we engage in these activities, and what better way to make sure we do something than to make it incredibly desirable?

It may be that when these powerful pleasure centers are activated, innervation of frontal control circuits that provide reasoning, judgment, and executive control is temporarily reduced; it is my theory that this occurs to facilitate survival behavior powered by the pleasure center in the nucleus accumbens. Why would this occur? It makes sense, from an evolutionary perspective, that thinking and reasoning behaviors (which are slower) could limit dopaminergic survival behavior; this would be contrary to engaging in the immediate-acting survival behaviors of sex and food. If you are hunting or finding food or attempting to have sex, anything that could slow this process down would reduce the likelihood of survival. It so happens that the same areas of the brain that makes survival behaviors pleasurable are involved with addiction.

Unfortunately, whenever anyone engages in addictive behavior, the body tends to diminish and limit access to the frontal lobes of the brain. Disengaged, the frontal lobes can’t buffer those strong desires for pleasure that are often characteristic of an addicted state. Why the body shuts down access to the frontal lobes when a person is engaged in addictive behavior is not fully understood, but one possible explanation is presented in the nearby sidebar “The evolutionary power of addictions.”