Nov 30 2009
Your Brain on Chemicals: Pleasure, Fear and Masculinity
Three recent, separate studies have illustrated how chemicals and chemical levels can influence thoughts, feelings, behavior: human psychology. In two of the studies, the chemicals were endogenous, or internally produced, in the third, exogenous.
1) Dopamine and pleasure.
The first sentence to the news release tells it:
Enhancing the effects of the brain chemical dopamine influences how people make life choices by affecting expectations of pleasure, according to new research from the UCL Institute of Neurology. [bold added][source]
Drugs that influence dopamine levels in the brain include cocaine, nicotine, and amphetamines. Caffeine, too.
2) Carbon dioxide and fear.
Yes, your body creates carbon dioxide. Oxygen comes in through the lungs, carbon dioxide out. Higher levels of carbon dioxide have been found to trigger fear and anxiety.
A new study by University of Iowa researchers shows that carbon dioxide increases brain acidity, which in turn activates a brain protein that plays an important role in fear and anxiety behavior. [source]
Like the above on pleasure, this finding on fear has important mental health implications.
[T]he study team, including first author Adam Ziemann, M.D., Ph.D., found that making brain tissue less acidic (raising brain pH) blunted fear behavior produced by carbon dioxide and reduced learned fear. [bold added]
This is your brain; this is your brain with an altered pH. This is your emotional state and behavior; this is your emotional state and behavior with acidic brain tissue.
3) Phthalates and effeminate play.
Phthalates do not naturally occur in the human body. They are used by industry to soften plastics. When humans are exposed to these the can be absorbed. And when in a mother’s body, the can influence the developing fetus.
Phthalates are also found in vinyl and plastic tubing, household products, and many personal care products such as soaps and lotions. Phthalates are becoming more controversial as scientific research increasingly associates them with genital defects, metabolic abnormalities, and reduced testosterone in babies and adults. [source]
The news release containing the above information reported this very interesting finding:
In Swan’s study, higher concentrations of metabolites of two phthalates, di(2-ethylhexyl) phthalate (DEHP), and dibutyl phthalate (DBP), were associated with less male-typical behavior in boys on a standard play questionnaire….Girls’ play behavior was not associated with phthalate levels in their mothers, the study concluded.
Phthalates have previously been recognized as anti-androgenic compounds: they act against or disrupt the male hormones. How could the mothers’ exposure to this chemical affect their boys’ style of play?
Swan hypothesized that phthalates may lower fetal testosterone production during a critical window of development – somewhere within eight to 24 weeks gestation, when the testes begin to function – thereby altering brain sexual differentiation. [bold added]
Who knew that studying chemistry in school could aid your understanding of human psychology? We now know better.
