Introduction
- Einstein's brain contained unusually many glial cells
- Jacob Moleschott: Just as kidneys produce urine, the brain produces mind.
1. Development, Birth, and Parental Care
- Labor is trigger when the child accounts for around 15% of the mother's metabolism.
- While still in the womb, the brain cells in the child's hypothalamus respond to a drop in blood sugar level in the same way that they later respond to a lack of food in adulthood, by stimulating the stress axis. This induces a series of hormonal changes, making the uterus contract. The contractions, stimulated by oxytocin, make the baby's head press against the cervix. This in turn triggers a reflex, via the mother's spinal cord, which causes the release of yet more oxytocin. The baby's head then exerts more pressure, triggering the same reflex. The child can only escape from this chain reaction by being born.
- We now know that schizophrenia is an early developmental brain disorder largely caused by genetic factors. So a difficult birth can be seen as a failure of interaction between the brains of mother and child.
- A difficult labor or premature or delayed labor tends to be the consequence of a problem in fetal brain development.
Maternal Behavior
- During pregnancy, the pituitary gland secretes the hormone prolactin, which prompts nesting behavior.Oxytocin, the "bonding hormone" - It's the messenger of affection, generosity, tranquility, trust, and attachment, and has been found to suppress fear by affecting the amygdala, the center of fear and aggression.Vasopressin makes men hostile but women more likely to approach strangers, because they are better at distinguishing friendly features.Society could be improved by giving men a whiff of oxytocin and women a whiff of vasopressin.Abnormal blood levels of vasopressin and oxytocin have been found in people with autism, who also display small genetic variations in the proteins that are the brain's vasopressin and oxytocin receptors.
Paternal Behavior
- Patriarchy is though to have developed when our ancestors had to exchange the protection of the jungle for a more vulnerable life in the savanna.
- The male's protection of the female and her child had an evolutionary advantage: Humans were able to reproduce every two to three years, while female chimpanzees, who were solely responsible for their young and therefore had to look after them and feed them for much longer, could reproduce only every six years.
- Scents given off by the pregnant female may cause the behavioral changes in expectant fathers.
- Fatherhood induces changes in the prefrontal cortex. The number of synapses in this area increases suggesting a reorganization of the local network. It also becomes more sensitive to vasopressin, the chemical messanger that promotes social behavior and aids fathers in their new tasks.
Early Brain Development
- Children who are seriously neglected during their early development also have smaller brains, their intelligence and linguistic and fine motor control are permanently impaired, and they are impulsive and hyperactive. Their prefrontal cortices can be particularly undersized. Studies have shown that orphans adopted before the age of two go on to develop normal IQs of 100, while those not adopted until 2-6, attain average IQs of 80.
- The frontal cortex is the site of Broca's area, which is crucial for language. When adults learn a second language, another sub-area of this region is involved. But if children are brought up bilingually from an early age, both languages use the same frontal areas and the left caudate nucleus check which language system is being used.
- When doing mental arithmetic, the Chinese use different parts of the brain than Western Anglophones.
- The bond between mother and child is first established during pregnancy through the mother's voice.
2. Threats to the Fetal Brain in the "Safety" of the Womb
- Thyroid hormones are necessary for normal brain development but can only function if sufficient iodine is incorporated into the hormone.
- Exposure to lead, mercury, DDT, PCBs, dioxins and many other substances can disrupt fetal brain development, as can ingestion of nicotine, alcohol, cocaine, and other addictive substances.
- Our levels of aggression and stress are set before birth for the rest of our lives.
- Body Integrity Identity Disorder (BIID) - Patients can want to have limbs amputated because they feel they don't belong to them. Scans show that their frontal and parietal cortices respond differently to a touch on the leg according to whether it's the accepted or the rejected leg.
3. Sexual Differentiation of the Brain in the Womb
- The brain differentiates along male or female lines in the second half of pregnancy, due to a male baby producing a peak of testosterone or a female baby not doing so. It's in this period that the feeling of being a man or woman - our gender identity - is fixed in our brains for the rest of our lives.
- Gender-base behavioral differences are fixed in our brains before birth.
- In Western culture women use eye contact to understand other women better while men experience eye contact as testing their place in the hierarchy and can feel threatened by it.
- Development after birth seems to have little impact on our sexual orientation.
- Homosexual behavior has now been observed in around 1,500 animal species from insects to mammals.
- Male-to-female transexuality (MtF) occurs in 1 in 10k individuals while FtM occurs in 1 in 30k.
- The differentiation of our sex organs takes place in the first months of pregnancy, while the sexual differentiation of the brain occurs in the second half. In the case of transsexuality we expect to find female structures in the brains of MtF transsexuals and vice versa in FtM and this has been the case.
- it may be that the neural body map of MtFs lacks a penis and FtMs lack breasts and so the individuals don't recognize these organs as their own and want to get rid of them.
- The smaller the amygdala, the more likely an individual was to commit pedophilic crimes.
4. Puberty, Love, and Sexual Behavior
5. Hypothalamus: Survival, Hormones, and Emotions
6. Addictive Substances
7. The Brain and Consciousness
8. Aggression
9. Autism
10. Schizophrenia and Other Reasons for Hallucinations
11. Repair and Electric Stimulation
12. The Brain and Sports
13. Moral Behavior
14. Memory
15. Neurotheology: The Brain and Religion
16. There Isn't More Between Heaven and Earth
17. Free Will, a Pleasant Illusion
18. Alzheimer's Disease
19. Death
20. Evolution
21. Conclusions
