WE ARE OUR BRAINS
DEVELOPMENT, BRITH AND PRENATAL CARE
The subtle interaction between mother and child and birth: both brains need to secrete oxytocin into the bloodstream to make the uterus contract. The mother's biological clock imposes a day - night rhythm, this is why most babies are born at night and in the morning hours, and when childbirth progresses fastest and with least assistance.
When the child accounts of 15% of the mother's metabolism, the mother can no longer provide enough nutrition, and the baby's blood sugar levels drop. The child's hypothalamus responds to this sugar drop in the same way as in adulthood: stimulation of the stress axis. Hormonal changes make the uterus contract, causing the head to press against the cervix. A reflex visa the mother's spinal chord then releases more oxytocin, the baby's head experts more pressure: the baby is born.
Less glucose for the foetus - hypothalamus activates stress axis - adrenal gland is stimulated by ACTH to produce cortisol - this reduces the effect of progesterone from the placenta and causes oestrogen production to increase - the uterus becomes more sensitive to oxytocin - labour starts.
A child with a developmental brain disorder can't fulfil its role during labour. Difficult labour may be a sign of brain disorder.
Anencephalic infants (born with most of their brain missing) are usually born extremely prematurely or overdue, with long labour, highlighting this.
During pregnancy the pituitary gland secretes the hormone prolactin, it prompts nesting behaviour: clean the house, fix the baby's room. Male rates build nests when given prolactin.
In the end of pregnancy both mother and child brains produce oxytocin to induce labour, to boost milk release.
If an epidural is given to offset labour pains, the signal from the cervix doesn't reach the brain, so the oxytocin cycle is broken, therefore the women need to be given oxytocin drips to restore contraction strength.
Oxytocin peaks during brith, which doesn't occur with C-section births, and these mother's brains react less strongly to their child's crying and maternal behaviour.
Playing with the child also causes oxytocin bonding. Children from orphanages don't experience normal oxytocin surges, they may have permanent or long-term bonding impairment.
Oxytocin also inhibits the stress axis and surprises fear, and influences our response to sexual contact, therefore it is called the "love hormone".
Farmers stimulate the sheep's vagina and uterus, causing oxytocin release and the ewe to bond with an orphan lamb.
Vasopressin is responsible for pair bonding and maternal aggression. Men with a tiny variation in a DNA building block for the vasopressin receptor are twice as likely to divorce and be unfaithful. If men are shown a strange man's face after being given vasopressin, they perceive him as unfriendly and more hostile. In women the opposite occurs, vasopressin makes them more likely to approach strangers, and to notice friendly features.
People with autism find it hard to interpret other's emotions and intentions from gestures, facial features or to feel empathy. They might not understand why a child cries, or emotion in a voice. Abnormal levels of oxytocin and vasopressin are found in people with Autism. Also genetic variation in the proteins for vasopressin and oxytocin in the brain. They improve their social behaviour when given oxytocin.
The problem with inhaling sold sprays of oxytocin for example is that you don't know how or if it works at all. These are very delicate systems: the brain produces the tiniest amounts exactly where it needs it. You can't replace the highly specialised functions of nerve cells just by administering their messengers.
Heavy, helpless babies of our ancestors needed the father to protect the mother and the baby. This had an evolutionary advantage: humans could reproduce every 2-3 years, as oppose to chimpanzees, where mothers were solely responsible for the young, and therefore could only reproduce every 6 years.
Fathers to be also produce prolactin, stimulating caring behaviour. Testosterone levels also drop: less aggression towards the child and less urge to procreate. Oxytocin is released in fathers who display affectionate and nurturing behaviour.
A stimulating environment is necessary for brain development. Brains of hares and rabbits grown confined were 15%-30% smaller than the wild ones. When placed in an enriched environment: a large enclosure full of objects that were renewed every day, their brains grew and developed more synapses.
Neglected children have smaller brains: their intelligence and linguistic and fine motor control skills are permanently impaired, they are impulsive and hyperactive.
Orphans adopted before the age of two, develop normal IQs of about 100. Orphans adopted between two and six have IQs of about 80.
The Pope's experiment in which he brought up dozens of children by nurses who were ordered never to speak to them in order to determine God's language: the children didn't speak at all and all died young.
Many children died during WWII because of physical and emotional neglect, or survived psychologically scarred.
The languages heard during the first few years of our life determine the configuration of your brains language system. After a certain period these systems become fixed - which is why we then have accents in other languages.
Between the ages of 9-11 the brain areas that process words and visual information still overlap. In adulthood they are separate.
The Broca's area in the frontal cortex processes our mother tongues. A sub-area of this region processes later-learned languages.
Our linguistic and cultural environment also determines how facial expressions are interpreted.
Stimulation form enriched environments promotes recovery from a developmental disorder - which is why people shouldn't be institutionalised.
A forensic study compared 412 suicide victims who were alcoholics and drug addicts with 2901 people in a control group. A link was made between events around the birth and self-destructive behaviour. Hanging with oxygen deprivation at birth, violent suicides with mechanical brith trauma, drug addition with administration of addictive substances like painkillers during labour.
When a pregnant woman relaxed every time she heard a piece of music, the foetus would start to move as soon as the music started. After birth, the same music would make the child stop crying and open its eyes.
Newborn babies prefer to hear their mother's voice, particularly if it is distorted in the way it would have been in the womb. But TV soap themes can also be registered by babies, and maybe they will become more prone to be addicted to them when grown up. So it is better not to watch TW shows or hear bad music, but to read books, even out loud to the foetus.
THREATS TO THE FOETAL BRAIN IN THE "SAFETY OF THE WOMB"
Our brains develop with incredible rapidity before birth and in the years immediately after. The brain cells grow at different rates and are extremely susceptible to different factors.
Growth is determined by 1)our genetic factors and 2)the activity of the neural cells which in itself depends on:
Availability of nutrients, chemical messengers, growth regulators, hormones.
Lack of nourishment: from hunger, placenta malfunctioning, excessive vomiting by the mother, dieting for weight issues, Ramadan fasting. These all impair the child's mental capacity, increase the risk for schizophrenia, depression and antisocial behaviour.
Iodine deficiency impairs thyroid hormone production: impaired brain and inner ear development.
Heavy metals cause brain disabilities.
DDT, PCBs, dioxins are called environmental disrupters because they disrupt hormonal regulation of sexual differentiation even when there is no chromosomal cause - gender identity and sexual orientation is affected.
Most problems are only small, children seem to be healthy at birth, but then manifest issues later. Smoking women can cause learning difficulties, behavioural and reproductive problems for example.
ALCOHOL
In early development, brain cells are created around the brain cavities. They migrate to the cerebral rotten, where they ripen and sprout tissue to establish contact with other brain cells. This migration can be so severely disrupted by alcohol that cells can end up migrating outside the brain. Alcohol also permanently activates the stress axis, increasing the risk of depression and phobia.
SMOKING
Is the most common cause of neonatal death. Doubles the risk of SIDS (sudden infant death syndrome). Increased risk for premature brith, low birth rate, impaired brain development, disturbed sleep patters, poor school performance, obesity, thyroid function, ADHD, aggressive behaviour, impulsiveness, speech defects, attention problems, impaired testes development.
SLEEP
REM sleep: rats with less REM sleep during comparable-to-human-foetal-development-stages, they had less REM sleep and were more fearful in adulthood. The sex drive in males diminished, they were hyperactive.
Heterotopias: are a group of cells that end up in the wrong part of the brain during their migration to the cerebral cortex.
The brain overproduces cells and synapses. When connections are promoted, they obtain growth substances that make them more active, enabling them to make more and better connections. The cells that fail to do so, die of. Extreme signals form the outside lead to the foetal brain being permanently modified to prepare the child for the outside world.
Nazi occupants of Netherlands during WWII lead to a famine. They babies born then were not only underweight, but more likely to become antisocial and obese later in life: to prefer fatty foods, exercise less. More likely to have HPB, schizophrenia, depression. Their brain was programmed to retain every calorie. Being antisocial they defend their own interests, giving an advantage in times of scarcity. But if they are born into normal surroundings these qualities are not good.
When a mother is stressed, the brain of the female foetus becomes more male and vice versa: a more competitive girl is more likely to survive and so is a less aggressive male.
Longevity is only a very recent accomplishment, it made sense for the foetus to be adapted to the immediate environment it came to.
PAIN TRANSMISSION
1) nerve fibres in the skin
2) along the spinal chord
3) the centre of the brain: the primary sensory cortex, the brain becomes aware of the brain; the thalamus: the cingulate cortex, the brain's alarm centre causes emotional and autonomic responses.
Because these are two separate centres, you can have responses to pain: heart rate, contorted face, movement, without actual awareness of it.
By week 7 of foetal development, the sensory nerves are there, so there will be a physical response to a needle for example, but this doesn't mean it can actually feel pain.
The cortex needs to be mature, and this happens around week 29 or 30.
General anaesthesia is a risk for the mother. If a procedure need to be done on the foetus before week 25-26, it would probably be better not to use anaesthesia because of the risks in brain development.
Body Integrity Identity Disorder: where someone early on is convinced that a part of their body doesn't belong to them and they become desperate to get rid of it, even though it can be fully functioning and healthy. They can get jealous of amputees or paralysed people. They will pretend not to have that limb. They will try to get a doctor to remove it. They can even damage the limb to the point that it has to be removed. They have very precise ideas where from they want the amputation. Scans show their frontal and parietal cortices respond differently to the touch of their two limbs.
This shows a similarity with transsexuality, and in fact 19% of BIID patients have a gender identity problem, and 38% are homosexual or bisexual.
SEXUAL DIFFERENTIATION OF THE BRAIN IN THE WOMB
The simple version: XX=girl and XY=boy. The presence or absence of testosterone makes the child develop into a boy or a girl. In the second half of the pregnancy a testosterone peak will differentiate a boy, fixing our brains and gender identity for life.
JOHN - JOAN - JOHN
John lost his penis from a botched circumcision at 8 months of age, his testicles were removed and they decided to turn him into a girl. He had girls clothes, psychological counselling, was given oestrogen in puberty. The child developed normally as a female. As an adult, Joan had the sex change reversed, married, adopted children, got separated and committed suicide. - his gender identity hadn't changed.
AIS: androgen insensitivity syndrome. The person produces testosterone but their bodies are insensitive to it. Both the external organs and brain are feminized. They become heterosexual women, even though they are XY.
CAH: congenital adrenal hyperplasia. Girls who have been exposed to a high dose of testosterone in the womb and have such a large clitoris they sometimes are registered as boys. They almost always are assigned a female gender, but 2% acquire male gender identity in the womb.
The preference of dolls or cars isn't forced by society, it's programmed in our brains to prepare us for our roles in life, even in monkeys the same choices are made. Girls are prepared for motherhood and boys for fighting and technical tasks.
The peak in testosterone is responsible for this. Girls with CAH are more boisterous and may be called tomboys.
Eye contact between women during negotiations leads to a better outcome, between men it prevents coming to terms. Men also prefer to sit side by side rather than face to face. Side by side is more friendly, as though they are on watch together.
How can homosexuality still be in genes? Heterosexual individuals with the same genes produce a larger-than-average number of offspring, keeping the genes in circulation and this may be a reason.
Girls with CAH are more likely to be bi or homosexual.
The more older brothers a boy has, the greater the chance for him to be homosexual. The mother's immune response to male substances produced becomes stronger with each pregnancy.
Pregnant women suffering from stress release cortisol with affects foetal sex hormone production.
The biological clock is twice as large in homosexual men.
Sexual orientation is determined by many structural and functional brain differences, all of which develop in the womb the second half of pregnancy, and which cannot be changed by the post-birth environment.
Transsexuality: feeling you have been born in the body of the wrong gender. Sex organ differentiation happens in the first months. Brain sexual differentiation happens in the second half of the pregnancy. Since they are separate events, they can be influenced independently of one-another.
BST- bet nucleus of the stria terminals is an area involved in many aspects of social behaviour. It is twice as large in men as women. In transsexuals, it is the opposite.
Sudden pedophilia may have many causes: a brain tumour in the prefrontal cortex, temporal cortex, hypothalamus, it may be a symptom of dementia, brain infections, Parkinsonism, multiple sclerosis, brain trauma, partial removal of the anterior lobe during operations to cure epilepsy.
Deviant sexual behaviour is displayed in 18% of first degree relatives of pedophile men, suggesting it may also be genetic.
There is less grey matter in the hypothalamus, the bed nucleus of the stria terminals, amygdala of pedophiles.
The smaller the amygdala, the more likely to commit pedophilic crimes.
PUBERTY, LOVE, AND SOCIAL BEHAVIOUR
PUBERTY
The pituitary gland starts to produce sex hormones. The annoying behaviour, clashing with family members makes it less likely that reproduction takes place in their own surroundings, reducing the risk of inherited defects. Craving new experiences, readiness for great risks is leaving the nest behaviour. But since the PFC (prefrontal cortex) isn't yet mature, decisions may be bad, thinking about only the short term, and less consideration of negative consequences.
Gene KISS1 initiates puberty: kisspeptins produced in the hypothalamus.
Women must have enough fat to nourish a foetus in order to get pregnant.
Leptin is a hormone produced by fat cells. The brain monitors the levels of fat in the body by the amount of leptin. If there is a mutation in the leptin gene, the brain can block the onset of puberty and send out signals to make fat reserves: causing extreme obesity.
Melatonin, a hormone produced by the pituitary gland prevents puberty in children.
"Young people today love luxury, have bad manners, contempt for authority and disrespect for older people. They are to lazy to train, they'd rather sit and chat. They no longer rise when elders enter the room, they contradict their parents, can't hold their tongues in company, gobble up food, tyrannise their teachers. "
-Socrates
PFC: control of impulses, complex actions, planning, organisation. Doesn't fully mature until around 25 years of age.
Adults distribute assignments across different brain areas. Adolescent PFC have to work harder, and can't distribute, so their capacity is reached earlier, and distractions can undermine its performance.
The surge of sex hormones causes aggression and risk-seeking behaviour. They curve of crime rates follows that of PFC maturation.
LOVE
Love: euphoria, a beating hard, perspiration, insomnia, emotional dependency, strongly focused attention, obsessive, possessive, protective attitude towards the partner, heightened energy.
Love, n. A temporary insanity curable by marriage.
Brain scans show activity in structures below the cerebral cortex. In the reward circuitry: addiction and withdrawal symptoms. Raised levels of the hormone cortisol. Testosterone levels rise in women, in men cortisone reduces testosterone production in testes.
Only when love has persisted for a certain amount of time, the PFC becomes involved.
The activity in the stress axis dies down and testosterone is normal. Only now can conscious choices be made for the first time.
ORGASM
Impulses caused by sex organ stimulation via the spinal chord reach the thalamus, centre for all erotic sensory information - to the ventral segmental area, the dopamine delivering reward circuitry - hypothalamus. If we orgasm, both dopamine and oxytocin are simultaneously released, nucleus accumbent for dopamine and oxytocin in the hypothalamus.
Orgasm activates the same reward pathways as heroin.
Different areas of the brain are activated in women and men during arousal - different sexes brains' use different routs to approach the same goal: orgasm.
Female: motor and sensory areas of the cerebral cortex are activated.
Male: occipital-temporal cortex, claustrum, insular cortex are activated. Periaqueductal grey matter is less activated in the brain stem, the same way as when addicts inject heroin.
The amygdala becomes less active in both sexes during orgasm, it usually inhibits sexual behaviour when we are supposed to be focused on something else.
Cerebellum - great increase in activity, it regulates muscle contractions of orgasm.
Prefrontal, Temporal Cortexes - less active, reduce inhibitions during sex.
DNA polymorphisms in the protein that receives dopamine's chemical message are correlated to the degree of sexual desire, arousal, activity.
Testosterone promotes women's and men's sexual drive. That's why it declines in older men with less testosterone. Women who's adrenal gland and ovaries produce more are more sexual.
Around ovulation, women subconsciously dress more provocatively, get tipped more, prefer more masculine faces, voices and behaviour.
Erotic images provoke greater stimulation in the brains of young men vs those of young women.
Women's degree of activation of the amygdala and hypothalamus to sexual stimulation also depends on their stage of menstrual cycle, being highest around ovulation and lowest during menstruation.
Oxytocin, produced in the hypothalamus and released visa the pituitary gland is important during sex.
In men, it stimulates contraction of smooth muscle fibres, facilitating sperm transport.
In women, it sends sperm one way and the egg another way to encounter one another. Because oxytocin is important in sperm transport, a partner who induces orgasm for the female has an evolutionary advantage.
Oxytocin also promotes pair forming. It inhibits the stress system and causes opiates to be released in the brain.
Depression lowers sex drive. The dopamine reward system is inhibited by high cortisol levels, and all pleasure in life can be gone: anhedonia. Testosterone levels decline. Antidepressants also lower libido and inhibit orgasm.
Diabetics can suffer from sexual dysfunction as a result of damage to nerve fibres. Diabetes is the most common cause of erectile dysfunction in men and painful intercourse in women.
Men with full spinal chord injury (paraplegia or quadriplegia) cannot have erections caused by the brain: seeing, felling smelling. But they can still have stimulation of the penis erections because those travel through the lowest part of the spinal chord.
In able-bodied people, psychogenic erections start in the brain and erotic impulses travel up from the spinal chord. They go up and own. But 38% of paraplegics still orgasm.
1) For some paraplegics the skin near the site where the loss of feeling starts become so hypersensitive, it turns into a new erogenous zone, which can be stimulated to orgasm.
2) In women injured above the navel, the impulses were sent via the cranial/vagus nerve to the brain.
3) Nerve cells low in the spinal chord take over functioning as the ejaculation centre.
Some epileptics feel as though they are having orgasms before seizures.
HYPOTHALAMUS, SURVIVAL, HORMONES, EMOTIONS
If a patient would urinate constantly, and the urine tasted sweet, they were diabetic. If it wasn't it was a kidney or brain problem.
DEPRESSION
Is usually a symptom of a physical problem. The spectrum of behaviours associated with depression: withdrawal, less eating, less activity so that your energy can be devoted to curing yourself.
It can also be a symptom of Parkinsonism, schizophrenia, other psychiatric conditions.
But it can also be a condition in its own right.
Genetic factors and womb development program the activity of our stress system for the rest of our lives.
Stress causes nerve cells in the hypothalamus to release corticotropin-releasing-hormone (CRH) to the pituitary gland and brain. The pituitary gland in turn stimulates the adrenal gland to produce cortisol hormone.
If we have too much CRH and cortisol in our bodies, depression results.
Female hormones stimulate the stress axis and male hormones relate it, which is why women are twice as likely to suffer from depression.
Depression may be a developmental disorder of the hypothalamus.
Stress axis = hypothalamus - pituitary - adrenal axis.
Low levels of serotonin and dopamine may trigger the stress axis, which is why SSRIs are used, even though they don't seem to work too well.
SSRI = selective serotonin reuptake inhibitor, increase the amount of serotonin in the brain by inhibiting its reuptake.
They need a couple of weeks to work, during which time there is a great risk of suicide.
They have a placebo effect in 50% of cases.
When you expect a placebo to alleviate your pain, you increase the activity in your PFC, inhibiting the hypothalamus, normalising the stress axis.
Transcranial magnetic stimulation of the cortex also reduces hypothalamus function, and so does cognitive therapy.
Physical activity and light help by stimulating the circadian clock which is smaller in people with depression.
Lack of vitamin D causes depression too, in older people.
OBESITY
80% of the variation in body weight is determined by genetic factors.
Normally the hypothalamus regulates fat by measuring the amount of leptin, a hormone produced by fat tissue.
If there are variations in the leptin gene, or leptin receptor gene, the hypothalamus will conclude that there is no fat - causing extreme obesity.
The brain may not produce alpha MSH: hair pigmentation and appetite inhibition, resulting, in overweight, red haired children who don't enter puberty.
Hormonal disorders or an excess of cortisol may also cause obesity.
Children born in famines, placental malfunctions, HBP in mothers, smoking, obese mothers, overfed babies all may cause obesity.
Lower socioeconomic status and comfort eating too.
ADDICTIVE SUBSTANCES
Affect the brain by mimicking its own chemical messengers or affecting the availability or action of natural chemical messengers.
ECSTASY
Raises serotonin, oxytocin and vasopressin levels.
This is why after you take a drug, your brain no longer functions normally; its natural levels of messengers get disrupted and the dopamine reward system has been affected.
Originally patented as an appetite suppressant in 1914.
20mins after swallowing, oxytocin, serotonin and vasopressin levels rise.
Tiredness vanishes and you have a desire to hug everyone.
Love and good social interaction feelings last for about one hour.
It can destroy the brain cells that produce serotonin. Users are therefore more likely to develop psychiatric and neurological disorders.
It causes brain blood vessels to dilate and constrict in the long term in different regions of the brain respectively, which may lead to brain infarcts or bleeding.
Too little water consumed after ecstasy may cause dehydration. But too much water may cause water poisoning and brain damage because the extra vasopressin the brain produces causes the kidneys to retain water. About a glass an hour is the amount of water that should be consumed under the influence of ecstasy.
CANNABIS
Anandamide is mimicked. Its receptors are mainly located in the stratum, which is responsible for blissful feelings, the cerebellum: responsible for the unsteady gait, the cerebral cortex for association, fragmented thoughts and confusion and the hippocampus, responsible for the memory impairment.
May induce schizophrenia in people who may come to develop it.
Daily smoking reduces the sizes of the hippocampus (memory), amygdala (fear, aggression, sexual behaviour), causes damage to the corpus callosum (connection between the left and right brain hemispheres).
It may also cause psychosis, derealisation, depersonalisation, concentration difficulties.
Too much THC in strong cannabis is dangerous.
THE BRAIN AND CONSCIOUSNESS
If something gets int he way of the brain's information supply, it starts to make up information to fill the gaps.
The same is true for all our memories.
Patients with a left-body paralysis due to a damage of their right-hemisphere are convinced that a doctor told them not to get up or move their paralysed hand or leg.
A coma is a situation where a patient doesn't awaken and doesn't respond to external stimuli. It results from damage to the cerebral cortex, the thalamus, or connection between them, or brain stem, which activates the cerebral cortex and thalamus.
A vegetative state is when only your brain stem functions, so breathing, heart rate, temperature, sleep-wake cycles are regulated, but you merely exist, like a vegetable.
Locked-in syndrome is the reverse of a coma. The brain and spinal chord are completely separated from damage low in the brain stem. The brain is otherwise intact and the patient fully alert. They cannot move or speak, just blink and move their eyes.
Brain death is defined by irreversibly fixed pupils, absence of brain stem reflexes and the permanent absence of higher brain functions: cognition and consciousness. They are kept alive even in indefinitely on ventilators.
Anosognia is unawareness that something is wrong with you. It is connected to reduced activity in the angular gyrus, where sensory information from the body and surroundings are combined. It is increasingly damaged as Alzheimer's progresses too.
Out of body experiences and near-death experiences are caused by malfunction in the angular gyrus because of lack of oxygen there.
Your body constantly manufactures the sense that your body belongs to you, using sensory information from muscles, joints, vision, sensation, self-consciousness, it isn't a metaphysical construct.
Phantom pain may be due to the brain getting signals back that it is impossible to move the amputated limb, ultimately forcing the phantom limb into an extremely painful, cramped position.
When the corpus callousum is damaged or severed, the two hemispheres of the brain cannot communicate, so consciousness is altered. The ability to speak and read, for example, are located in different hemispheres. So if someone would read instructions, to get up and leave, they'd do so. And if asked why, they'd say they wanted hot chocolate for example because the instruction has not been consciously registered.
Lack of input causes the brain to make up information. If almost deaf, it can constantly repeat a song, if in low light, it can see objects that aren't there, if half-paralysed, convince the person that they were told not to move, if drunk it can fake memories to fill in gaps.
Blindsight is knowing where something is, without consciously seeing it. it happens when because of damage, the visual information reaches the brain via an abnormal route.
AGRESSION
Stems from the testosterone peak produced halfway through pregnancy in boys. Girls with adrenal gland abnormalities that produce too much testosterone before birth are also more aggressive later.
Less serotonin also causes more aggression.
Malnourishment in the womb may cause aggression in later life.
Mother's consumption of nicotine, alcohol, medication during pregnancy may put the offspring at a higher risk of being more aggressive.
As testosterone levels rise during puberty, so does the incidence of murder. It peaks between the ages of 20 and 24 and has its lower values at 50 to 54. The declining levels in the late twenties are not due to less testosterone in the body, but do to the completion of the prefrontal cortex development. The prefrontal cortex function may be further dampened by alcohol.
Violent video games, religious texts read by religious people, high temperatures also may cause higher levels of aggression.
Amygdala stimulation can stop aggression, shown to be able to halt a charging bull and tame sewer rats. Some psychopathic individuals have malfunctions of their amygdala which prevent them from understanding their victims facial expressions .
Sleep can be compared to a psychiatric and neurological disorder in the sense that:
- higher visual centres n the brain are activated and we hallucinate as though schizophrenic
- the amygdala is activated during emotional or aggressive dreams
- we make up stories like people with alcohol dementia
- we then forget everything like from sever dementia
- we lose muscle tension, like narcolepsy suffered with cataplexy when awake
If you do not lose muscle tension when you sleep, you end up sleepwalking.
AUTISM
Severely disrupted social skills and a very confined repertoire of activities and interests are effects of autism.
Too much brain volume between the ages of two and four is observed in children with ASD, delaying growth in some areas and prematurely ending it in other areas.
Main known causes: genetics, paternal age, metabolic disorders of infections in womb, older parents, oxygen deprivation at birth.
Motor problems may be due to an underdevelopment of the cerebellum.
Problems interpreting emotion in others. Shying away from bodily contact.
Oversensitive to certain sounds. They can focus so hard on their task that they fail to hear what is being said to them.
Savants about a tenth of children with autism have a talent that sharply contradicts their mental disability and handicaps. Few of them become creative adults, either because their kind of talent or their personality.
Talents are largely possessed by boys and are in the fields of art, music, calendar calculation, instantaneous mental calculation, almost hand in hand with a remarkable memory.
There has to be brain damage, and at an early stage, so other connections can be reinforced to allow the development of savant qualities.
One theory states that everyone possesses savant qualities localised in the lower regions below the cerebral cortex that are suppressed by higher processes. They can be expressed by switching off the part of the brain that controls the higher functions. Savant qualities go hand in hand with loss of language and social skills.
SCHIZOPHRENIA AND OTHER REASONS FOR HALLUCINATIONS
Schizophrenia affects only 1% of the population, but because suffered have it for such a long time, half of the beds in psychiatric hospitals are filled with schizophrenic patients.
They are often depressed and 10% of them try to kill themselves.
"Positive" symptoms: delusions and hallucinations. Areas of the brain that process auditory and visual input are extremely active. They cannot be distinguished from real experiences because they are processed in the same brain regions as them. Delusions are the belief that they are being watched or controlled by mysterious powers.
Negative symptoms: loss of normal abilities: taking initiative, organising one's life, tidying up one's room, looking after oneself, muted emotions, cognitive deterioration. Many take drugs or addictive substances to try to combat the negative symptoms, but they exacerbate the positive symptoms. The negative symptoms are caused by reduced activity in the prefrontal cortex.
Schizophrenia is more common in men. Psychosis starts around the age of twenty. It is largely due to genetic factors. In women there is a second peak of symptoms around menopause.
Female hormones reduce the negative symptoms if taken alongside standard medication.
With its progression, the brain shrinks and its ventricles become larger. The same is seen in ageing and dementia. There are no brain changes specific to schizophrenia, so diagnosis depends on psychotic investigation.
There is an 80% genetic component to the disease. Tiny variations in genes for brain development and/or production and breakdown of chemical messengers in the brain.
Maternal malnourishment in the first three months of pregnancy doubles the risk for schizophrenia.
There is also higher risk if the child is born in winter or if the mother had the flu during her sixth month of pregnancy.
Toxoplasmosis and Borna disease virus also increase the risk.
Life events: the death of a relative or stress during pregnancy.
Problems during birth: forceps delivery, low birth weight, need for an incubator period, premature birth.
Many cells of the hippocampus are in disarray, there are also groups of cells that have failed to migrate to the right place in the cerebral cortex: early development problems even though the symptoms start later in life.
If the brain stop receiving information the normal way, it starts making up information. A deaf patient hearing non-stop songs in his head until magnetic stimulation of the auditory cortex can stop it temporarily and hearing glasses can stop it permanently.
Charles Bonnet Syndrome: visual hallucinations in individuals with impaired eyesight.
Korsakoff's Syndrome: demential that causes fake memory confabulations.
The same principle applies to schizophrenic hallucinations, which is why magnetic stimulation of those areas reduces them. Conversely, isolation cells which they are usually put in in institutions, diminish brain input even further, making the symptoms worse.
Mountaineers, especially when alone, may have very vivid hallucinations, out of body experiences or be overcome by fear.
Delirium: confusion, restlessness, memory problems, aggression, noisy, hyperactive. The people do not know where they are, can't think or concentrate, often hallucinate, see creepy crawlies everywhere, refuse food because it is filled with bugs, believe their bed is a grave etc. It is cause by a dopamine overdose, so your susceptibility to it depends on your polymorphisms in the DNA of the gene that produces the protein that receives the dopamine message in brain cells. Delirium causes brain damage and increases dementia risk. it can cause long-term effects: problems walking, reading, writing, memory never fully recovers. A third of people who suffer a delirium episode over the age of 65 die within a few months.
Delirium is mostly seen in older patens who have been under anaesthesia. Up to 80% of patients in intensive care develop it. Pneumonia, dehydration, medication, drugs, malnourishment, low oxygen levels, blood sugar, infarcts, alcohol poisoning are risk factors.
Hearing voices: between 7-15% of the population hear voices, yet only a fraction have mental health problems. In healthy people it starts at a young age and runs in families. When a symptom of a mental health problem, usually the voices are with threatening, negative messages. Healthy people alone can control them, tell them to leave or call them up.
THE BRAIN AND SPORTS
Boxing: shows the onset of neurological damage during the sport itself: unsteady gait, impaired speech, eyes flickering left to right, epileptic fits, reduced consciousness, coma, death. Long term damage is more common than acute dam ante. 17% of professional boxers have Parkinson's. When someone is knocked out, their brain is slammed into the hole under the skull, compressing the medulla, which regulates vital functions. Blows destroy the hypothalamus and pituitary gland, causing hormonal deficiencies in 50% of boxers.
Two factors determine human lifespan: metabolism and brain size. The higher the metabolism, the shorter the lifespan. Top athletes at Harvard have shorter lifespans than their non-athletic colleagues. The more flight movements a fly makes, the faster it dies. If you confine it, it can live up to three times longer.
The larger and more active the brain is the longer you live. Brain stimulation also delays the onset of Alzheimer's. So it may be healthier to watch a sport than to partake in it.
MORAL BEHAVIOUR
Empathy is the capacity to recognise and share the feelings of others. It provides the basis for all moral behaviour.
Moral precepts serve to promote cooperation and support within social groups, they act as a social contract, imposing restraint on the individual to benefit the community at large.
It is hardwired in us, shown in other animals, and infants, who comfort others. There are altruistic actions done without the incentive of a short or long term reward, the roots of altruism go back a long way.
Mirror neurons come into play when we observe the actions of others. When you see someone move a hand, the same neurons fire in your brain as if you were making the movement. They help us learn by imitation.
Damage to the prefrontal cortex leads to amoral behaviour, lack of empathy.
The amygdala is involved in calculating the social significance of facial expressions.
"Man is a chimpanzee with ideas above his station."
The origins of empathy lie in a mother's caring behaviour for her offspring. They are just as important and ancient as feelings of competition.
Women empathise with cheaters when they are punished, while men don't.
If you are open and trust everyone, others will perceive your behaviour as abnormal and shut you out.
The reason humans are so good at torture is because they excel in imagining what others would feel. The more empathetic, the crueler you can be.
MEMORY
Mental activity stimulates the development of nerve cells and their axons in the part of the brain being used. So existing connections between groups of cells can be reinforced by an increase in the number of terminal arborisations.
Short term memory is limited in the amount of information and time it can be held.
Long term memory requires the synthesis of new proteins, because it involves forming new connections between neurons. this amounts to a structural change for which glial cells produce lactate, the essential fuel.
Highly emotional events often bypass the short term memory and immediately be stored in the long term memory.
"If memory is localised anywhere, it is everywhere."
Functional scans show whether a brain area is involved with a certain function, but brain damage only reveals whether it is crucial to that function.
Hippocampus: means seahorse because of the shape of the structure. When there is severe damage to the hippocampus, the person may be rendered completely incapable of making new memories.
It specialises in combining sensory information, and if it wants to retain this information it transfers it to the long term memory. It does this with the entorhinal cortex - here the first sings of Alzheimer's appear, this is why people with Alzheimer's may not remember what happened an hour ago. It is also involved in spatial orientation. London taxi drivers show a gradual increase in grey matter at the back of the hippocampus. It is also necessary for imagining the future.
The deciding factors for storing information in the long term memory are the importance of the information and the emotional charge of the moment.
The amygdala, just in the front of the hippocampus in the temporal lobe imprints memories that have a strong emotional charge under the influence of the stress hormone cortisol, registering them immediately in the long term memory. This is why 80% of our earliest memories have negative associations - remembering bad events is more important for survival.
Post traumatic stress disorder happens when the amygdala has done its work too well, preventing the prefrontal cortex for signalling the the threat is over. The amygdala is activated by noradrenaline so beta-blockers are used to prevent the amygdala from so strongly labelling dramatic experiences and the individual from being overwhelmed by negative emotions.
Borderline personality disorder: emotional instability and impulsiveness, negative emotions are linked to such a strong stress reaction that the person runs an increased risk of retrograde and anterograde amnesia.
During sleep the hippocampus constantly activates memories and transmits them to the cerebral cortex.
Different aspects of an event are stored in different sites of the brain. They have to be pieced together to recall the memory, and the empty bits are filled by our brains.
eg. Prospognosia - face blindness; you ca see well but not regonize the face.
eg. Capgras syndrome - being convinced that someone is an imposter of the person they are supposed to be.
The various components of vision are processed in different parts of the brain - some people can't see things while they are in motion, and then can see them normally when they stop.
The safest place for information to be stored is our remote memory: language and music are stored there, which are also the last to go in illnesses that affect the memory, such as Alzheimer's.
80% of our neurons are in the cerebellum.
- they ensure our movement and speech are flowing and coordinated.
- they contain the memory of how to do things
- they keep track of motor learning and steer performance of these tasks
- surprise the impact of your own actions on other parts of the brain - you can't tickle yourself
Damage to the cerebellum makes you very clumsy; stumble, not able to touch your own nose etc.
Alcohol and cannabis affect the cerebellum and hence your movement and coordination.