Discovery The Brain - Our Universe Within
From the blog 100422
We have spent two classes getting through this film – a film with many details and a lot of
new (and interesting!) material to learn. To simplify learning for you I have assembled the
document below (based on my notes from the film). I have concentrated on the parts most
useful for you – either because they are needed to respond to the learning outcomes (i.e. the
exam questions) or because they will be, or are already, useful in other parts of the syllabus.
This document contains:
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A very brief explanation of the neurotransmitter serotonin and the effect it has on
human behaviour (like perception/hallucination). Referring to research by Kasamatsu.
Dopamine and how it might explain schizophrenia and paranoia as well as Parkinson’s
disease, why people endure pain in sports, have poor working memory and in love.
Oxytocin – the glue that bonds us together with a study on rodents and how they treat
their offspring. Lack of oxytocin in the brain make bad mothers.
Finally there is a piece about the chemical background to violence and aggression
together with a possible treatment (Prozac)
Principles linked to this material:
 There are biological correlates of behaviour
 Animal research can provide insight into human behaviour.
The reductionist approach the biological researchers often adopt can also easily be discussed
based on this material. Can and should a complex behaviour/feeling like love be reduced to
only a chemical level?
Relevant learning outcomes
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 Explain, using examples, the effects of neurotransmission on human behaviour.
 Explain, using examples, functions of two hormones on human behaviour.
These learning outcomes will be partly covered in the process:
 Explain how principles that define the biological level of analysis may be
demonstrated in research (through theories and/or studies)
 Discuss ethical considerations related to research studies at the biological level of
analysis.
 Discuss how and why particular research methods are used at the biological level of
analysis.
 Discuss the use of brain-imaging technologies in investigating the relationship
between biological factors and behaviour.
The brain chemicals link to perception
Neurotransmitters – molecule chemicals that are sent from one neuron to the next (over the
synapse) to transmit messages. These modify and shape human behaviour like sadness, love,
joy, violence and the way we see world.
Serotonin – has different roles in different parts of the brain affecting for example mood,
appetite, learning and memory.
Especially two parts of the brain are important here – the frontal lobes and Thalamus.
Thalamus is the first stop and this part of the brain controls all our senses. The serotonin
neurotransmitter is helping or hindering the Thalamus which then will influence what
information is sent to the frontal lobes (in its turn affecting decision making and plans)
Psychoactive drugs do the same thing. The mushrooms used by shamans for ages for example
are found to contain psilocin, which is remarkably alike serotonin. What psilocin does is to
bind with serotonin receptors which results in too many electrical signals reaching too many
parts of the brain. An informational overflow will occur which in its turn distorts perception
resulting in hallucinations.
Religious rites using sensory deprivation and fasting in order to reach a state of transcendent
experience and get messages is thought to produce a change in serotonin levels/receptor sites.
Research in Japan by Kasamatsu, 1999 shows that serotonin levels are in fact changed and
Thalamus is affected (read more in CC).
The varied role of dopamine
Dopamine – regulates activity in the brain. It acts as an inhibitor dampening activity so that
we are rooted in the world we know and not overwhelmed.
It plays different roles, in different parts of the brain. It can be seen to affect smooth and
controlled motion in the Basal Ganglia and if there is disturbance this will result in
Parkinson’s disease. Dopamine also flows into the frontal lobes where it regulates flow of
information from other parts of the brain. A compromise is thought to lead to disruptive or
incoherent thoughts.
The dopamine pathways may offer insight into schizophrenia. The causes for schizophrenia
are still not clear but the dopamine hypothesis is based on the idea that there is a direct link
between dopamine activity in the frontal lobes and schizophrenia. PET-scans will help to
show decreased blood flow in the frontal lobes.
Dopamine plays a significant role also in minor disorders. Too much in the limbic system and
not enough in the cortex may produce an overly suspicious personality or may inhibit social
interaction. A shortage of dopamine in the frontal lobe may also lead to a poor working
memory.
Dopamine is also thought to produce feelings of bliss. It is sometimes referred to the pleasure
chemical. One theory even suggests dopamine helps regulate feelings of pain in the body.
When an injury occurs several receptors in the skin become activated. When stimulated they
then produce an electrical signal that travels through the spiral cord and eventually reaches the
brain – the brain evaluates the pain and responses with sending out its natural pain killers
called Endorphines to mediate the pain. Researchers now think that endorphins may increase
the dopamine flows through the pathways to the frontal lobes. More dopamine is secreted in
the frontal lobes - replacing pain with pleasure. This is used to explain the high that often
accompanies growling endurance sports.
Brain chemicals and true love
There are different brain chemicals playing a role in love. Infatuation – the first rush of being
in love is based on a system of dopamine, noradrenaline and phenylethylamine (also in
chocolate). This is the chemical that produces true attachments, family bonds. Dopamine
plays a role here too as it stimulates the production of another chemical called oxytocin.
Oxytocin (a hormone) is the glue to bond us, to keep us monogamous, strengthens the bond
between mother and child. It is called the cuddle chemical and is present in high levels in
women that have just given birth and increases the mother’s urge to cuddle and take care of
her newborn baby.
Oxytocin’s effect has been dramatically shown in experiments at the University of Maryland.
These are prairie voles, rodents that live in family units, they mate for life and are
monogamous. Their cousins, the montane voles play the field, they are promiscuous,
commitment means nothing to them. They look the same but their brains differ in one
significant way. There are far more receptor sites for oxytocin in prairie voles versus montane
voles, can be seen in Pet scans. Distinct differences become apparent in the behaviour of the
species if the young are separated from their mothers. The montane voles are pretty
indifferent when separated while the prairie voles young cling to their mother and the mother
runs back to protect them.
Not very romantic (dopamine and oxytocine) – perhaps science should be left away from
science. Leading neuroscientists, among them Demasio – searching for love in the brain.
Dedicated his career to mapping aspects of the mind using scanning techniques. Oxytocine
and attachment among individuals.
Violence and aggression
Might it be so, as some argue, that cemicals also dictate roots ov violence and aggression.
Getting some people in jail, not just once but repeatedly. Violence, in that case could be both
influenced by the paths we take in life as well as brain chemistry.
What researchers know is that early experience can change the brain’s chemistry for lif. What
we go through when we are young can change our mood and personality. For example, too
much stress as children can lead to permanent low levels of serotonin and high levels of
noradrenaline – which is associated with aggression.
A program created to treat the biological roots of aggression is proposed by Dr. Emil Coccaro
who is researching causes of violence in Phiadelphia. Coccoro has found a remarkable
correlation between low serotonin and aggression – the breaks are low.
What he uses is Procaz as treatment which will higher the levels of serotonin. Procaz is
normally used as an anti-depressant but can also be used to treat mood disorders like
aggression and suppress the emotions.
This is a hotly debated topic and the results are highly individual. More angles are definitely
needed to treat violent criminals.
Behaviour is deeply rooted in biology. This cannot be argued. But what can be discussed is a
chemically improved society. And what is improvement? What does this say about who we
really are. Are we the chemically improved people or are we our orginal selves?