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The Biological Bases of BehaviourHow does our BRAIN work??

Brain facts

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BBC History of the Brain UCLA1 UCLA 2 UCLA 3 UCLA 4 UCLA 5 Brain Surgery 8:00 Brain surgery 2

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Ways of studying the brain

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1. Studying patients with brain damage can link loss of structure with loss of function. A. Phineas Gage was the level-headed, calm

foreman of a railroad crew (1848) until an explosion hurled a spike through his head. After the injury destroyed major parts of his prefrontal

lobes, Gage became extremely volatile and violent. Studying people who suffered gunshot wounds,

tumors, strokes, Alzheimer’s disease and so on has enabled further mapping of the brain.

Sarah Video

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2. Producing lesions (damaging the structure through medical procedures) at specific brain sites enabled systematic study of loss of function. This is mostly done on animals although it

can also happen when doctors have to remove brain tumours from humans.

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3. Microscopic Examination of neural tissue by scientists led to the understanding of the neuron as the basic unit of structure and function of the nervous system.

4.Direct electrical stimulation of the brain provides another way to test the functions of certain brain areas. Wilder Penfield (1952) used an electrode to localize the

origin of seizures in patients. Stimulating different areas caused movement for different body parts, enabling mapping of the brain.

Wilder Penfield

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5. An EEG (electroencephalogram) maps regions of the brain

produced when electrodes positioned in direct contact with the scalp transmit signals about the brain’s electrical activity (“brain waves”) to an electroencephalograph machine.

http://www.youtube.com/watch?v=8Q57q_kQPQY

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6. Imaging techniques in widespread use provide images of brain anatomy. A. CAT scan (also called CT)—

computerized axial tomography B. MRI—magnetic resonance imaging, the

most accurate method of studying what is happening in the brain when we think or experience emotions .

Inside the teenage brain.

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Brain Trivia Number 1 http://www.nature.com/neurosci/index.ht

ml

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The Neuron—Unit of Structureand Function of the NervousSystem

The neuron is the basic cell of the nervous system. There are many types of neurons, each performing different functions, but they are structured similarly.

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The neuron, or nerve cell, sends and receives signals that affect many aspects of behavior and motor control.

Neurons are individual cells in the nervous system that receive, integrate and transmit information.

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http://science.nbcnews.com/_news/2013/02/28/17123686-two-rats-thousands-of-miles-apart-cooperate-telepathically-via-brain-implant?lite=&ocid=ansmsnbc11

http://www.nature.com/nature/journal/v479/n7372/pdf/nature10489.pdf

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Three major structures in the neuron enable the cell to communicate with other cells. Soma Dendrites Axons

https://www.youtube.com/watch?v=FR4S1BqdFG4

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1. The cell body (or soma) contains cytoplasm and the nucleus, which includes the chromosomes.

2. Extending outward from the soma are dendrites (Greek=little trees), the receiving/input branches of the neuron.

3. The axon emerges from the soma as a long thin fiber that transmits signals away from the soma to other neurons, muscles or glands. The axon ends in a cluster of terminal buttons that

secrete chemicals called neurotransmitters

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http://www.massinformation.org/wp-content/uploads/2010/10/Neurons.gif

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Outside the neuron Glia are cells found throughout the

nervous system that help the neurons. They supply nourishment, remove waste products and provide insulation around the axons

Glial cells may play an important role in memory formation

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The Neural Impulse The neurons use energy to send

information. When a neuron is stimulated, an

electrical signal or neural impulse, moves through the neuron.

The neuron at rest is like a tiny battery with a negative charge of about -70 millivolts.

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Anytime a neuron’s charge changes an action potential is created. The action potential is a very brief shift in

a neuron’s charge that travels along an axon.

The neural impulse is an all or nothing proposition, like firing a gun.

Neural impulses move up to 100m/second or 300 km/hr.

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The Synapse Neurons do not actually touch The neural message travel across these

gaps by the release of neurotransmitters. These are chemicals that transmit

information from one neuron to another. The closest point between the neurons t

is called a synapse. https://

www.youtube.com/watch?v=LT3VKAr4roo&list=PL480008A7A1FAE820

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http://fromyourdoctor.com/ext/neural_synapse.gif

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Neural networks: Integrating the signals One neuron can get signals from 1000s

of other neurons and pass its own message along to 1000s more.

A neuron therefore has to do more than just pass the messages along, it must integrate the signals that arrive at its synapses before it “decides” whether to fire a neural impulse.

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It takes millions of neurons firing together to even have your eyelid twitch when you are asleep, let alone produce a thought.

There are about 100 billion neurons in the human brain.

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Neurotransmitters and Behaviour Remember the nervous system relies on

neurotransmitters to communicate information between neurons.

These play a key role in everything from muscles movement to moods and mental health.

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There are 9 well-established, classic transmitters and about 40 other additional bio-chemicals that can act part-time as neurotransmitters.

The most important transmitters are Acetylcholine Monoamines ( Dopamine.

Norepinephrine ,serotonin) GABA and Glutamates Endorphins

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Neurotransmitter

Has effects on

Is affected by

Monoamines Pleasure emotions, sleep, eating, agression

Cocaine, amphetamines, Prozac

Acetylcholine Attention, arousal, memory, skeletal muscles

Nicotine

GABA and Glutamates

Learning and memory, anxiety

Valium

Endorphins Pain relief (Runner’s High), pleasure

Opiate drugs: Heroin, Morphine, Oxycontin

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http://static.sfdict.com/img/neuron-180866-400-320.jpg

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The Nervous System This is divided into two parts:

The peripheral nervous system The central nervous system

https://www.youtube.com/watch?v=xRkPNwqm0mM&list=PL480008A7A1FAE820

Crash course Make me Genius School House Rock

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http://www.exploringnature.org/graphics/anatomy/nervous_system_diagram150.jpg

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The Peripheral Nervous System This is made up of all of the nerves that

lie outside the brain and spinal cord. Nerves are bundles of axons that are

routed together in the peripheral nervous system

These together control a person’s voluntary and involuntary muscle movements.

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http://www.indiana.edu/~p1013447/dictionary/perinerv.htm

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The central nervous system This is made up of the brain and spinal

cord. The spinal cord connects the brain to

the rest of the body through the peripheral nervous system and is really an extension of the brain.

It runs from the base of the brain to just below the waist.

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http://health.allrefer.com/pictures-images/central-nervous-system-1.html

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The Brain “the brain is the part of the central nervous system

that fills the upper portion of the skull” It weighs about 1.5 kg but contains billions of

interacting cells that integrate information from inside and outside the body co-ordinate the body’s actions enable us to talk, think, remember, plan, create and

dream. http://www.youtube.com/watch?v=9UukcdU258A https://

www.youtube.com/watch?v=LT3VKAr4roo&list=PL480008A7A1FAE820

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http://www.brainhealthandpuzzles.com/images/labeled_diagram_human_brain_sagittal.jpg

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The Brain and Behaviour The brain can be divided into three

major regions: The hindbrain The midbrain The forebrain

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http://facultypages.morris.umn.edu/~ratliffj/images/brain_slides/slide_5.htm

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The Hindbrain Includes the cerebellum, the medulla

and the pons The medulla attaches to the spinal cord

and is in charge of unconscious but vital functions such as Circulating blood Breathing Reflexes such as sneezing and coughing

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The pons or bridge connects the brainstem to the cerebellum

It is involved with sleep and arousal The cerebellum (Little brain) co-

ordinates movement and balance and fine motor skills.

It is one of the parts of the brain first affected by alcohol.

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The Mid-brain This section of the brain is concerned

with integrating sensory process such as vision and hearing.

It is also involved in the perception of pain.

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http://facultypages.morris.umn.edu/~ratliffj/images/brain_slides/slide_6.htm

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The Forebrain This the largest and most complex

region of the brain. It includes:

the thalamus The hypothalmus The limbic system The cerebrum and cerebral cortex

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The thalamus is the structure in the forebrain through which all sensory information (except smell) must pass through to get to the cerebral cortex.

It helps to put together the information we gather from our senses.

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The hypothalmus is involved in controlling basic biological needs.

These include the “four Fs” Fighting Fleeing Feeding and… Mating ;-)

When researchers damage the hypothalmus in animals, they must be fed intravenously or they will starve.

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The limbic system is involved in the regulation of memory, emotion and motivation.

It appears to be linked to an optimistic attitude towards life.

It is one of the areas that is rich in emotional pleasure centers and maybe most affected by cocaine and amphetamines.

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The cerebrum is the largest and most complex part of the human brain.

It is involved in learning, remembering, thinking and consciousness.

It is divided into two halves or hemispheres that are connected by the corpus callosum

The cerebrum is in charge of taking in all of the information from the rest of the nervous system and making it make sense.

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Right Brain/Left Brain The left hemisphere is the one that

processes language/ verbal information more quickly This means that it tends to be better at

language, speech, reading and writing The right hemisphere is faster on visual

spatial tasks It is better at musical, spatial and visual

recognition tasks and the perception of other people’s emotions.

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http://www.wirandha.com/right-brain-left-brain-function-make-kids-smart.html

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The Plasticity of the Brain This term refers to the brain’s ability to change

structure and function over time. Violinists’ brains enlarge in the area that control

the left hand since that is the one that fingers the strings.

Blind people’s the visual processing areas begin to help with verbal processing

Scientists have also recently discovered that even the adult brain can create new neurons and therefore change.

http://www.youtube.com/watch?v=2MKNsI5CWoU

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The Endochrine System Another way the brain communicates

with the rest of the body is by the endochrine system/hormones.

Hormones are like neurotransmitters: they are stored in the body and are released as chemical messengers in the BLOODSTREAM

VENN DIAGRAM

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http://upload.wikimedia.org/wikipedia/commons/c/c6/Illu_endocrine_system.jpg

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Most of the endocrine system is controlled by the hypothalmus and the pituitary gland.

The adrenal hormones control our behaviour in times of stress, fear (fight or flight response)

Testosterone is connected to aggression, dominance, sexual behaviour and spatial abilities.

Hormones are also connected to sexual development and identity.

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Heredity and Behaviour One of the oldest and newest topics in

psychology is question of how much of a person’s behaviour is controlled by genetics.

Nature vs Nurture

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Every human cell (except eggs and sperm) contain 46 chromosomes These operate as 23 pairs in which one

chromosome came from the mother and one from the father.

Each chromosome is made up of 1000s of genes that contain our DNA.

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http://ghr.nlm.nih.gov/handbook/illustrations/normalkaryotype.jpg

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Click icon to add picture

http://www.somethingofthatilk.com/comics/177.jpg

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You are a combination of each of your parent’s 23 chromosomes that can be scrambled in over 8 million different ways.

When the sperm and egg unite the chromosomes can combine in roughly 70 trillion possible combinations.

This does not included any mutations that might occur as well.

This is why every human on earth (except identical twins) is unique.

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http://dels-old.nas.edu/plant_genome/images/DNA.jpg

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Your genes control all of your natural physical and many of your psychological characteristics

It appears that most of these are affected by an extremely complex inheritance from your parents .

Hereditary influences in humans are studied by three methods: family studies, twin studies and adoption studies

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Family Studies This is a method by which researchers

assess the influence of heredity by examining blood relatives to see how much they resemble one another on a specific trait.

If heredity affects the trait then researchers should find that the more closely people are related the more similar the trait is.

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Schizophenia affects 1% of the population in general but 9% of the siblings of schizophrenia

patients show schizophrenic tendencies 4% of cousins, nieces or nephews 2% of second cousins

Family studies can indicate whether a trait runs in families but does not prove that it does.

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Twin studies Researchers compare the resemblance

of identical and fraternal twins with respect to a specific trait.

Since identical twins are clones whereas fraternal twins are just like any other siblings genetically but share more environmental conditions than convential siblings in terms of home life, birth order, school years etc.

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http://www.scienceaid.co.uk/psychology/approaches/images/twins.png

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Twin studies show that identical twins tend to be more like each other than fraternal twins in intelligence and personality which suggest these can have a strong hereditary component.

However the fact that their intelligence and personality are not exactly the same shows the influence of the environment.

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Adoption studies These assess hereditary influence by

examining the resemblance between adopted children and both their biological and adoptive parents .

These are usually only done with people who were adopted as infants before they could experience many environmental conditions .

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If the children resemble their biological parents more than their adoptive parents more on a given trait, researchers can assume that it has a strong hereditary component.

If the children resemble their adoptive parents more than their biological parents more on a given trait, researchers can assume that it has a strong environmental component.

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Heredity and Environemnt “ We inherit dispositions not destinies”

(Rose and Dick. 2002) Many researchers believe that we

inherit the tendency or vulnerability towards a certain trait, but the environment often determines whether the trait actually gets activated or appears

ALCOHOLISM

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Evolution and Behaviour Just as certain physical traits gave organisms a

competitive edge in their evolution, evolutionary psychologist believe that some of our behaviours are also the result of natural selection.

Among many animals the female requires elaborate mating rituals before she allows the male to mate with her.

This means that the male with the most “attractive” dance will get to mate with the female and pass his genetic material on. This means that his “dancing behaviour” is more

likely to be passed on as well.

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http://science.discovery.com/top-ten/2009/mating-ritual/mating-ritual.html

http://www.wired.com/wiredscience/2009/02/animalcourting/

http://www.youtube.com/watch?v=DfOAwpbDOhY