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Neuroscience
There is no principle more central to today’s psychology than this:
Everything psychological is simultaneously biological
Your every mood, every urge is a biological happening. You love, laugh and cry
with your body. Without your body, you are indeed nobody. Although we find it
convenient to talk separately of biological and psychological influences on
behaviour we need to remember to think, feel or act without a body would be like
running without legs.
Football Vs American IDOL Discussion
Our understanding of how the brain gives birth to the mind has come a long way.
Plato correctly located the mind in the spherical head, his idea of the perfecto
form. His student, Aristotle, believed the mind was in the heart which pumps
warmth and vitality to the body. The heart remains our symbol for love but the
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science has longs since overtaken philosophy on this issue. It’s your brain, not
your heart that falls in love.
We have come far since the early 1800’s when German physician Franz Gall
invented Phrenology.
Phrenology: a popular but ill-fated theory that claimed bumps on the skull could
reveal our mental abilities and our character traits
At one point Britain had 29 phrenological societies and phrenologists travelled
North America giving skull readings.
Phrenology did however; correctly focus attention on the idea that various brain
regions have particular functions. You and I enjoy a privilege Gall did not have, we
are living in a time when discoveries about the interplay of our biology and our
behaviour and mental processes are occurring at an exhilarating pace. Within the
last century, researchers seeking to understand the biology of the mind have
discovered that:
- The body is composed of cells
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- Among these are nerve cells that conduct electricity and talk to one
another by sending chemical messages across a tiny gap that separates
them
- Specific brain systems serve specific functions
- We integrate information processed in these different brain systems to
construct our experience of sights and sounds, meanings and memories
and pain and passion.
- Our adaptive brain is wired by our experience.
By studying the links between biological activity and psychological events
BIOLOGICAL PSYCHOLOGISTS continue to expand our understanding of sleep and
dreams, depression and schizophrenia, hunger and sex, stress and disease.
We have also realized that we are each: a system composed of subsystems that
are in turn composed of even smaller subsystems. Tiny cells organize to form such
body organs as the stomach, heart and brain. These organs, in turn, form larger
systems for digestion, circulation, and information processing and those systems
are part of an even larger system: the INDIVIDUAL.
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Immortal Jellyfish 
Individuals in turn group to become families, cultures and communities. Thus, we
are bio-psychosocial systems, and to understand our behaviour, we need to study
how these biological, psychological and social cultural systems work and interact.
In order to understand how we act in the world... we need to work backwards…
the furthest backwards is our brains.
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Neural Communication
Smoking Monkey
For scientists, it is a happy fact of nature that the information systems of humans
and other animals operate similarly, so similarly in fact that you could not
distinguish between small samples of brain tissue from a human and a monkey.
This similarity allows researchers to study relatively simple animals such as squids
and sea slugs to discover how our neural systems operate. It allows them to study
other mammals brains to understand the organization of our own. Cars are
different but all have engines, accelerators, steering wheels and brakes. A Martian
could study any one of them and get how they work. In the same way Animals are
different, however their nervous system works much the same way.
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Nervous Systems
- Central Nervous System (CNS): Made up of the Brain and Spinal Cord. The
CNS is like the Highway of the body.
-
Peripheral Nervous system (PNS): Made up of the all nerves leaving the
spine. The PNS is like the side streets of the body.
There are two types of Functions produced by the Nervous system
Autonomic  “Auto” means automatic or without you choosing to do it. This
includes Breathing, blinking and cell production.
Somatic  These are things you choose to do. You have to think to do these
things. This is Muscle movement (running, moving, ect)
So if the CNS and the PNS are the Highways and side streets... what are the
cars?
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Neurons
Our neural information system (our brain) is very complex however when broken
down to it’s base parts its actually quite simple. These base parts are neurons, or
nerve cells.
Neurons_and_how_they_work.mp4 -1min in
Sensory neurons – carry messages from the body’s tissues and sensory organs
inward to the brain and spinal cord, for processing. So sensory neurons are the
messages IN
Motor neurons – The brain, via the spinal cord, sends messages and instructions
out to the body’s tissues. So Motor neurons are the messages OUT
Interneuron – These are the information processors in the brain. Think of them as
the school intercom. They make communication between different parts of the
brain possible.
So the sensory neurons and the motor neurons are very basic. We can actually
reproduce their functions very well with technology. Night Vision Cameras for
example can see better at night then most humans can, thus we can create better
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sensory data than we possess naturally. Same token we have constructed motion
mass information transportation systems (the internet for instance) which is far
faster than motor neurons can work. Where our brains get complex are with the
INTERNEURON. Our bodies have a few million sensory and motor neurons
however we have BILLIONS upon BILLIONS of interneurons.
All are variations on the same theme. Each consists of a cell body and its
branching fibres. The bushy dendrite fibres receive information and conduct it
toward the cell body. From there the cell’s axon passes the message along to
other neurons or to muscles or glands. Axons speak Dendrites listen.
Neural Impulse
THIS MAY BE ON A TEST... **Cough Cough**
Unlike the short Dendrites, axons are sometimes very long, projecting several feet
through the body. A motor neuron carrying orders to a leg muscle, for example,
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has a cell body and axon roughly on the scale of a basketball attached to a rope 4
miles long.
Myelin Sheath: A layer of fatty tissue, the myelin sheath insulates the axons of
some neurons and helps speed their impulses. This layer grows up to about age
25, neural efficiency, judgment and self control grow. If the myelin sheath
degenerates communication to muscles slows with eventual loss of muscle
control. This is called multiple sclerosis.
Think of a light bulb not getting enough energy... the light would go dimmer and
dimmer until it goes dark. Same idea... the Messages are coming they just aren’t
getting there. Think of how awful that would be... to be fully together in your own
head but unable to control your body to match.
Speed: Neural impulses travel at speeds ranging from 2 miles per hour to 200
miles per hour. This top speed is 3 million times slower than that of electricity
through a wire however (told you we aren’t that complex in this area). We
measure brain activity in milliseconds (thousandths of a second) and computer
activity in nanoseconds (billionths of a second). Meaning your nervous system is
WAAAY slower than a computer.
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So how does the communication work?
Neurons transmit messages when stimulated by signals from other neurons.
When that happens, the neuron fires an impulse called the ACTION POTENTIAL
This action potential then travels down the axon and then to the next neuron.
Now this is extremely complicated, sufficed to say once the cell body accumulates
enough charge it release it fires and sends the message down the Axon. This only
happens once the cell body “fills” up with electricity it reaches it’s Threshold. It
never gets over full and never fires before it is full. So it’s what’s called an ALL OR
NOTHING RESPONSE.
Hand on a stove example (Show the video again)
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RECAP
Dendrites :
- Short
- Responsible for listening to other neurons and sending the messages to the
Axons.
Axons:
- Long
- Responsible for telling other neurons to do things
Myelin Sheath
- Fatty layer that helps with communication and protects Axons
- Break down of this layer is called Multiple sclerosis
- Messages can travel anywhere from 2 miles per hour to 200 or more miles
per hour.
Action Potential
- Is the message sent from the cell body down the axon towards another set
of dendrites
All or nothing Response
- Once the charge is enough (threshold) in the cell body it FIRES (Action
Potential). It is neither strong nor weak but simply fires.
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Neuron Communication
Neurons interweave so intricately that even with a microscope you would have
trouble seeing where one neuron ends and another begins. Scientists once
believe that the axon of one cell fused with the dendrites of another in a
uninterrupted fabric. We now know they don’t touch and that the very small
space in-between axon and dendrite are called the Synapse. So how do neurons
communicate if they never touch? Well when an action potential reaches the
“knob-like” terminals at an axon’s end, it triggers the release of chemical
messengers called neurotransmitters. Within 1/10000th of a second the
neurotransmitter molecules cross the synaptic gap and bind to receptor sites on
the receiving neuron. Just like a key into a lock. For an instant the
neurotransmitter unlocks tiny channels at the receiving site and electrically
charged atoms flow in, exciting or inhibiting the receiving neuron’s readiness to
fire. Then in a process called reuptake(Re-up-take), the sending neuron reabsorbs
the excess neurotransmitters.
Confused? Watch thisFunction_of_Neurotransmitters.mp4
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Neurotransmitters
1) Norepinephrine: Helps control alertness and arousal. An undersupply can
depress mood. Very prominent in smokers. Smoking releases
norepinephrine so if you don’t have your smoke, you get edgy... moody.
2) Acetylcholine (ACh): Enables muscle action learning and memory.
Alzheimer’s disease causes acetylcholine producing neurons to deteriorate.
Too little and you get Botox... it paralyses the affected area. On a body wide
scale you become paralyzed. Too much, such as from a byte from a Black
widow spider and you literally shake yourself to death.
Inside_the_Brain_Unraveling_the_Mystery_of_Alzheimers_Disease_[HQ].mp4
3) Dopamine: Influences movement learning, attention and emotion. Excess
dopamine receptor activity is linked to schizophrenia. Starved of dopamine,
the brain produces the tremors and decreased mobility of Parkinson`s
disease. Since it affects emotion many drugs affect dopamine levels.
4) Endorphins: Pain inhibitors. Similar to the chemical morphine, are
responsible for pleasure as well as allowing people to do crazy things like
lift cars off loved ones for example. (http://www.dailymail.co.uk/news/article-1190759/Mighty-motherssuperhuman-strength-lift-1-400kg-car-run-schoolboy.html).
Also responsible for `runners high`.
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5) Serotonin: Affects mood, hunger, sleep and arousal. Undersupply liked to
depression. Prozac and some other anti-depressant drugs raise serotonin
levels.
The easy way to remember these guys is by
NADES
Not All Dogs Eat Scoobysnacks
Not All Defensive Ends Suck
Not All Dates End Swell
Norepinephrine Acetylcholine Dopamine Endorphins Serotonin
Activity : Intelligence Test
Awakenings  Autonomic response affected by L-Dopa (Oliver Sax)
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The Brain
For centuries we had no tools high powered yet gentle enough to explore the
living human brain. Clinical observations of patients revealed some brain-mind
connection. Physicians noticed that damaged to one side of the brain often
caused numbness or paralysis on the bodies opposite side, suggesting that the
body’s right side is wired to the brain’s left side and vice versa. Other notable
discoveries by Clinical observation:
- Damage to the back of the brain affects vision
- Damage to the left front part of the brain produced speech difficulties.
Now within a lifetime (50 years) the whole brain-mapping process has changed.
Now we have the ability to lesion (destroy) tiny clusters of normal or defective
brain cells, leaving the surrounding tissue unharmed. Such studies have revealed
that damage to one area of the hypothalamus in a rats brain reduces eating,
causing the rat to starve unless force-fed. Damage in another area produces
overeating. We can now stimulate various parts of the brain : electrically,
chemically or magnetically. All the while watching and listening for how
everything from a single neuron to the entire CNS responds.
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Let’s look at the different techniques at modern brain mapping
Electrical: Right now your mental activity is giving of telltale electrical metabolic
and magnetic signals that would enable neuroscientists to observe your brain at
work. The tips of modern microelectrodes are so small they can detect the
electrical pulse in a single neuron. For example, we can now detect exactly where
the information goes in a cat’s brain when someone strokes its whisker. Electrical
activity in the brain’s billions of neurons sweeps in regular waves across its’
surface. An Electroencephalogram or EEG is an amplified readout of such waves.
If you have someone hooked up to the EEG you can give them a stimulus... and
then filter out everything else out by repeating giving them the stimulus until only
the stimulus is registering and thus tell what wave is actually the stimulus.
Neuroimaging Techniques
Computed tomography or CT scan examines
the brain by taking x-ray photographs that
can reveal brain damage. Even more dramatic
is the Positron emission tomography scan or
PET scan, which depicts brain activity by
showing each brain area’s consumption of its
chemical fuel, the sugar glucose. Active
neurons are glucose hogs. After a person
receives temporarily radioactive glucose, the
PET scan detects where this “food for
thought” goes by locating the radioactivity.
Rather like weather radar showing rain
activity PET scan hot spots show which brain
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areas are more active as the person performs various tasks.
In MRI or Magnetic resonance imaging brain scans, the head is put into a strong
magnetic field, which aligns the spinning atoms of brain molecules. Then a radio
wave pulse then momentarily disorients the atoms. When the atoms returns to
their normal spin, they release signals that provide a detailed picture of the
brain’s soft tissues. MRI scans have revealed a larger than average neural area in
the left hemisphere of musicians who display perfect pitch. They have also
revealed enlarged, fluid-filled brain areas in some patients who have
schizophrenia.
FMRI or Functional MRI can reveal the brain’s functioning as well as its structure.
When there is activity in the brain, the brain needs blood. By taking MRI pictures
less than a second apart you can actually see the brain “light up”
fMRI_--_View_a_Brain_in_Motion.mp4
This is truly the golden age of brain discovery. Much the way Magellan and
Columbus became immortal in the age of discovery... and Neil Armstrong when
he landed on the moon... the man that maps out the mind, will join the
immortals.
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The Brain: Dissected
If you could open the skull
and look inside the first
thing you might note is the
brain’s size. Dinosaur’s
brain’s represents
1/100000th of the body’s
weight, whales 1/10000th,
elephants 1/600th, in humans 1/45th. It looks as though a principle is emerging by
in mice the brain is actually 1/40th the body’s weight and in marmosets 1/25. So
there are exceptions tot eh rule that the ratio of brain to body weight provides a
clue to a given species’ intelligence. So what makes up intelligence then? It isn’t
size... it’s complexity. Let’s look at our brain structures from oldest to newest.
Brainstem: The brain’s oldest and innermost region is the brainstem. It begins
where the spinal cord swells slightly after entering the skull. This slight swelling is
the MEDULLA. Here lie the controls for your heartbeat and breathing (autonomic
functions) Just above the medulla sits the PONS, which helps coordinate
movements. If stimulated the Pons will cause someone to go into a pounce like
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state... aroused and aware of everything around you, however, if it was severed
the subject would go into a coma. If a cat’s brainstem is severed from the rest of
the brain about
it the animal will
still breathe and
live and even
run climb and
groom but with
its brainstem
cut off from the
brain’s higher
Thalamus
regions the cat
won’t purposefully run or climb to get food. The brainstem is also a crossover
point. Where most nerves to and from each side of the brain connect with the
body’s opposite side. The peculiar cross wiring is but one of the brain’s many
surprises.
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Thalamus
Sitting on top of the Brainstem is the THALAMUS. This joined pair of egg-shaped
structures acts as the brains’ sensory switchboard. It receives information from all
the senses except smell and routes it to the higher brain regions that deal with
seeing, hearing, tasting and touching. This is Grand central station of the brain...
almost all senses run through the Thalamus. The ability for you to enjoy
everything from a cool breeze to a hot shower is because of the Thalamus.
The Cerebellum
Baseball sized structure at the rear of the brainstem. Cerebellum actually means
little brain. The cerebellum enables one type of nonverbal learning and memory.
It helps us judge time, modulate our emotions and discriminate sounds and
textures. It also coordinates voluntary movement (somatic responses) with help
from the Pons. Damage to the Cerebellum would cause difficulty walking, keeping
your balance or shaking hands. Your movements would be jerky and exaggerated.
Under alcohol’s influence on the cerebellum walking may lack coordination as
many a driver has learned after being pulled over and give a roadside test.
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***It is important to note... All old brain functions occur without any conscious
effort. This illustrates another of our recurring themes. Our brain processes most
information outside of our awareness. We are aware of the results of our brain’s
labour (say what you are seeing right now) but not of how we construct the visual
image.
The Limbic System
The limbic system is the link between the “Old brain” and the “New Brain”. It is
literally the part in the middle.
The Amygdala:
In the limbic system two lima bean-sized neural clusters, the amygdale,
influence aggression and fear. In 1939 psychologist Heinrich Kluver and
neurosurgeon Paul Bucy surgically lesioned (destroyed) the part of a rhesus
monkeys brain that includes the amygdala, the result? The normally ill-tempered
monkey turned into the mellowest of creatures. Poke it, pinch it, do virtually
anything that normally would trigger a ferocious response and the monkey stayed
calm, cool, collected. If we stimulate the amygdala in one place, say on a mouse,
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we can make that mouse as fearless as a lion...another place, we can make that
same mouse quite timid.
Amygdala_Plays_Role_in_Food_and_Fear_(PT._1).mp4
Amygdala_Plays_Role_in_Food_and_Fear_(PT._2).mp4
We have to be careful however to not generalize function to structure. Modern
psychologists have found, through many modern mapping methods that Fear and
Courage come from many different parts of the brain.
The Hypothalamus
Just below (hypo) the thalamus is the hypothalamus, an important link in the
chain of command governing bodily maintenance. Some neural clusters in the
hypothalamus influence hunger; others regulate thirst, body temperature and
sexual behaviour. The hypothalamus both monitors blood chemistry and takes
orders from other parts of the brain. Because it regulates hunger and other such
functions it is possible to think yourself hungry. The hypothalamus is also one of
the “reward centers” of the brain. Because the hypothalamus can tell the
pituitary gland (the part of the brain that is responsible for the release of
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hormones) to excrete hormones the hypothalamus can actually affect how we
feel.
Ex: Rats with the proper part of the hypothalamus stimulated will press a button
that stimulates this reward center more than 7000 times before they die of
exhaustion.
The reason we call these “reward centers” and not “pleasure centers” is because
we must refrain from putting human emotions on animals. We don’t know exactly
how the rats feel, so reward is a better word.
Some researchers believe that addictive disorders, such as alcohol dependence,
drug abuse and binge eating may stem from a reward deficiency syndrome. A
genetically disposed deficiency in the natural brain systems for pleasure and wellbeing that leads people to crave whatever provides that missing pleasure or
relieves negative feelings. Basically if we can understand the hypothalamus and
be able to modify it in such a way we may be able to cure addiction... period.
The hypothalamus also maintains homeostasis in the body
Homeostasis means balance. If the body is out of balance, or homeostasis we die.
Having a fever used to kill people. It moved them too far out of Homeostasis
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Hippocampus
The hippocampus plays important roles in the consolidation of information from
short-term memory to long-term memory and spatial navigation. Humans and
other mammals have two hippocampi, one in each side of the brain. The
hippocampus is closely associated with the cerebral cortex, and in primates is
located in the medial temporal lobe
The Cerebral Cortex
80% of the brain’s weight, the Cerebral Cortex is what we think of when we think
about the brain. This is the association center of the brain. The Cerebral Cortex is
comprised of billions of neurons and nine times as many Glial Cells (glue cells).
Neurons are like queen bees. On their own they cannot feed or sheathe
themselves. Glial cells are the worker bees. They provide nutrients and insulating
myelin, guide neural connections and mop up ions and neurotransmitters. Glial
may also play a role in learning and thinking, by “chatting”: with neurons they
may participate in information transmission and memory. Moving up the ladder
of animal life the proportion of glia to neurons increases, this is BRAND SPANKING
NEW. We may find out in 10 years that it is these Glial cells that allow for our
consciousness. Who knows!
Plasticity: The brain’s ability to reorganize. Originally we thought once you lost
brain cells they were gone for ever... now we know that they re-grow. It is
relearning that is the difficult part. It’s like taking the middle out of a Janga tower
without the tower falling down then being asked to put it back together. With
hard work, we are finding it can be done.
The basic fact is however any injury, brain or otherwise, is much easier to come
back from if you are young. The older you get the worse off you are.
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**the myth that we only use 10% of our brain’s capacity is FALSE**
The Cortex is divided into a 4 lobe map.
Frontal lobe: Executive function. This is what makes
you smart. This is the last lobe to develop during
pregnancy and development. The frontal lobe is also
responsible for temperament
Temperament: someone’s disposition. Are they nice,
brutal, blunt, angry, etc...
Phineas Gage
Damage to the frontal lobe changed Phineas’
personality to the point where he had many
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problems dealing with his family and coworkers. He spent the rest of his life as a
kind of oddity.
 This is the Spike going through Gage’s
skull and right through the frontal cortex.
Other than his change in temperament
Gage was otherwise unharmed.
Temporal Lobe: Resides above the ears. It
is responsible for learning. The more
developed this lobe the easier it is for
subject to learn. Multiple intelligences
allows for some people to learn in specific ways. A well developed temporal lobe
allows for learning in all ways.
Parietal Lobe : Middle of the brain. It is responsible for special geography. Being
able to conceptualise in 3D and being able to visualize things in the real world.
Dense is better.
Occipital Lobe: located at the back of the brain, the occipital lobe is responsible
for vision, insofar as the eyes are physically connected to the occipital lobe and
actually develop out of it. Meaning your eyes are actually part of your brain!
The more folds in your Cortex, the denser your cortex is  the smarter you are
capable of being.
*** So now that we have seen the three MAIN constructs of the brain from oldest
to newest are Old brainLimbic SystemCerebral Cortex***
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Motor Cortex
Located at the back of the frontal lobe, the motor cortex is an arch shaped
structure that is responsible for sending OUT information from the brain to the
body. Scientist had better luck in localizing simpler brain functions. For example in
1870 when German physicians Gustav Fritsch and Eduard Hitzig applied mild
electrical stimulation to parts of a dog’s cortex they made an important
discovery... they could make body parts move! Lucky for brain surgeons and their
patients the brain has no sensory receptors (if you poke it, it can’t feel) Knowing
this scientists were able to map the motor cortex in hundreds of WIDE AWAKE
patients by stimulating different cortical areas and observing the body’s
responses. They discovered that body areas requiring precise control, such as
fingers and mouth, occupied the greatest amount of cortical space. In one human
patient the stimulated spot on the left motor cortex triggered the right hand to
make a fist. When asked to keep his hands open the subject could not. He
remarked “I guess you electricity is stronger than my will”  SCARY
This is also the part of the body that will be responsible for modern prosthetics to
be used to create robotic, working, arms.
Neural_Control_Prosthetic_Hand.mp4
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Sensory Cortex
Located at the Front of the parietal lobes, the Sensory cortex is responsible for all
information coming IN to the brain in relation to touch and movement. Stimulate
a certain point in the sensory cortex and the subject will FEEL you touch their
shoulder... even if you aren’t in the same room. The more sensitive the region on
the body, the more space devoted to it in the sensory cortex. This is the part of
the brain responsible for phantom limb syndrome. Where soldiers could actually
still feel amputated legs as if they were still there. What could be some future
implications of this device? VIRTUAL REALITY! If we can send messages out with
prosthetics, that also means we can send messages in... Meaning we can make
you feel your video game... kind of cool.
The Right Brain Vs. the Left Brain
We’ve already talked about how the brain and body are backwards in the sense
that our right brain controls our left side and vice versa. But are there any other
differences between the hemispheres of our brain?
Left brain is responsible for Speaking, writing, math and calculations and reading
Your Right Brain is responsible for facial recognition, problem solving, moral
reasoning and logic as well as artistic expression (being able to draw,paint,ect)
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This is of course a generalization. As we’ve talked about it before, most brain
functions are spread out across different structures of the brain, albeit with a
specialized core.
Gender Differences
Yes men and women’s brains are wired differently.
Women are language based. Have a much greater emphasis on smell then men
and are more prone to depression
Men are Picture/visual based. Have a more developed special geography (can
read maps better) and have way more psychiatric disorders (women serial killers
are so rare that it is very difficult to catch them as most suspects are
automatically men)
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