MAKING NEUROSCIENCE FUN
BRAIN MYTHS
(Grade 8)
♥ SLIDE #1: INTRODUCTION
Good Morning (Afternoon)!
My name is __________ and I am a Neuroscience student (or you can say you study Neuroscience – or you are a Neuroscientist) at Johns Hopkins University.
Question : Does anyone know or can anyone guess what neuroscience is (or what a Neuroscientist studies?
Let’s look at our little friend up here.
Question: Do you know what this is a picture of?
This is a cartoon of a brain. This is a brain that is having fun – because this little brain is skateboarding.
Neuroscience is the study of the nervous system – which includes the brain. If you study the nervous system you are a Neuroscientist.
(Next, tells the students why you are visiting them. I usually sa y something like this…..)
I am here because I LOVE NEUROSCIENCE and I wanted to share some things I know about the nervous system with you.
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SLIDE #2: NERVOUS SYSTEM
Question : What is the nervous system?
It is your brain, your spinal cord, and all of your nerves.
Your nervous system is connected to every part of your body. It is what makes your body work.
There is so much to know about the nervous system…..
♥ SLIDE #3: TODAY’S TALK
Today I am going to talk to you about some common brain myths .
I have titled my presentation, “BRAIN MYTHS – FACT OR FICTION ” .
Question: What is a myth?
According to the dictionary, a myth is a traditional or legendary story with or without a determinable basis of fact or a natural explanation.
Because there is still so much that we do not know about the nervous system, there are lots of stories or myths that are out there.
Hopefully after today you will have the facts about some of these brain myths.
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♥ SLIDE #4: FACT OR FICTION
We use only 10% of our brains.
FICTION: It is a myth.
This is the biggest brain myth that is our there.
There is no scientific evidence to suggest that we only use 10% of our brain potential.
We use all of our brain.
Brain imaging, such as Single Photon Emission Computerized Tomography (SPECT), Positron Emission
Tomography (PET), and Functional Magnetic Resonance Imaging (MRI) produce images of localized functional or metabolic activity of the brain.
The red areas in the picture to the right indicate high levels of activity. Blue or black areas indicate little or no activity in those brain structures. Colors between red and black indicate various levels of activity. By superimposing the PET scan over an MRI scan, researchers can determine the level of activity in specific structures of the brain.
Where Did the 10% Myth Begin?
The 10% statement may have been started with a misquote of Albert Einstein .
♥ SLIDE #5: LASHLEY
Perhaps it was the work of Karl Lashley in the 1920's and 1930's that started it.
Lashley trained rat on a maze.
Lashley removed large areas of the cerebral cortex in rats and found that these animals could still relearn specific tasks.
He did these experiments because he was looking for the place where memory was located.
Lashley concluded that it was the amount of the brain – not the place that was important.
♥ SLIDE#6: WE USE 100% OF OUR BRAINS
If we only used 10% - we would be using a brain the size of a sheeps!!!
Why would we have such a big brain if we did not use it….there is a saying in neuroscience – Use it or Lose it.
If we weren’t using our parts of our brain it would die off.
People who use there brains have healthier and happier brains.
♥ SLIDE #7: FACT OR FICTION
You can burn more calories studying for an exam than by running a mile.
FACT: it is NOT a myth .
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♥ SLIDE #8: BRAIN METABOLISM
Your brain is your most metabolically active part of your body.
Based on information from http://www.healthstatus.com/calculate/cbc, if you ran a 12 minute mile you would burn about 264 calories.
Studying you burn about 122 calories per hour, so if you studied about 2 ½ hours this would be a fact.
♥SLIDE #9: FACT OR FICTION
Dogs are Color Blind.
FICTION: It is a myth.
♥ SLIDE #10: COLOR VISION
You all know that in order to see color you need your cones .
Color vision is based on the types of cones that you have and the each one of the cone receptors is maximally sensitive to different wavelengths.
Almost all mammals possess some degree of color vision.
Animals with all three cone types have excellent trichromatic color vision – humans, rhesus monkeys (other diurnal primates).
Species with 2 cone types have robust dichromatic vision
– dog , pig, New World monkeys (marmoset, squirrel monkey).
Animals that have 2 kinds of cones, but don’t have a lot of cones have feeble dichromatic color vision
– domestic cats.
Animals with only one kind of cone must depend on differences in rods and cones to distinquish wavelengths, these animals have minimal color vision – owl monkey and raccoon.
♥ SLIDE #11: COLOR VISION – GENDER EFFECTS
Genes for the photopigment in the M and L cones (red and green color vision) are on the X chromosome.
If there is a mutation in this gene – an impairment in color vision occurs. This is more prevalent in males b/c they only have one X chromosome. Rarely is there a mutation in 2 X’s – so females have less impairment in color vision.
♥ SLIDE #12: FACT OR FICTION
Addiction is a brain disease.
FACT: It is NOT a myth.
Addiction causes compulsive, uncontrollable behavior to seek and use a substance, even in the face of negative social consequences or health consequences. It is a chronic, relapsing disease.
Here we see a decrease in metabolism of a cocaine user (right) as compared to a normal control.
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♥SLIDE #13: REWARD PATHWAY
The reward pathway is actually the mesolimbic reward circuit.
The connection between the dopaminergic substantia nigra and ventral tegmental area (midbrain) to the nucleus accumbens (forebrain) and then the output to the ventral pallidum and back to the substantia nigra
(extrapyramidal system) appears to be key in all kinds of reinforcement.
Whenever you are happy – this pathway is activated.
All drugs that cause addiction activate this pathway.
But drugs activate the pathway faster and stronger than any of our natural reinforcers – like food, water, shelter.
♥SLIDE #14: DRUGS CHANGE YOUR BRAIN
When you take drugs, it changes your brain. Now your brain is only happy when you are taking the drugs.
But, then what happens is you have to take more and more drugs to make your brain happy.
Your brain is now a sad, addicted brain.
♥ SLIDE #15: ADDICTION IS A BRAIN DISEASE
A disease has symptoms – heart disease is characterized by high blood pressure.
Addiction is characterized by a craving for the drug that pushes the person to behave in ways that they would not normally behave.
Their brain – which has a disease – wants the drug over everything else.
This compulsion – or psychological dependence – is the main symptom of addiction.
♥ SLIDE #16: FACT OR FICTION
Intelligence can be determined by brain size.
FICTION: It is a myth.
♥ SLIDE #17: BRAIN SIZE AND INTELLIGENCE
Question: What is something that you do that is intelligent?
Working on the computer, taking an exam, playing chess, etc.
If we just look at brain size – then an elephant is smarter than a human.
Do we think that an elephant can do any of the “intelligent” behaviors?
If we look at brain size in relationship to body size…..whoa, the order is all messed up.
It turns out that there is a constant – encephalation – that takes into account the size of the cortex.
Using this formula you can rank the “intelligence”.
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♥ SLIDE #18: WHAT IS INTELLIGENCE?
But, what is intelligence ?
Studies correlating fMRI, to get actual brain size, with IQ test results have found a 0.38 correlation – this is a very modest correlation. (Corrections were made for body size).
If intelligence is the ability to adapt to the environment, so that the animal can survive and the species can propagate – and it also takes into account the complexity of the environment – and the complexity of the behaviors, then the bumpiness of an animal ’s brain should correlate with intelligence.
♥SLIDE #19: FACT OR FICTION
The left side of your face is more emotionally expressive than the right.
FACT: It is not a myth.
♥ SLIDE #20: FACIAL EXPRESSION
Part of your ability to communicate is the use of facial expressions.
Most of the emotions are represented by facial expression.
These facial expressions are cross-cultural . Meaning that they are recognizable across many different cultures and socioeconomic backgrounds.
Facial expression of emotion may be used as an addition to communication (verbal or sign) .
Facial expressions are a way of sharing your emotions.
In fact, when using sign language where you do not have the auditory cues that relate emotional context, facial expressions are often exaggerated.
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SLIDE #21: INNATE AND IMITATED
When people see someone expressing an emotion, they tend to imitate the expressions.
This phenomenon appears to be innate, because infants even imitate expressions.
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SLIDE #22: LEFT SIDE OF YOUR FACE IS MORE EXPRESSIVE
Using a composite-photo technique, a number of studies looked at facial asymmetry in emotional expression.
It was concluded that the right cerebral hemisphere is dominant for facial expression of emotion .
(Remember the right side of your brain controls the left side of your body).
This is true for both posed and spontaneous faces, for pleasant and unpleasant emotions, and for both sexes and all ages.
♥ SLIDE #23: FACT OR FICTION
Sleep walkers are “acting out” their dreams.
FICTION: It is a myth.
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♥ SLIDE #24: DREAMING AND MUSCLE ACTIVITY
During REM (rapid eye movement) sleep is when you have your most vivid dreams.
It is known that during REM there is no muscle tone.
You can actually lift up a person’s arm and then drop it!!!
There is actually a brain circuit that goes down to your spinal cord – where the cells (called motor neurons) are that control your muscles – and shuts off the motor neurons.
So….you couldn’t sleep walk while you were dreaming – because the parts of the nervous system that controls your muscles are shut off.
HMMMM…I wonder if we were built like this on purpose so we could not act out our bizarre dreams!!!!
♥ SLIDE #25: FACT OR FICTION
Our brains make chemicals similar to heroin, marijuana and valium.
FACT: It is NOT a myth.
Our brains make endogenous opioids – endorphins, enkephalins, etc. to help us to alleviate pain.
Heroin is only one of the compounds that comes from the opium plant. Morphine – a powerful pain reliever
– also comes from the opium plant.
Our brains also make endocannabinoids – anandamide and 2-AG – which are similar to the THC in marijuana.
Marijuana does a lot of different things – makes you hungry, stupid, etc. and it turns out that the endocannabinoids work in a number of different behaviors.
Valium, is a drug that helps to calm us down. Well our brain makes a compound – allopregnanolone – which also works to calm us down.
♥SLIDE #26: FACT OR FICTION
Only humans ingest mind altering chemicals.
FICTION: It is a myth
Apparently, other animals have a need to relieve pain, control anxiety and pursue pleasure.
According to R.K. Siegel, who wrote Intoxication: Life in Pursuit of Artificial Paradise,
“Almost every species of animal has engaged in the natural pursuit of intoxicants.”
I can think of cats and catnip (mint).
♥SLIDE #27: FACT OR FICTION
Marijuana makes you stupid.
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FACT: It is NOT a myth.
♥SLIDE #28: MARIJUANA MAKES YOU STUPID
The endogenous cannabinoids actually help you to learn.
When one neuron (the cell that is involved in the learning circuit) is active, it makes an endocannabinoid – like 2-AG.
The 2-AG travels to the GABA neuron – which was also “talking” to the neuron “trying to learn”.
The endocannabinoids “tells” the GABA cell to be quiet and not send information.
The normal effects of the endogenous cannabinoids would last tens of seconds and occur in specific areas.
The affect of smoking marijuana exposes the entire brain to high levels of THC for a much longer period of time, which would swamp the system.
An analogy in Science says “THC flooding the brain would eliminate the local activity pattern set up by DSE and DSI, just as spilling a bottle of ink across a page would obliterate any words written there.”
♥SLIDE #29: FACT OR FICTION
You can learn while you are sleeping.
FICTION: It is a myth.
♥ SLIDE #30: BRAIN BLOCKS OUT SOUNDS
One of the stages of sleep - Stage 2 sleep begins about 10 minutes after the onset of stage 1 sleep.
The EEG during this stage is generally irregular, but contains periods of theta activity, sleep spindles and K complexes.
Some investigators believe that this activity is a mechanism that decreases the brain’s sensitivity to sensory input (like sounds) and keeps the person asleep (differences could define light vs. heavy sleepers).
The sleep of older people contain fewer sleep spindles and older people typically have more awakenings during the night.
SO….our brains try to keep the outside world from disturbing us while we sleep.
But… sleep appears to aid memory consolidation.
Little or no new learning occurs during sleep, but evidence suggests that memory for new material is improved if learning is followed by sleep.
Sleep following learning is characterized by the presence of more REM than usual.
♥SLIDE #31: FACT OR FICTION
Chocolate makes you happy.
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FACT: It is NOT a myth.
♥SLIDE #32: CHOCOLATE AND THE REWARD PATHWAY
There are actually a number of compounds in chocolate that activate the reward center in your brain and make you happy.
♥ SLIDE #33: BUT…NO CHOCOLATE FOR SCOOBY
Chocolate is not good for dogs, because it contains a compound known as theobromine .
Dogs can not digest theobromine – and it makes their hearts beat too fast.
Too much chocolate can send a dog to puppy heaven – so keep the chocolate away from Scooby!!!
♥ SLIDE #34: CONCLUSION
Well, those are some of the more common brain myths , but that is by no way all of them.
I hope you have learned some fun and interesting things about the brain.
I have enjoyed talking to you today, and I hope that next time you hear someone telling a brain myth that you will set them straight..
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