1. Random Brain Facts
Mr. Koch
AP Psychology
Andover High School

2. Random Brain Facts
We’ve learned more about the brain in last 20 yrs than all time previous to that
No two brains are identical
Brain is mostly water (78%), fat (10%), and protein (8%)
Living brain is so soft it can be cut w/ butter knife
Phrenology

3. Random Brain Facts
The adult human brain weighs about 3 pounds (1,300-1,400 gm)
Elephant brains = 6,000gm
Cat brains = 30 gm
Brain is ~2% of body weight, but consumes ~20% of body’s energy
Total surface area of cerebral cortex = ~2.5 sq ft
Bigger brains are not necessarily better
Einstein’s was about average size
(but unusual composition)
We use all of our brain
That 10% thing is a myth

4. Random Brain Facts
Human brain has ~100,000,000,000 neurons
How many is that?...
If you were to count them at a rate of 1 neuron per second, it would take about 3,171 years to count them all
If all neurons were lined up, they would stretch about 600 miles
Every second, brain receives 100 million messages from the senses
¾ of body’s neurons are in brain
On day you’re born, brain cells are already in place
They’re just immature – still developing
Explains why don’t have memories until ~3-4 y.o.
Once believed this is all you get
Recent research on neurogenesis is challenging this idea…

5. Random Brain Facts ~10 trillion pieces of information in the brain
There are 1,000 – 10,000 synapses for a typical neuron
Human brain is capable of processing 10,000,000,000,000,000,000,000,000,000 bits of data per second
Intelligence has nothing to do with number of neurons – it has everything to do with number of synaptic connections

6. Random Brain Facts World record for time w/o sleep:
264 hours (11 days) – Randy Gardner, 1963
Unconsciousness occurs 8-10 sec after loss of blood supply to brain

7. Random Brain Facts Changing brain:
525 billion neurons in brain at 26 wks gestation
200 billion on day born
100 billion today
Brain is ultimate “use it or lose it” machine
“neural sculpting” happens during REM sleep
Computer/TV has huge impact on brain
Recommend no TV/internet 0-2 yrs
Sesame Street?

8. Random Brain Facts Humans can process 400-600 words/min
Talk about words/min
Speaker needs to fill in gaps to avoid boredom, mind wandering
Aphasia – language impairment – usually from damage to Wernicke’s or Broca’s Area in left hemisphere
Some can speak but not read, some understand reading but can’t speak, some can write but not read, read but not write, read numbers but not letters, sing but not speak (language processing appears complex)

9. Random Brain Facts
Before age 5, brain is very plastic (neuroplasticity) – can adapt/reorganize after injury, build new neural pathways
After age 5, severe, permanent damage more likely (although adult brain is more plastic than previously thought)
Ex – 5 y.o. boy w/ severe seizures had entire left hemisphere removed – paralyzed on right side, but scored above avg on intelligence tests, finished college & grad school – today an executive

10. Random Brain Facts
Brain disorders cost Americans more than $760 billion a year
Alcohol use in teens devastating to the pre-frontal cortex
Mature neuron has myelin sheath protection, young adolescent brain does not
MN in top 5 for alcohol consumption
Also top 5 for FAS cases

11. WARNING: REALLY CORNY JOKES AHEAD

12. Bad brain jokes
What does a brain do when it sees a friend across the street?
Gives a brain wave
What did the hippocampus say during its retirement speech?
Thanks for the memories
What did the right hemisphere say to the left hemisphere when they couldn’t agree on anything?
“let’s split”

13. Bad brain jokes What happens if you break the brain scanner?
You will have a CATastrophe
What kind of fish performs brain operations?
A neurosturgeon
What do you call a skull without 100 billion neurons?
A no brainer

14. Bad brain jokes When does a brain get afraid?
When it loses its nerve
Why didn’t the brain want to take a bath?
It didn’t want to be brainwashed
Why was the neuron sent to the principal’s office?
It had trouble controlling its impulses