Perception and Reality Things Are Not Always As They Seem...

Perception and RealityThings Are Not Always As They Seem... Brain Basics Facts and Misconceptions

Brain BasicsOverview Brain Facts Discussion and Questions General Facts Parts of the Brain Functions Brain Misconceptions Discussion Properties of Neurons Discussion

Brain Facts The adult human brain is about 4 to 5 pounds. A baby’s brain weighs about 1.5 pounds. However, a baby’s body weighs about 15-30 times smaller than an adult’s body. So a baby’s brain is 6 times bigger compared to its body weight!!! (that is why babies have huge heads compared to their bodies) Human brain has over 100 billion! neurons (a type of brain cell); that’s about 20 times the total number of people in the world. Neurons require a lot of energy: Your brain uses over half of all the energy in your body.

Brain Lobes The Cerebral Cortex (wrinkled outside part of the brain) is arbitrarily divided into 4 lobes based upon the things that scientists think they do The occipital lobe processes the visual information from your eyes The frontal lobe makes high-level decisions, plans movements, coordinates speech, and has a large role in determining personality and morality (Phineas Gage)

Brain Lobes The parietal lobe processes you sense of touch, processes your concept of spatial relationships (where things are) The temporal lobe helps identify things (what things are), helps you remember things, and processes sounds (hearing)

Other Brain Parts The Cerebellum has as many neurons as the entire cerebral cortex! Its main role it to coordinate movements or brain activities (make sure their timing is right) The Brainstem controls the body processes that you don’t have to think about (like your heart beat)

Brain Misconceptions10% Do people only use 10% of their brain? No. Different parts of your brain do different things. So not all of your brain needs to be doing something all of the time. However, using modern technology we have shown almost every area of the brain active during some task. For many hard tasks, a large percentage of your brain may be active at one time.

Brain MisconceptionsWrinkles Why are there wrinkles in the brain? Do more wrinkles appear when you learn something new? No. Your cerebral cortex is essentially a flat sheet (like a large sheet of paper) that it has to fit in your skull (which is like a cup)… A crumpled up sheet of paper fits in a cup easier than an unfolded one. Most scientists think that new learning is changed connections between neurons (brain cells; similar to different wiring in a computer).

Brain MisconceptionsGender and Brain Size Do boys have bigger brains and are they smarter than girls or the opposite? (1) Men on average actually do have larger brains than women (just like they have bigger bodies on average). But, elephants have much bigger brains than humans (4 times as heavy) and cats are about 45 times smaller. (2) A bigger brain does not mean you are smarter. Men and women have the same intelligence level on average (although there is some evidence that each may be slightly better at specific tasks). Two people with the biggest and one of the smallest brains ever found both belong to professional writers!

Brain MisconceptionsComputers (1) Is the brain like the CPU of a computer? Not really. Computers are made of metal and use electricity to process information. Brains are made of organic cells and use a mix of electrical signals and chemicals to process information. If one part of a computer breaks it can do almost nothing. If one part of your brain gets damaged only certain things are hard to do and it can sometimes gradually repair itself.

Brain MisconceptionsComputers (2) Are humans smarter than computers or computers smarter than people? Neither, they work in different ways. Computers are currently all programmed to do a specific task by people who give them specific instructions about how to do it. Computers are much faster at doing many of these things. Currently, computers are not able to do things they are not specifically told how to do. This is changing as people figure out ways to make computers learn to do new tasks on their own. Humans, however, are very good at figuring out creative ways to do things on their own.

Brain MisconceptionsDrug Addiction (1) If you are careful you won’t get addicted to drugs, right? Examples of addictive Drugs – all types of Cocaine (crack); Heroin; Opium; Ecstasy; … Mostly affect the parts of your brain that process reward (pleasure) information or help you manage pain: when they work normally, they help you in emergencies or to encourage you to become addicted to good behavior (like eating nutritious food) to make you want to do it again and again The problem: these drugs either overuse or kill off cells in these systems so they work too strongly or eventually not enough… Some brain areas cause a little addiction even when working correctly; drugs cause these areas to work way too much…

Brain MisconceptionsDrug Addiction (2) Do drugs really hurt you long-term? Yes. Long-term overuse of the systems of reward through drugs: Strong addiction to the drugs. Leads to less sense of reward for other activities that are actually good for you so you stop doing them. As cells die from overuse (or become habituated), you need more and more drugs to get the same high. Then when you are not doing drugs you feel worse than you did before you started. In other words: Drugs damage your brain more the longer and more you do them (much of which will never recover). They trick your brain into thinking life is great when you are on them and much worse when you are not (even compared to before you started) so they are harder to stop.

Neuron s These brain cells share most of the properties of cells in every living organism. They have a nucleus; and a membrane through which they exchange things with the blood. They require nutrients and energy (from the blood). They must get rid of waste and heat (to the blood). They require time to perform any of their functions and also time to reset, so they can perform the function again.

Dendrites, Cell Body, Axon A neuron is made up of 3 parts (diagram in next slide): The dendrites (sometimes called a dendritic tree) get the chemical inputs from other neurons The axon is the output mechanism that sends messages to other neurons The cell body does all of the processing of the information received from the dendrite and determines what message should be sent out through the axon The connection between one cell (from an axon) and another (usually to a dendrite) is called a synapse

Neuron Diagram Dendrites Cell Body Axon Synapse

Similarities with Other Cells These brain cells share most of the properties of the cells in every living organism. They have a nucleus; and a membrane through which they exchange things with the blood. They require nutrients and energy (from the blood). They must get rid of waste and heat (to the blood). They require time to perform any of their functions and also time to reset, so they can perform the function again.

Differences There are some differences however: Neurons are extremely energy expensive cells; over a third (and sometimes more than a half) of all our energy goes to our brains. Because of this, neurons create a lot of heat. Neurons require special chemical nutrients (most cells just need glucose, water,…). Neurons communicate with other cells (most cells do not).

Perception and Reality Things Are Not Always As They Seem...