Biological Psychology
Unit Two AC Mr. Cline Marshall High School Psychology * The Brain
• The Parts of the Brain
• Is your brain preprogrammed and unchangeable or adaptive and malleable?
• We are going to next explore how the brain, a more resilient and resourceful machine than any computer, responds to damage and new experiences.
• Your brain is amazing and complex!
• Think about how the famous railroad worker Phineas Gage, who was still able to walk and talk minutes after an iron rod was accidentally shot straight through his head!
• Even though Phineas Gage suffered severe damage to the left side of his brain, he was able to recover and go on to work as a stagecoach driver and farmhand for more than a decade.
• Approximately one million Americans have brain damage that affects their ability to talk.
• This kind of impairment is known as aphasia.
* The Brain
• The Parts of the Brain
• Just to put this in perspective, imagine if the entire city of Philadelphia had trouble speaking!
• One of the most common causes for this kind of brain damage is stroke.
• When someone has a stroke, the blood doesn't reach part of their brain, causing the brain cells to die.
• The resulting brain damage can lead to a disorder, such as Broca's aphasia.
• People with Broca's aphasia have damage to the Broca's area in their frontal lobe, which is one of the parts of the brain that processes our ability to speak.
• People with this kind of damage can usually understand what other people are saying but have trouble speaking themselves. * The Brain
• The Parts of the Brain
• A trick to remember this is to say that people with Broca's aphasia have a broken speech center in their brain.
* The Brain
• The Parts of the Brain
• Sometimes we say that the brain is like a computer, but it can do things no computer can do.
• If you have brain damage, then other parts of your brain can start performing the missing functions and allow you to recover your ability to speak.
• We say the brain is plastic, or shaped by its experiences.
• Neuroplasticity is a fancy word for the brain's ability to adjust to damage or new experiences.
• With treatment, rehabilitation and time for the brain to reorganize and access its other language centers, people with Broca's aphasia can recover some of their ability to communicate.
• Neuroplasticity isn't always about bad news.
• Damage isn't the only thing that changes our brain, and changes aren't only functional. * The Brain
• The Parts of the Brain
• The structure of your brain can change, too.
• When you 'flex' your 'mental muscles' you can actually grow a larger temporal lobe for processing sound!
• One way to do this is to play an instrument every day. And if you learn a second language, your parietal lobe actually becomes denser.
• So learning things isn't just like storing information in a computer; parts of the brain grow denser and grow larger in response to our experiences.
• In other words, neuroplasticity gives us hope for improving our brains!
• Our hormones also play a big part in how we feel and behave throughout the day. * The Brain
• The Parts of the Brain
• Hormones also affect important bodily functions.
• Teenagers aren't the only ones with hormones, and hormones don't just cause mood swings.
• The Endocrine System • The hormones of your endocrine system help to regulate your energy levels, growth, emotions and ability to reproduce.
• Hormone-producing glands make up your endocrine system.
• Hormones are chemicals that your body produces to tell your cells how to behave.
• They can regulate growth and energy consumption.
• Your thyroid gland is in your neck. • Your thyroid regulates your metabolism, or how fast your body uses energy. * The Brain
• The Endocrine System
• Low levels of thyroid hormones may make you feel tired and lead to weight gain.
• But, if you have a hyperactive thyroid, your heart may race and you may feel jittery and have trouble falling asleep.
• Your pancreas is a gland in your belly that also affects your energy levels.
• Your thyroid controls the rate at which your body uses energy, and your pancreas regulates how much energy your body gets.
• Your pancreas produces insulin, the hormone that helps your body absorb sugar in your bloodstream to give it energy.
• You feel sluggish in the morning when you have low blood sugar.
• Once you eat breakfast, sugar from the food is carried by your blood.
* The Brain
• The Endocrine System
• Insulin from your pancreas helps your cells take in the sugar that fuels your body.
• In your belly, you also have adrenal glands, which rest on top of your kidneys.
• Your adrenal glands pump out adrenaline hormones when you're faced with stress or excited.
• Say you're driving, and suddenly see a baby in the road.
• Your nervous system sends signals to the glands in your endocrine system to put your reactions in motion.
• Your adrenal glands in your endocrine system release adrenaline to trigger a reaction.
• You get scared and react quickly as you slam on the brakes. * The Brain
• The Endocrine System
• And, you laugh when you realize it was just a doll that someone lost!
• Difficulties with any of these glands can lead not just to health problems, but also to long-term changes in behavior.
• They can affect moods and the choices we make.
• Male and female sex glands are also part of the endocrine system.
• If you're a guy, your testes produce the male sex hormones testosterone.
• If you're a girl, your ovaries produce the female sex hormones estrogen.
• Changing hormone levels are responsible for the physical and emotional changes that occur when you hit puberty. * The Brain
• The Endocrine System
• The pituitary gland in your brain is called the 'master gland' because it secretes hormones that trigger your other glands.
• It regulates the amount of hormones released by your thyroid, adrenal glands, pancreas and sex glands.
• It's the command center that controls your body's growth, and signals your ovaries or testes to make testosterone or estrogen.
• Sensory and Perception
• What is the difference between sensation and perception, and how do they work?
• Imagine your phone rings. You take it out and see that it's an unfamiliar number.
• You're wary of telemarketers, but you're also procrastinating doing homework, so you pick up the call anyway. * The Brain
• Sensory and Perception
• What is the difference between sensation and perception, and how do they work?
• Imagine your phone rings. You take it out and see that it's an unfamiliar number.
• You're wary of telemarketers, but you're also procrastinating doing homework, so you pick up the call anyway.
• You hear a voice say, 'hello'; you perceive that the voice is your friend Robert's.
• He explains that he's calling from a friend's phone because his is dead, and you make plans to see a movie.
• Even though you didn't recognize Robert's number, you heard his voice and recognized it as his.
• Hearing his voice was sensation; recognizing it was perception. * The Brain
• Sensory and Perception
• Sensation is passively receiving information through sensory inputs, and perception is interpreting this information.
• If you've ever been to kindergarten, you've probably heard of the five senses: seeing, hearing, smelling, touching and tasting.
• You probably didn't learn about proprioception, which is just a fancy way of saying your ability to be aware of your body's motions and position.
• All of these senses give us information (sensation) which our brains have to interpret (perception).
• The senses get their messages to the brain through a process called transduction, or transforming information from the eyes or ears, for example, into electrical impulses that the brain can understand.