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. .