Ch 3 – Biological Basis of Behavior: The Brain Thanks to KAP at www.appsychology.com! Major changes by Mr. C. Further changes by T Little

Human Brain (coronal section) (1) cerebrum (2) thalamus (3) midbrain (4) pons (5) medulla (6) top of the spinal cord Human brain (coronal section). The divisions of the brain include the (1) cerebrum, (2) thalamus, (3) midbrain, (4) pons, and (5) medulla. (6) is the top of the spinal cord http://people.eku.edu/ritchisong/301notes2b.htmlla oblongata. (6) is the top of the spinal cord 

Ways we Study the Brain Accidents Lesions EEG CAT Scan PET Scan MRI fMRI

Accidents Phineas Gage story Personality changed after the accident. What does this tell us? That different parts of the brain control different aspects of who we are.

Lesions Purposeful removal or destruction of some part of the brain/brain tissue. e.g., Frontal Lobotomy

EEG Electroencephalogram Detects brain waves through their electrical output. Used mainly in sleep research.

CAT or CT Scan Computerized Axial Tomography 3D X-Ray of brain Good for tumor locating, but tells us nothing about function.

MRI Magnetic Resonance Imaging More detailed picture of brain using magnetic field Takes many still pictures and turns images into a movie like production. Does not study function!

PET Scan Good for studying function. Positron Emission Tomography Measures how much of a chemical the brain is using (usually glucose consumption). Good for studying function.

fMRI Functional MRI PET + MRI Good for studying function (hence the f).

f MRI example The Superbowl Brain Amygdala activation 2006 UCLA experiment using (fMRI) to measure brain responses in a group of subjects while they were watching the Super Bowl ads. Amygdala activation Another interesting finding is the following one. Remember the end of the FedEx ad, when the caveman is crushed by the dinosaur? We looked at the activity in the amygdala, a tiny brain structure (see picture below) critical for emotional processing in general, especially responding to threat and fearful stimuli. There is a big jump in amygdala activity when the dinosaur crushes the caveman, as shown below. The scene looks funny and has been described as funny by lots of people, but your amygdala still perceives it as threatening, another example of disconnect between verbal reports on ads and brain activity while viewing the ads. http://edge.org/3rd_culture/iacoboni06/iacoboni06_index.html

Cerebrum 85% of the brain’s weight Divided into two hemispheres, each with four lobes Densely packed neurons we call “gray matter” Cerebral Cortex - exterior surface of cerebrum Bulges are called gyri. Small grooves are called sulci. Large grooves are called fissures. Adult Cerebral Cortex ~16’2” CC ~ 1/16” – 3/16” thick http://falnaufal17.blogspot.com/2011/03/what-does-cerebrum-do.html Most high level of brain functions take place in the cerebrum. Its two large hemispheres make up approximately 85 percent of the brain's weight. the exterior surface of the cerebrum, the cerebral cortex, is a convoluted, or folded, grayish layer of cell bodies kwown as the gray matter. Your cerebrum makes up most of your brain. Your cerebrum solves problems and makes wishes. All of your thinking goes on in your cerebrum. Speech, language, and emotions come from your cerebrum, especially your cerebral cortex. The cerebral cortex is the outer part of the cerebrum. Your cerebrum also gets signals from your senses. Nerves carry the signals. Nerves from your eyes and ears go to parts of the cerebrum that let you see and hear. Nerves carry signals to your cerebrum that let you feel, smell, and taste. Your cerebrum sends messages out along nerves. The messages tell your legs to walk or run. They tell your arm and hand to wave when you see a friend across the street. http://biology.about.com/od/anatomy/p/cerebral-cortex.htm The cerebral cortex covers the outer portion (1.5mm to 5mm) of the cerebrum. It is the layer of the brain often referred to as gray matter. The cortex (thin layer of tissue) is gray because nerves in this area lack the insulation that makes most other parts of the brain appear to be white.

Two Hemispheres Generally, Left Hemisphere = logic & sequential tasks. Language! Right Hemisphere = spatial & creative tasks. Understanding emotions. stereognosis /ster·e·og·no·sis/ (ster″e-og-no´sis) 1. the faculty of perceiving and understanding the form and nature of objects by the sense of touch.

Four Lobes of the Cerebral Cortex Stop here to draw the first picture on the board

Frontal Lobes Contains Motor Cortex Contains Broca’s area (left hemisphere only) Abstract thought, emotional control & planning. Lobotomies are performed on this area. Broca’s area = speech production, left hemisphere Damage to the frontal lobe can result in a language disorder known as Broca’s aphasia, which is characterized by deliberate, telegraphic speech with very simple grammatical structure, though the speaker may be quite clear as to what he or she wishes to say and may communicate successfully.

Four Lobes of the Cerebral Cortex Stop here to draw the first picture on the board

Parietal Lobes Contains Sensory Cortex Contains Wernicke’s Area (left hemisphere only) Wernicke area, region of the brain involved in the comprehension of speech. Damage to the temporal lobe may result in a language disorder known as Wernicke aphasia. An individual with Wernicke aphasia has difficulty understanding language; speech is typically fluent but is empty of content and characterized by circumlocutions, a high incidence of vague words like “thing,” and sometimes neologisms and senseless “word salad.” Where would this girl sense the pain from her sunburn?

Four Lobes of the Cerebral Cortex Stop here to draw the first picture on the board

What are Motor and Sensory Cortexes? The wires are “switched”…right controls left.

Sensory Homunculus A visual representation of how much brainpower is required to operate parts of your body.

LanguageAreas Broca's Area Wernike's Area: makes words (L frontal lobe) Broca’s Aphasia: disrupts organization of speech Wernike's Area: comprehends words (L temporal lobe) Wernike's Aphasia: unable to understand language Broca’s aphasia = speech is slow, halting, but makes sense; can sing and make sense, though! Wernike’s aphasia = speech is fluent but without meaning Which side of brain are we seeing?

Hearing, Seeing, & Speaking Words Brain Activity when Hearing, Seeing, & Speaking Words Which side of the brain are we seeing?

Specialization and Integration in Language

Occipital Lobes Think “optical”. Contains Visual Cortex: interprets messages from our eyes into images we can understand.

Four Lobes of the Cerebral Cortex Stop here to draw the first picture on the board

Temporal Lobes Contains Auditory Cortex Interprets sound sensed by our ears.

Four Lobes of the Cerebral Cortex Stop here to draw the first picture on the board

Notice how close the auditory cortex is to the ear.

Functions associated with the Four Lobes of the Cerebrum

Brain Plasticity The idea that, when damaged, the brain will attempt to find news ways to reroute messages. Children’s brains are more plastic than adults.

Divides the cerebrum into hemispheres. The corpus callosum is a thick band of nerve fibers that divides the cerebrum into left and right hemispheres. It connects the left and right sides of the brain allowing for communication between both hemispheres. The corpus callosum transfers motor, sensory, and cognitive information between the brain hemispheres. Divides the cerebrum into hemispheres. Connects the left & right sides of the brain.

The Brain: Lateralization The left and right hemispheres of the brain specialize in particular operations.

What is Split Brain?

Split Brain Patients Those who, due to epilepsy, have their corpus callosum cut or removed. The corpus callosum is lesioned to prevent seizures from spreading from one hemisphere to the other.

Split-Brain Research Severing the corpus callosum provides data regarding the functions of the brain’s two hemispheres.

Experiment #1 Split-brain patients Researcher shows fork to left hemisphere (presents to right side) Participant is asked what he saw Response “fork” Researcher shows spoon to right hemisphere (presents to left side) Response: “I don’t know” Participant is asked to reach in a bag with left hand (right hemisphere) to retrieve what he saw He pulls out a spoon…explain?

Split-Brain Research

Testing the Divided Brain

"The great pleasure and feeling in my right brain is more than my left brain can find the words to tell you." Roger Sperry (Nobel Prize Winner, 1981) Psychobiologist Roger Sperry discovered that human beings are of two minds. He found that the human brain has specialized functions on the right and left, and that the two sides can operate practically independently. After receiving a bachelors degree in English literature, he studied psychology and zoology, followed by several years of research at Harvard, Yerkes Laboratory of Primate Biology, and the National Institutes of Health. In 1954, he joined the faculty of Cal Tech where he remained for 30 years. In the early 1960s, Sperry and colleagues, including Michael Gazzaniga, conducted extensive experiments on an epileptic patient who had had his corpus collosum, the "bridge" between the left and right hemispheres of the brain, split so that the connection was severed. At first the patient seemed quite normal, but experimentation showed certain activities such as naming objects or putting blocks together in a prescribed way could only be done when using one side of the brain or the other. (Since the right eye connects to the left brain, the left hand to the right brain, and so on throughout the body, the stimulus would be given to the side of the body opposite the brain hemisphere being tested.) These abilities were not absolute, but it seemed that the left hemisphere specialized in language processes and the right is dominant in visual-construction tasks. Sperry's work helped chart a map of the brain and opened whole fields of psychological and philosophical questions. Sperry received the Nobel prize in 1981.

Dear Left Brain… KIA Optima commercial 2012 http://www.youtube.com/watch?v=ySrymOeWjM8

On the next slide, say the COLOR of the word without reading the word that is written.

Your right brain tries to identify the color, but your left brain wants to read the word.

Brain Structures Hindbrain Midbrain Forebrain (Cerebral Cortex is part of forebrain) (R hemisphere, medial view)

Structure & Function The brain was built like a house, bottom to top. The hindbrain controls basic functions like breathing. The forebrain is the most complex and is responsible for functions like decision making.

Hindbrain Structures at the top of the spinal cord. Controls basic biological functions. All animals have hindbrains! HINDBRAIN

Hindbrain: Cerebellum Bottom rear of the brain means “little brain” Responsible for balance & muscle coordination

Hindbrain: Medulla Oblongata Located just above the spinal cord. Involved in control of basic functions: blood pressure heart rate breathing

Hindbrain: Pons Located above the medulla. Bridge between the cerebral cortex & the medulla oblongata Involved in facial expressions. (Pons = yawns) Pons = Latin for bridge In Latin, the word pons literally means bridge. The pons is a portion of the hindbrain that connects the cerebral cortex with the medulla oblongata. It also serves as a communications and coordination center between the two hemispheres of the brain. As a part of the brainstem, the pons helps in the transferring of messages between various parts of the brain and the spinal cord. http://biology.about.com/od/anatomy/p/pons.htm

The Brainstem Connects cerebrum to spinal cord consists of Midbrain Medulla Pons parts of hindbrain The brainstem is the region of the brain that connects the cerebrum with the spinal cord. It consists of the midbrain, medulla oblongata, and the pons. Motor and sensory neurons travel through the brainstem allowing for the relay of signals between the brain and the spinal cord. The brainstem coordinates motor control signals sent from the brain to the body. The brainstem also controls life supporting autonomic functions of the peripheral nervous system.

Midbrain Smallest, innermost region of the brain A relay station for auditory & visual information Involved in controlling body movement

Midbrain: Reticular Formation Coordinates simple movements with sensory information Most important structure in Midbrain controls arousal & ability to focus our attention. stimulated damaged

Midbrain Reticular Activating System RAS or ARAS Top of reticular formation - responsible for regulating arousal & sleep-wake transitions Affects consciousness Sleep meds affect this part of the brain. Damage leads to a coma. ARAS = ascending reticular activating system

Forebrain What makes us human (homo sapien not homo erectus) Most recently developed part of brain Largest part of the brain Thalamus, limbic system & cerebral cortex Cerebral cortex All gray = forebrain.

Forebrain: Limbic System Directly connects lower & higher brain functions Influences emotions & visceral responses to emotions, motivation, mood & sensations of pain & pleasure Involved with memory Thalamus

Forebrain: Limbic System Directly connects lower & higher brain functions Influences emotions & visceral responses to emotions, motivation, mood & sensations of pain & pleasure Involved with memory pituitary gland

Forebrain: Thalamus Switchboard “relay station” of the brain. Receives sensory signals from the spinal cord & sends them to other parts of the forebrain. Every sense except smell. Olfactory buls connects directly to the amygdyla

Forebrain: Hypothalamus Controls & regulates the Four F’s Fighting Fleeing Feeding “Fornicating”(mating) Controls the endocrine system Maybe most important structure in the brain.

The ventromedial nuclei gives a signal when to stop eating. Forebrain: Hypothalamus The ventromedial nuclei gives a signal when to stop eating. The lateral hypothalamus tell your body you’re full.

Forebrain: Hippocampus Involved in the processing and storage of memories. Proximity to emotional centers helps explain why memories & emotions are so linked!

Forebrain: Amygdala Involved in telling your body to produce norepinephrine (adrenaline) More involved in volatile emotions like fear or anger Thanks to KAP at www.appsychology.com! Major changes by Mr. C. Further changes by T Little The emotions of fear & anger have not changed much throughout evolution.