We are here Nervous System Central Nervous System Brain Brain Imaging Peripheral Nervous System Building Blocks Genetics Evolutionary Endocrine System Neurotransmitters Somatic Autonomic Sympathetic Parasympathetic Biological Psychology Spinal Cord Neurons SensoryMotor

The Brain

Facts about the brain Weight= pounds Men’s brains are slightly larger than women’s brains (HOWEVER size does Not equal intelligence level! )

Ways we Study the Brain Accidents/Injuries Lesions/Stimulation CAT Scan PET Scan MRI Functional MRI

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

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Lesions Removal or destruction of some part of the brain. Destroyed part of the temporal lobe in Rhesus monkeys, and they became less aggressive and less fearful. (Destroyed the area that controlled aggression.

Stimulation Electrodes may be used to set off the firing of neurons EX: If you apply a current to the temporal lobe of the brain during surgery, you might hear a familiar song so clearly you think the song is playing in the operating room! –Also used to relieve intolerable pain of cancer patients and to control violent behavior in otherwise uncontrollable patients.

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Electroencephalogram EEG Detects brain waves through the electricity of neural communication. Used frequently in sleep research.

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

Magnetic Resonance Imaging MRI More detailed picture of brain using magnetic field to knock electrons off axis. Takes many still pictures and turns images into a movie like production.

Positron Emission tomography (PET Scan) Used to see which brain areas are being activated while performing tasks –The scan changes when one is talking v. when one is looking at a piece of art. Involves injecting a slightly radioactive solution into the blood and then measuring the amount of radiation absorbed by blood cells. –Active neurons absorb more radioactive solution than non-active ones.

Functional MRI Combination of PET and MRI

We are here Nervous System Central Nervous System Brain Brain Imaging Peripheral Nervous System Building Blocks Genetics Evolutionary Endocrine System Neurotransmitters Somatic Autonomic Sympathetic Parasympathetic Biological Psychology Spinal Cord Neurons SensoryMotor

The Brain i. Brain Stem Medulla, Pons, Reticular Formation, Cerebellum, and the Thalamus ii. Limbic System Hypothalamus, Amygdala, and the Hippocampus iii. Cerebral Cortex (Left and Right Hemispheres and the corpus callosum) Occipital Lobe, Parietal Lobe, Temporal Lobe, and the Frontal Lobe, Primary Motor Cortex and Primary Sensory Cortex, Wernicke's Area and Broca's Area

26 “Older” Brain Structures The Brainstem is the oldest part of the brain, beginning where the spinal cord swells and enters the skull. It is responsible for automatic survival functions.

27 Brain Stem

The Brain Stem/Hindbrain (Automatic Functions) Brain StructurePrimary FunctionSecondary Function MedullaRespiration, blood pressure, heart rate Vomiting PonsPuts you to sleep Reticular FormationAttention, regulates awareness CerebellumBalance&coordination; implicit memory ThalamusDirects sensory information to the rest of the brain (except smell)

Hindbrain: Cerebellum Means “little brain”

30 The Limbic System is a doughnut-shaped system of neural structures at the border of the brainstem and cerebrum, associated with emotions such as fear, aggression and drives for food and sex. It includes the hippocampus, amygdala, and hypothalamus. The Limbic System

Limbic System (Emotion Center) Brain StructurePrimary Function HypothalamusFood, fight/flight, Fahrenheit, sex AmygdalaFear & Agression HippocampusSTM to LTM

32 Rats cross an electrified grid for self- stimulation when electrodes are placed in the reward (hypothalamus) center (top picture). Reward Center Sanjiv Talwar, SUNY Downstate

Cerebral Cortex /Forebrain The intricate fabric of interconnected neural cells that covers the cerebral hemispheres. It is the body’s ultimate control and information processing center.

The Cerebral Cortex Made up of densely packed neurons we call “gray matter” Glial Cells: support brain cells. Wrinkles are called fissures. If you lay brain out it would be as big as 2 large Pizzas.

Cerebral Cortex Brain StructurePrimary Function Occipital LobeVisual Processing Parietal LobeSpatial Reasoning Frontal LobeDecision Making Temporal LobeAuditory sensory information Motor CortexMovement Sensory CortexSensation Wernicke’s AreaUnderstanding Speech Broca’s AreaProducing Speech

Structure of the Cortex Each brain hemisphere is divided into four lobes that are separated by prominent fissures. These lobes are the frontal lobe (forehead), parietal lobe (top to rear head), occipital lobe (back head) and temporal lobe (side of head).

Frontal Lobes Abstract thought (planning) and emotional control (think Gage). Contains Motor Cortex: sends signals to our body controlling muscle movements. Contains Broca’s Area: responsible for controlling muscles that produce speech. Damage to Broca’s Area is called Broca’s Aphasia: unable to make movements to talk.

Parietal Lobes Contain Sensory Cortex: receives incoming touch sensations from rest of the body. Most of the Parietal Lobes are made up of Association Areas. Where would this girl feel the most pain from her sunburn?

Temporal Lobes Process sound sensed by our ears. Interpreted in Auditory Cortex. Contains Wernike's Area: interprets written and spoken speech. Wernike's Aphasia: unable to understand language: the syntax and grammar jumbled.

Occipital Lobes Deals with vision. Contains Visual Cortex: interprets messages from our eyes into images we can understand.

41 Functions of the Cortex The Motor Cortex is the area at the rear of the frontal lobes that control voluntary movements. The Sensory Cortex (parietal cortex) receives information from skin surface and sense organs.

Visual/Auditory Function The functional MRI scan shows the visual cortex is active as the subject looks at faces.

Language Aphasia is an impairment of language, usually caused by left hemisphere damage either to Broca’s area (impaired speaking) or to Wernicke’s area (impaired understanding).

Association Areas Any area not associated with receiving sensory information or coordinating muscle movements. More intelligent animals have increased “uncommitted” or association areas of the cortex.

Brain Activity when Hearing, Seeing, and Speaking Words

Decreasing Left-handers

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