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PSYCHOLOGY (8th Edition) David Myers

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1 PSYCHOLOGY (8th Edition) David Myers
PowerPoint Slides Aneeq Ahmad Henderson State University Worth Publishers, © 2006

2 Neuroscience and Behavior Chapter 2

3 Neuroscience and Behavior
Neural Communication Neurons How Neurons Communicate How Neurotransmitters Influence Us The Nervous System The Peripheral Nervous System The Central Nervous System

4 Neuroscience and Behavior
The Endocrine System The Brain The Tools of Discovery Older Brain Structures The Cerebral Cortex Our Divided Brain Left Brain-Right Brain

5 Ancient Conceptions About Mind
History of Mind Ancient Conceptions About Mind Plato correctly placed mind in the brain. However, his student Aristotle believed that mind was in the heart. OBJECTIVE 1| Explain why psychologists are concerned with human biology, and describe the ill-fated phrenology theory. Today we believe mind and brain are faces of the same coin. Everything that is psychological is simultaneously biological.

6 History of Mind Phrenology
In 1800, Franz Gall suggested that bumps of the skull represented mental abilities. His theory, though incorrect, nevertheless proposed that different mental abilities were modular. Bettman/ Corbis

7 Biological Psychologists study the link between biology and behavior
Neural Communication Neurobiologists and other investigators understand that humans and animals operate similarly when processing information. Biological Psychologists study the link between biology and behavior

8 Neural Communication The body’s information system is built from billions of interconnected nerve cells called neurons.

9 We are a biopsychosocial system.
Neural Communication We are a biopsychosocial system. Cellular Level (Interconnected Neurons) Ethnic Level (Culture) Community Level (Society) Organ Level (Brain) Group Level (Family) OBJECTIVE 2| Explain how viewing each person as a biopsychosocial system helps us understand human behavior, and discuss why researchers study other animals in search of clues to human neural processes. System Level (Information Processing) Individual Level (Human Being)

10 Glial Cells Astrocytes provide nutrition to neurons, and carry away waste. Oligodendrocytes and Schwann cells insulate neurons (myelin). Astrocytes

11 A nerve cell, or a neuron, consists of many different parts.
OBJECTIVE 3| Describe parts of a neuron and explain how its impulses are generated.

12 Parts of a Neuron Cell Body (Soma): Life support center of the neuron.
Dendrites: Branching extensions at the cell body. Receive messages from other neurons. Axon: Long single extension of a neuron Myelin [MY-uh-lin] Sheath to insulates and speeds up messages through neurons. Terminal Branches of Axon: Branched endings of an axon that transmit messages to other neurons.

13 Action Potential A neural impulse. A brief electrical charge that travels down an axon and is generated by the movement of positively charged atoms in and out of channels in the axon’s membrane.

14 Stimulus Threshold Each neuron receives depolarizing and hyperpolarizing currents from many neurons. When the depolarizing current (positive ions) minus the hyperpolarizing current (negative ions) exceed minimum intensity (threshold) the neuron fires an action potential.

15 Polarization, Depolarization & Hyperpolarization
Polarization: The natural state of the resting axon consists of negatively charged ions on the inside, and a positive charged environment on the outside. Resting Potential refers to this same negative inside, positive outside state that the neuron returns to after action potential. Depolarization: Depolarization occurs when positive ions enter the neuron, making it more prone to firing an action potential. Hyperpolarization: When negative ions enter the neuron, making it less prone to firing (action potential).

16 Refractory Period & Pumps
All-or-None Response: When the depolarizing current exceeds the threshold, a neuron will fire. If the depolarizing current fails to exceed the threshold, a neuron will not fire. Refractory Period: After a neuron fires an action potential it pauses for a short period to recharge itself to fire again. Sodium-Potassium Pumps: Sodium-potassium pumps pump positive ions out from the inside of the neuron, making them ready for another action potential.

17 Action Potential Properties
Repolarization: The process of the neuron returning to its polarized condition, or resting potential.

18 Synapse Synapse [SIN-aps] a junction between the axon tip of the pre-synaptic (sending) neuron and the dendrite or cell body of the post-synaptic (receiving) neuron. This tiny gap is called the synaptic gap or cleft. OBJECTIVE 4| Describe how nerve cells communicate. Synapse was coined by Lord Sherrington ( ) who inferred it through behavioral experiments. Cajal ( ) described the synapse based on his anatomical studies of the brain.

19 Neurotransmitters Chemicals released from the axon terminals (the end of the neuron) of the sending neuron which travel in synaptic vesicles (the containers for the neurotransmitter) across the synapse and bind to receptor sites on the receiving neuron, thereby influencing it to generate an action potential. This process is known as, synaptic transmission.

20 Reuptake Neurotransmitters in the synapse are reabsorbed into the sending neurons through the process of reuptake. This process applies the brakes on neurotransmitter action.

21 Excitatory or Inhibitory
Excitatory neurotransmitters, such as Glutamate, stimulate the body to perform helpful functions, like memory. Inhibitory neurotransmitters, such as GABA help the body to stop actions like tremors and seizures OBJECTIVE 6| Explain how drugs and other chemicals affect neurotransmission, and describe the contrasting effects of agonists and antagonists.

22 Neurotransmitters pg. 58

23 Other Neural Chemicals
Opiates (from the poppy seed) like opium, heroin and morphine, depress neural activity thereby relieving pain and anxiety. OBJECTIVE 5| Describe how neurotransmitters affect behavior and outline the effects of acetylcholine and endorphins. From Mapping the Mind, Rita Carter, © 1989 University of California Press

24 Other Neural Chemicals
Endorphins are natural opiates created by the body to deal with pain and anxiety. From Mapping the Mind, Rita Carter, © 1989 University of California Press

25 Agonists

26 Antagonists

27 Blood-Brain Barrier: Enables the brain to filter out unwanted chemicals circulating around in the blood stream Acupuncture can relieve pain by stimulating the neurons responsible for releasing endorphins into the blood stream naturally, thereby bypassing the blood-brain barrier. OBJECTIVE 20| Discuss the relationship among brain organization, handedness, and mortality.

28 The Nervous System Nervous System: The body’s speedy, electrochemical communication system. Nerves consist of neural “cables” containing many axons. They are part of the peripheral nervous system and connect muscles, glands, and sense organs to the central nervous system. Sensory Neurons carry incoming information from the sense receptors to the CNS. Interneurons connect the two neurons. Motor Neurons carry outgoing information from the CNS to muscles and glands.

29 Nervous System Central Nervous System (CNS) Peripheral Nervous System
(PNS) OBJECTIVE 7| Describe the nervous system’s two major divisions, and identify the tree types of neurons that transmit information through the system.

30 The Nervous System

31 Division of the Nervous System
Central Nervous System (CNS): brain and spinal cord. Peripheral Nervous System (PNS): the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

32 Peripheral Nervous System
Somatic Nervous System: The division of the peripheral nervous system that controls the body’s skeletal muscles. Autonomic Nervous System: Part of the PNS that controls the glands and other muscles. OBJECTIVE 8| Identify the subdivisions of the peripheral nervous system, and describe their functions.

33 Autonomic Nervous System (ANS)
Sympathetic Nervous System: Division of the ANS that arouses the body, mobilizing its energy in stressful situations. Parasympathetic Nervous System: Division of the ANS that calms the body, conserving its energy.

34 Autonomic Nervous System (ANS) pg. 62
Sympathetic NS “Arouses” (fight-or-flight) Parasympathetic NS “Calms” (rest and digest)

35 The Spinal Cord and Reflexes
Simple reflex pathways are processed in spinal cord for faster reactions (pulling your finger out of a flame). OBJECTIVE 9| Contrast the simplicity of the reflex pathways with the complexity of neural networks. Simple Reflex

36 Neural Networks Interconnected neurons form networks in the brain. Theses networks are complex and modify with growth and experience. Complex Neural Network

37 The Endocrine System The Endocrine System is the body’s “slow” chemical communication system. Communication is carried out by hormones synthesized by a set of glands. OBJECTIVE 10| Describe the nature and functions of the endocrine system and its interaction with the nervous system.

38 Hormones Hormones are chemicals synthesized by the endocrine glands that are secreted in the bloodstream. Hormones affect the brain and many other tissues of the body. For example, the hormones/neurotransmitters epinephrine and norepinepherine (adrenaline) increase heart rate, blood pressure, blood sugar and feelings of excitement during emergency situations.

39 Adrenal Glands Adrenal glands consist of the adrenal medulla and the cortex. The medulla secretes hormones, epinephrine and norepinephrine (neurotransmitters/hormones) which excite the body and raise the levels of most of its systems during stress, while the adrenal cortex regulates salt and carbohydrate metabolism.

40 Pituitary Gland Is called the “master gland.” The anterior pituitary lobe releases hormones that regulate other glands. The posterior lobe regulates water and salt balance.

41 Hypothalamus The Hypothalamus lies below (hypo) the thalamus. It directs several maintenance activities like eating, drinking, body temperature, and control of emotions. It helps govern the endocrine system via the pituitary gland.

42 Thyroid & Parathyroid Glands
Regulate the metabolic and calcium rates.

43 Gonads Sex glands are located in different places in men and women. They regulate bodily development and maintain reproductive organs in adults.

44 The pancreas regulates the amount (level) of sugar in the blood.

45 Clinical Observation Clinical observations have shed light on a number of brain disorders. Alterations in brain morphology due to neurological and psychiatric diseases are now being catalogued. Tom Landers/ Boston Globe

46 The Brain Techniques to Study the Brain A brain lesion experimentally destroys brain tissue to study animal behaviors after such destruction. OBJECTIVE 11| Describe several techniques for studying the brain. Hubel (1990)

47 Electroencephalogram (EEG)
An amplified recording of the electrical waves sweeping across the brain’s surface, measured by electrodes placed on the scalp. CAT Scan Computerized axial tomography takes axial scans (pictures of slices of the brain) in order to view the structures of the brain. AJ Photo/ Photo Researchers, Inc.

48 PET Scan PET (positron emission tomography) Scan is a visual display of brain activity that detects a radioactive form of glucose while the brain performs a given task. Courtesy of National Brookhaven National Laboratories

49 MRI Scan MRI (magnetic resonance imaging) uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of brain tissue. The fMRI (functional MRI)reveals the brains functioning, as well as its structures. It can detect the flow of blood to the areas of the brain that are experiencing activity. Both photos from Daniel Weinberger, M.D., CBDB, NIMH James Salzano/ Salzano Photo Lucy Reading/ Lucy Illustrations

50 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. OBJECTIVE 12| Describe the components of the brainstem and summarize the functions of the brainstem, thalamus and cerebellum.

51 The Pons sits just above the Medulla and helps coordinate movement.
The Medulla [muh-DUL-uh] is the base of the brainstem that controls heartbeat and breathing. Reticular Formation is a nerve network in the brainstem that plays an important role in controlling arousal. Moruzzi and Magoun identified the purpose of the RF. The Pons sits just above the Medulla and helps coordinate movement. Brain Stem

52 Brain Stem The Thalamus [THAL-uh-muss] is the brain’s sensory switchboard, located on top of the brainstem. It directs messages to the sensory areas in the cortex and transmits replies to the cerebellum and medulla.

53 Cerebellum The “little brain” attached to the rear of the brainstem. It helps coordinate voluntary movements and balance.

54 The Limbic System 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 (helps us lay down new memories), amygdala, and hypothalamus. OBJECTIVE 13| Describe the structures and functions of the limbic system, and explain how one of these structures controls the pituitary gland.

55 Amygdala The Amygdala [ah-MIG-dah-la] consists of two almond-shaped neural clusters near the tip of the hippocampus. It is linked to the emotions of fear and anger.

56 Hypothalamus The Hypothalamus lies below (hypo) the thalamus. It directs several maintenance activities like eating, drinking, body temperature, and control of emotions. It helps govern the endocrine system via the pituitary gland.

57 Reward Center Rats cross an electrified grid for self-stimulation when electrodes are placed in the reward (hypothalamus) center (top picture). This was the results of the experiments by Olds and Milner in 1954 Sanjiv Talwar, SUNY Downstate

58 The Cerebral Cortex The intricate fabric of interconnected neural cells that covers the cerebral hemispheres. It is the body’s ultimate control and information processing center. The Glial cells help to nourish and insulate the brain. OBJECTIVE 14| Define cerebral cortex and explain its importance fro the human brain.

59 Structure of the Cortex
Frontal lobe (forehead) involved in speaking, muscle movements and making plans and judgments; the parietal lobe (top to rear head) receives sensory input for touch and body position; the occipital lobe (back head) is chiefly responsible for vision and the temporal lobe (sides of head) which are largely responsible for processing sound. OBJECTIVE 15| Identify the four lobes of the cerebral cortex.

60 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. OBJECTIVE 16| Summarize some of the findings on the functions of the motor cortex and the sensory cortex, and discuss the importance of the association areas.

61 Visual Function The functional MRI scan shows the visual cortex is active as the subject looks at faces. Courtesy of V.P. Clark, K. Keill, J. Ma. Maisog, S. Courtney, L.G. Ungerleider, and J.V. Haxby, National Institute of Mental Health

62 Auditory Function The functional MRI scan shows the auditory cortex is active in patients who hallucinate.

63 Association Areas Those areas of the brain, not involved in primary motor or sensory functions. They are involved in higher mental functions such as: learning, remembering, thinking and speaking.

64 Phineas Gage The railroad foreman had an iron rod blasted through his head, cutting the connection between the frontal lobe (specifically, the pre-frontal cortex) and the limbic system. After the accident, he could not control his emotions, and his behavior was erratic.

65 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 of speech). OBJECTIVE 17| Describe the five brain areas that would be involved if you read this sentence aloud.

66 Specialization & Integration
The angular gyrus works with the visual cortex to help us read, and understand the words we are seeing.

67 The Brain’s Plasticity
Plasticity refers to the brain’s ability to modify, and/or heal, itself after some type of injury or illness. Stem Cells are specialized neurons that have the ability to transform into any type of cell that the brain, or body, needs. OBJECTIVE 18| Discuss brain’s plasticity following injury or illness.

68 Corpus Callosum The connecting fibers (200 million nerves) between the two hemispheres of the brain. It is capable of transferring more than a billion bits of information per second. Corpus Callosum Courtesy of Terence Williams, University of Iowa Martin M. Rother

69 Split Brains The surgery on epileptic patients to relieve seizures, provided a key to understanding the functions of the two complimentary hemispheres of the brain.

70 Our Divided Brain Psychologist Michael Gazzaniga split the brains of cats and monkeys with no serious effects on mental or physical abilities. Later he experimented on epileptic patients, as a way to stop their seizures (pg ) OBJECTIVE 19| Describe split-brain research, and explain how it helps us to understand the functions of our left and right hemispheres.

71 Gazzaniga’s Experiment
The subjects could easily repeat numbers or words or describe images projected in their right visual field, because the left hemisphere, which received and processed this information, is the dominant hemisphere for language. Similarly, when asked to close their eyes and feel an object with their right hand, they could describe the object readily. But when the visual stimuli were projected in the subjects’ left visual field or when they were asked to feel objects with their left hand, their performance was quite different: they could not describe the stimuli or objects concerned. In fact, for the visual stimuli, they even said that they hadn’t seen anything at all! Gazzaniga’s Experiment

72 Disappearing Southpaws (Left Handed People)
The percentage of left-handed individuals decreases sharply in samples of older people (Coren, 1993).

73 Famous Left-Handers BBC

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