Introduction to Psychology v4.0 Biological Psychology PDF

Introduction to Psychology v4.0 Charles Stangor and Sue Frantz ©FlatWorld 2023 Published by: FlatWorld ©2023 by FlatWorld. All rights reserved. Your use of this work is subject to the license agreement available on our website at https://catalog.flatworldknowledge.com/terms. No part of this wo...

Introduction to Psychology v4.0 Charles Stangor and Sue Frantz ©FlatWorld 2023 Published by: FlatWorld ©2023 by FlatWorld. All rights reserved. Your use of this work is subject to the license agreement available on our website at https://catalog.flatworldknowledge.com/terms. No part of this work may be used, modified, or reproduced in any form by any means except as expressly permitted under the licensing agreement. ©FlatWorld 2023 Chapter 3 Biological Psychology: The Brain at Work ©FlatWorld 2023  Biological Psychology: The Brain at Work The body is controlled by an information highway known as the nervous system: Nervous System: a collection of hundreds of billions of specialized cells that transmit information between different parts of the body. Central Nervous System (CNS): the brain and the spinal cord. Peripheral Nervous System (PNS): the nerves that link the CNS to the skin, muscles, and glands. Behavior is influenced by the Endocrine System: Endocrine System: the chemical regulator of the body that consists of glands that secrete hormones. ©FlatWorld 2023  3.1 Learning Objectives 1. Describe the structure and functions of the neuron. 2. Draw a diagram of the pathways of communication within and between neurons. 3. List seven of the major neurotransmitters and describe their functions. 4. Explain how agonists, antagonists, reuptake inhibitors, and enzyme inhibitors work. ©FlatWorld 2023  The Neuron is the Building Block of the Nervous System A neuron is a cell in the nervous system whose function is to receive and transmit information. Sensory neurons send signals from the body to the brain. Motor neurons send signals from the brain to the muscles. Interneurons allow sensory and motor neurons to communicate with each other. ©FlatWorld 2023  Components of the Neuron This motor neuron illustration shows the major parts of a neuron as described below. ©FlatWorld 2023  The Neuron is the Building Block of the Nervous System (Continued) Major Parts Cell body (soma) of a Neuron contains the cell’s nucleus keeps the cell alive Dendrite collects information from other cells sends the information to the cell body Axon transmits information away from the cell body and towards other neurons or to the muscles and glands ©FlatWorld 2023  The Neuron is the Building Block of the Nervous System (Continued 2) Specialized parts of an axon: Myelin sheath: a layer of fatty tissues surrounding the axon. Insulates the axon. Speeds the transmission of the electrical signal. Axon terminals: branching toward the end of an axon. Also called terminal buttons. ©FlatWorld 2023  Neurons Communicate Using Electricity and Chemicals Within a Neuron Between Neurons Communication is electrical, Communication is chemical taking the form of a charge via neurotransmitters, which called a nerve impulse or an travel across the gap between action potential. two neurons. ©FlatWorld 2023  Neurotransmitters: The Body’s Chemical Messengers Areas where the axon terminals at the Synapse end of an axon nearly touch another neuron’s dendrites. Chemicals that relay signals across the Neurotransmitter synapses between neurons. Neurotransmitters in the synapse are Reuptake reabsorbed into the transmitting axon terminals. ©FlatWorld 2023  Neurotransmitters: The Body’s Chemical Messengers (Continued) action potential neurotransmitters neurotransmitter reaches the axon travel across release terminal synapses neurotransmitters bind to receptor neurotransmitter sites on the reuptake dendrite ©FlatWorld 2023  Neurotransmitters: The Body’s Chemical Messengers (Continued 2) When the nerve impulse reaches the terminal button, it triggers the release of neurotransmitters into the synapse. The neurotransmitters fit into receptors on the receiving dendrites in the manner of a lock and key. ©FlatWorld 2023  Neurotransmitters: The Body’s Chemical Messengers (Continued 3) Excitatory Inhibitory neurotransmitters— neurotransmitters— increase the likelihood decrease the likelihood that a neuron will fire. that a neuron will fire. ©FlatWorld 2023  Neurotransmitters: The Body’s Chemical Messengers (Continued 4) Agonist Antagonist A drug that mimics or enhances A drug that blocks or inhibits the influence of a given the activity of a given neurotransmitter. neurotransmitter. e.g., cocaine is a dopamine e.g., curare is an agonist. acetylcholine antagonist. ©FlatWorld 2023  Neurotransmitters: The Body’s Chemical Messengers (Continued 5) Reuptake inhibitor Enzyme inhibitor A drug that blocks the reuptake A drug that stops a certain of the transmitter itself. enzyme from breaking down e.g., MDMA (Ecstasy or Molly) any of the neurotransmitter is a serotonin and dopamine remaining in the synapse. reuptake inhibitor. e.g., MAOIs, used to treat depression, are monoamine oxidase inhibitors. ©FlatWorld 2023  Neurotransmitters: The Body’s Chemical Messengers (Continued 6) Neurotransmitter Description and Function Notes A common neurotransmitter used in the spinal Alzheimer’s disease is associated with an undersupply of Acetylcholine (ACh) cord and motor neurons to stimulate muscle acetylcholine. Nicotine is an agonist that acts like contractions. It’s also used in the brain to acetylcholine. regulate memory, sleeping, and dreaming. Involved in movement, motivation, and emotion, Schizophrenia is linked to increases in dopamine, whereas Dopamine dopamine produces feelings of pleasure when Parkinson’s disease is linked to reductions in dopamine released by the brain’s reward system. It’s also (dopamine agonists may be used to reduce symptoms). involved in learning. Released in response to behaviors such as Endorphins are natural pain relievers. They are related to Endorphins vigorous exercise, orgasm, and eating spicy the compounds found in drugs such as opium, morphine, foods. and heroin. ©FlatWorld 2023  Neurotransmitters: The Body’s Chemical Messengers (Continued 7) Neurotransmitter Description and Function Notes A lack of GABA can lead to involuntary motor actions, including tremors and seizures. Alcohol stimulates the GABA (gamma-aminobutyric acid) The major inhibitory neurotransmitter in the release of GABA, which inhibits the nervous system and brain. makes us feel drunk. Low levels of GABA can produce anxiety, and GABA agonists (tranquilizers) are used to reduce anxiety. The most common neurotransmitter, it’s Glutamate released in more than 90% of the brain’s Excess glutamate can cause overstimulation, migraines, and synapses. Glutamate is found in the food seizures. additive MSG (monosodium glutamate). Low levels of serotonin are associated with depression, and Involved in many functions, including mood, some drugs designed to treat depression (known as Serotonin appetite, sleep, and aggression. selective serotonin reuptake inhibitors, or SSRIs) serve to prevent their reuptake. ©FlatWorld 2023  Research Focus: Randomized Controlled Trial Placebo effect: our expectations of receiving a treatment can make us feel better or make us experience side effects. Experimenter bias: the researcher’s expectations of how a participant should feel or behave can inadvertently influence how the participant feels or behaves. Double blind study: both the participants and the researchers are blind to conditions. ©FlatWorld 2023  3.1 Key Takeaways The Central Nervous System (CNS) is the collection of neurons that make up the brain and the spinal cord. The Peripheral Nervous System (PNS) is the collection of neurons that link the CNS to our skin, muscles, and glands. Neurons are specialized cells found in the nervous system that transmit information. Neurons contain a dendrite, a cell body, and an axon. The dendrite is a treelike extension that receives neurotransmitters from other neurons and transmits electrical stimulation to the cell body. ©FlatWorld 2023  3.1 Key Takeaways (Continued) The axon is an elongated fiber that sends an electrical signal from the cell body to the axon terminals. Neurotransmitters relay information chemically from the axon terminals across the synapses to the receiving dendrites. The many different neurotransmitters work together to influence cognition, memory, and behavior. ©FlatWorld 2023  3.1 Key Takeaways (Continued 2) Agonists are drugs that mimic the actions of neurotransmitters, whereas antagonists are drugs that block the action of neurotransmitters. Reuptake inhibitors block the transport of neurotransmitters back into the axon terminals. Enzyme inhibitors block the breakdown of neurotransmitters. Both processes result in more neurotransmitters remaining in the synapse, increasing the likelihood of the receiving neuron firing again and again. A randomized controlled trial is an experimental design wherein participants are randomly assigned to receive either the treatment or placebo and wherein participants and researchers are blind to conditions. ©FlatWorld 2023  3.2 Learning Objectives 1. Describe the structures and function of the “old brain” and its influence on behavior. 2. Explain the structure of the cerebral cortex (its hemispheres and lobes) and the function of each area of the cortex. 3. Define the concepts of brain plasticity, neurogenesis, and brain lateralization. ©FlatWorld 2023  Major Structures in the Human Brain ©FlatWorld 2023  The Old Brain: Wired for Survival The old brain: includes the brain structures that are nearest to the spinal cord. regulates basic survival functions, such as breathing, moving, resting, and feeding. contributes to experiencing emotion. ©FlatWorld 2023  The Brain Stem and the Thalamus ©FlatWorld 2023  The Old Brain: Wired for Survival (Continued) The Brainstem Medulla controls heart rate and breathing Pons helps control movement plays a major role in balance and walking Reticular Formation filters stimuli from the spinal cord plays a role in motor control and the sleep/wake cycle ©FlatWorld 2023  The Old Brain: Wired for Survival (Continued 2) Thalamus: a relay station filtering information between the brain and the body. Cerebellum: the “little brain” – coordinates voluntary movement and balance; it plays a part in learning and remembering movement skills. ©FlatWorld 2023  The Limbic System ©FlatWorld 2023  The Old Brain: Wired for Survival (Continued 3) The Limbic Amygdala System regulates our experience of emotions, especially fear and anxiety Hippocampus helps store information in long-term memory Hypothalamus links the nervous system to the endocrine system via the pituitary gland helps regulate body temperature, thirst, hunger, sleep/wake cycles, and sexual motivation ©FlatWorld 2023  Cerebral Cortex In addition to the old brain, humans have a large and highly developed outer brain layer known as the cerebral cortex. The cortex provides humans with excellent memory, outstanding cognitive skills, and the ability to experience complex emotions. ©FlatWorld 2023  The Cerebral Cortex Creates Consciousness and Thinking Cerebral cortex: the outer, bark-like layer of the human brain associated with higher cognitive functions like language, learning, perception, and planning. Its wrinkled texture gives it a large surface area that increases capacity for learning, remembering, and thinking. It’s only about 0.1 inch thick but makes up about 80% of the brain’s weight. Divided into two hemispheres: the left hemisphere and the right hemisphere. ©FlatWorld 2023  The Brain Hemispheres ©FlatWorld 2023  The Sensory Cortex and the Motor Cortex ©FlatWorld 2023  Functions of the Cortex Sensory cortex: an area just behind and parallel to the motor cortex that receives information from the skin’s sensory receptors and the movements of different body parts. Visual cortex: the area located in the occipital lobe that processes visual information. Auditory cortex: an area located in the temporal lobe that is responsible for processing sounds. In addition to its motor and sensory areas, the cerebral cortex contains association areas. Association areas: regions in which incoming information is combined and related with stored knowledge. ©FlatWorld 2023  The Brain is Flexible: Neuroplasticity Neuroplasticity: the brain’s ability to change its structure and function in response to experience or damage. Neurogenesis: the formation of new neurons. ©FlatWorld 2023  The Left and Right Hemispheres Brain Lateralization: The left and right hemispheres are specialized to perform different functions. The corpus callosum is a band of fibers connecting the two hemispheres. Gazzaniga’s research on split brain patients contributed to our understanding of brain lateralization. ©FlatWorld 2023  The Left and Right Hemispheres (Continued) Right Hemisphere Left Hemisphere Corpus Callosum connects left and — perceptual — language right hemispheres — mathematics skills — recognizing — judging time and objects and faces rhythm — recognizing — sequencing patterns and complex melodies movements — drawing pictures ©FlatWorld 2023  3.2 Key Takeaways The old brain—including the brain stem, medulla, pons, reticular formation, thalamus, cerebellum, amygdala, hypothalamus, and hippocampus—regulates basic survival functions, such as breathing, moving, resting, feeding, emotions, and memory. The cerebral cortex, made up of billions of neurons, is divided into the right and left hemispheres and into four lobes on each side. The frontal lobes are primarily responsible for the sense of taste, thinking, planning, memory, judgment, decision-making, and personality. The parietal lobes are primarily responsible for touch and knowing our body position. The occipital lobes are primarily responsible for vision including detecting colors, shapes, and motion, as well as reading. The temporal lobes are primarily responsible for hearing, smell, and facial recognition. ©FlatWorld 2023  3.2 Key Takeaways (Continued) Other areas of the cortex act as association areas that responsible for integrating information. The motor cortex controls voluntary movements. Body parts requiring the most control and dexterity take up the most space in the motor cortex. The sensory cortex receives and processes bodily sensations. Body parts that are the most sensitive occupy the greatest amount of space in the sensory cortex. The left cerebral hemisphere is primarily responsible for language and speech in most people, whereas the right hemisphere specializes in spatial and perceptual skills, visualization, and the recognition of patterns, faces, and melodies. ©FlatWorld 2023  3.2 Key Takeaways (Continued 2) The severing of the corpus callosum, which connects the two cerebral hemispheres, creates a “split-brain patient,” with the effect of creating two separate minds operating in one person. Studies with split-brain patients as research participants have been used to study brain lateralization. The brain changes due to experiences and physical damage in a process known as neuroplasticity. The brain can generate new neurons through neurogenesis. ©FlatWorld 2023  3.3 Learning Objective Compare and contrast the techniques that scientists use to view and understand brain structures and functions. ©FlatWorld 2023  Lesions Provide a Picture of What is Missing Lesions: In living humans, lesions are areas of brain damage resulting from strokes, falls, automobile accidents, tumors, or other injuries. Lesions may also be created intentionally in animals. Lesions allow scientists to observe any resulting loss of brain function. ©FlatWorld 2023  Lesions Provide a Picture of What is Missing (Continued) Areas in the frontal lobes of Phineas Gage were damaged when a metal rod was blasted through them. Gage’s personality, emotions, and moral reasoning were influenced. The accident helped scientists understand the role of the frontal lobes in these processes. ©FlatWorld 2023  Recording Electrical Activity in the Brain In animals, detectors can be placed in the brain to study the electrical activity caused by the firing of specific neurons. In living humans, the electrical activity of the brain’s neurons can be studied using scalp electrodes—this is called electroencephalography or EEG. ©FlatWorld 2023  Recording Electrical Activity in the Brain (Continued) Advantages of EEG Disadvantage of EEG Useful in understanding brain Does not provide a clear picture abnormalities such as epilepsy. of the brain’s structure. Participants can move around during recordings. Allows changes in brain activity to be tracked very quickly. ©FlatWorld 2023  Peeking Inside the Brain: Neuroimaging Functional Magnetic Resonance Imaging (fMRI): A type of brain scan that uses a magnetic field to create images of the activity in each brain area. Detects the blood flow in each brain region. Currently the most common method of learning about brain structures. ©FlatWorld 2023  Recording Electrical Activity in the Brain (Continued 2) Advantages of fMRI Disadvantage of fMRI Provides very clear and detailed Scanners are expensive. pictures of brain structures. It is non-invasive. ©FlatWorld 2023  3.3 Key Takeaways Lesion studies inform researchers about the impact of damage on different areas of the brain. Measures of electrical activity in the brain, such as electroencephalography (EEG), are used to assess brain wave patterns and activity. Functional magnetic resonance imaging (fMRI) measures blood flow in the brain during different activities, providing information about the activity of those brain areas. ©FlatWorld 2023  3.4 Learning Objectives 1. Summarize the primary functions of both the CNS and the subsystems of the PNS. 2. Explain how the electrical components of the nervous system and the chemical components of the endocrine system work together to influence behavior. ©FlatWorld 2023  The Functional Division of the Nervous System ©FlatWorld 2023  Electrical Control of Behavior: The Nervous System Central Nervous System Brain Spinal Cord ©FlatWorld 2023  Electrical Control of Behavior: The Nervous System (Continued) Nerves: Sensory Neurons Bundles of interconnected carry information from the neurons that fire together to sensory receptors carry messages. Motor Neurons transmit information to the muscles and glands Interneurons communicate information ©FlatWorld 2023 among neurons  Electrical Control of Behavior: The Nervous System (Continued 2) Reflex: involuntary, nearly instantaneous movement in response to a stimulus. Triggered when powerful sensory information allows spinal cord interneurons to send a message back through the motor neurons without relaying the information to the brain. ©FlatWorld 2023  Electrical Control of Behavior: The Nervous System (Continued 3) Peripheral Nervous System connects the Central Nervous System to sense receptors, glands, and muscles Autonomic Somatic Nervous Nervous System System governs the controls external body’s internal aspects of the body activities Sympathetic Parasympathetic Nervous System Nervous System ©FlatWorld 2023  Electrical Control of Behavior: The Nervous System (Continued 4) Parasympathetic Nervous Sympathetic Nervous System System Prepares the body for behavior, Calms the body. especially in response to Slows the heart rate and stress. breathing. Activates the organs and the Allows the body to recover glands in the Endocrine from activities that the System. Sympathetic Nervous System causes. ©FlatWorld 2023  The Autonomic Nervous System Our everyday activities are controlled by the interaction between the Sympathetic Nervous System and the Parasympathetic Nervous System. The two systems work together to maintain vital bodily functions, resulting in homeostasis. Homeostasis: the natural balance in the body’s systems. ©FlatWorld 2023  The Body’s Chemicals Help Control Behavior: The Endocrine System Gland: a group of cells that functions to secrete hormones. Hormone: a chemical that moves throughout the body to help regulate emotions and behaviors. ©FlatWorld 2023  The Body’s Chemicals Help Control Behavior: The Endocrine System (Continued) Pituitary Gland: Adrenal Glands: A small gland in the center of the brain. Located on top of the kidneys. This “master gland” has an influence Produce hormones that regulate body’s on other glands. salt and water balance. Secretes hormones that influence Involved in metabolism, the immune responses to pain. system, and sexual development and Secretes hormones that signal the function. ovaries and testes to create sex Secrete the hormones epinephrine and hormones. norepinephrine when we are excited, Controls ovulation and the menstrual threatened or stressed. cycle in women. Epinephrine and norepinephrine stimulate the sympathetic nervous system. ©FlatWorld 2023  The Body’s Chemicals Help Control Behavior: The Endocrine System (Continued 2) The pancreas The pineal gland secretes hormones to secretes melatonin to supply the body with regulate the sleep energy. cycle. The thyroid and parathyroid glands control how quickly energy is used and the amount of calcium ©FlatWorld 2023 in blood and bones.  The Body’s Chemicals Help Control Behavior: The Endocrine System (Continued 3) Testes (Male Sex Glands) Ovaries (Female Sex Glands) Secrete testosterone. Secrete estrogen and Testosterone regulates body progesterone. changes related to sexual Estrogen is involved in the development. development of female sexual features. Both hormones are involved in pregnancy and the regulation of the menstrual cycle. ©FlatWorld 2023  3.4 Key Takeaways The body uses both electrical and chemical systems to create homeostasis. The Central Nervous System is made up of bundles of nerves that carry messages to and from the Peripheral Nervous System. The Peripheral Nervous System is composed of the Somatic Nervous System and the Autonomic Nervous System. The Autonomic Nervous System is further divided into the Sympathetic (activating) and Parasympathetic (calming) nervous systems. These divisions are activated by glands and organs in the Endocrine System. Different types of nerves, made up of, for example, sensory neurons, motor neurons, and interneurons, each have specific functions. ©FlatWorld 2023  3.4 Key Takeaways (Continued) The spinal cord may use reflexes to bypass the brain to respond rapidly. The pituitary gland is a master gland, which affects many other glands. Hormones produced by the pituitary and adrenal glands regulate growth, stress, sexual functions, and chemical balance in the body. The adrenal glands produce epinephrine and norepinephrine, the hormones responsible for our reactions to stress. The sex hormones—testosterone, estrogen, and progesterone—play an important role in sex differences. ©FlatWorld 2023