Behavioral Neuroscience Chapter 1 PowerPoint PDF
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2021
Gaskin
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This chapter introduces behavioral neuroscience, focusing on brain-behavior relationships. It covers different levels of analysis such as the molecular, cellular, systems, cognitive, and social levels. The chapter also explains how genes and environmental factors influence behavior.
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Chapter 1 Behavioral Neuroscience: Understanding Brain-Behavior Relat...
Chapter 1 Behavioral Neuroscience: Understanding Brain-Behavior Relationships 1 Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. Module 1.1 What Is Behavioral Neuroscience Learning Objectives 1.1.1 Know and understand what constitutes the study of brain- behavior relationships. 1.1.2 Have a broad understanding of the global structural aspects of the brain and some of its basic functions. 1.1.3 Explain the different levels of analysis that constitute the study of brain-behavior relationships. 1.1.4 Understand the basics of how genes influence behavior and how the environment influences genes. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 2 1.1 What is Behavioral Neuroscience? What is Behavioral Neuroscience? The Study of Brain-Behavior Relationships Behavioral neuroscience is the scientific study of how brain activity influences behavior. The study of behavioral neuroscience includes the study of how the brain is involved in both overt and covert behavior. Behavioral neuroscientists are aware that behavior is influenced by environmental factors and life experiences. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 3 1.1 What Is Behavioral Neuroscience? 1.1.1 The Study of Brain–Behavior Relationships Cognitive Neuroscience focuses on the processes within the brain that are associated with cognitive functions such as reasoning, problem solving, memory, and attention. Affective Neuroscience focuses on the neurobiological processes that underlie emotions. Social Neuroscience focuses on the neurobiological processes of social behaviors such as those involved in empathy, affiliation, and morality. Decision Neuroscience focuses on the neurobiological basis of choice behavior; sometimes known as neuroeconomics. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 4 1.1 What Is Behavioral Neuroscience? 1.1.1 The Study of Brain– Behavior Relationships: The Importance of Environment and Experience Teratogens. Fetal Alcohol Spectrum Disorders. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 5 1.1 What Is Behavioral Neuroscience? 1.1.2 A Quick Look at the Brain General Structure and Views of the Brain. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 6 1.1 What Is Behavioral Neuroscience? 1.1.2 A Quick Look at the Brain: Brain cells Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 7 1.1 What Is Behavioral Neuroscience? 1.1.3 Levels of Analysis: Putting Brain– Behavior Relationships in Perspective Molecular level of analysis Involves studying the genes and the chemistry of proteins within neurons. Cellular level of analysis Involves studying the morphology and physiological properties of cells within the brain. Systems level of analysis Involves studying how activity in patterns of neuronal connections gives rise to overt and covert behaviors. They are also interested in how information is encoded and stored in the patterns of connections between neurons that are part of functional systems. Cognitive level of analysis Involves studying the neurobiological basis of higher mental processes. This includes the processes involved in language, attention, self- awareness, consciousness, and mental imagery. Social level of analysis Involves studying how neurobiological processes are involved in social behavior. 8 Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 1.1.3 Levels of Analysis: Putting Brain– Behavior Relationships in Perspective (the molecular level of analysis) Researchers reported that they could tell which rats were exposed to stress by studying the expression of a subset of their genes. In addition, by looking at the expression of other genes, they could tell the type of stressors to which the rats were Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 9 1.1.3 Levels of Analysis: Putting Brain– Behavior Relationships in Perspective (the cellular level of analysis) Scientists studying the brain at the cellular level found that the degeneration of what are known as gatekeeper cells, which control the flow of blood inside the brain, is partly responsible for Alzheimer’s disease, in which people suffer a slow decline in memory and other thinking skills. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 10 1.1.3 Levels of Analysis: Putting Brain–Behavior Relationships in Perspective (the systems level of analysis) Researchers found that networks of neurons in a part of the brain called the entorhinal cortex are involved in representing time in rats as they encode new experiences. They proposed that this information is combined with the memory for places and objects, which is encoded by networks of neurons in other brain areas. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 11 1.1.3 Levels of Analysis: Putting Brain–Behavior Relationships in Perspective (the cognitive level of analysis) Researchers found that interpreters, who perform the simultaneous translation of one language into another, have hyperconnectivity between the frontal parts of the two hemispheres of their brains compared to non– language experts who speak more than one language Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 12 1.1.3 Levels of Analysis: Putting Brain–Behavior Relationships in Perspective (the social level of analysis) Researchers have found that prosocial behavior in adolescents was associated with levels of activity in a part of the brain called the anterior cingulate cortex. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 13 1.1 What Is Behavioral Neuroscience? 1.1.4 A Closer Look at the Molecular Level: Genetics Genetics The study of inherited traits and their variation. Deoxyribonucleic Acid (DNA) A molecule composed of sequences of smaller molecules called nucleotides, bound together by molecules of sugar and phosphate. Once referred to as the basic functional units of heredity, genes are sequences of deoxyribonucleic acid (DNA), some of which code for proteins. Chromosomes and Karyotype Chromosomes contain the DNA that compose genes. A karyotype is a picture of an individual’s set of chromosomes. Synthesis of Proteins: phenotype and genotype The information contained in DNA dictates the synthesis of proteins. The variations in the proteins synthesized give rise to the differences in phenotype, which are the characteristic traits observed in individuals resulting from their genotype. Gaskin, Behavioral Neuroscience: essentials and 14 beyond 1e. © SAGE Publications, 2021. 1.1 What Is Behavioral Neuroscience? 1.1.4 A Closer Look at the Molecular Level: Genetics How Genes Are Transmitted From Parent to Offspring? Genes are passed on to the next generation through the division of sex cells, a process known as meiosis Meiosis leads to the creation of cells having only half of the total number of chromosomes. In humans, out of a total of 46 chromosomes in somatic cells, each sex cell ends up with 23 chromosomes. Therefore, half of the genes you have inherited came from the set of 23 chromosomes provided by your mother and the other half came from the set provided by your father. Behavioral Genetics The field of study that seeks to understand how the variation of a trait in a population is related to the variation of genes within that population. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 15 1.1 What Is Behavioral Neuroscience? 1.1.4 A Closer Look at the Molecular Level: Genetics Epigenetics The study of changes in gene expression with no changes in DNA sequences, which can occur naturally or through the influence of environmental factors. These changes in the expression of genes can be passed on to the next generations. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 16 Module 1.1 Test Yourself 1.1.1 Explain what the study of brain-behavior relationships consists of. 1.1.2 Describe the main structural aspects of the brain and some of the functions associated with each of the areas you read about. 1.1.3 Name and describe the levels of analysis that constitute the study of brain-behavior relationships. 1.1.4 Briefly explain how phenotypes result from the interactions between genes and environment. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 17 Module 1.2 The Evolution of Brain–Behavior Relationships (2 of 2) Learning Objectives 1.2.1 Explain the concept of natural selection. 1.2.2 Understand the adaptive variations that gave rise to brain-behavior relationships. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 18 1.2 The Evolution of Brain–Behavior Relationships 1.2.1 Natural Selection Descent With Modification The idea that current forms of life evolved from preexisting forms. Natural Selection The process by which evolution can be explained. Two Observations and Inferences by Darwin Observations 1) Members of a population often vary in inherited traits. 2) All species can produce more offspring than the environment can support. Inferences 1) Some individuals will have inherited traits that will give them a survival advantage and higher probability of reproducing than individuals that do not have those traits. 2) This survival advantage and higher reproductive probability will lead to the accumulation of those traits in subsequent generations. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 19 1.2 The Evolution of Brain–Behavior Relationships 1.2.2 Neuroecology: How Natural Selection Accounts for Brain–Behavior Relationships High Vocal Center The brain area at the center of a song-learning system in song-birds Researchers found that the song system is larger in males than in females and that the size of the HVC and other regions of the song system are enlarged during the spring breeding season. The enlargement of the HVC region in the spring coincides with the production of birdsongs, which are used to attract mates and to ward off rivals. How is this related to natural selection? Females were found to prefer to mate with males that sing at a high rate and that have a large repertoire of songs relative to those that do not. It is not difficult to apply the observations and inferences made by Darwin to this situation (see the previous unit). That is, males with a better developed song system would have been selected for and have greater reproductive success. Consequently, the genes associated with the development of effective song systems were passed on to later generations. Changes in hippocampal size Memory for spatial locations, otherwise known as spatial memory, is dependent on a brain area called the hippocampus (discussed at length in Chapter 12). The hippocampus of food-storing birds was found to be larger (relative to their brain and body size) than the hippocampus of birds that do not store their food. Further, the hippocampus of food-storing birds increases in size during the autumn and winter. This coincides with when food-storing birds cache the most food, due to the rarity of insects and plant seeds during those months. Exaptation The adaptation of a trait that differs from the one it was selected for. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 20 Module 1.2 Test Yourself 1.2.1 Explain the concept of natural selection. 1.2.2 Discuss how variations in brain structures evolved to give rise to brain-behavior relationships. Give two examples. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 21 Module 1.3 The Origins of Behavioral Neuroscience Learning Objectives 1.3.1 Describe some of the views associated with brain function throughout antiquity. 1.3.2 Explain the philosophical roots that underlie the relationship between brain and body. 1.3.3 Understand how the idea that brain functions are localized to specific areas developed. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 22 1.3 The Origins of Behavioral Neuroscience 1.3.1 Antiquity The Egyptians thought the heart was the seat of the soul and all of the functions we attribute to the brain today. The Edwin Smyth Papyrus shows that Egyptians knew that brain damage could affect bodily functions ranging from hand-eye coordination problems to paralyzed limbs. The Greeks Hippocrates believed that the brain, and not the heart, was the seat of all mental faculties. Aristotle thought that the heart was at the center of all faculties. believed that the brain served only as a radiator to cool the blood heated by the seething heart Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 23 1.3 The Origins of Behavioral Neuroscience 1.3.2 The Mind–Body Problem How does the mind, which is immaterial, interact with the material body? Dualism Descartes believed that the mind and the body were distinct and that they could exist independently of each other Fluid-mechanical theory The idea that movement can be explained by the movement of fluids, called animal spirits, through hollow tubes in the body. Correlation between Descartes theory and current discoveries The pineal gland now known to produce a chemical called melatonin, which is involved in regulating physiological processes on a 24-hour cycle Descartes’s hollow tubes are now known as nerves, and what flows through them are not Gaskin, Behavioral Neuroscience: essentials and animal spirits but, rather, electrical impulses beyond 1e. © SAGE Publications, 2021. 24 called nerve impulses or action potentials 1.3 The Origins of Behavioral Neuroscien 1.3.3 Localization of Function The theory that individual brain areas are dedicated to distinct functions Gall Phrenology The idea that bumps on the skull reflect the size of the underlying brain region, which is associated with a particular faculty. Marie-Jean-Pierre Flourens found that what affected function in animals was the size of the lesion but not the specific area Gaskin, Behavioral Neuroscience: essentials and damaged beyond 1e. © SAGE Publications, 2021. 25 1.3 The Origins of Behavioral Neuroscien 1.3.3 Localization of Function: Localization of language Aphasia The loss of an individual’s ability to speak Cerebral Dominance The idea that the left hemisphere is dominant in the control of speech function. Broca’s Area The area of the third convolution of the left frontal lobe, associated with speech production Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 26 1.3 The Origins of Behavioral Neuroscience 1.3.3 Localization of Function: Motor representations in the cortex. Brain had sensory and motor functions Electrical stimulation of the brain Topographical map of the body A map, within the brain, that represents different areas of the body in an orderly way. Motor homunculus Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 27 Module 1.3 Test Yourself 1.3.1 Discuss the views associated with brain function that prevailed throughout antiquity. 1.3.2 What are some of the philosophical roots that underlie the thinking about the relationship between brain and body? 1.3.3 Trace the history of the idea that brain functions are localized to specific areas. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 28 Module 1.4 Studying Brain–Behavior Relationships Today Learning Objective 1.4.1 Explain how the study of brain-damaged patients can inform neuroscientists about brain-behavior relationships. 1.4.2 Describe how brain-behavior relationships can be inferred by lesioning, stimulating, and measuring the brain’s activity. 1.4.3 Define the different fields of study related to behavioral neuroscience. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 29 1.4 Studying Brain–Behavior Relationships Today 1.4.1 Brain-Damaged Patients and Structural Brain Imaging Traumatic Brain Injury An injury that results from a blow to the head or from an object penetrating the skull. Structural Brain Imaging Imaging techniques that permit the detection of brain injury. Magnetic Resonance Imaging (MRI) A method by which an image of any part of the body can be created with the use of a powerful magnetic field and the emission of a resonant frequency. Computed Tomography (CT) A method in which X-ray images are taken from many angles and processed by a computer to produce virtual cross- sections, permitting the examination of structures deep within the brain.Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 30 1.4 Studying Brain-Behavior Relationships Today 1.4.2 Lesioning, Stimulating, and Measuring the Brain’s Activity Manipulation Techniques A technique in which the structure or function of the brain is altered and the resulting effects on behavior are observed. Lesions Brain stimulation Temporary inactivation Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 31 1.4 Studying Brain–Behavior Relationships Today 1.4.2 Lesioning, Stimulating, and Measuring the Brain’s Activity Measurement Techniques Functional Magnetic Resonance Imaging (fMRI) Inferring brain function using MRI technology to image the brain in a way that detects the amount of oxygen used by neurons. Positron Emission Tomography (PET) An imaging method in which brain function is inferred by detecting the consumption of glucose by neurons. Electroencephalography (EEG): A method in which brain function is inferred by detecting differences in the electrical energy emitted from different brain areas. Event-realated potentials (ERP) Small voltage changes, called waveforms, in brain areas responsive to specific events or stimuli. Magneto encephalography (MEG) A method in which brain function is inferred by detecting differences in the electromagnetic fields emitted from different brain areas. Electrophysiological Measurements A method by which tiny electrodes Gaskin, Behavioral Neuroscience: essentials and arebeyond inserted directly inside neurons to 1e. © SAGE Publications, 2021. 32 record their electrical activity. 1.4 Studying Brain–Behavior Relationships Today (Measurement Techniques) fMRI PET EEG Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 33 1.4 Studying Brain–Behavior Relationships Today 1.4.3 Fields of Study Related to Behavioral Neuroscience Neuroanatomy Neuropharmacology The scientific study of the structures and The scientific study of how drugs and other agents organization of the nervous system. already inside the brain affect the function of cells. Neurochemistry Neuropsychopharmacology The scientific study of how chemicals in the brain The scientific study of how drugs produce are synthesized and involved in brain function. psychotropic effects. Neuroendocrinology Neurophysiology The scientific study of how hormones, which are The scientific study of brain function by using chemicals that control important bodily functions, various methods to stimulate, measure, or record interact with the nervous system the activity of individual brain cells or entire brain areas. Neuropathology Neuropsychology The scientific study of the changes in the brain that occur when it becomes diseased. The scientific study of how psychological functions are localized in certain brain areas. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 34 1.4 Studying Brain–Behavior Relationships Today Who Is Interested in Findings From Behavioral Neuroscience? Neurologists trained to diagnose and treat disorders of the nervous system; psychiatrists, who are trained to diagnose and treat mental disorders. Neurosurgeons trained to perform surgery on the nervous system. Psychologists Professors Various health practitioners Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 35 Module 1.4 Test Yourself 1.4.1 Explain how the study of brain-damaged patients informs neuroscientists about brain-behavior relationships. 1.4.2 How are brain-behavior relationships inferred by lesioning, stimulating, and measuring the brain’s activity? 1.4.3 Name and differentiate between the areas related to behavioral neuroscience. Gaskin, Behavioral Neuroscience: essentials and beyond 1e. © SAGE Publications, 2021. 36 Applications Brain Imaging as a Lie Detector: Not So Fast! Gaskin, Behavioral Neuroscience: essentials and37 beyond 1e. © SAGE Publications, 2021.