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Unit 1: Biological Bases of Thought and Behaviour esearch Methods 1 R Two Reasons to Love Research Methods It allows you to get at the why question It allows you to critically evaluate the conclusions that others have reached Step 1: Coming up with a research quest...
Unit 1: Biological Bases of Thought and Behaviour esearch Methods 1 R Two Reasons to Love Research Methods It allows you to get at the why question It allows you to critically evaluate the conclusions that others have reached Step 1: Coming up with a research question, and making a prediction about the expected relationship between variables (i.e., a hypothesis) Example: Research question: Is there a relationship between watching violence on TV and aggressive behavior in children? Translate into a testable prediction: ○ H0: There will be no differences in the number of aggressive behaviors between children who watch a violent TV show and children who watch a nonviolent TV show. ○ H1: Children who watch a violent TV show will exhibit more aggressive behaviors than children who watch a nonviolent TV show. Step 2: Design a study to test your hypothesis! First, operationalize your variables ○ Define your variables in a way that allows you to test your hypothesis ○ Example: H1: Children who watch a violent TV show will exhibit more aggressive behaviors than children who watch a nonviolent TV show. How should we operationalize each of these variables? Different types of designs: ○ Experiments ○ Correlational studies Determine whether a causal relationship exists between two or more variables. Hallmarks of Experiments ○ Independent Variable – manipulated by experimenter, hypothesized to cause some effect on another variable Different conditions are called different levels Important to have a control group, which does not get the manipulation, as a comparison ○ Dependent Variable – also called the “outcome” variable, it is the variable that is hypothesized to be affected ○ “We want to test the effects of ________ on ________.” Example: C hildren who watch a violent TV show will exhibit more aggressive behaviors than children who watch a nonviolent TV show. Independent Variable: Type of television show (violent vs. nonviolent) Dependent Variable: Number of aggressive behaviors (as operationally defined) ○ Random Assignment: each person has an equally likely chance to get placed in each condition ○ In experiments, we try to vary one factor (the IV) and keep other aspects of the situation constant. Only then can we say the IV “caused” the DV. ○ Studies can be between-subjects or within-subjects Between-subjects = participants are in separate conditions (i.e., they are exposed to only 1 level of the independent variable Within-subjects = participants are in multiple conditions (i.e., the same subjects are exposed to multiple levels of the independent variable) ○ Studies can be blind or double-blind Blind experiment – subject is ‘blind’ to treatment condition Double-blind experiment – Observer and subjects are both blind to treatment condition Causation 1. Covariance ○ The IV and the DV should covary/co-occur/be correlated 2. Temporal precedence ○ The IV (the cause) should clearly come first in time, before the DV (the effect) 3. No plausible alternative explanations ○ Keep as much constant as possible between the experimental and control conditions Research Methods 2 Correlational Designs Correlational research measures statistical relationship between two or more variables. (No experimental manipulation of variables; no IV) Correlation coefficient (“r”) – ranges from -1.0 to +1.0 Positive correlation = when one variable increases, the other variable increases Negative correlation = when one variable increases, the other variable decreases Correlation does not equal causation Key Concepts for Research Reliability→Does your measure consistently achieve similar results? Validity→Is your measure accurate? Construct validity→Do you have good operationalizations? ○ ○ External validity→Do your results generalize? ○ Internal validity→Can you rule out alternative explanations? Step 3: Analyze the data Results support the hypothesis or results do not support the hypothesis? Statistics = measurements of samples, in order to make an inference about the broader population Descriptive Statistics Central tendencies = summarizes the entire data set ○ Mean = “average” (sum of scores / number of scores) ○ Median = when data are ordered from lowest score to highest score, median divides the group of scores in half ○ Mode = most frequently occurring score(s) Variability = how the sample is spread out from the mean in one or both directions ○ Standard deviation (average deviation, or difference, of a score from the mean) 68% of data falls within one standard deviation of the mean 95% of the data falls within 2 standard deviations of the mean Inferential statistics Allow us to generalize findings from our sample to our population Establishing the confidence that results are not due to chance (determine the likelihood of obtaining a particular value for a sample, given that the null hypothesis is true) Probability of a chance finding (p-value) is the significance level Convention is that we accept 5% chance or less Step 4: Interpret the results and plan further research enes and Inheritance (Behavioral Genetics) G Nature vs. Nurture Behavioral Genetics The role of genetics in behavior and trait variation Genes Build and modify physical aspects of the body Code and regulate protein production Indirectly affect behavior Behavioral Genetics: Important Terms Genotype: Set of inherited genes Phenotype: Observable traits/behaviors associated with genes and the environment Monozygotic twins: Individuals who are genetically identical Dizygotic twins: Fraternal twins, same degree of genetic similarity as any non-twin siblings Concordance rate: If one twin has a particular trait, the likelihood of the other twin having the same trait Nature vs. Nurture / Genes vs. Environment What do we mean by genes? ○ Gene = segment of a DNA molecule that forms/modifies the anatomy and physiology of the body via building/activating proteins. What do we mean by environment? ○ Everything else. For example… Prenatal environment(in the womb) Early experience Peer influence Physical features of the environment Cultural norms It’s not one or the other – it’s both! Gene BY Environment interactions A Common Misconception: Number of Genes Most of the normal variability in behavior is due to multiple genes and their interactions with the environment ○ Eye color – 6 genes ○ Skin color – 40 genes ○ Weight – 500+ genes Environments Influence Genes [epigenetics] What about Genes Influence Environments? Passive Evocative Active Genetics and Stress Genes code for the susceptibility for a particular clinical disorder (e.g., anxiety) Stress in the environment can trigger the onset of such disorders Genes code for susceptibility to the environment For those more “sensitive” to their environment, there can be both negative and positive effects Heredity Alleles ○ Genes that occupy same locus on chromosome pairs ○ Dominant genes produce effects no matter pair (hetero- or homozygous) ○ Recessive genes only produce effect with matched pair (homozygous) Autosomal recessive conditions ○ Autosomal: non-sex chromosome ○ Recessive: Carried on a recessive allele ○ With two carrier parents, 25% chance that child will have condition, 50% for carriers, 25% do not carry gene ○ e.g., cystic fibrosis, sickle cell anemia, phenylketonuria (PKU) Evolutionary Psychology Darwin’s Theory of Evolution Charles Darwin, The Origin of Species, 1859 Primary goal of behavior: reproduce All species ○ Share common ancestry (hence, similarities) ○ Have adapted to their environments (hence, differences) Selection occurs… ○ Naturally, through influences on reproductive success, e.g., food ○ supply, mate attraction ○ Artificially, through, e.g., selective breeding Sexual Selection Focused on adaptations that arise due to successful mating (not necessarily survival) Two pathways ○ Intrasexual competition = competition between members of one sex, the outcomes of which determine access to the other sex ○ Intersexual competition = preferential mate choice Theory of Evolution Modern synthesis Genes are the unit of selection ○ Genetic variation ○ Random shuffling of genes (meiosis) ○ Mutations (errors in DNA replication) Cross-Species Comparisons Homology: Any similarity that exists because of different species’ common ancestry ○ Example: Smiling and laughing in both chimps and humans Analogy: Any similarity that exists because of convergent evolution (independent evolution of similar traits) ○ Example: Wings in both birds and bats Parental Investment Theory Key difference between males and females: extent to which they are biologically obligated to invest in offspring Because of these biological differences… ○ The sex that invests more in offspring will be more selective about mating (“choosy”) ○ The sex that invests less in offspring will be more competitive for sexual access to the high-investing sex (“compete”) Fallacies about Evolution Evolution has foresight Naturalistic fallacy All traits are adaptations ○ Vestigial traits—no longer adaptive ○ Byproducts—no actual benefit on its own ○ Exaptations—originally evolved for something else ○ Context—something might be adaptive sometimes, but not always Concluding Points Not everything can be explained by evolution Evolutionary explanations and social/cultural explanations can co-exist; they are not mutually exclusive! Neurons and Synapses Nervous system is a network of neurons that run throughout your brain and body. nerves—collections of neurons—carry signals to and from your brain, relating perceptions, thoughts, and feelings into actions. Spinal cord: major bundle of nerves that connects your body to your brain The nervous system also allows us to have some important behaviors such as reflexes without requiring the brain at all Neuron Fundamentals Neuron = Nerve cell in the brain & nervous system ○ S ensory neuron: Carry messages from sensory organs to CNS. Carry information from within your body and the outside world to your brain ○ Interneuron: Carry messages from one set of neurons to another. They interpret, store, and retrieve information about the world, allowing you to make informed decision before you act ○ Motor neuron: Carry messages from CNS to muscles and glands Divisions of the Nervous System The central nervous system consists of the brain and spinal cord. The peripheral nervous system has two divisions: the somatic nervous system and the autonomic nervous system. Somatic nervous system is related to voluntary commands-or commands that we choose to do ○ not only senses the body, but also controls your conscious body movements ○ includes your skeletal muscles. Autonomic nervous system is related to involuntary commands, those largely not in your control ○ maintains the operations of the inside of your body-for example, your heart-and is mostly outside of your conscious control. ○ includes your organs, blood vessels, and glands, which are hormone-secreting organs ○ branches into the sympathetic and parasympathetic nervous systems sympathetic branch ensures that your body provides essential resources needed for the fight-or-flight response, To make fight-or-flight possible, your body redirects energy from processes that are not essential in the moment, such as digestion and sexual reproduction. a cts on blood vessels, organs, and glands in ways that prepare the body for action, especially in life-threatening situations The parasympathetic nervous system acts on blood vessels, organs, and glands in a way that returns the body to a resting state by both counteracting and complementing the actions of the sympathetic system. The restorative function of the rest-and-digest response allows you to regenerate the energy that your body needs when it is safe to do so. Eating is one important restorative activity. "Emotional eating" is their attempt to regulate stress by engaging the parasympathetic nervous system's anti-stress response. Although often working in opposition to each other, the sympathetic and parasympathetic nervous systems work together to prepare the body for the challenges that the brain sees lying ahead. The Structure of Neurons Cell Body: The cell body collects neural impulses, contains the nucleus, and provides life-sustaining functions for the cell Dendrites : receive chemical messages from other neurons. The axon: transports electrical impulses called action potentials to the terminal branches, where they are converted into chemical messages that are sent to other neurons. Myelin: is a layer of fatty tissue that covers and insulates the axon to ensure electrical messages are kept intact and travel quickly. ○ Degradation of myelin, called demyelination, is a central characteristic of neurodegenerative diseases ○ Shrinks with aging ○ Glia: cells that make up the myelin. Insulate, support, and nourish the neuron. Serve as cellular glue contribute to information processing during childhood development and into adulthood Are essential for brain development, providing a scaffold along which axons grow and guiding them to their correct location in the nervous system A id in the formation of neural networks: cluster of cells that work together as a functional unit Terminal branches: convert electrical signals into chemical messages that they then send to other neurons. Action Potential and How Nerves Fire Them Neurons are bathed in extracellular fluid composed of positively and negatively charged particles or ions (sodium (NA+), chloride (Cl-), potassium (k+), and calcium (CA2+)) The membrane that separates the intracellular (inside the cell) and extracellular (outside the cell) fluids is selective, which means that only certain ions can pass through the membrane to the inside of a neuron Normally, at resting potential, positively charged ions are outside the cell so the intracellular fluid is relatively positive compared to the negative intracellular environment ○ A neuron cannot fire an action potential as long as this resting potential is strongly negatively polarized If a neuron is stimulated sufficiently to pass its voltage threshold, an action potential fires ○ When other neurons sufficiently stimulate a neuron’s dendrites ion changes open allowing positively charged sodium (Na + ) ions into the neuron. As these positively charged ions flood into the neuron, they set off a chain reaction as they spread down the axon, causing more channels to open. 1) Depolarization: occurs when the voltage of a neuron becomes less negatively polarized and moves toward and past a critical voltage threshold to fire an action potential. a) positive ions flowing into the axon. 2) Voltage threshold: the critical voltage(around -50 millivolts) that the neuron must reach to fire an action potential. The neuron's voltage then surges rapidly and becomes positive as it passes zero. 3) Repolarization: occurs as the neuron returns to its resting state voltage a) positive ions flowing out of the axon. 4) Refractory period: is the time required before a neuron is able to fire its next action potential a) during which it is difficult or impossible to get a neuron to fire an action potential again Neuron Signals One of two kinds: Excitatory or Inhibitory e xcitatory messages: move the voltage of the neuron closer to its threshold. inhibitory messages: move it farther away from its voltage threshold. ○ If the excitatory (positive/+) messages outweigh the inhibitory (negative/-) messages enough to reach the voltage threshold, then the neuron fires an action potential ○ If the neuron receives many inhibitory (negative/-) signals, it is much less likely to reach the threshold necessary for firing. Neurotransmission: How Neurons Communicate Synapse: The gap where a sending neuron communicates with the dendrites or the cell body of the receiving neuron The process of neurotransmission allows the electrical message to bridge the synaptic gap by converting the electrical signal into a chemical one, thus allowing neurons to transmit their signals to one another. Electrical-to-chemical translation is critical for communication between neurons-from the sending presynaptic neuron's terminals to the receiving postsynaptic target neuron's dendrites Without making anatomical contact, the terminal branches release chemical messengers called neurotransmitters , across the synaptic gap toward the target, receiving neuron On the surface of target neurons are receptors that recognize and bind with specific neurotransmitters. Each neurotransmitter has specific receptors that selectively recognize it. 'Thus, each receptor is like a lock with a key-a neurotransmitter-that will open it. Once the neurotransmitter binds to its receptor ion channels open hereby inducing changes in on flow across the target neurons cell membrane. As a result an electronic signal is generated in the target neuron Receptor Response to Neurotransmitters Receptors targeted by neurotransmitters produce excitatory or inhibitory electrical signals in the target neuron Ions enter the receptor, moving the target neuron closer to or farther from its action potential threshold The receptor's response, not the neurotransmitter itself, determines whether the signal is excitatory or inhibitory Neurotransmitter Inactivation Inactivation of neurotransmitters in the synapse is crucial after signal generation P revents constant stimulation and maintains neuronal balance Mechanisms for neurotransmitter removal: ○ a) Diffusion: Neurotransmitters drift out of the synapse into extracellular space ○ b) Degradation: Chemical reactions break down neurotransmitters in the synapse ○ c) Reuptake: Presynaptic terminals reabsorb neurotransmitters Antidepressants and Neurotransmitter Function Some antidepressants prevent neurotransmitter reuptake Selective Serotonin Reuptake Inhibitors (SSRIs) keep neurotransmitters in the synapse longer Can be helpful for depression but may cause side effects like upset stomach or insomnia Class of neurotransmitters Amino acids: such as glutamate and gamma-aminobutyric acid (GABA), are the brain’s most abundant neurotransmitters Monoamines: are important for fight-or-flight response activation Acetylcholine: can behave as both an inhibitory and an excitatory signal. It supports heart and skeletal muscle, and cognitive function. Brain Mapping and the Nervous System Terminology: The Compass of the Brain Brain Structure CEREBRAL CORTEX Frontal lobe ○ ○ Parietal lobe ○ Temporal lobe Occipital lobe (Insular lobe) SUBCORTICAL STRUCTURES ○ Basal ganglia ○ Hippocampus ○ Amygdala ○ Thalamus and hypothalamus ○ Corpus callosum OTHER ○ Brainstem ○ Midbrain ○ Pons ○ Medulla oblongata ○ Reticular formation ○ Cerebellum Brain Mapping Caveats Certain parts of the brain are responsible for certain functions, but… ○ Individual differences ○ Most behaviors require multiple areas ○ Brain can reorganize through early experience or reaction to trauma “plasticity” Major Brain Divisions The brain is organized into three major structures during development: ○ Forebrain ○ Midbrain ○ Hindbrain The Cerebral Cortex T he cerebral cortex is the largest and outermost portion of the human brain, supporting complex mental activity. Neocortex The majority of the cerebral cortex is neocortex, which: ○ Is evolutionarily the youngest part of the brain ○ Develops through late adolescence and young adulthood ○ Supports complex functions like language, thought, problem-solving, and imagination ○ Is extensively folded to accommodate a large number of neurons Cerebral Hemispheres and Lobes The cerebral cortex is divided into two hemispheres, each with subdivisions called lobes: 1. Occipital Lobe Located at the back of the head Primarily devoted to vision Contains the primary visual cortex 2. Temporal Lobe Runs alongside the ears Contains the primary auditory cortex Responsible for hearing, language understanding, and object/people recognition 3. Parietal Lobe Located above and behind the ears Contains the primary somatosensory cortex Supports body mapping, sense of touch, and attention to visual world 4. Frontal Lobe Located in the front of the head Contains the primary motor cortex Includes the prefrontal cortex, responsible for thought, planning, decision-making, and self-control 5. Insular Lobe Hidden under the temporal, frontal, and parietal lobes Allows perception of internal body states Includes the primary taste cortex Sensory and Motor Areas Each lobe contains specific sensory and motor areas: Primary sensory areas for each of the five senses Primary motor cortex for voluntary movements Association Cortex The association cortex: Integrates sensory information with existing knowledge Helps interpret and recognize sensory patterns Supports connections between sensory regions and pleasure Is present in every lobe Is responsible for the brain's most sophisticated abilities Comparative Brain Anatomy The cerebral cortex varies among species: Primates have a higher proportion of association cortex compared to other mammals The size of the frontal cortex and number of convolutions differ among species Dogs have a densely packed cerebral cortex, potentially supporting a rich mental life The Subcortical Brain: Emotion, Motivation, and Memory Subcortical Structures S ome of these subcortical structures are older forms of cortex, but most are clusters of cells, called nuclei, that are very distinct from the cortex. The Limbic System ○ The limbic system bridges the newer, higher brain structures that are more related to complex mental functions with the older, lower, brain regions that regulate your body and its movements (MacLean, 1990). The limbic system consists of multiple interconnected yet distinct structures, including the hippocampus, amygdala, basal ganglia, thalamus, and hypothalamus (FIGURE 3.14). The limbic system is often described as the "emotional brain," but that description is not entirely accurate because the limbic system also plays important and diverse roles in smell, learning and memory, and motivation (Nishijo et al., 2018). Hippocampus ○ One of the best-understood limbic structures, the hippocampus, is crucial for certain aspects of memory and your ability to navigate the environment (Maguire et al., 2006). The hippocampus is an older region in the depths of the temporal lobe that creates memories of an event's time and place, supporting mental time-travel into the past (Moscovitch et al., 2016). The hippocampus is related to emotions insofar as it helps you remember emotionally prominent events from your life and think about your hopes and desires for your future (K. L. Campbell et al., 2018). Amygdala ○ An essential component of the limbic system that is dedicated to emotion is the almond-shaped amygdala (Latin for "almond"), which is cradled in the outstretched arms of the hippocampus. It plays an essential role in how you register the emotional significance of events. In lab animals, the removal of the amygdala can dramatically change emotional behavior. A once-ferocious animal may become tame, and fearful animals may become fearless. As FIGURE 3.15 shows, a rat without an amygdala will snuggle up to a predator, a cat -at least a partially sedated one (C. I. Li et al., 2004). ○ Abnormalities in the amygdala can result in what was once called psychic blindness: Animals could still see, but the psychological importance of what they saw appeared to be absent. Because the amygdala is one of the most interconnected regions of the brain, it touches on many aspects of what the brain does, including how you see, think, and remember (Pessoa, 2008; Todd et al., 2013). Your most vivid memories are likely to be emotionally significant, and the amygdala enhances these memories by influencing the hippocampus (Cahill & McGaugh, 1998; LaBar & Cabeza, 2006; Roozendaal et al., 2009). Basal Ganglia ○ The basal ganglia are a group of interconnected structures that are an evolutionarily older subcortical motor system that is necessary for planning and executing movement. They bridge the motor regions of the cerebral cortex with nuclei that communicate with the spinal cord, sending signals to your muscles to act. Degeneration of the basal ganglia results in slow, rigid, tremor-filled movements or involuntary writhing, suggesting that the basal ganglia are critical for both starting and stopping (or inhibiting) movement. Parkinson's disease, which affects the basal ganglia, compromises the ability to plan, initiate, execute, and control movement (A. B. Nelson & Kreitzer, 2014; Zhuang et al., 2017), leading to a substantial difficulty in initiating actions that results in slow movements and tremors. As we will discuss, certain components of the basal ganglia are also involved in learning and motivation, the psychological forces that will us to move. Thalamus ○ Located between the basal ganglia and resembling two large symmetrical eggs, the thalamus serves as a central subcortical hub for the signals it receives from all of the sensory systems except the olfactory (smell) system. There is two-way communication between the thalamus, which sits deep in the middle of the brain, and the brain regions that receive its messages. This communication is critical to how your brain determines what is out there in the world (Rauss et al., 2011) ○ As you sleep, the thalamus helps you shut out the outside world by turning down its relaying of sensory inputs. In dreams, your world becomes one with the possibilities your brain can imagine. Because the thalamus plays a central role in relaying sensory information to and from the cerebral cortex, damage to it can result in a wide variety of impairments, from loss of touch, to blindness, to memory loss. Hypothalamus ○ Despite its small size, the hypothalamus, which sits below the thalamus, is the major interface between the brain and the body, integrating internal bodily signals with their associated feelings and behaviors. Like the thalamus, the hypothalamus is composed of many specialized nuclei that regulate specific functions, including hunger, biorhythms, reward seeking, and aggression. The Brainstem and Cerebellum: Key Components of the Central Nervous System The Brainstem ○ Overview Located at the base of the skull Regulates vital functions like breathing and heart rate Connects most sensory nerves to the brain Evolutionarily oldest and most primitive brain region Structure From top to bottom ○ Midbrain Pons ○ ○ Medulla oblongata ○ Reticular formation (runs through the brainstem) Functions of Brainstem Components Midbrain ○ Includes the tegmentum for reflexive head and eye movements ○ Contains the ventral tegmental area, part of the motivation and reward system ○ Houses the substantia nigra, involved in movement regulation Pons ○ Controls breathing rate ○ Relays sensations like hearing, taste, and balance Medulla Oblongata ○ Controls autonomic functions (heart rate, blood pressure) ○ Manages critical reflexes (coughing, swallowing) Reticular Formation ○ Central to arousal and attention ○ Regulates sleep and wakefulness ○ Plays a role in ADHD ○ Important for maintaining cognitive abilities with age The Cerebellum Overview ○ Located behind the pons and medulla in the hindbrain ○ Shaped like a small brain at the back of the brainstem Functions ○ Contributes to coordination, precision, balance, and accurate timing ○ Adjusts head and eye movements for balance ○ Critical for learning precision movements ○ Plays a role in thought and planning Importance in Movement and Cognition ○ Enables complex and detailed movements (e.g., sports activities) ○ Involved in mental practice for learning movements ○ Increasingly recognized for its role in overall cognition Neural Plasticity: Key Concepts and Implications Neural plasticity refers to the brain's ability to physiologically modify, regenerate, and reinvent itself throughout a lifetime. Key Concepts Critical Periods ○ Early life stages where specific experiences are crucial for normal development ○ Example: Cataract removal in infants for normal face recognition ability Damage Plasticity ○ Neural modification following injury ○ Involves brain reorganization in response to altered inputs Adult Plasticity ○ Shaping and reshaping of neural circuits in adulthood ○ Examples: Learning to navigate complex city streets, practicing musical instruments Mechanisms of Neural Plasticity Synaptogenesis ○ Generation of new synapses between neurons ○ Supports learning and memory Neurogenesis ○ Birth of entirely new neurons throughout the lifespan ○ Potentially involved in new memory formation ○ May be related to stress and depression Conclusion Understanding and harnessing neuroplasticity offers promising avenues for improving human lives and treating various neurological conditions. rain Function and Lateralization B Functional Categorization Primary sensory areas Primary motor area Association areas Lobes of the Brain Frontal lobe ○ Executive function, risk-taking, planning, creativity, emotions, smell, muscle movements, personality...and much more! ○ Includes the prefrontal cortex, the primary motor cortex, Broca’s area (left hemisphere) ○ Disorders associated with the frontal lobe Apraxias = disorders of action Aphasias = disorders of language (e.g., Broca’s/nonfluent aphasia) Personality… Parietal lobe ○ Perception, pain, integration of sensory input ○ Includes the primary somatosensory cortex ○ Disorders associated with the parietal lobe Agnosias = disorders of perception Prosopagnosia = difficulty recognizing faces Astereognosis = inability to recognize common objects by feeling them Occipital lobe V ○ ision, color perception ○ Includes the primary visual cortex ○ Disorders associated with the Occipital Lobe Impaired visual recognition Blindness Brain Lateralization Hemispheres are symmetrical with respect to primary sensory and motor functions (same job, different half of the body - contralateral) Association areas have some different functions Left & Right Hemisphere Functions LEFT ○ Language ○ Logic ○ Analytical thought RIGHT ○ Spatial relations ○ Facial recognition ○ Perceiving emotion Intuitive thought ○ Musical ability Individual Differences Handedness ○ Left-handers & language: 70% on the left 15% on the right 15% both hemispheres Gender ○ Men are more lateralized for language than women Evidence of Hemispheric Asymmetry “Split-brain” patients Prosopagnosia Demo How can we study lateralization in people without split brains? Reaction time – takes slightly more time for info to go from right hemisphere to left hemisphere, compared to going only to the right hemisphere fMRI scanning to localize active brain regions Transcranial magnetic stimulation temporary brain damage!* *(no actual brain damage; makes it so that particular neurons cannot fire, temporarily; perfectly safe!) Contralateral transmission Hemispatial Neglect Most commonly a result of damage to the right parietal cortex; left visual field is affected ○ An issue of attention, not vision Lateralization Conclusions Despite the split-brain examples… The two sides of our brain are constantly working together Both hemispheres are responsible for complex human capacities Don’t believe the popular press—being ‘left- or right- brained’ is too simplistic Two Hemispheres, One Mind: Understanding Brain Lateralization 1. Brain Symmetry and Function The brain has anatomical symmetry, similar to most body organs Each hemisphere has corresponding structures, but functions are not always equally divided Early studies revealed left hemisphere dominance for language 2. Hemispheric Specialization Broca's area (left frontal lobe): Important for speech production Wernicke's area (left temporal lobe): Crucial for speech comprehension Left hemisphere: Usually dominant for language Right hemisphere: Silent but important partner in language processing 3. Corpus Callosum: The Brain's Bridge Connects the two hemispheres, allowing information sharing Supports contralateral communication between brain and body Can be severed in split-brain procedures to treat severe epilepsy 4. Contralateral Organization Right side of the body is controlled by the left hemisphere, and vice versa Applies to sensory information and motor control Visual information from each side of the visual field goes to the opposite hemisphere 5. Split-Brain Studies Roger Sperry's Nobel Prize-winning experiments Revealed independent functions of right and left hemispheres Demonstrated how each hemisphere processes information separately in split-brain patients 6. Hemispheric Differences Left hemisphere: More involved in verbal and conceptual tasks, focuses on details Right hemisphere: More engaged with perceptual and some emotional tasks, focuses on the big picture Myth debunked: People are not strictly "left-brained" or "right-brained" 7. Unified Mind The singularity of our mind and self results from the cooperation between hemispheres Both hemispheres work together in daily life for normal brain function tress and Health S Biopsychosocial Model of Health’ Biopsychosocial Model & Stress “A physiological response to an environmental event that is perceived as taxing or even exceeding one’s ability to adapt” Uncertainty Lack of control Concern with being evaluated and/or being treated negatively by others General Adaptation Syndrome Alarm Stage ○ “Fight or flight” ○ Increased heart rate ○ Palms sweat ○ Release of cortisol and epinephrine ○ Stress resistance is low Resistance Stage ○ Greater cardiovascular support ○ Greater immunological functioning ○ Stress resistance is high (temporarily) Exhaustion Stage ○ Weakened immune system ○ Inability to physically adapt to ongoing stressor ○ Stress resistance is sharp decline Stress, Health, and Demographics Health disparities: Differences in health outcomes due to various demographic characteristics Higher socioeconomic status (SES) is consistently related to better health outcomes. ○ Access to health care, medicine, and other resources There are also known links between SES and healthy behavior Individuals who believe they have lower status than others in the community: ○ Feel less in control of their experiences ○ Report other negative emotions Can prolong body’s response to stress ○ Find it harder to fall asleep at night Have a higher resting heart rate ○ Are at higher risk of obesity What Is Health Psychology? Key Questions What is health psychology? What kinds of questions does a health psychologist ask? Historical Perspective Early explanations: Divine punishment, harmony with nature Later explanations: Genetics, pathogens, injury Modern understanding: Includes social and psychological factors Emergence of Health Psychology Developed over the past 50 years Focuses on positive environments and actions for well-being Interdisciplinary field linking behavior, cognition, and physical health Scope of Health Psychology Investigates risk behaviors, personality traits, and mind-body connections Career opportunities in various fields (medicine, public health, psychology, etc.) Key Health Trends Shift in leading causes of death (e.g., heart disease, infectious diseases) Role of modern lifestyle in health outcomes Importance of behavioral science in public health (e.g., vaccination efforts) Relevance of Health Psychology Addresses complex health puzzles Examines risk factors for various diseases Focuses on promoting healthy behaviors and environments ○ Are more susceptible to illness The Biopsychosocial Model Definition and Overview The biopsychosocial model is a foundational concept in health psychology that recognizes the interconnectedness of biological, psychological, and social factors in health outcomes. Key Components Biological factors Psychological factors Social context Benefits of the Biopsychosocial Approach Allows for targeting multiple factors to create healthier outcomes Enables researchers to address health promotion and disease prevention from various levels of analysis Application Example: Smoking The biopsychosocial model can be applied to understand why people continue to smoke despite known health risks: Biological level: Nicotine addiction and brain reward pathways Psychological level: Rationalizations for continuing to smoke Social level: Influence of social norms and legislation on smoking behavior Integration in Medical Education There is a growing recognition of the need to integrate biopsychosocial perspectives in medical training: Association of American Medical Colleges' 2011 report emphasizing behavioral, psychological, and interpersonal factors Inclusion of behavioral and social sciences in the Medical College Admission Test (MCAT) since 2015 Importance in Healthcare The biopsychosocial model promotes better patient care by encouraging physicians to consider complex patterns of social and psychological characteristics that influence health behaviors. 10.3 What is stress Stress: It is a physiological response to some type of environmental event that is subjectively appraised as taxing or even exceeding one’s ability to adapt 10.4 What stresses us out? Catastrophic events major life events disrupt the social safety nets that support our everyday experiences ○ daily hassles Key Concepts in Stress Appraisals 1. Objective Stressors vs. Perceived Stress Objective stressors are environmental factors that can be identified as potentially stressful. Perceived stress is the subjective evaluation of how stressful an event is to an individual. 2. Stress Appraisal Theory Developed by R. S. Lazarus and Folkman (1984, 1999) Focuses on how individuals appraise events and their role in shaping emotional experiences 3. Types of Appraisals Primary Appraisal: Perception of the demands of a situation Secondary Appraisal: Assessment of one's ability to deal with those demands 4. Perceived Stress High perceived stress occurs when primary appraisal (demands) exceeds secondary appraisal (ability to cope) 5. Role of Cognition in Stress Can amplify, mitigate, or trigger stress responses Thinking about stressful events can trigger physiological stress responses Not all objectively stressful events are perceived as stressful by everyone 6. Resilience in Face of Trauma Example: 20-50% of childhood abuse victims show no increase in mental health symptoms Resilience partly due to effective appraisal of negative events and coping strategies Implications Understanding stress appraisals can help in developing more effective stress management techniques and interventions. Individual differences in stress perception highlight the importance of personalized approaches to stress management. The General Adaptation Syndrome: Stages of the Body's Response to Stress Background Hans Selye's accidental discovery in the 1930s at McGill University led to the development of the general adaptation syndrome theory. Stage 1: Alarm Reaction Brain mechanisms are alerted to a threat Initial shock may cause resistance to dip below normal Energy stores are mobilized for fight or flight response Stage 2: Resistance Body's defense systems gear up Cardiovascular support increases to provide oxygen to muscles Immunological functioning is enhanced Growth-oriented processes (e.g., digestion, reproduction) are stalled to conserve energy Stage 3: Exhaustion Marked by inability to physically adapt to ongoing stressor If no relief, adrenal failure can occur Prolonged stress response can be as damaging as the stressor itself Most people rarely experience this stage Significance This model highlights the physiological impact of stress on the body and its potential long-term health consequences if not managed properly. wo Systems of Physiological Response: The SAM and HPA Axes T Introduction The body's response to stress involves two main physiological systems: Sympathetic-adreno-medullary (SAM) axis Hypothalamic-pituitary-adrenal (HPA) axis Stress Response Activation Both systems are activated by the hypothalamus through the release of corticotrophin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH). Sympathetic-adreno-medullary (SAM) Axis Function Responsible for the body's immediate or acute response to stress. Process Releases epinephrine and norepinephrine from the adrenal medulla Activates the sympathetic nervous system for "fight or flight" response Physiological Changes Increased heart rate Quickened breathing Elevated blood pressure Response Patterns The SAM axis can produce two different cardiovascular patterns: Challenge reactivity: Heart beats faster with greater force and volume; arteries expand Threat reactivity: Increased heart rate and force, but blood vessels constrict Role of Parasympathetic Nervous System Helps restore homeostasis after a stressor has passed by down-regulating the sympathetic nervous system. Hypothalamic-pituitary-adrenal (HPA) Axis Function Responsible for the body's prolonged response to stress. Process Adrenal cortex releases cortisol into the bloodstream Effects of Cortisol Increases blood sugar for energy Suppresses the immune system by inhibiting inflammation Interaction between SAM and HPA Axes While considered separate systems, the SAM and HPA axes work together: SAM axis: More involved in the cardiovascular response to stress HPA axis: More involved in the immune system's response to stress Health Implications Exaggerated or prolonged response by either system can have negative health consequences. The Impact of Chronic Stress on Health 1. Evolution of Stress Response Stress response evolved for survival in ancestral environments Adaptive for short-term physical threats (e.g., predators, rival clans) Less suited for modern, socially-created stressors 2. Modern Stressors Primarily subjective and socially created Examples: interpersonal conflicts, academic pressures, daily annoyances Often involve rumination and intrusive thoughts 3. Physiological Effects of Chronic Stress Prolonged activation of physiological systems Inability to return to homeostasis Concept of allostatic load: wear and tear on bodily tissues and organs 4. Consequences of Chronic Stress Increased risk of health problems (e.g., ulcers) Accumulation of damage from daily stressors Potential intensification of symptoms 5. Comparison to Animal Stress Animals (e.g., zebras) face periodic acute stress Humans deal with prolonged mental and emotional stress Human stress response less adapted to modern stressors 6. Importance of Stress Management Need for recovery and relaxation periods Importance of addressing chronic stressors Potential benefits of developing resilience through mild stress exposure Gene × Environment Interactions in Health and Stress 1. Diathesis-Stress Model Traditional view of gene-environment interaction Genes provide inherent susceptibility (diathesis) for health outcomes Stressful events trigger latent vulnerabilities Genetic predisposition influences sensitivity to stressors 2. Differential Sensitivities Hypothesis Alternative approach to gene-environment interaction Some individuals are genetically predisposed to be more affected by their environment Sensitive individuals: More impacted by stressful events Benefit more from supportive environments Other individuals are more resilient to environmental influences . Genetic Factors in Environmental Sensitivity 3 Serotonin transporter gene variants: Two short alleles associated with higher environmental sensitivity Increased reactivity to stressful experiences Greater benefit from positive environments 4. Epigenetics Study of how life events change gene expression Stress or lack of caregiving can lead to gene methylation Key findings from rat studies: Neglected pups showed more methylated genes and higher stress reactivity Environmental factors (caregiving) impacted gene expression more than biological parentage Drug treatment could reverse genetic changes and reduce stress levels Conclusion Gene × environment interactions play a crucial role in determining individual responses to stress and overall health outcomes. Understanding these interactions can lead to better prevention and treatment strategies for stress-related health issues. otivation and Reward M Social Support Social support: The degree to which people believe they can turn to other people for information, help, advice, or comfort. People who report having a larger and more supportive social network have: ○ Lower blood pressure ○ Fewer stress hormones ○ Stronger immune systems ○ A decreased likelihood of depression ○ Increased lifespans Motivation and Reward Broadly, why do we do what we do? Drives motivate us towards rewards. ○ Drives: A state of internal bodily tension, such as hunger, thirst, or the need for sleep ○ Motivate: A force that leads an individual to behave in a particular way ○ Rewards: A positive, pleasurable outcome Homeostasis ○ The body’s tendency to maintain equilibrium through various forms of self-regulation Mammalian Drives for Survival and Reproduction Regulatory drives ○ Towards homeostasis, e.g., hunger, thirst Non-regulatory drives Safety drives, e.g., shelter ○ ○ Reproductive drives, e.g., ○ care/protection of offspring, sex ○ Social drives, e.g., respect, favors, manners ○ Educative drives, e.g., exploration Other Drives ○ Artificial drives, e.g., gambling, addictive substances ○ Aesthetic drives, e.g., art, music, literature, dance Reward Mechanisms Endorphins ○ Are critical for “liking” a reward (receiving a pleasurable stimulus) ○ Opiates bind to endorphin receptor sites Dopamine ○ Is critical for “wanting” (anticipating) a reward ○ Boosts associative learning between stimuli and rewards, including addictive substances and behaviors ○ Released by midbrain neurons terminating in the nucleus accumbens Reward Mechanisms Liking: the subjective feeling of pleasure or satisfaction that occurs when one receives a reward Wanting: the desire to obtain a reward/anticipation of receiving a reward Reinforcement: the effects that rewards have in promoting learning Reward Circuitry Hierarchy of Needs Maslow’s theory of a “hierarchy of needs” suggests that higher-level motives (e.g., esteem, self-actualization) only shape our behavior once lower-level motives (e.g., safety) are fulfilled. Drugs vs. Neurotransmitters Agonists: mimic/enhance the action of a NT Antagonists: oppose/inhibit the action of the NT Example: Acetylcholine, a NT between motor neurons and voluntary muscles ○ Nicotine is an Ach agonist Curare is an Ach antagonist ○ Synaptic Transmission How do drugs influence activity at a synapse? 1) Act on presynaptic neuron (facilitating or inhibiting the synthesis or release of the NT) Ex. Amphetamines 2) Act in synaptic cleft (facilitating or inhibiting reuptake or enzyme deactivation) Ex. Cocaine 3) Act on the post-synaptic binding sites (producing same effect or blocking NT from producing normal effect) Ex. Opiates Intrinsic vs. Extrinsic Motivation INTRINSIC ○ An incentive to engage in a specific activity that derives from pleasure in the activity itself (e.g., a genuine interest in a subject studied) rather than because of any external benefits that might be obtained (e.g., money, course credits) EXTRINSIC ○ An external incentive to engage in a specific activity, especially motivation arising from the expectation of punishment or reward (e.g., completing a disliked chore in exchange for payment) rom Instincts to Drives: Understanding Human Motivation F Introduction to Motives Motives are internal forces that move us to act in certain ways. They explain why we don't remain idle and why we engage in various activities. Early Theories of Motivation 1. Instinct Theory Proposed by early psychologists like William James and William McDougall Defined instincts as genetically endowed tendencies to behave in particular ways McDougall proposed 13 instincts, including parenting, food seeking, and curiosity Criticism: Different theorists proposed vastly different lists of instincts (over 5,000 counted) 2. Drive Theory Based on Claude Bernard's concept of internal environment Emphasizes the importance of maintaining a consistent internal state (homeostasis) Walter Cannon introduced the term "homeostasis" Drives are internal states of tension that motivate behavior to restore equilibrium Key Concepts Homeostasis The process of maintaining internal equilibrium despite external changes. It involves: Sensing aspects of the internal environment Brain control centers producing adjustments Actions or behaviors to keep the internal environment within desired ranges Drive-Reduction Theory Explains motivation as a process of reducing drives to return the body to equilibrium. Conclusion While instinct theory proved inadequate, drive theory provided a more comprehensive framework for understanding motivation. However, as we'll explore in later sections, even drive theory doesn't fully account for the complexity of human motivation. The Avoidance of Pain: An Overview 1. The Purpose and Nature of Pain Pain as a motivator for action The pain matrix: A common brain network for various types of pain Specific and general motivational roles of pain 2. Pain Avoidance vs. Pain-Seeking Behaviors Common pain avoidance behaviors Instances of pain-seeking behaviors Nonsuicidal self-injury (NSSI) 3. Understanding Nonsuicidal Self-Injury (NSSI) Definition and examples of NSSI Prevalence and demographics Media representation and public awareness 4. The Escape-from-Self Hypothesis Explanation of the hypothesis How NSSI may function to decrease overall suffering 5. Key Points to Consider The complex relationship between pain and behavior The importance of understanding seemingly counterintuitive behaviors The need for further research and treatment options for NSSI This organization provides a structured overview of the main topics discussed in the text, including the nature of pain, pain-related behaviors, the phenomenon of NSSI, and theories explaining seemingly paradoxical pain-seeking behaviors. The Pursuit of Pleasure: Key Concepts 1. Purpose of Pleasure Pleasure serves as a motivator for positive behaviors and experiences, complementing pain avoidance. 2. Intrinsic vs. Extrinsic Rewards Intrinsic rewards: Inherent in the activity itself (e.g., playing basketball for fun) Extrinsic rewards: External to the activity (e.g., getting paid for mowing the lawn) 3. Pleasure vs. Pain Unlike pain, pleasure involves distinct processes for anticipation (wanting) and receipt (liking). 4. Brain Bases of Reward Early research: Electrical stimulation of rat brains (Olds & Milner, 1954) Modern neuroimaging: Confirmed early findings and revealed distinct brain regions for wanting and liking 5. Neuroimaging Studies Knutson et al. (2001) used fMRI to demonstrate the dissociation between reward anticipation and delivery in humans. 6. Key Findings Different brain regions are associated with: Anticipation of reward (wanting) Receipt of reward (liking) This organization highlights the main points discussed in the text while maintaining its original content and depth. he Motive to Belong: Understanding Our Need for Connection T 1. Introduction to the Motive to Belong he desire to belong, have friends, and fit in is universal. We actively seek and maintain T friendships, and feel upset when relationships end. 2. Importance of Belonging Influences thoughts, feelings, and behaviors Affects choices in clothing, food, and even political opinions Shapes how we interact with others and perceive ourselves 3. Psychological Impact of Belonging Loneliness can lead to depression Perception of social isolation matters more than objective measures Social interaction predicts positive emotions 4. Physical Health Consequences Loneliness increases risk of cardiovascular problems Can lead to early mortality 5. Benefits of Social Connection Reduces feelings of loneliness and isolation Increases happiness and sense of belonging Provides tangible support (e.g., practical help, emotional support) 6. Modern Forms of Connection: Social Media New ways to build and maintain connections High usage rates, especially among younger adults Benefits: increased communication, enhanced learning, better access to information Potential downsides: "Facebook depression," cyberbullying Conclusion Our connections with others provide psychological benefits, reduce loneliness, increase happiness, and offer both practical and emotional support, giving our lives texture and meaning. The Motive to Achieve: An Overview 1. Understanding Achievement Motivation The motive to achieve goes beyond basic needs and has two aspects: Desire for success (approach motivation) Fear of failure (avoidance motivation) These aspects are independent and operate differently. 2. Performance vs. Mastery Orientation Two main orientations in school contexts: Performance orientation: Focus on looking smart or avoiding looking stupid Mastery orientation: Focus on learning and improving Mastery orientation is associated with higher engagement and resilience in face of challenges. 3. Fixed vs. Growth Mindset Fundamental assumptions about abilities: Fixed mindset: Abilities are relatively unchangeable Growth mindset: Abilities can change and grow with experience indsets shape motivations and behaviors, leading to different outcomes. M 4. Impact of Mindsets on Behavior Fixed mindset: Goal: Looking smart Behavior: Avoid challenges, feel helpless after setbacks Growth mindset: Goal: Mastering new knowledge and skills Behavior: Seek challenges, increase effort after setbacks 5. Cultivating Intelligence Research shows: Teaching about brain plasticity can change mindsets Believing in the ability to grow intelligence can improve academic performance Conclusion: A powerful way to cultivate intelligence is to believe it can grow. Organizing Motives: Key Concepts 1. Hierarchical Organization of Motives Motives are often viewed as hierarchically organized, with some considered "lower" and others "higher". 2. Maslow's Hierarchy of Needs Physiological needs (lowest) Safety needs Belonging needs Esteem needs Self-actualization Self-transcendence (highest) Maslow's theory suggests that lower needs must be satisfied before higher needs become active. 3. Criticisms of Maslow's Hierarchy Limited empirical support Exceptions exist (e.g., starving artists, martyrs) Cultural variations in motive ordering 4. Dweck's Approach to Psychological Motives Basic Needs: Need for acceptance Need for predictability Need for competence Compound Needs: Need for trust (acceptance + predictability) Need for control (predictability + competence) Need for self-esteem/status (acceptance + competence) Need for self-coherence 5. Relationship Between Needs and Goals According to Dweck, needs provide energy for behavior, while goals give behavior its specific direction. 6. Universal Needs vs. Situational Goals While needs (like acceptance) are universal, the goals they generate are tailored to specific situations. rtificial Neurotransmission: Psychoactive Drugs and Addiction A Introduction to Psychoactive Drugs Definition and prevalence of psychoactive drugs Common examples: caffeine, nicotine, alcohol Endorphins and Opioids Endorphins as natural opioids Opioids as pain relievers Increase in opioid prescriptions and related overdose deaths The Addictive Nature of Opioids Connection between pain and pleasure in the brain Role of dopamine in the brain's reward system Brain changes caused by chronic opioid use Opioid Tolerance and Dependence Development of tolerance requiring higher doses Physical dependence and withdrawal symptoms Shift from seeking pleasure to avoiding discomfort Mechanism of Action: Agonists and Antagonists Opioids as agonists mimicking endorphins Naloxone as an antagonist for overdose treatment Limitations of antagonists in addiction treatment Addiction Treatment Approaches Medication-assisted therapies: methadone and buprenorphine Management of withdrawal symptoms Challenges in widespread adoption of replacement therapies Individual Differences in Pain and Addiction Variability in pain experiences and drug responses Gender differences in pain perception and addiction susceptibility Need for personalized approaches to pain management and addiction treatment motions E Terminology E motion: the coordinated behaviors, feelings, and physiological changes that occur when a situation becomes relevant to our personal goals Mood: a short-lived emotional state, usually of low intensity; generally undirected towards any particular target Affect: any experience of feeling or emotion, generally considered along a positive-negative dimension; both emotions and moods are affective states Discrete Emotion Theory The idea that basic emotions are… ○ Innate ○ Universal ○ Identifiable by unique facial expressions ○ Associated with distinctive bodily responses The most common classification identifies 6 primary emotions ○ Happiness, Sadness, Anger, Fear, Surprise, and Disgust But... There is evidence both for and against the idea of discrete, universal emotions Dimensional Approach (some) Important dimensions ○ Valence: Pleasant vs. unpleasant (or positive vs. negative) ○ Activation: High vs. low arousal (or intense vs. mild) ○ Motivation: Approach vs. avoidance Examples Anger = negative / high arousal / approach Excitement = positive / high arousal / approach Sadness = negative / low arousal / avoidance Theories of Emotion James-Lange Theory Cannon-Bard Theory Schachter-Singer Theory Emotion Regulation Up-regulation→strategies to increase an emotion Down-regulation→strategies to decrease an emotion Emotion Regulation Strategies Situation selection: exposing yourself to/avoiding emotional situations Situation modification: changing something about the situation you’re already in Attentional deployment: directing your attenti
