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Psychological Science chapter review notes from 1 - 6.doc

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Dan Dolderman

Chapter 1: Introduction to psychological science • Goal: understand people by considering how a person’s brain processes information about others, and contextual factors; how societal beliefs shape how we behave to other individuals • Fundamental aspects to study psych. ; biological, individual, and social Psychological science: The study of mind and brain and behaviour • Mind- mental activity, experiences you have interacting with the world, thought, speech, smell , taste, hear, touch (sensory input), mental activity results from biological processes you have form the brain • Brain- action of nerves and associated chemical reactions o The physical brain enables what the mind does o Mind is what the brain does. • Behaviour- a term used to describe variety of actions from subtle to complex, that occur in organisms from ants to humans What are the themes of Psychological Science? • The themes guide and direct the way psychological scientists study the mind, brain, and behaviour • Psychological scientists – use methods to understand how people think, feel and act. • Scientific method refers to the use of objective, systematic procedures that lead to an accurate understanding of being studied. The principles of psychological science are cumulative • THEME # 1- research on mind, brain, behaviour has accumulated over time to produce the principles of psychological science o Science builds on the foundation of shared knowledge • PRINCIPLE # 1- harder to recall old info than it is to recognize old info A new biological revolution is energizing research • THEME # 2- A new biological revolution of profound significance is in progress at dawn of the twenty first century, bringing with it deeper understanding of the human mind and behaviour • Brain Chemistry: st o 1 major development in the biological revolution o Brain works through actions of chemicals known as neurotransmitters, which communicate messages through nerve cells o 100s of different substances play critical role in mental activity and behaviour. • Human Genome o Mapped out human genome and various behaviours associated with that genome o Expression of genes helps give rise to mind and behaviour o Gave scientists a foundational knowledge to study how specific genes affect thoughts, actions, feelings, and various disorders • Watching the Working Brain o Some localization of function in the brain but many different brain regions participate to produce behaviour and mental activity. The mind is adaptive • THEME # 3- mind has been shaped by evolution o Humans are product of both biological and cultural evolution. • Evolutionary theory- emphasizes the inherited adaptive value of behaviour and mental activity throughout the entire history of a species • Natural selection- Darwin’s theory that those who inherit characteristics that help them adapt to their particular environment have a selective advantage over those who do not • Adaptations- the physical characteristics, skills, and abilities that increase the chances of reproduction or survival and are therefore likely to be passed along to future generations • The brain has adapted circuits and structures that solve problems by adapting • Also have built in mechanisms to assist in solving problems ex. infants have fear or heights • Culture- the beliefs, values, rules, norms, and customs that exists within a group of people who share a common language and environment, and that are transmitted through learning from one generation to the next Culture provides adaptive solutions • Westerners tend to be more “independent” and self-directed, stressing their individuality • Easterner’s tend to more “dependent” on each other stressing be collective as a group • Westerner’s more likely to emphasize their strengths • Easterner’s more likely to emphasize their need for self-improvement • Cultural rules are learned as norms Psychological Science crosses levels of analysis • THEME # 4- the mind and behaviour can be studied on many levels of analysis Category Levels What is studied? Summary Social • Cultural • Norms, beliefs, values, symbols, ethnicity Examination of how cultural and social contexts affect the ways • Interpersonal • Groups, relationships, persuasion, influence, workplace people interact and influence each other. Individual • Individual • Personality, gender, developmental age groups, Individual differences in personality differences Self-concept and mental processes that concern and perceive how we know our • Perception and • Thinking decision making, language, memory, worlds. cognition seeing, hearing • Behaviour • Observable actions, responses, physical movements Biological How the physical body contributes • Brains Systems • Neuroanatomy, animal research, brain imaging • Neurochemical • Neurotransmitters and hormones, animal to the mind and behaviour, such as • Genetic studies, drug studies the neurochemical and genetic • Gene mechanisms, heritability, twin and processes that occur with the body adoption studies and brain • Pleasant music releases serotonin in the brain What are the intellectual Origins of Psychology? • Nature-nurture debate- the arguments concerning whether psychological characteristics are biologically innate or acquired through education, experience, and culture o Both are very interwoven and inseparable, both play important roles • Mind-body problem- mind and body are separate and distinct or whether the mind is simply the subjective experience of the physical brain • Dualism- mind exists separately form the body • Mental testing movement- individual differences provide the basis of evolutionary development and some psychological differences in nature can be tested How did the scientific Foundations of Psychology develop? • Wundt established psychological laboratories throughout Europe, Canada and USA o Wanted to measure conscious experiences and so he developed the introspection o Introspection- a systematic examination of subjective mental experiences that requires people to inspect and report on the content of their thoughts ex. describing “blueness” of the sky, ex. asked people to compare subjective experiences, which is more pleasant?  This way of thinking became structuralism o Structuralism- an approach to psychology based on the idea that conscious experience can be broken down into its basic underlying components or elements • Problem with introspection: its subjective hard to see whether subjects were using criteria in a similar way • Stream of consciousness – phrase by William James (physiology prof) believed mind is more complex than its elements; mind consists of a continuous series of ever-changing thoughts • Functionalism- approach to psychology concerned with the adaptive purpose, or function of mind and behaviour Profiles in Psychological science- Early women pioneers • Championing the rights of women to become scholars • Gestalt Theory- a theory based on the idea that the whole is different from the sum of the parts • Phenomenological approach – investigating the totality of subjective experience • The mind perceives the world in an organized fashion that cannot be broken down into its constituent elements • Unconscious- mental processes that operate below the conscious level of awareness o Freud believed that often unconscious and conscious thought were conflicting that lead to discomfort and psychological disorders • Psychoanalysis- a method developed by Sigmund Freud that attempts to bring the contents of the unconscious into conscious awareness so that conflicts can be revealed o Through free association patients were able to talk about whatever they wanted for as long as they wanted and Sigmund Freud believed that this would eventually cause the patient to reveal the unconscious problems that was causing the conflicts • Behaviourism- the psychological approach that emphasizes the role of environmental forces in producing behaviour • Cognitive psychology-concerned with higher order mental functions, such as intelligence, thinking, language, memory and decision making • Information processing theories: the brain takes in information as a code, processes it, stores relevant sections, and retrieves stored information as required • All people are influenced by social situations How can we apply Psychological Science • Psychological scientist- one who uses the methods of science to study the interplay between brain, mind, and behaviour and how the social environment affects these processes • Psychological practitioners- those who apply findings from psychological science in order to assist people in their daily lives; design safe and pleasant work environments, counsel people on career paths, or help teachers design better curricula Psychologists • Social psychologist- focus on the influences that other situations and people have on how we act think and feel • Personality psychologist- individual preferences • Developmental psychologist- address changes in mind and behaviour over the life span and so they might study how kids learn the basic structure of music • Cognitive psychology- mental processes such as thinking perceiving, remembering, decision making • Cognitive neuroscience- understand the brain systems involved in the perception of sensory input • Experimental psychopathologist- study abnormal or disordered behaviour Chapter 2: Research methodology Steps in Research What is scientific Inquiry? • Contains 4 goals o Description- what is the behaviour? o Prediction- When the behaviour occurs? o Causal control- varying the situation to produce a change in behaviours or mental state o Explanation- understanding why something happens • Replication- repetition of an experiment to confirm the results • Theory- a model of interconnected ideas and concepts that explains what is observed and makes predictions about future events • Hypothesis- a specific prediction of what would be observed in the world if a theory is correct • Research – scientific process that involves the systematic and careful collection of data • Data- objective observations or measurements • Serendipity- the unexpected stumbling upon something important What are the Types of Studies in Psychological Research? • 3 main types of designs to choose from o Experimental o Correlational o Descriptive • Experiment- a study that tests causal hypotheses by measuring and manipulating variables • Independent Variable- in an experiment the condition is manipulated by the experimenter to examine its impact on the dependent variable • Dependent variable- in an experiment the measure that is affected by the manipulation of the independent variable • Confound- anything that affects a dependent variable that may unintentionally vary between the different experimental conditions of a study • Random assignment- the procedure for placing research participants into the conditions of an experiment in which each participant has an equal chance of being assigned to any level of the independent variable o Only way to ensure equivalency in groups • Correlational study- a research method that examines how variables are naturally related in the real world, without any attempt by the researcher to alter them • Third variable problem- when the experimenter cannot directly manipulate the independent variable and therefore cannot be confident that another, unmeasured variable is not the actual cause of differences in the dependent variable • When there are two cases that seem equally plausible this is called directionality problem • Descriptive studies- a research method that involves observing and noting the behaviour of people or other animals in order to provide a systematic and objective analysis of behaviour o Naturalistic observation- a passive descriptive study in which observers do not change or alter ongoing behaviour o Participant observation- a type of descriptive study in which the researcher is actively involved in the situation What are the Data-Collection Methods of Psychological Science? • Observational techniques- a research method of careful and systematic assessment and coding of overt behaviour; ex. such as watching people’s gestures during social interaction • Reactivity- when someone knows they are being observed, the action that alters their behaviour due to this fact • Observer bias- systematic errors in observation that occur due to an observer’s expectations • Experimenter expectancy effect- actual change in the behaviours of people or animals due to observer bias • Self- report methods- a method of data collection in which people are asked to provide information about themselves, such as in questionnaires of surveys. • Socially desirable responding- when people respond to a question in a way that is most socially acceptable or that makes them look good • Case studies - a research method that involves an intensive examination of one person Profiles in Psychological Science What makes Killers Kill? • Anecdotal cases can be exceptions to general rules of behaviour • Combinations of early child abuse, paranoia, frontal lobe dysfunction in more than 90% of killers • Frontal lobe in adolescents still developing not at full function yet, therefore leading adolescents to be more impulsive, and easily influenced by others Response Performance Measures Stimulus Processing • Response performance- a research method in which researchers quantify perceptual or cognitive processes in response to a specific stimulus • Reaction time- a quantification of performance behaviour that measures the speed of a response • Certain emotional states can influence the body in different ways Body and Brain Activity can be Directly Measured • Psychophysiological assessment- a research method that examines how changes in bodily functions are associated with behaviour or mental state • Polygraphs- lie detectors assess bodily states • Electrophysiology- a method of data collection that measures electrical activity in the brain • Electroencephalogram (EEG)- record of brain activity- measures all brain activity very noisy therefore cannot pick up specific responses to stimuli • Brain imaging allows researchers see which parts of brain are being stimulated when • Positron emission tomography (PET)- a method of brain imaging that assesses metabolic activity by using a radioactive substance injected into the bloodstream, research participant lies in a scanner which detects radiation and a 3-d map of the density o Works by measuring the flow of blood directly • Magnetic resonance imaging (MRI)- relies on the fact that protons contained in hydrogen (major component of fat and water), behave like tiny magnets o Magnetic field causes protons to line up with it, radio waves are then sent through the magnetic field and cause the protons to briefly align to a different orientation (besides pointing with magnetic field north) o Since protons in fat and muscle release different types of energy back to MRI get image • Functional magnetic resonance imaging (fMRI)- an imaging technique used to examine changes in the activity of the working human brain o Works by assessing changes in the levels of o2 in blood (indirect measure of blood flow • Brain imaging used to assess psychological disorders or epilepsy, or brain structure disintegration Research with Animals Provides Important Data • Transgenetic mice- genes were manipulated directly to examine effects on behaviour Ethical Issues to Consider • Institutional Review Boards- groups of people responsible for reviewing proposed research to insure that it meets the accepted standards of science and provides for the physical and emotional well-being of research participants • Informed consent- a process in which people are given full information of a study, which allows them to make a knowledgeable decision to participate or not • Deception- misleading participants about the goals of the study, or not fully telling them what will takes place because this may alter the behaviours of the participants • Debriefing=Explanation time! How are Data Analyzed and Evaluated? • Validity- the extent to which the data collected address the research hypothesis in the way attended • Reliability- the extent to which ta measure is stable and consistent over time in similar conditions • Accuracy- the extent to which an experimental measure is free from error • Two types of error o Random- value of error is different every time o Systematic- when the measurement is always overstated therefore consistent • Central tendency- a measure that represents the typical behaviour of the group as a whole • Mean- the average of a set of numbers in central tendency • Median- central tendency measurement that is the value in a set of numbers that falls exactly halfway point between the lowest and the highest • Mode- central tendency measurement that is the most frequent score or value in a set of numbers • Variability- in a set of numbers, how widely dispersed the values are from each other and from the mean • Standard deviation- a statistical measurement of how far away each value is from the mean • Correlation- a statistical procedure that provides a numerical value, between +1 and -1 indicating the strength and direction of the relation between 2 variables o Negative correlation- as one increases in value other decreases in value o Positive correlation- variables increase of decrease together • Inferential statistics- a set of procedures used to make judgements about whether differences actually exists between sets of numbers o To decide whether differences actually exist between different sets of numbers Psychological Science in Action Understanding Consumers • Consumer psychology- using the principles and methods of psychological science to understand how people spend their money Chapter 3: Genetic and Biological Foundations Good to know from pages 73-84, but otherwise blackboard says not to worry about it. • Genetics- how characteristics of people are passed on through inheritance; and the expression of genes (turning genes on and off) How does the Nervous System Operate? • Nervous system- a communication network that serves as the foundation for all psychological activity o Takes in information from the environment evaluates info and body makes adjustments to adapt to the environment Neurons are specialized for Communication • Neurons- the basic unit of the nervous system that operates through electrical impulses, which communicate with other neurons through chemical signals. Neurons receive, integrate, and transmit information in the nervous system o Have three basic functions: take information from neighbouring cells (reception), integrate those signals (conduction), and pass the signals to others neurons (transmission)  Dendrites- branchlike extensions of the neuron that detect information from other neurons  Cell body- second region of the neuron where information from thousands of other neurons is collected and processed • Site for metabolism and genetic action  Axon- a long narrow outgrowth of a neuron by which information is transmitted to other neurons  Terminal buttons- small nodules at the ends of axons that receive electrical impulses and release chemical signals from the neuron to an area called the synapse  Synapse- site for chemical communication between neurons TYPES OF NEURONS • 3 basic types of neurons: sensory, motor, interneurons o Sensory neurons- detect information from the environment and pass that information along to the brain, usually via spinal cord , (afferent neurons)  called afferent neurons because they send signals from body to brain  efferent neurons send signals from the brain to the body • efferent as in exiting the brain to the body o motor neurons- efferent neurons that direct the muscles to contract or relax, thereby producing movement o interneurons- communicate only with other neurons, typically within a specific brain region  inter= between therefore only communicate between other neurons o somatosensory- general term for sensations experienced from within the body • neurons communicate with other neurons to form neural networks or circuits Action Potentials Cause Neuronal Communication • action potential- a.k.a. neuronal firing; the neural impulse that passes along the axon and subsequently causes the release of chemicals from the terminal buttons THE RESTING MEMBRANE POTENTIAL IS NEGATIVELY CHARGED • resting membrane potential- the electrical charge of a neuron when it is not in use  neuron has different charges inside and outside when not in use, slightly more negative inside the neuron and positive outside of the neuron  measured using microelectrodes –register electric current and displayed on oscilloscope monitor  polarization -differential electrical charge inside and outside of neuron • provides electrical energy to power action potential THE ROLES OF SODIUM AND POTASSIUM IONS • sodium ions and potassium ions move into the neuron through ion channels structured to match specific ion because the lipid cell membrane is selectively permeable • more potassium ions inside the neuron than sodium that contributes to polarization Changes in Electrical Potential Lead to Action • dendrites receive chemical signals either excitatory (stimulate firing by depolarizing) or inhibitory (don’t stimulate firing by hyperpolarizing ) from nearby neurons DEPOLARIZATION AND HYPERPOLARIZATION o depolarization causes change in permeability in cell membrane, which lets sodium enter neuron, causing the inside to be slightly more charged than the outside = basis of the action potential o signals inhibitory = hyperpolarization sodium channels are more resistant to the passage of sodium therefore neuron is still slightly more negative and remains at resting state Action Potentials Spread along the Axon • propagation- more excitatory signals than inhibitory therefore depolarization from sodium rushing in occurs in neuron membrane and moves like a wave through the axon o sodium rushes in, an influx occurs where there isn’t any more space for sodium to be therefore it rushes out as fast as it can outside of the neuron and potassium from the outside is forced in until equilibrium ABSOLUTE AND RELATIVE REFRACTORY PERIODS o absolute refractory period- after potassium leaves neuronal cell through the ion gated channels hyperpolarization occurs, this keeps the action potential from repeating up and down the axon in a ripple effect ALL OR NONE PRINCIPLE o all-or-none principle- a neuron fires with the same potency each time, although frequency can vary; it either fires or not, it cannot partially fire THE MYELIN SHEATH o myelin sheath- a fatty material, made up of glial cells, that insulates the axon and allows for the rapid movement of electrical impulses along the axon o nodes of Ranvier- small gaps of exposed axon between the segments of myelin sheath, where action potentials are transmitted o salutatory conduction enables signals to move through the nervous system extraordinarily fast by jumping from one node of ranvier to the next o multiple sclerosis occurs from demyelination of axons permitting very slow movement and hardening in the brain from genetics and environment Neurotransmitters bind to Receptors across the Synapse • neurotransmitter- a chemical substance that carries signals from one neuron to another • receptors- specialized protein molecules on the postsynaptic membrane that neurotransmitters bind to after passing across the synaptic cleft • synaptic cleft- the small space between neurons that contains extracellular fluid o site of chemical communication between neurons o neuron that sends the signal is presynaptic, the neuron that receives signal is postsynaptic Neurotransmitter Action 1. Neurotransmitters are synthesized from chemical building blocks called precursors. 2. Neurotransmitters are stored in vesicles. 3. Action potentials cause vesicles to fuse to the presynaptic membrane and release their contents into the synapse. 4. Released neurotransmitters bind to the postsynaptic receptors. 5. Neurotransmission is terminated by reuptake enzyme deactivation or autoreception. RELATIONSHIP BETWEEN RECEPTORS AND NEUROTRANSMITTERS • Drugs such as cocaine and heroin mimic neurotransmitters and the receptors are unable to differentiate between the ingested drug and the real neurotransmitter TERMINATING SYNAPTIC TRANSMISSION • 3 events that terminate the influence of transmitters in the synaptic cleft o Reuptake- the process whereby the neurotransmitter is taken back into the presynaptic terminal buttons, thereby stopping its activity o Enzyme deactivation- the process where the neurotransmitter is destroyed by an enzyme, terminating its activity o Autoreceptor- a neuron’s own neurotransmitter receptors, which regulate the release of the neurotransmitter when excess of neurotransmitter is detected Keep in mind: The How do Neurotransmitters Influence Emotion, Thought, and Behaviour? effects of • Drugs and toxins alter the amount of neurotransmitters released neurotransmitters • Drugs and toxins can change how the neurotransmitter is deactivated by blocking reuptake or enzyme of the chemicals deactivation Agonists- drugs that enhance the actions of the Antagonist- drugs that inhibit the action of a specific neurotransmitter neurotransmitterr a function of the receptors to Drugs increase the synthesis of neurotransmitters Drugs block the synthesiwhich they bind.itters Drugs increase the release of neurotransmitters Drugs block release of neurotransmitters Drugs bind to autoreceptors and block their inhibitory Drugs activate autoreceptors so that they inhibit release of effect. neurotransmitters. Drugs block deactivation or reuptake of drugs from the Drugs destroy the neurotransmitter in the synapse. synapse. Drugs bind to postsynaptic receptors and either activate Drugs bind to postsynaptic receptors thereby blocking them or increase the effect of the neurotransmitter. neurotransmitter binding. Nicotine • Excites ACh receptors • Shown that can heighten attention, improve problem solving and can facilitate memory but when smoker stops proven major cognitive deficits o Which is another reason it is so hard to quit smoking, recent ex-smokers find it difficult to think and concentration Common Neurotransmitters and their Functions Acetylcholine • Motor control over muscles, learning, memory, sleeping and dreaming • Acetylcholine (ACh) both excites skeletal muscles and inhibits heart muscles this all depends on the receptor • Toxins that mimic ACh can cause paralysis ex. curare Monoamines • Arousal and attention, eating behaviour Norepinephrine • Epinephrine=adrenaline- a burst of energy caused by bodies release Dopamine • Reward and motivation, motor control over voluntary movements • Cocaine blocks reuptake of dopamine causing pleasure and happiness • Parkinson’s disease- depletion of dopamine kills off voluntary control of muscle movements causing tremors o Treatment of transplanting fetal cells into brain in hope that they cause dopamine • L-DOPA- dopamine producing neurons Serotonin • Emotional states and impulsiveness, dreaming • Low levels  sad anxious moods, food cravings, aggressive behaviour • Drugs that block reuptake of serotonin are used for depression, obsessive-compulsive • LSD – drug structurally similar to serotonin causes hallucinations Amino Acids • Inhibition of action potentials, anxiety and intoxication GABA (gamma- • Inhibition works throughout the brain to hyperpolarize postsynaptic membranes therefore aminobutyric acid) without GABA too much excitation • Alcohol has similar effect as GABA which is why people find alcohol relaxing Glutamate • Enhances action potentials, learning and memory • Primary excitatory in the nervous system. • Opens sodium gates in postsynaptic membranes and causes depolarization • Aid learning by strengthening synaptic connections • Released by astrocytes- type of glial cell causes change in activity of calcium ions Peptide Modulators • Peptides- 2 or more amino acids can act as neurotransmitters or modify the quality of CCK neurotransmitters (cholecystokinin) • Learning and memory, satiety (fullness in eating) • Triggers panic attacks, doom, feeling of suffocation in those who have a panic disorder • Administration of CCK antagonists leads to more social interaction CCK agonists leads to opposite effect Endorphins • Pain reduction and reward • Short for endogenous morphine • Body’s natural defense against pain in order to continue on Substance P • Pain perception • Found in chilli peppers , known as capsaicin causes burning How are Neural Messages Integrated into Communication? • Central nervous system- brain and spinal cord • Peripheral nervous system- includes somatic and autonomic nervous systems The Central Nervous System Consists of the Brain and the Spinal Cord • Behaviour and mental activity is produced in specific location in the brain • Spinal cord main job is to receive sensory signals from the body to transmit to the brain and then receive signals from brain and relay back to the body to control muscles and organs • Central nervous system is separated from the rest of the body through the blood-brain barrier, which refers to the selectively permeable nature of blood vessels throughout the CNS that prevents toxins and poisons in blood coming into brain and spinal cord The Peripheral Nervous System Includes the Somatic and Autonomic Nervous System • Somatic nervous system- transmits sensory signals from specialized receptors in skin, muscles, and joints to the CNS via nerves to the brain • Autonomic nervous system- regulates bodies internal organs by stimulating glands o Nerves ANS carry somatosensory signals to the CNS providing information o EXAMPLE: fullness in stomach or how anxious you feel Sympathetic and Parasympathetic Divisions • Sympathetic nervous system- fight or flight! o Autonomic nervous system prepares body for action • Parasympathetic nervous system- returning to normal state from fight or flight o Chill and digestion phase • Most of your body is controlled by both sympathetic and parasympathetic systems, anything to do with arousal bring out sympathetic system Endocrine System Communicate through Hormones • Endocrine system- a communication system that uses hormones to influence thoughts, behaviours, and actions • Hormones- chemical substances typically released from endocrine glands, that travel through the bloodstream to targeted tissues, which are subsequently influenced by the hormone o Travel through the bloodstream therefore can take anywhere from an hour to seconds to exert effects, can last a while and can affect multiple targets • Endocrine and brain work together- ex. brain interprets physical threats and directs action in the endocrine system to prepare for battle or deal with possible injury EFFECTS OF HORMONES ON SEXUAL BEHAVIOUR • Gonads- males are testes, females are ovaries • Gonadal hormones apparent in both males and females but different quantities o Androgens- testosterone prevalent in males o Estrogens- estradiol  prevalent in females • Finite period of time when female is estrus female is fertile • Sexual behaviour in women has more to do with androgens than estrogens Actions of the Nervous System and Endocrine System are Coordinated • Most of the control of the endocrine system is initiated at the hypothalamus, located just above the roof of the mouth • Pituitary gland- located at the base of the hypothalamus, the gland sends hormonal signals that control the release of hormones from endocrine glands • Growth hormone is released from the pituitary gland to facilitate for muscles, bones, regeneration after injury • Growth hormone releasing factor neurons are connected to an area of the hypothalamus that is involved in sleep- wake cycles o Needs protein when available • CNS, PNS and endocrine system are integrated to ensure that behaviours provide the body with substances it needs for survival at the times they are required Chapter 4: The Brain & Consciousness The Brain and Consciousness • Patient > has epilepsy (seizures). She has agreed to undergo surgery to find and remove the part of her brain in which seizures began. Penfield was deactivating the region near the electrode & reactivated more distant brain regions that were connected to neurons. > Resulted in the vivid reawakening of specific memories in the patient. > The physical reawakening of mental events demonstrate the physical nature of the mind. • The coordinated action of a number of different brain regions contributes not only to consciousness but also to variations in conscious experience. • A while ago, Egyptians thought the heart was more important than the brain • Phrenology - assessing personality traits and mental abilities by measuring bumps on the skull. • Lashley – conducted experiments on rodents and birds by removing brain regions and observed their behaviour. He found that the specific brain regions were involved in motor control and sensory experience. He believed that all parts of the cortex contributed equally to mental abilities. – His theory is discredited now. • Broca – discovered that damage to the left frontal region causes loss of speech. > Broca’s area – left frontal region is crucial for the production of language What are the basic brain structures and their functions? • Today’s brain is viewed as a collection of interacting neuronal circuits that have accumulated and developed throughout human evolution. The spinal cord is capable of Autonomous function • Spinal Cord – Part of the CNS, a rope of neural tissue than runs inside the hallows of the vertebrae from just above the pelvis and into the base of the skull. - Each segment is marked by its own pair of spinal nerves which communicates info to and from the rest of the body. • Grey matter – A segment of the spinal cord that is dominated by the cell bodies of neurons. • White matter – A segment of the spinal cord that consists mostly of axons and the fatty sheaths that surround them. • Sensory information from the body enters the spinal cord and is passed up to the brain. The spinal cord is able to take action on its own. Stretch Reflex • Spinal Reflex - The conversion of sensation into action by a handful of neurons and the connections between them. Ex : Stretch Reflex – reflexive kick when the tendon attached to kneecap is tapped with a rubber hammer. • All muscles have stretch receptors which sense changes in length. These receptors are the dendritic tips of receptor neurons whose cell bodies are located in the spinal cord. Stretching the muscle causes the stretch receptor to fire which causes motor neurons to increase their firing which allows the muscle to contract. The brainstem houses the basic programs of survival • Brainstem – in the base of the skull (the spinal cord continuation into the bottom of brain). Important for survival > breathing, swallowing, vomiting, urinating, orgasm, and reflexes. > has nerves that connect it to the skin and muscles of the head. • Reticular Formation – A large network of neural tissue within the brainstem involved in behavioural arousal and sleep- wake cycles. The Cerebellum is Essential for movement (motor function) • Cerebellum – at the back of the brainstem; essential for coordinated movement and balance. • Lesions to the cerebellum produce different effects: • Damage to the node at the bottom causes head tilt, balance problems and a loss of smooth compensation of eye movement of the head. • Damage to the ridge that runs up its back affects walk • Damage to bulging lobes cause loss of limb coordination.  Ataxia – clumsiness and loss of motor coordination. Patients show lack of normal emotional responses > disorder of the cerebellum. Subcortical structures control basic drives and emotions • Forebrain – consists of two cerebral hemispheres. Its above the brainstem and cerebellum. • Subcortical Regions – lie under the cerebral cortex.  Includes the Hypothalamus, Thalamus, Hippocampus, Amygdala and the Basal Ganglia. • Hypothalamus – the master regulatory structure of the brain and is indispensable to the organism’s survival. Regulated vital functions such as body temperature, sexual behaviour, blood pressure, glucose level. It’s a vital region because it receives input from almost everywhere. • - controls the pituitary gland, releasing hormones into the blood stream • Read Pg 123 • Thalamus – role in attention  The gateway to the cortex. Almost all incoming sensory information must go through before it reaches the cortex. (Except smell which has a direct route to the cortex). • Hippocampus – role in the storage of new memories. It does this by creating new interconnections within the cerebral cortex. It changes size with increased use.  Study: Taxi drivers in London > their hippocampus was larger because they had greater navigational expertise (constantly using their brain to find buildings/places for their customer). They found that the hippocampus increases its volume of grey matter to store more accurate and larger representations of the spatial world. • Amygdala - Emotion  In front of the hippocampus. It intensifies memory during times of emotional arousal such as a frightening experience that stays in our minds for entire life. It’s a hard wire circuit that developed through evolution. Also plays a role in greater responsiveness- ex: becoming overly excited and developing a seizure. • Basal Ganglia – Planning and producing movement  Receives input from the entire cerebral cortex and project to the motor centres of the brain stem and, via the thalamus, back to the cortex’s motor-planning area.  Damage to the basal ganglia can produce Parkinson and Huntington’s disease.  Nucleus Accumbens – important for experiencing reward. - Activation of dopamine levels > Ex: when men view fancy expensive cars ( greater activation of N.A) The Cerebral Cortex Underlies Complex Mental Activity • Cerebral Cortex – the outer layer of the cerebral hemisphere and gives the brain its distinctive appearance. It’s the site of all thoughts, detailed perceptions, communication and consciousness (everything that makes us human).  Has 4 lobes: Occipital (vision) , Parietal (touch, spatial relations), Temporal (hearing and memory), and Frontal (thought and planning movement) • Corpus Callosum – connects two hemispheres and allows information to flow between them. • Occipital Lobe – visual areas ( back of the rain)  Primary visual cortex – major destination for visual information (images)  Each hemisphere takes half of the information: the left hemisphere gets info from the right side of the visual world.  Secondary visual areas – process visual images such as colour, motion and forms. • Parietal Lobe – Touch, Spatial - (in front of the occipital lobes and behind the frontal lobes)  Contains: Primary somatosensory cortex: a strip running from the top of the brain down the side.  Somatosensory Homunculus – tells the brain how much power is needed for sensory perception. It’s distorted because the more sensitive area of the body such as the face and fingers have much more cortical area devoted to them. • Hemineglect – result of a stroke or damage to the parietal region. The patient cannot notice/see anything on their left side. (Only can see things on the right side). These people are not aware that part of their visual world is missing. • Temporal Lobe – The lower region of the cerebral cortex that is important for processing auditory info and also for memory. • contains: left hemisphere, hippocampus formation, amygdala  Primary auditory cortex – an area for hearing analogous to the primary visual and somatosenory cortices (pg. 127 for better description). • Fusiform Face Area – at the intersection of the temporal and occipital cortices. This area is more activated when people look at faces rather than looking at things. However, other regions of the temporal cortex are more activated by objects.  Damage to the fusiform face area causes impairments in recognizing people but not in recognizing objects. • Frontal Lobe – Planning and movement  Primary motor cortex – send info towards the body. They project directly to the spinal cord to move the muscles of the body. (Contralateral body action from hemisphere – ex : the left hemisphere controls right arm).  Prefrontal Lobe – not directly responsible for movement. Occupies 30% of human brain. Responsible for attention, working memory, decision making, social behaviour, personality and acting on plans. (Defines who we are as people)  The thing that separates humans from animals is the complexity and organization of neural circuits. It does NOT matter how much of the brain is occupied by the prefrontal cortex. • Orbitofrontal Cortex –In the centre of the prefrontal cortex. Important for personality, emotion, and impulse control. Part of the limbic system.  Damage – causes people to be easily distracted and engaged in improper social behaviour. • Lobotomy- procedure that treated mental patients with damage to their frontal lobes. It left many patients emotionally flat and lethargic which made them easier to deal with in mental hospitals. How does the Brain Change? • The brain is extremely malleable. • Plasticity – A property of the brain that allows it to change as a result of experience, drugs or injury. • The brain follows a predictable development pattern, with different structures and abilities progressing at different rates and maturing at different points in life. The interplay of genes and the environment wires the brain • The brain’s development follows set sequences programmed in the genes: Babies vision develops before their ability to see in stereo. Ex: The prefrontal cortex is not fully mature until early adulthood. • The behaviour of genes is dependent on the environment. The environment affects our DNA activity and products of our DNA. Chemical signals guide growing connections • Read> on Pg 130 (a lot of info) Experience Fine Tunes Neural connections • Critical Periods – Times in which certain experiences must occur for development to proceed. • Ex: Cat > the cat’s eyes are sutured closed at birth, depriving it of visual input, the maps in its visual cortex fail to develop properly; when the sutures are removed the cat is blind. Yet, the adult cat that did the same experiment didn’t lose his/her eye sight. ( which indicates that the younger cat past its critical period and that’s why he/she was blind) • Experiment: Rats raised in enhanced environments grew up to have bigger brains than those raised in normal laboratories. > The enhanced conditions were an approximation of rat life in the wild allowing rat development. While the being in the laboratories caused atrophy in the rats because of their unused brains. Change in the strength of connections underlies learning • Hebbian Learning – theory that says, two neurons firing at the same time strengthens the synaptic connections between them, making them more likely to fire together. Not firing at the same time weakens the two neurons connection. > allows us to recall events and ingrains habits. • Neurogeneis – new neurons are produced in the adult brain (in the hippocampus).  Implication: we may be able to reverse the loss of neurons and slow down aging. Dominant animals – those who posses the highest social status, show greater increases in new neurons than do subordinate. Changes in use Distort Cortical Maps • Plasticity doesn’t take place if the brain is not paying attention • Example of changes in cortical maps: monkey’s finger will expand if it’s repetitively stimulated. Also the London taxi driver> hippocampus was larger (mentioned earlier). • Phantom limbs - the intense sensation that the amputated body part still exists.  Cortical reorganization can have bizarre results: People feel sensations o
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