Psych Bible Ch.1-3.pdf

Chapter 1 – Psychology: The Science of Behaviour Psychology = The scientific study of behaviour and the factors that influence it. Taking into account Biological, Individual and Environmental factors. Basic and Applied Science Two types of research: o Basic research: Knowledge ga...

Chapter 1 – Psychology: The Science of Behaviour Psychology = The scientific study of behaviour and the factors that influence it. Taking into account Biological, Individual and Environmental factors. Basic and Applied Science Two types of research: o Basic research: Knowledge gained purely for its own sake. The goals are to describe how people behave and to identify factors that influence it. Research maybe carried out in lab or real world e.g. Robert Cave – Jigsaw case study - showed how competition leads to hostility but could be reduced by making them dependent on each other. o Applied research: Knowledge gained to solve specific practical problems. Uses principles discovered via basic research to solve practical problems. Goals of Psychology Four basic goals: o Describe how people and animals behave o Explain and understand the causes of the behaviour o Predict how people and animals behave under certain conditions o Influence or control the behaviour through knowledge and control of causes Importance of Perspectives Diverse viewpoints allows for enriched understanding of behaviour and its causes Six different perspectives: biological, cognitive, psychodynamic, behavioural, humanistic, and sociocultural. o Biological - physical side of human nature, brain and genes o Cognitive - though process o Psychodynamic - unconscious forces motivating behaviour o Behavioral - role of external environment on out action o Humanistic - self actualization and free will o Sociocultural - culture and behaviour relate The Biological Perspective Focuses on the physical side of human nature o Emphasizes role of brain, including biochemical processes Mind-body dualism: The belief that the mind is a spiritual entity not subject to the physical laws that govern the body o No amount of research on the body could ever explain the mind o Ancient widely-held view, especially by Greeks Monism: The belief that the mind and body are one, and mental events are a product of physical events o Modern view by most scientists Discovery of Brain-Behaviour Relations Late 1700s, Luigi Galvani discovered severed leg of frog moved with electrical current applied to it o Defied prior belief that bodily movements were caused by soul By 1870, researchers applied electrical stimulation directly to brains of animals o Stimulation of specific areas on brain resulted in movements of particular muscles Karl Lashley damaged specific regions of brain and studied effects on learning and memory abilities in animals trained to run through mazes In 1929, invention of electroencephalogram (EEG) allowed researchers to measure electrical activity of large areas of brain  Evolution and Behaviour Darwin’s theory of natural selection demonstrated that inheritable characteristics that increase likelihood of survival will be maintained. Proposed that humans and apes arose from the same ancestor. Evolutionary psychology focuses on role of evolution in development of human behaviour o Psychologists stress organism’s biology determine its behavioural capabilities and behaviour Sociobiology holds that complex social behaviours are built into human species as products of evolution o Natural selection favors behaviours that increase ability to pass on genes (aggression, competition, dominance in males, cooperation and nurturing in females, etc.) o Sociobiologists believe that one’s genetic survival is more important than one’s own physical survival (altruism) o Criticized for overemphasizing innate biological factors at expense of cultural and social learning factors in explaining complex human social behaviour Behaviour Genetics Study of how behavioural tendencies are influenced by genetic factors Animals can be bred not only for physical, but also behavioural traits (aggression, intelligence, etc.) Identical twins, with identical genetic makeup, are very similar in behaviour compared to fraternal twins o Found even when identical twins reared in different homes The Cognitive Perspective Views humans as information processors and problem solvers whose actions are governed by thought and planning. What sets humans apart is that we have mental capabilities. o Studies how mental processes influence our motives, emotions, and behaviour Several schools and individuals contributed to modern cognitive perspective: o Structuralism ▪ Analysis of mind in terms of its basic elements ▪ Studied sensations through introspection (“looking within”)Patients were exposed to stimuli and asked to explain their experiences. ▪ Wilhelm Wundt wanted to model study of the mind after physical and biological sciences. Believed mind could be studied via breaking it down to its basic parts, this was called structuralism. Believed sensations were basic elements of consciousness. Founded first laboratory of experimental psychology in 1879 o Functionalism ▪ Psychology should study the functions of consciousness rather than its structure- the Whats ▪ Influenced partly by Darwin’s evolutionary theory (adaption to succeed) ▪ William James broad functionalist approach helped widen the scope of psychology to include biological/mental processes and behaviour o Gestalt Psychology ▪ Concerned with how elements of experience are organized into wholes Opposite of structuralism ▪ Wolfgang Kohler concluded that ability to perceive relationships is the essence of intelligence Defined “insight” as sudden perception of a useful relationship or solution to a problem Demonstrated insight by observing chimpanzee use various items in a cage to reach a banana at the top o Jean Piaget ▪ Studied how children think, reason, and solve problems  ▪ Concerned with how the mind and its development contribute to our ability to adapt to our environment o Albert Ellis and Aaron Beck ▪ Attempted to understand how mental distortions and irrational thought patterns create emotional problems ▪ Emphasized that distress and maladaptive behaviour are caused by the ways situations are thought about, not by external situations Modern Cognitive Science Artificial intelligence develops computer models of complex human thought, reasoning, and problem solving Interested in how people produce and recognize speech and how creative solutions to problems are produced Social constructivism: What we consider reality is in large part our own mental creation o Little shared reality exists apart from what groups of people socially construct through subjective meaning they give to their experiences o Believe male and female sex roles created not by nature, but by shared world view that exists within social groups The Psychodynamic Perspective Searches for causes of behaviour within workings of personality, emphasizing role of unconscious processes and unresolved conflicts from past Sigmund Freud emphasized role of complex psychological forces in controlling human behaviour o Focused on hysteria, condition where physical symptoms develop without organic cause o Found improvement in patients after they reported and relived painful childhood sexual experiences o Led Freud to believe that most of human behaviour is influenced by unconscious forces o Believed repression was a defense mechanism to keep anxiety-arousing impulses, feelings, and memories in unconscious depth of mind o All behaviour is a reflection of unconscious internal struggle between conflicting psychological forces of impulse and defenses Freud opposed laboratory research, and depended on clinical observations and personal self- analysis The Behavioural Perspective Focuses on the role of the external environment in shaping and governing our actions o Behaviour influenced by learned habits and by stimuli in the environment History rooted in school of philosophy known as British Empiricism o All ideas and knowledge are gained empirically o John Locke: The human mind is initially a white paper, to be furnished by experience o Observation overrules reasoning, since “seeing is believing” while reasoning has potential for error o Pavlov found involuntary learning in dogs from external stimulus John Watson lead movement of behaviourism in 1920s o Proper subject matter of psychology is observable behaviour, not unobservable inner consciousness o Devoted efforts to discovering laws that govern learning and performance B. F. Skinner believed mental events, images, and feelings from within are behaviours and not causes Behaviour modification techniques alter problem behaviours and increase positive behaviours through alterations in environmental factors Cognitive behaviourism is an attempt to bridge gap between behavioural and cognitive perspectives o Environment exerts effects on behaviour by affecting thoughts o Mental abilities allow control of behaviour and influence of environment (control varies from environment → person and person → environment) The Humanistic Perspective Emphasizes free will, innate tendencies towards growth, and attempt to find ultimate meaning in one’s existence o Rejected images of behaviour control from unconscious forces Understand role of internal personality processes, but stress importance of conscious motives, freedom, and choice Active force toward growth and self-actualization (reaching individual potential) Terror management theory constructs reality, often involving afterlife and sense of order and stability, to have sense of personal value The Sociocultural Perspective Focuses on the manner in which culture is transmitted to its members and on similarities/differences that occur among people from diverse cultures Culture: Enduring values, beliefs, behaviours, and traditions shared among a large group of people Each culture develops social norms o Norms: Rules that specify what is acceptable and expected behaviour Humans have need to develop cultures o Introduce order and particular world view into social system, creating predictability, guidelines for thought and behaviour, and a map for life Margaret Mead found striking differences in normal behaviour among men and women of three tribes o Cultural expectations and learning experiences can affect behaviour One of most important differences in cultures is emphasis on individualism vs. collectivism o Individualism – North America, Europe o Collectivism – Asia, Africa, South America Perspectives in Historical Context 1879 – Structuralism (Wilhelm Wundt) End of 19th century – Functionalism (William James) End of 19th century – Psychodynamic (Sigmund Freud) 1920s – Behaviourism (B.F. Skinner, Ivan Pavlov, John Watson) 1960s – Cognitive (Allan Paivio) Always – Biological Integrating the Perspectives Three levels of analysis for describing various aspects of behaviour and classifying casual factors: Biological, Psychological, Environmental Biological o Everything psychological is biological o Can analyze behaviour in terms of brain processes, hormones, and genetics o Cannot explain experiences and feelings Psychological o Can analyze role of thought, memory, planning, and problem solving o Takes into account motivational, emotional, and personality processes that influence people Environmental o Takes into account the environment, past and present, and personal and cultural that shape and stimulate behaviour Example: Depression o Biological – Genetic factors, disrupted brain rhythms, chemical factors o Psychological – Pessimism, severe losses/rejections from past o Environmental – Non-rewarding environment, loss of social support Chapter 2 – Studying Behaviour Scientifically Steps in the Scientific Process Initial observation/question Form hypothesis o Tentative explanation or prediction about some phenomenon o Gather clues and logically analyze them Test hypothesis o Conduct research, gather evidence Analyze data o Analyze information and draw tentative conclusions Further research and theory building o Theory: Set of formal statements that explain how and why certain events are related to one another New hypothesis derived from theory o Theory used to develop new hypotheses, which are then tested by conducting additional research and gathering evidence o Allows for self-correcting theories Two Approaches to Understanding Behaviour Hindsight Understanding – Arrive at explanations after-the-fact o Major limitation is due to various explanations for behaviour with no sure way to determine correct alternative Understanding through Prediction, Control, and Theory Building o Theory development is strongest test of scientific understanding, because good theories generate an integrated network of predictions ▪ Incorporates existing facts and observations within single broad framework ▪ Testable, generating new hypotheses whose accuracy can be evaluated by gathering new evidence ▪ Predictions supported by findings of new research ▪ Conforms to law of parsimony: If two theories can explain and predict the same phenomena equally well, the simpler is preferred o Theory never regarded as absolute truth, as future observation can contradict it o Prediction does not require understanding Defining and Measuring Variables Variable: Any characteristic that can differ (Gender, age, ethnicity, etc.) o Certain variables can cause problems due to different meanings in different cases (Levels of intelligence, etc.) Operational definition: Defines variable in terms of specific procedures used to produce or measure it o Translate an abstract term into something observable and measurable Various techniques of measuring processes o Self-Report Measure – Ask people to report on their knowledge, beliefs, feelings, experiences, or behaviour ▪ Accuracy depends on people’s ability to respond honestly Social desirability bias: Tendency to give answer that gives good impression rather than the truth o Reports by Others – Obtain reports from others who know useful information about a person o Physiological Measures – Biologically obtain physical reports ▪ Interpretive problems don’t explain emotional or thought processes o Behavioural Observations – Observes overt behaviours in real-life or laboratory settings ▪ Requires coding system to measure diverse behaviours ▪ Observers and researchers must use system identically for reliable measurements  ▪ Archival measures: Use of already existing records or documents to gather behavioural information ▪ Humans and animals may behave differently when they know they’re being observed (Solved through unobtrusive measures) Methods of Research Descriptive research – seeks to identify how humans and other animals behave, particularly in natural settings o Case studies: In-depth analysis of an individual, group, or event ▪ Vibrant source of new ideas and hypotheses that may be examined using more controlled research methods ▪ Enables scientists to study and collect large amount of data ▪ May challenge the validity of a theory or widely held scientific belief ▪ Can illustrate effective intervention programs developed by clinical psychologists to treat special populations ▪ Poor method for determining cause-effect relationships ▪ Drawing broad conclusions from one or several case studies can be risky ▪ Possible lack of objectivity in the way the researcher gathers and interprets the data o Naturalistic observation: Researcher observes behaviour as it occurs in a natural setting ▪ Used extensively in studies of animal behaviour ▪ Takes long periods of time until able to observe without interfering ▪ Does not permit cause-effect conclusions about the relationships between variables o Survey research: Information obtained by administering questionnaires or interviews to many people ▪ Population – all individuals about whom a conclusion can be drawn ▪ Sample – a subset of individuals drawn from the population of interest ▪ Representative sample – reflects important characteristics of the population Findings closely portray population as a whole ▪ Random sampling – everyone has equal probability of being chosen in sample ▪ Unrepresentative samples can lead to faulty generalizations ▪ Rely on self-reports ▪ Can be distorted by social desirability bias, interviewer bias, or inaccurate perceptions of own behaviour Correlational research – searches for association between naturally occurring events or variables o Three components: ▪ Researcher measures one variable (x) ▪ Researcher measures a second variable (y) ▪ Researcher determines statistically whether x and y are related o Bi-directional causality problem: situation where either x could cause y, or where y could cause x (eg. Parental warmth improves adjustment in children, or Adjusted children improve parental warmth) o Third-variable problem: situation where a third variable (z) is responsible for the cause- effect relationship (eg. Genetic factors cause parental warmth and adjustment in children) o Correlation does not demonstrate causation o Correlation coefficient – a statistic that indicates the direction and strength of the association between two variables o Correlational data allows predictions Experimental research – most direct method for testing explanations of cause-effect relationships o Three essential characteristics: ▪ Researcher manipulates one variable ▪ Researcher measures whether this manipulation produces changes in a second variable ▪ Researcher attempts to control for extraneous factors that might influence the outcome of the experiment  o Independent variable – factor that is manipulated by the experimenter ▪ “Experimental group” receives treatment or active level of the independent variable ▪ “Control group” is not exposed to treatment (purpose is to provide standard of behaviour to compare to experimental group) o Dependent variable – factors that is measured by the experimenter and may be influenced by the independent variable o Two ways to design an experiment: ▪ Random assignment – equal likelihood for all participants to be in any group Doesn’t eliminate fact that participants differ from each other in important ways Balances these differences across various conditions ▪ Exposure to all conditions – each participant is exposed to all conditions Important details about individuals can be noted Counterbalancing mixes up conditions as to eliminate possible problems from exposure to multiple conditions (predictability, boredom, fatigue, etc.) Experimental vs. Descriptive/Correlational Experimental – researcher manipulates one or more independent variables, measures effect on dependent variables Descriptive/Correlational – all variables measured Experimental – often occurs in laboratory Descriptive/Correlational – typically conducted in natural setting Experimental – researcher is able to keep extraneous factors constant Threats to the Validity of Research Internal validity – the degree to which an experiment supports clear causal conclusions (if experiment is well-designed and properly conducted) Confounding of Variables – two variables are intertwined in such a way that we cannot determine which one has influenced a dependent variable (music does not affect ability to do a test, but mood resulting from music does) Demand Characteristics – cues that participants pick up about the hypothesis of a study or about how they are supposed to behave Placebo Effects – decrease internal validity by providing an alternative explanation as to why responses change after exposure to an independent variable (patients improving after psychotherapy may be a result of the therapy itself, or the placebo effect: the expectation to improve afterwards) Experimenter Expectancy Effects – subtle and unintentional ways in which experimenters influence their participants to respond in a manner that is consistent with the hypothesis o Double-blind procedure – participant and experimenter are kept blind as to which experiment condition the participant is in (both patient and doctor are unaware of whether patient received drug or placebo) Replicating and Generalizing the Findings o External validity – the degree to which the results of a study can be generalized to other people, settings, and conditions o Replication – the process of repeating a study to determine whether the original findings can be duplicated ▪ Problem lies in whether or not experiment is replicated identically Chapter 3 – Biological Foundations of Behaviour Neurons Basic building blocks of the nervous system 100 billion at birth, lose 10,000 every day Three main parts: o Cell body or Soma ▪ Contains biochemical structures needed to keep the neuron alive ▪ Nucleus carries genetic information that determines how the cell develops and functions o Dendrites ▪ Branch-like fibres that emerge from the cell body ▪ Collect messages from neighbouring neurons and send them to cell body o Axon ▪ Extends from cell body, conducting electrical impulses to other neurons, muscles, or glands ▪ Branches out to form axon terminals ▪ Connect with dendritic branches from numerous neurons Glial cells surround neurons and hold them in place o Also manufacture nutrients, form myelin sheath, absorb toxins and waste o Guide newly divided neurons to place in brain during development Blood-brain barrier prevents substances from entering brain Nerve Conduction Neurons surrounded by salty liquid environment o High concentration of sodium (Na+) o Inside of neuron is more negative, causing it to be more electrically negative o Resting potential across the membrane: -70 mV Action potential (nerve impulse) is a sudden reversal in neuron’s membrane voltage o Depolarization - changes from –70 mV to +40 mV o Graded potentials – changes proportional to the amount of incoming stimulation ▪ If potentials aren’t very strong, the neuron will be partially depolarized, but not enough for action potential ▪ If strong enough, graded potential reaches action potential threshold – about –55 mV (obeys all-or-none law) o Graded potentials changes membrane potential by acting on tiny protein structures in the cell membrane called ion channels ▪ Open channels allow rushing in of Na+, making neuron less negative ▪ Creates state of partial depolarization that may reach action potential o When membrane reaches action potential threshold, Na+ rushes in due to attraction to negative force in cell ▪ Ion channels close quickly, K+ channels open and K+ leaves cell ▪ Restores neuron to resting potential ▪ Na+ and K+ flow back to respective positions to restore distribution o Refractory period – time period during which the membrane is not excitable and cannot discharge another action potential ▪ Occurs immediately after impulse passes ▪ Limits rate at which action potentials can be triggered (300 impulses per second in human) o Rate of firing or number of neurons fired help differentiate between strength of stimuli Myelin sheath is a fatty, whitish insulation layer derived from glial cells that covers axons o Thins out at regular intervals, by nodes of Ranvier o Allow for high conduction speeds along axon (still slower than speed of electricity in electrical wire) Synaptic Transmission Otto Loewi discovered that neurons release chemicals to pass over to next neuron  Researchers found synaptic cleft between axon terminals of one neuron and dendrite of the next Neurons produce neurotransmitters to carry messages across synapse to excite or inhibit other neurons o Process involves five steps: ▪ Synthesis – chemical molecules formed inside neuron ▪ Storage – molecules stored in synaptic vesicles ▪ Release – Action potential causes vesicle to move to surface of terminal, molecules are released into fluid-filled space ▪ Binding – molecules cross the space and bind to receptor sites (large protein molecules embedded in the membrane) ▪ Deactivation o Binding of neurotransmitters to receptor site causes two possible effects: ▪ Excitation – depolarizes the postsynaptic cell membrane by stimulating flow of Na+ (excitatory transmitters) ▪ Inhibition – hyperpolarizes the postsynaptic cell membrane by stimulating ion channels that allow K+ to flow out of the neuron, or negatively charged ions to flow in (changes potential from –70 mV to –72 mV) Makes it more difficult for excitatory transmitters at other receptor site to depolarize the neuron to the threshold o Neurotransmitters continue to function until deactivation: ▪ Some deactivated by other chemicals in synaptic space that break them down ▪ Reuptake – transmitters reabsorbed into presynaptic axon terminal o Examples of neurotransmitters: ▪ Acetylcholine (Ach) – functions in excitatory and inhibitory systems (related to memory, motor, behavioural inhibition) ▪ Norepinephrine (NE) – functions in excitatory and inhibitory systems (related to arousal, eating) ▪ Dopamine (DA) – functions in inhibitory, sometimes excitatory, systems (related to arousal, voluntary movement) ▪ Seratonin (5-HT) – functions in inhibitory and excitatory systems (related to sleep, thermoregulation) ▪ Gamma Aminobutynic Acid (GABA) – functions in inhibitory systems (related to motor behaviour) o Drugs function by affecting neurotransmitters ▪ Increase or decreases amount of transmitter, stimulates or blocks receptor sites, terminates transmitter function ▪ Examples: Cocaine – stimulates release of dopamine, prevents reuptake Curare – blocks receptor sites for ACh, causes complete paralysis Black widow venom – stimulates release of ACh Botulism toxin – Blocks release of ACh Nicotine – stimulates receptor molecules, “duplicating” effects of ACh Caffeine – blocks adenosine receptor sites o Disinhibition – inhibition of inhibitory neurons to bring system back to normal state The Nervous System Three major types of neurons the carry out functions: o Sensory neurons – carry input messages from the sense organ to the spinal cord and brain o Motor neurons – transmit output impulses from the brain and spinal cord to the muscles and organs o Interneurons – link input and output function, perform connective or associative functions with the nervous system ▪ Allow connection with mental functions, emotion, and behavioural capabilities Peripheral Nervous System – contains all neural structures that lie outside of the brain and spinal cord o Neurons help carry input and output functions to sense and respond to stimuli o Two major division of nervous system:  ▪ Somatic nervous system – consists of sensory neurons that transmit messages from sensory receptors (eyes, ears, etc.) and motor neurons that send messages from the brain and spinal cord to muscles controlling voluntary movements ▪ Autonomic nervous system – controls glands and smooth (involuntary) muscles (heart, blood vessels, etc.) Concerned with involuntary functions (respiration, circulation, digestion, etc.) Two subdivisions: o Sympathetic nervous system – activation or arousal function (causes increased heart rate, dilated pupils during stress) o Parasympathetic nervous system – slows down body processes and maintains state of tranquility Homeostatis – balanced state achieved by equilibrium among two divisions Central Nervous System – contains the brain and spinal cord, which connects most parts of the peripheral nervous system with the brain o Spinal cord’s neurons are protected by the vertebrate ▪ Spinal reflexes allow stimulus responses triggered without involvement of the brain o Brain is comprised of protein, fat, and fluid Various methods for studying brain structure and activity: o Neuropsychological tests – measure verbal and non-verbal behaviours that are known to be affected by particular types of brain damage o Destructive and Stimulation techniques – controlled damage allows researchers to observe consequences ▪ Electrical stimulation can allow for similar observations o Electrical recording – electrodes can record brain activity (electroencephalogram (EEG) perform this) o Brain imaging: ▪ Computerized axial tomography (CT scans) use x-ray imaging to study structures ▪ Positron emission tomography (PET scans) measure brain activity ▪ Magnetic resonance imaging (MRI) combine scans, creating an image based on how atoms in living tissue respond to a magnetic pulse delivered by the device The Brain: Structures and Behavioural Functions Hindbrain – comprised of brain stem and cerebellum o Brain stem ▪ Medulla plays important role in vital body functions such as heart rate and respiration Allows functions to occur automatically Two-way stem for sensory and motor tracts coming from spinal cord and descending from brain ▪ Pons serves as bridge carrying nerve impulses between higher and lower levels of nervous system Also helps control vital functions o Cerebellum ▪ Looks like little brain attached to rear of brain stem ▪ Concerned primarily with muscular movement coordination (also plays role in learning and memory) ▪ Timing and coordination of motor movements depend on cerebellum (but are initiated in higher brain centres) Midbrain – comprised of clusters of sensory and motor neurons, as well as tracts that connect higher and lower portions of nervous system o Reticular formation ▪ Acts as a sentry, alerting higher centres of brain that messages are coming, and either blocking or allowing them through  ▪ Without reticular stimulation of higher brain regions, sensory messages do not process despite the impulse reaching the destination ▪ Affects sleep, wakefulness, and attention Forebrain – comprised of two large cerebral hemispheres that wrap around the brain stem o Outer portion is covered by the cortex o Thalamus ▪ Important sensory relay station ▪ Organizes inputs from sense organs and routes them to appropriate brain area o Basal Ganglia ▪ Critical for voluntary motor control ▪ Plays important role in the deliberate and voluntary control of movement o Hypothalamus ▪ Plays a major role in controlling many different basic biological drives (sexual behaviour, temperature regulation, eating, drinking, aggression, etc.) o Limbic System ▪ Helps coordinate behaviours needed to satisfy motivational and emotional urges that arise in the hypothalamus Hippocampus – involved in forming and retrieving memories Amygdala – organizes emotional response patterns o Can produce emotional response without higher regions of brain realizing Cerebral Cortex – thick sheet of grey cells that form the outermost layer of the brain o Divided into four lobes: frontal, parietal, occipital, temporal ▪ Each lobe is associated with particular sensory and motor functions o Motor Cortex ▪ Controls muscles involved in voluntary body movements ▪ Amount of cortex devoted to each body part depends on complexity of movements of that part o Sensory Cortex ▪ Somatic sensory cortex receives sensory input that allows for sensations as well as senses of balance and body movement ▪ Amount of cortex devoted is dependant on sensitivity of part ▪ Body structures lie along side those of motor cortex o Speech comprehension and production ▪ Wernicke’s area Involved in language comprehension ▪ Broca’s area Necessary for normal speech production o Association Cortex ▪ Found within all lobes of cerebral cortex ▪ Involved in highest level of mental functions o Frontal Lobes ▪ Includes Broca’s speech production area, motor cortex, and associative cortex ▪ Also involved in emotional experience ▪ Prefrontal cortex – region responsible for mental abilities allowing people to direct behaviour in an adaptive fashion Hemispheric Lateralization Corpus callosum is a neural bridge that acts as communication link between two hemispheres Lateralization – relatively greater localization of a function in one hemisphere or the other o For most people, left hemisphere involved in verbal abilities, speech, mathematical, and logical abilities o Right hemisphere involved in mental imagery, musical/artistic abilities, and ability to perceive and understand spatial relationships o Left: positive emotions, Right: negative emotions If corpus collosum is cut, visual input to one hemisphere is restricted by projecting stimulus to only one side of visual field Plasticity in the Brain Neural plasticity – the ability of neurons to change in structure and function Early experiences during brain development can alter brain areas involved in certain skills Greater amount of synapses in children allow for greater chance of recovery from damage to brain o Adults can also maintain or recover functions by surviving neurons that modify themselves (extended axons, increased neurotransmitters, etc