IB Biological Perspective Review

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  • 1. IB - The Biological Perspective Introduction The focus of this perspective is the interaction between the physiological and psychological factors that contribute to behavior. Changes in behavior can arise from an interaction of dispositional and environmental factors. Research has frequently, but not exclusively, used the experimental method. Key issues that are relevant to the biological perspective include criticisms that it often involves a reductionist approach and that behavior exhibited by non-human animals is not always relevant to humans. In this unit students will evaluate the relevance of this perspective to modern psychology. You need to be able to: Describe and evaluate the cultural context and development, the conceptual framework, the methodology, and the application of the biomedical model. Cultural context and development: Methodology: - Darwin (Evolution – Natural Selection) Correlational studies, double blind trials, experiments (use of animals and - Dualism humans = ethically controversial), interviews, case studies and - Later shift from Dualism to Materialism questionnaires. Conceptual Framework (Key Applications: Concepts): - comparison with other perspectives physiological (biological) concepts affect - application of genetic research and behavior. ethical implications Neurotransmitters (excitatory, inhibitory). - changes in education, work and The Brain (localization of functions). therapy. Bodily Rhythms Describe and evaluate theories and empirical studies within this perspective. Theories: Biological researchers tend to view behavior has purely physical. Their basic assumption is that the brain determines behavior. Dualism – the view, first attributed to Descartes, that mind and body are distinct, Descartes believed that the two could interact via the pineal gland in the brain. However, now most psychologist disregard this assumption.
  • 2. Materialism – assumption that all behavior has a physiological basis. The two primary concerns of the biological perspective are the workings of the nervous system, and the role of hereditary on behavior. Assumptions: • Materialism (body and mind are the same) • All psychological behavior is first physiological (mind appears to reside in the brain, therefore all thoughts, feelings, and behaviors ultimately have a physical/biological cause) • Genes have evolved over millions of years to adapt behavior to the environment. Therefore, much behavior will have a genetic basis. Heredity – the biological transmission of characteristics from one generation to the other. This is a main aspect of the biological approach. Natural Selection – the evolutionary process by which those random variations within a species which enhance reproductive success lead to perpetuation of new characteristics, in essence, individuals possessing traits which enhance survival and reproduction are likely to have more offspring (Darwin). Empirical Studies: Darwin – His theory of natural selection published in his book “The Origin of Species” (1859) was a major influence on the biological perspective. Darwin was advocating not only the inheritance of characteristics, but also an evolutionary link between humans and all other species. Even though, his theory caused much controversy, it laid the basis for the study of hereditary influences on behavior. 1861 – A French doctor, Paul Broca, encountered a case in which a man lost the ability to speak coherently after a head injury. Later, Broca, was able to demonstrate, by post mortem autopsy, that the cause of the man’s deficit lay in damage to a specific point in the brain. The proof of this localization of function (connecting a specific behavior to a specific brain area) was crucial to this perspective. Wernicke - Interested in psychiatry, traditionally he studied anatomy initially and neuropathology later. He published a small volume on aphasia which vaulted him into international fame. In it was precise pathoanatomic analysis paralleling the clinical picture. He is best known for his work on sensory aphasia and poliomyelitis hemorrhagia superior. The aphasia syndrome, as described by Wernicke in 1908, consists of loss of comprehension of spoken language, loss of ability to read (silently) and write, and distortion of articulate speech. Hearing is intact. Wernicke aimed at a natural system for the classification of mental disorders, chiefly based on the anatomy and pathology of the nervous system. His pattern of thought was based on the concept that psychiatric diseases were caused by disturbances of
  • 3. the associative system. It was, in other words, a sort of localisation doctrine. 1950s -Sperry severed the optic chiasm (the place where nerve cells from the two eyes cross) and corpus callosum of monkeys. Each eye went to one half of the brain. It proved that each half of the brain became two separate learning centers. Sperry got together people who had their Corpus Callosum split to try and control their sever epilepsy. He showed them different visual stimuli really quickly so only one visual field could take up the information, and then got the patient to identify the word in different ways. He also tried this using touch identification and by showing two different symbols to either visual field. He found that the right visual field was connected to the left side of the brain and vice versa and that the Left side of the brain could write it or say the information, and the right side could identify the information by pointing. Still this gave no indication of what might happen in humans. One obvious difference between primates and people is that monkeys do not speak, and Broca has shown that speech was found in only one hemisphere. Consequently, no one was sure what would happen if the hemispheres were separated in a person. Implications: Support of localization of the brain theory. Mirror sites, connecting to old memories. 1960s – In Los Angeles, Philip Vogel was trying to treat patients with a long history of epilepsy. While in many cases epileptics could be treated with anti-seizure drugs, these patients did not respond to the drug treatment. When all treatments failed, Vogel tried a new and radical approach: by cutting the fibres of the corpus callosum, he hoped to restrict the seizure activity to one hemisphere and thus prevent major seizure attacks. While he knew of Sperry’s work, and there had been occasional clinical reports of damage to the corpus callosum, no one had purposely separated the hemispheres before. Medically, the treatment worked, and it reduced the frequency of more limited seizures. Initial observations suggested that the patients were normal, everyday actions such as walking and eating seemed to occur naturally. However after further testing, they found that the patients behaved in many ways as if they had two independent streams of conscious awareness, one in each hemisphere, each of with is cut from and out of contact with the mental experience of the “other”. In other words, two minds functioning separately from each other. To assess the effects of the surgery, the researchers had to use techniques whereby information was presented to only one hemisphere. The simplest case, involved touch: if the split brain person were given an object in there life hand while blindfolded, the left hand could pick it out again, by touch, from a selection of several objects. However, if the right hand attempted to pick out the article previously held in the left hand, it did no better than chance. In the case of vision, the situation is a bit more complicated, because each eye is connected to both hemispheres. The division of visual processing is such that the visual world of both eye is divided in two, so that the objects on the left side of the visual world are seen by the right hemisphere, while objects on the right side are seen by the left hemisphere, regardless of which eye is used. Since only the left hemisphere had language, the split brain person presented with a word or picture on the left side (conveyed to the right hemisphere) could not say what they had seen. The left hemisphere also specializes in logic and math skills. They also discovered that the right hemisphere has musical and spatial abilities which the left hemisphere lacks. However the right hemisphere is not completely ignorant of language because if a split person was presented with a word or picture, it can point to a corresponding word or picture. Thus, if the right hemisphere sees the word “key”, the left
  • 4. hand can correctly choose a key. Explain how cultural, ethical, gender, and methodological considerations affect the interpretation of behavior from a biological perspective. Effectiveness of the perspective in explaining psychological and/or social questions: Comparison with other perspectives on questions such as aggression, gender differences or stress. It addresses the question of gender differences: Nature or nurture? When looking at gender differences it looks at issues such as sex, relationships, eating disorders etc. Eating disorders have many causes, they can be physiological, cultural, emotional. Society’s impact on women and the correlation that exists between eating disorders and genders is studied as the great difference from male: to female ratio increases (1:7). Gender: There are a great deal of differences between males and females, in terms of physiology and personality. However, in terms of the brain, there is a distinct difference between the two genders. Females actually have a larger and more developed corpus callosum than men, which suggests that they have better communication between the two sides of the brain. While the male brain is, on average, approximately 10 percent larger than the female brain, females have a larger frontal lobe than men, which might explain the fact that women seem to have a heightened perception of emotions than men. Females have evolved mechanisms that enable them to detect men that will transfer resourced to their offspring (i.e. health and paternal investment). Males, however, have evolved mechanisms that enable them to detect females that promise rapid production of offspring, and disinclination to mate with other men (i.e. health, fertility, and faithfulness). This could explain why men expect women to be faithful, and why women seek out faithful men, however males do not feel compelled to remain faithful to women. Compare theories, empirical studies and the conceptual framework of this model with the other perspectives.
  • 5. Biological Psychodynamic Learning Key terms and concepts: Key terms and Key terms and concepts: Physiological concepts: archetypes, Reinforcement (biological) concepts defense mechanisms, (positive/negative), operant affect behavior. ego, id, superego, conditioning, learning, Neurotransmitters psychosexual stages of classical conditioning, (excitatory, inhibitory). development, conditioned response, The Brain (localization inferiority complex, conditioned stimulus, of functions). Oedipal conflict, schedules of reinforcement, Bodily Rhythms conscious etc. shaping etc. Hormones, Endocrine gland, Drugs, Stress, Sleep, Materialism, Hereditary, Central nervous system etc. Key theorists: Key theorists: Key theorists: Sperry, Vogel, Broca, Freud, Jung, Adler Watson, Skinner, Thorndike Wernicke Assumptions: Assumptions: Assumptions: Based on the assumption Attempts to understand Emphasizes the study of of materialism, which behavior in terms of the observable responses, and asserts that all behavior workings of the mind, rejects attempts to study has a physiological with an emphasis on internal processes like basis. motivation and the role thinking. Genes have evolved over of past experience. Focus on learning as a millions of years to Emphasizes the primary factor in explaining adapt behavior to the importance of innate changes in behavior. environment. Therefore, drives, the continuity of Parsimony: The principle much behavior will have normal and abnormal that states that one should a genetic basis. behavior and the role of always seek the simplest the unconscious mind. possible explanation for an By making the event. assumption of psychic Associationism: determinism, views all Mental processes, behavior as having a particularly learning, are meaning. based on forming connections between ideas and/or events. Methodology: Methodology: Methodology: Correlational studies, Case studies, interviews Experiments, interviews, double blind trials, surveys, observation experiments, interviews, case studies and questionnaires. Identify and explain the strengths and limitations of biological explanations of behavior. Strengths – with the biological approach a Limitations – the biological approach better understanding of how the brain emphasizes “getting inside the black works has been achieved. Such as with box”, that is look at internal structure of Broca’s work, “localization of the brain” the organism. However, they do not psychologists were able to connect a take in to account outside factors, such
  • 6. specific behavior to a specific area of the as the environment, effect of society, brain). Also the developments of family etc. on behavior. Not every techniques to study the brain have behavior can be explained solely on the improved with time. Different techniques brain. Other past experiences can have are EEG, MRI, CAT scans, PET. an effect on our behavior. Such as when trying to understand aggression The biological perspective has also helped and why someone might change acquire us understand the effect that drugs have in a violent behavior. The biological the organism (such as cocaine, alcohol etc) perspective proposes that in order for a and understand what happens to different person’s behavior to change drastically, areas of the brain and to neurotransmitters. two out of these three things must The study of psychoactive (mind happen: 1) caused by physical damage affecting) drugs is a concern in both to the brain, 2) have a mental disease, psychology and medicine, and has given 3) or have been abused as a child. This rise to a hybrid field called last one however does not seem to go psychopharmacy. This extensive study with the perspective since it takes into has helped to understand in depth humans’ account past experiences. behavior under the influence of drugs. Another strength of this perspective is the understanding of the effects of hormonal change on behavior. Explain the extent to which free will and determinism are integral in this perspective. Free Will: Since this perspective Determinism: The biological acknowledges the presence of the mind perspective is deterministic in that it (basic assumption of materialism), and states that certain psychological focuses on how processes in the brain (personality) traits are pre-determined, account for behavior, it can be assumed or inherited. The emphasis on genetics that free will is integral to this perspective. and the biological basis of behavior However, such theories as those that makes determinism integral to this explain aggression, suggest that there are perspective. some behaviors which are hereditary and which we have no control over. Explain and evaluate claims that correlates exist between physiological and psychological behavior. Localization of function: it has been determined that certain areas of the brain are primarily used for certain functions and determine specific behaviors. This also allows us to determine the effects of damage on these particular areas of the brain. Discuss controversies surrounding a reductionist approach, as adopted by many biological psychologists.
  • 7. The biological approach can be said to be a reductionist approach because it focuses specifically on neurological processes. It doesn’t take other possible explanations of behavior into account, such as cognitive processes (mental models), or the role of the environment. Historical Development and Cultural Context A long history of interest in mind-body dilemma The influence of Darwin The development of genetics and scanning technology Paradigm shift toward the scientific method • The Greeks (Hippocrates and Galen) • Early brain research (Broca and Gage) • Darwin • Gene research (Mendel, Watson & Crick and the Genome project) • Brain research (Lesions, Electrical stimulation, ECG, CAT, MRI) • Discoveries in medicine and biology (neurotransmitters, Hormones, Drugs) • Philosophy (Dualism Vs Materalism) Assumptions • All that is psychological is first physiological; behavior is biologically determined. • Human genes have evolved over millions of years to adapt behavior to the environment. Therefore, much behavior has a genetic basis. • Psychology should investigate the brain, nervous system, endocrine system, neurochemistry, and genes. • Animals may be studied as a means of understanding human behavior. Key Concepts and Ideas
  • 8. Overview: Structure and Function of the Neuron 1. Glial cells Techniques to Learn about Structure and 2. Neurons Function 3. Cell body Measuring Brain Function 4. Dendrites • EEG (electroencephalogram) – used to 5. Axon study states of arousal – sleeping 6. Terminal buttons /dreaming and detect abnormalities and 7. Myelin sheath study cognition. 8. Neurotransmitters • PET (positron emission tomography) – 9. Acetylcholine color graphics depend on the amount of 10. Dopamine – stimulated the hypothalamus to metabolic activity in the imaged brain synthesize hormone region. 11. Serotonin – sexual activity, concentration and • MRI (magnetic resonance imaging) – attention show brain at work at higher resolution 12. endorphins than PET = Changes in oxygen in the 13. Reflex Action – reflex arc blood of an active brain area. Explore The Endocrine System well-known systems like perception to • Endocrine system consists of glands that less understood systems like motivation secrete chemical messengers called and emotion. hormones into your blood. The hormones Organization of Nervous System travel to target organs where they bind to • Central nervous system – brain and specific receptors. spinal cord • Pineal gland, hypothalamus, pituitary gland, • Peripheral nervous system – somatic thyroid gland, parathyroid, adrenal glands, and autonomic pancreas, ovaries and testes • Somatic nervous system – motor Genetics and Evolution Psychology neuron – stimulate skeletal (voluntary) • Nature vs. Nurture muscle. Genetics and Behavior • Autonomic – neuron that stimulates • Heritability – Twins smooth (involuntary) and heart muscle. • Transmission of hereditary characteristics • Autonomic – antagonistic sympathetic • Chromosome, gene, Turner’s syndrome, nervous system and parasympathetic Klineflether’s syndrome, Down syndromes, nervous system. • Spinal Cord The Brain Evolution Three division 1. Reptilian brain – maintains homeostasis and instinctive behavior 2. Old mammalian brain – limbic system 3. New mammalian brain – cerebral cortex 80% of brain volume higher function Split brain Key Theorists and Their Contributions Hubel and Weisel (Vision) Hubel & Wiesel inserted microscopic electrodes into the visual cortex of
  • 9. experimental animals to read the activity of single cells in the visual cortex while presenting various stimuli to the animal's eyes. They found a topographical mapping in the cortex, i.e. that nearby cells in the cortex represented nearby regions in the visual field, i.e. that the visual cortex represents a spatial map of the visual field. Roger Sperry (Brain) Roger Wolcott Sperry (August 20, 1913 – April 17, 1994) was a neuropsychologist, neurobiologist and Nobel laureate who, together with David Hunter Hubel and Torsten Nils Wiesel, won the 1981 Nobel Prize in Medicine for his work with split-brain research. In his Nobel-winning work, Sperry separated the corpus callosum, the area of the brain used to transfer signals between the right and left hemispheres, to treat epileptics. Sperry and his colleagues then tested these patients with tasks that were known to be dependent on specific hemispheres of the brain and demonstrated that the two halves of the brain may each contain consciousness. In his words, each hemisphere is the lateralization of brain function. Charles Darwin (evolution) His 1859 book On the Origin of Species established evolution by common descent as the dominant scientific explanation of diversification in nature. He examined human evolution and sexual selection in The Descent of Man, and Selection in Relation to Sex, followed by The Expression of the Emotions in Man and Animals. Paul Broca (brain) Broca is most famous for his discovery of the speech production center of the brain located in the ventroposterior region of the frontal lobes (now known as the Broca's area). He arrived at this discovery by studying the brains of aphasic patients (persons with speech and language disorders resulting from brain injuries), particularly the brain of his first patient in the Bicêtre Hospital, Leborgne, nicknamed "Tan" due to his inability to clearly speak any words other than "tan". . Pierre-Paul Broca, Flourens and Lashley, Fred Gage, Joe Martinez, Sperry & Gazzaniga, Hobson & McCarley, Simon LeVay, Bailey & Pillard, W. Greenough, Saul Schanberg, E Roy John, Tiffany Field. Attitude Toward Determinism • Behavior is mainly determined (genetically and environmentally). People have no choice over heredity or environment and these factors interact to produce behavior. • Biological approaches to psychology look at the deterministic influence of genetics, brain structure and biochemistry. Sociobiologists investigate evolutionary determinism. Methods
  • 10. Invasive vs. non-invasive techniques. Invasive techniques, such as split brain studies are not only un- ethical, but leave patients in what can be considered a worse condition than their previous one. Although when the corpus callosum was cut on severe epileptics, their seizures stopped, but so did the communication between left and right brain. These techniques are dangerous and messy. Non-invasive techniques, however, such as MRI, CAT scans, or PET scans, are safer, and are a lot more helpful in determining areas of the brain which may be malfunctioning. Correlational studies, double blind trials, experiments (use of animals and humans = ethically controversial), interviews, case studies and questionnaires. • Correlational Studies • Quasi-Experiments & Natural Experiments • Twin research (a type of correlational research) • Experimentation • Lab research vs. naturalistic research • Reliability and validity of research • Ethical considerations Applications (Where and how is this perspective used with specific examples) comparison with other perspectives - application of genetic research and ethical implications - changes in education, work and therapy. Ethical Issues Evaluation of the Strengths and Weaknesses • The approach is very scientific, and • Reductionist - Bio-psychological theories thus is reliable. often over-simplify the huge complexity • Practical applications have been of physical systems and their interaction extremely effective. with the environment. • It has not explained how mind and body interact - consciousness and emotion are difficult to study objectively.
  • 11. Key Terms action tiny electrical current that is autonomic regulates heart rate, breathing, blood pressure, other potential generated when positive sodium nervous mainly involuntary movements ions rush inside the axon system all-or-none if an action potential starts at the central made up of the brain and spinal cord; carries law beginning of an axon, it will nervous information back and forth between brain and body continue to very end of axon system Alzheimer's incurable, fatal disease involving cerebellum located at back of brain; involved in coordinating (but disease brain damage, with memory loss, not in initiating) voluntary movements deterioration of personality curare a drug that enters bloodstream and cortex a thin layer of cells covering the entire surface of the blocks receptors on muscles, forebrain; folds over on itself to form a large area causing paralysis dendrites branchlike extensions that arise endocrine a system of glands which secrete hormones that from cell body and receive and system affect organs, muscles, and other glands in the body pass signals to cell body end bulbs miniature containers at extreme fight-flight a state of increased physiological arousal that helps ends of axon branches; store response body cope with and survive threatening situations chemicals called neurotransmitters glial cells brain cells that provide scaffolding, forebrain the largest part of the brain; has right and left sides insulation, chemicals to protect and (hemispheres) responsible for many functions support neuron growth ions chemical particles that have frontal lobe electrical charges; opposite a relatively large cortical area at the front part of the charges attract and like charges brain; involved in many functions; like an executive repel mescaline a drug that causes arousal, visual gene a specific segment on the strand of DNA that contains hallucinations; acts like instructions for building the brain and body neurotransmitter norepinephrine mind-body asks how complex mental activities gonads glands (ovaries in females, testes in males) that question can be generated by physical regulate sexual development and reproduction properties of the brain nerve impulse series of separate action potentials homeostasi keeping the bodyUs level of arousal in balance for that take place segment by s optimum functioning segment down length of axon neuron brain cell with specialized limbic core of the forebrain; involved in many motivational extensions for receiving and system behaviors and with organizing emotional behaviors transmitting electrical signals neurotransmit MRI scan chemical keys with a particular ters (magnetic passing nonharmful radio frequencies through brain shape that only fits a similarly resonance and measuring how signals interact with brain cells shaped chemical lock or receptor imaging) Parkinson's branchlike extensions that arise occipital core of the forebrain; involved in many motivational disease from cell body and receive and lobe behaviors and with organizing emotional behaviors pass signals to cell body phantom limb vivid experience of sensations and parietal located directly behind the frontal lobe; its functions feelings coming from a limb that lobe include the sense of touch, temperature, and pain has been amputated reflex an unlearned, involuntary reaction peripheral all nerves that extend from the spinal cord and carry to some stimulus; prewired by nervous messages to and from muscles, glands, sense genetic instructions system organs reuptake PET scan process of removing (positron measuring a radioactive solution absorbed by brain neurotransmitters from synapse by emission cells; shows the activity of various neurons reabsorbtion into terminal buttons tomography ) sodium pump a chemical process responsible for somatic a network of nerves that connect either to sensory keeping axon charged by returning nervous receptors or to muscles you can move voluntarily sodium ions outside axon system stereotaxic fixing a patientUs head in a holder temporal involved in hearing, speaking coherently, procedure and drilling a small hole through the lobe understanding verbal and written material
  • 12. skull; syringe guided to a rain area synapse very small space between terminal amygdala involved in forming, recognizing, and remembering button and adjacent dendrite, emotional experiences and facial expressions muscle fiber, or body organ autonomic regulates heart rate, breathing, homeostasi keeping the bodyUs level of arousal in balance for nervous blood pressure, other mainly s optimum functioning system involuntary movements central made up of the brain and spinal limbic core of the forebrain; involved in many motivational nervous cord; carries information back and system behaviors and with organizing emotional behaviors system forth between brain and body cerebellum MRI scan located at back of brain; involved in (magnetic passing nonharmful radio frequencies through brain coordinating (but not in initiating) resonance and measuring how signals interact with brain cells voluntary movements imaging) cortex a thin layer of cells covering the occipital core of the forebrain; involved in many motivational entire surface of the forebrain; folds lobe behaviors and with organizing emotional behaviors over on itself to form a large area endocrine a system of glands which secrete parietal system hormones that affect organs, lobe located directly behind the frontal lobe; its functions muscles, and other glands in the include the sense of touch, temperature, and pain body fight-flight a state of increased physiological peripheral all nerves that extend from the spinal cord and carry response arousal that helps body cope with nervous messages to and from muscles, glands, sense and survive threatening situations system organs forebrain PET scan the largest part of the brain; has (positron measuring a radioactive solution absorbed by brain right and left sides (hemispheres) emission cells; shows the activity of various neurons responsible for many functions tomography ) frontal lobe a relatively large cortical area at the somatic a network of nerves that connect either to sensory front part of the brain; involved in nervous receptors or to muscles you can move voluntarily many functions; like an executive system gene a specific segment on the strand of temporal involved in hearing, speaking coherently, DNA that contains instructions for lobe understanding verbal and written material building the brain and body gonads glands (ovaries in females, testes in males) that regulate sexual development and reproduction 1. EXAM SHORT ANSWER and ESSAY QUESTIONS a. Describe one theoretical explanation of behavioural change in humans based on the biological perspective. [4 marks] b. Explain the strengths and limitations of the explanation of behaviour described in part (a). [4 marks] May 2003 2. Explain and evaluate claims that correlates exist between physiological processes and psychological behaviour. [20 marks] May 2003 3. Explain why a reductioninst approach adopted by many biological psychologists is controversial. [8 marks] Nov 2003 4. “Behavioural change can be regarded as arising from an interaction between innate disposition and environmental factors.” Describe and evaluate theories or studies within the biological perspective related to this statement. [20 marks] Nov 2003 5.
  • 13. a. Outline what is meant by the reductionist approach. [2 marks] b. Explain how one theory or empirical study from the biological perspective demonstrates a reductionist approach. [6 marks] May 2004 6. Discuss how ethical and methodological considerations affect the interpretation of behaviour from a biological perspective. [20 marks] May 2004 7. Outline historical or cultural considerations that have given rise to the biological perspective. [8 marks] Nov 2004 8. Discuss strengths and limitations of research methods used within the biological perspective. [20 marks] Nov 2004 9. Explain how determinism relates to the biological perspective. [8 marks] May 2005 10. a. Describe assumptions on which key concepts from the biological perspective are based. [10 marks] b. Evaluate the assumptions described in part (a). [10 marks] May 2005 11. Identify and explain one contribution of the biological perspective to the scientific study of behaviour. [8 marks] Nov 2005 12. Identify one key concept from the biological perspective and discuss its contribution to the understanding of behaviour. [20 marks] Nov 2005