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Psychology 2220A/B
Beth Mac Dougall- Shackleton

Lecture 1 January-12-12 2:33 PM Behavioural neuroscience - Emphasizes basic neural mechanisms and processes (behaviours such as sleep, emotions, sensation, motorcontrol) - Emphasizes animal models Cognitiveneuroscience - Emphasizes higher cognitive functions (e.g., attention,memory,language, consciousness) - Emphasizes human function - Enabled by recent technologies (MRI, EGIs, etc) Distinction is fairly artificial What is Biopsychology? - Scientific study of the biology of behaviour (psychology) - Psychology:scientific study of behaviour - Hebb is the pioneer: psychologicalbehaviour is produced by brain activity Neuroanatomy: structure of the nervous system, from an anatomicalpoint of view Neurochemistry: chemical basis of neural activity Neuroendocrinology: interactions between the nervous system and the endocrine system Neuropathology: study of brain disease - nervous system disorders Neuropharmacology: effects of drugs on neural activity Neurophysiology: functions and activities of the nervous system (neurons: alterations in firing patterns affects behaviour) Research: Why use nonhuman species? - Simpler/ different brains reveals brain-behaviour interactions - Comparativeapproach: gain insight by making comparisonswith other species - Fewer ethical reasons Why use humans? - Follow instructions - Make subjective reports - Cheaper to work with Non-experiments: no control of variables - Quasi-experimentalstudies/ natural experiments: groups aren't randomly assigned/ don't control everything - Case studies Generalizability – the degree to which results can be applied to other cases Pure research: conducted for the purpose of acquiring knowledge Applied research: intended to bring about some direct benefit to mankind - creating/ finding a drug *research often has aspects of both Physiologicalpsychology: neural mechanismsof behaviour Controlled experimentswith direct manipulation of the brain Psychopharmacology: controlled experimentsof the effects of drugs on the brain and behaviour Neuropsychology: psychological effects of brain damage on humans; clinical emphasis Psychophysiology: Relation between physiological activity and psychologicalprocesses; Example:visual tracking is abnormal in schizophrenics Cognitiveneuroscience: neural bases of cognition; functional brain imaging is the major method of cognitive neuroscience Comparative psychology: comparing different species to understand evolution, genetics, and adaptivity of behaviour Lab and/or ethological research (from a natural perspective - field work rather than lab work) Table 1.2 from text book Lecture 2 January-19-12 2:32 PM Converging Operations - ex: Korsakoff's syndrome: condition characterized by severe memoryloss and most commonlyseen in alcoholics ○ Is the syndromethe result of alcohol's toxic effects on the brain ○ But the syndromeis also seen in peoplewho are malnourishedand have little to no alcohol ○ Thiamine (Vit B1)- deficientrats exhibit memorydeficits ○ Thus if you look at different views - vitamin deficiency, alcohol consumption and malnourishment, realize the converging operations ○ Korsakoff's syndromeis the result of thiaminedeficiency that is accelerated by a alcohol consumption Scientific Inference - Empirical method used to study the unobservable - Measurewhat you can observe, and use these measures as a basis for inferring what they can't observe - Ex: 'seeing' movement ○ Brain has to correct for the movementof retinal image that isn't related to the motion of object Efference Copy Model - Efferent - from the brain - going out - Afferent - coming in to the brain - Comparator: compares what's coming from the retina to retinal motion Questions: What happens when somethingmoves in the world while your eyes stay still? - perceive motion What happens when you push on your eyeball? There is motion in the visual field, but eye is not moving - perceive motion What happens when your eye muscles are paralyzed? Curare - It’s a poison extracted from plants - Blocks acetylcholine receptors thus muscles cannot move - Can kill at high doses, becauserespiratory muscles aren't moving ○ Respiratoryparalysis Experiment Logic Hypothesis - If Helmholtz is right aboutefference copy, if you try to move your eye but can't, you should see the world move ○ Brain sends out a messageto move your eye, but it can't ○ Thus you think that you havemoved your eye, and since everything w/in your visual field is in the same place, you think the world has moved too Critical Thinking: the ability to evaluate scientific claims by identifyingpotential omissions or weaknessesin the evidence Case 1: Delgadoclaims that a chargingbull can be tamed by stimulation of its caudate nucleus Morgan's Canon/ Occam's Razor: give precedenceto the simplest interpretation for a behavioural observation Other possible explanations such as causes the bull to get dizzy, stuns it, immobilizes Case 2: Monizwins Nobel Prize for prefrontallobotomy ○ Prefrontal lobotomy:cut off connection b/w prefrontal lobes and the rest of the brain- claims to cure mental illness - Adopted as human therapybased on a singly study of a chimpanzee - Inadequate postoperative evaluation of humanpatients - Undesirableside effects such as amorality, lack of foresight, emotional unresponsiveness, epilepsy, and urinary incontinence Chapter5: The research methodsof biopsychology - Xrays are useful for visualizing the brain - Contrast X-rays: inject something that absorbsX-rays (radioactive) less or more than surroundingtissue ○ Inject in the blood vessels of the brain, and then able to visualizethe place where you put the contrasting agent ○ Cerebral angiography - Using a combination of X-rays and radio waves from multiple views from different angles and comparing them in 3D = X-ray computed tomography - Computerassisted x-ray procedure - CAT (Computer Assisted Tomography) Scan or CT scan - Can visualize other body parts too Anatomical Imaging: MRI Scan - pieces together the different sections of you brain to create an image (structural) - More or less replaced CT scanning New Section 1 Page 3 - More or less replaced CT scanning - High resolution images - Constructed from measurementof waves that hydrogen atoms emit when activated within a magnetic field - Sagital section? - side view Technical challenged of MRI - Uses a very large magnet- 1.5 to 10 Tesla - Earth's magnetic field in 0.00005 Tesla - 3 Tesla = 60000x earth's magnetic field (higher the Tesla, b/c provides higher resolution - Adds radio waves with frequencies that resonate with atomic nuclei (typically hydrogen) - Doesn't use x-rays which is good - Superior spatial resolution - Tells you what the brain looks like, and not what it's doing **Thus need different techniques and methods to measure changes in activity*** (whatthe brainis doing) PET - Positron emission tomography - Provides images of brain activity - Brain needs to be administered with something that gives off low level positrons (radiolabeled substance) - Scan is an image of levels of radioactivity in various parts of one horizontallevel of the brain - Not measuring neuralactivity directly ○ Measurepositron emissions, coming from extra blood in a certain area, b/c that area has been activated ○ Warmer colours- higher activity/ emission;cooler colours- lower activity/ emission fMRI (functionalmagnetic resonance imaging) - Replaced PET scans - Places brain in a strong magnetic field and detects emissionsfrom molecules in the brain - Computer then calculates where the emissions come from, and create 3D structure of activity in the brain - **measuresblood flow in the brain: BOLD signal ○ BOLD: blood oxygenation level dependent ○ Increase neural activity, increase blood oxygen, increase fMRI signal - Blood flow to a certain part of the brain increasesas that part of the brain being used more - Blood carries hemoglobin to the active brain part, to provide oxygen, and then once it releases oxygen, it changesshape - the changein magnetic of the blood - is what fMRI detects - the emissions from blood - MRI (anatomical)has a higher resolution than fMRI - MRI gives one image, fMRI gives manyimages, every few seconds ***some studies combine anatomical and fMRI Magnetoencephalography(MEG) - Less expensive - Measures neural activity at the surface, and not at the core of the brain - Measures changesin magnetic fields on the surface of the scalp ○ Created by underlying patterns of neural activity (ex: detects if prefrontalcortex is working very hard) - Fast temporal resolution Transcranailmagnetic stimulation (TMS) - Manipulates the brain (does not measureneural activity) - Provides an experimental probe to alter neural activity - TMS appliesa brief, strong magnetic field that alters neural activity ○ Can either activate or "deactivate" brain structures ○ Observe changesin behaviour - Can impair or facilitate local processing ○ Mechanism not well understood - Impairments - temporary"virtual lesions" ○ Effects can last from msec to mins ○ Brain ****From here, move from imaging the humanbrain to recording Psychophysiological Activity**** Scalp electroencephalography(EEG) - Measureof gross electrical activity of the brain - Used electrodes attached to the scalp - Many techniques of EEG ○ Wave form assessment (e.g. alpha waves)  Indicationof state of consciousness, pathology ○ Event-related potentials (ERPs)  Measureactivity accompanyingpsychological events ○ Combination of EEG with MRI Muscle tension - Electromyographyis the technique of measuring the electrical activity of muscles - EMG indicates tension of muscles under the skin New Section 1 Page 4 Eye movement - Electroolucagraphy(EOG) is the techniqueof recording eye movements - Indicates changesin electrical potential between the front and back of the eyeball - Modern eye-tracking technology also exists Skin conductance - Measures of electrodermal activity - Techniques include measurementof skin conductancelevel (SCL) and skin conductanceresponse(SCR) ○ Ex if someone is lying Cardiovascularactivity - Often used to link physiological changeswith emotionalstate - Heart rate, blood pressureand blood volume Invasive Physiological Research Methods Stereotaxic surgery: requires use of stereotaxic atlas and instrument - Any kind on surgery that requires you to know exactly where you're going in the brain Lesion methods - Bilateral and unilateral lesions - All have the same goal to induce experimental lesions - Several procedures each requiring careful interpretation of effects ○ Aspiration lesions (when lesions made to cortical tissue that is accessible to the eyes) ○ Radio-frequencylesions ○ Knife cuts (cutting the axons/ nerves) ○ Cryogenic blockade(reversible- similar to TMS- cooling so that the neuronsno longer work. Assess the changeand after removing the cooling can see the effect come back Lesions - Provide a powerful experimental tool ○ Removes,damages or inactivates a structure - Results must always be interpreted carefully Electrical stimulation - Activate a structure - May have opposite effect as to if the structure is lesioned Invasive Electrophysiological Recording methods - Intracellular unit recording:membrane potential of a neuron - Extracellular unit recording:firing of a neuron - Multiple unit recording:firing of many neurons - want to know what an area of the brain is responsiblefor - InvasiveEEG recording ○ Putting the electrodes on the surface of the brain = greater and more sensitive resolution (as oppsed to the scalp in normal EEG) Pharmacological Research Methods Routes of drug administration(chemicalcommunicationw/in the cells) Selective chemical lesions Agonists: drug mimics/ facilitates endogenous compound Antagonists: drug inhibits/ blocks endogenouscompound 2-deoxyglucose (2-DG) technique - Inject animal w/ radioactive2-DG and allow it to engage in behaviour of interest - Use autoradiographyto see where radioactivity accumulates in brain slices - Use of this method is getting rare (uses C-14 that has a very long half-life, so doesn't disappear - which is annoying) Cerebral dialysis (micro-dialysis) - Small fluid from the brain is needed - Quantify the amountof neurotransmitters or moleculesin the fluid and how is changesover time - Measures extracellular concentrationof specific chemicals in live animals Locating Neurotransmitterand Receptors in the Brain - Dye or radioactive labels used to visualizethe protein of interest - Immunocytochemistry:(labels proteins) based on the binding of labeled protein-specificantibodies ○ Immuneresponse- antibodies created that bind and remove/ destroy antigens - In situ hybridization:(labels RNA) uses labeled RNA to locate neurons with complementarymRNA Immediate - early genes - Genes that produce transcription factors, control expression of other genes - Many are produced in neurons following repeated depolarization - End-products include molecules that may changelong-term connectivity - Can be used as a marker of neuralactivity following a stimulus or activity - Protein labeled with immunocytochemistry, RNA labeled with in situ hybridization Genetic engineering Gene knockouttechniques New Section 1 Page 5 Gene knockouttechniques - Subjects missing a given gene can provideinsight into what the gene controls - Difficult to interpret results - most behaviouris controlled by many genes and removing one gene may alter the expression of others, including compensation for missing gene ○ Have to be careful in the sense as in lesion - doesn’t mean the gene is only responsiblefor that - Antisense drugs block expression of a gene Gene replacementtechniques - Insert pathologicalhuman genes in mice Neuropsychological Testing: - Time consuming:only conducted on a small portion of those with brain damage - Assists in diagnosingneural disorders - Serves as a basis for counselling/caring - Provides information on effectiveness and side effects of treatment Single test: used to differentiate brain damagefrom functional(psychological) causes - abandoned b/c too specific Standardized-test-battery: same goal as single test, but tests a whole range Customizedtest battery: give a whole range; characterizesnature of psychological deficits Tests of the CommonNeuropsychologicalTest Battery Intelligence: Wechsler AdultIntelligence Scale (WAIS, and IQ test) Memory: digit span subtest Language: problems of phonology, syntax or semantics Language lateralization: used to identify language-dominanthemisphere - Sodium amytal:anesthetize one hemisphere - Dichotic listening: ear contralateral to dominanthemisphereshows superiorhearing ability Tests of Specific Neuropsychological Function Memory: exploring nature of deficits - Short-term/ long-term or both? - Anterogradeor retrograde - Semantic or episodic - Explicit or implicit - repetition priming tests Language: problems of phonology, syntax or semantics Frontal-lobe function: Wisconsin Card Sorting Task (have to determinethe correct rule for sorting) BehaviouralMethods of Cognitive Neuroscience Assumptions Each complex cognitive process results from the combined activity of simple cognitive processes (constituent cognitive processes) Each complex cognitive process is mediatedby neural activity in
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