Methods In Cognitive Psychology PDF

METHODS IN COGNITIVE PSYCHOLOGY  SCIENTIFIC METHODS Theories Systematic explanations of natural phenomena E.g., Piaget’s cognitive development Empirical evidence Theoretical predictions or hypotheses are tested against empirical...

METHODS IN COGNITIVE PSYCHOLOGY  SCIENTIFIC METHODS Theories Systematic explanations of natural phenomena E.g., Piaget’s cognitive development Empirical evidence Theoretical predictions or hypotheses are tested against empirical observations Evidence is available for public examination and critiques Public verification E.g., publication in peer-reviewed journals, pre-registration hypotheses, open data Theories that can be disproven or disconfirmed Falsifiability Risky hypothesis: Risk of being refuted Theories that only look for confirmation is pseudo-science  SCIENTIFIC PROCESSES https://www.ted.com/talks/stuart_firestein_the_pursuit_of_ignorance?ut m_campaign=tedspread&utm_medium=referral&utm_source=tedcomsha re  TESTING COGNITIVE THEORIES Example: Memory Search Remember 5 flavors of candy  TESTING COGNITIVE THEORIES Example: Memory Search How did you search through your memory? Can you rely on your participant’s self-report? Perhaps you want to conduct an experiment and gather some data  DEVELOP ALTERNATIVE THEORIES There could be more than one way to search memory Let’s consider three possibilities 1. Compare one at a time. Stop when target is found. 2. Compare one at a time. Never stop and continue searching until the end of the list 3. Compare every item at once Assumptions: Searching takes time Key: Design your predictions and study in attempt to disprove your theory (i.e., risky predictions)  DERIVE SIGNATURE PREDICTIONS FOR EACH THEORY If 1 is true, then Search with target ‘present’ on the list will take shorter amount of time Search with target ‘absence’ will take longer amount of time Longer list à longer time If 2 is true, then Target ‘present’ = ‘absence’ Longer list à longer time If 3 is true, then Target ‘present’ = ‘absence’ Length of the list does not matter Which one is correct?  OBTAIN DATA TO COMPARE THEORIES Run an experiment Number of participants Controlling for confounding factors Age Intelligence Language – can a meaning of the word improve your memory? Experiences – can someone who eat a lot of instant noodle be better at this? Environment – distractions, noises, heat  TYPES OF RESEARCH DESIGN Descriptive, relational, and experimental research  DESCRIPTIVE RESEARCH Naturalistic observation Observe behavior without intervening Many observations Case study Rare events or occurrences, e.g., brain damage from an accident Involve only one or a few cases being studied in details E.g., H.M. Descriptive research is only a starting point in cognitive research, rather than a conclusive evidence  RELATIONAL RESEARCH 6 5 Also called correlational research (not the statistics) 4 Study association between two or more variables Y3 2 Positive relationship 1 Negative relationship 0 Common misconceptions: 0 2 4 6 X Conclusion: X causes Y Correlation ≠ causation 6 If a study use a correlation analysis, it is a relational 5 research 4 Data analysis ≠ research design Y3 2 1 0 0 2 4 6 X  EXPERIMENTAL RESEARCH Four key elements of a true experiment Independent variable (ตัวแปรอิสระ) – factors that an experimenter manipulates or varies, Manipulation of an independent variable e.g., number of items on the list, presence Use of control group (กลุม่ ควบคุม) of the target Random sampling/selection Dependent variable (ตัวแปรตาม) – a factor that is thought to vary because of changes in Random assignment independent variable, e.g., response time IV DV Experimental Random Post-test sampling Condition Random Population Samples assignment Control Post-test Condition  C AUSAL INFERENCES Three conditions of causality 1. Covariation 2. Temporal precedence 3. Control for ‘third variables’  VALIDITY OF RESEARCH Construct validity Does the study observing the behavior that actually representing the construct? E.g., participants drink more soda after exercise. Thirsty? Or something else? Internal validity How confidence you can conclude causal relationship among variables in your study? Can it be explained otherwise? External validity How confidence that your results will generalize to other situations? WEIRD samples (Western, Educated, Industrialized, Rich, and Democratic) No single study can provide a conclusive evidence—we need to accumulate evidence  COMMON MEASUREMENT IN COGNITIVE PSYCHOLOGY Accuracy Hit – how many items you can recall from the list? Miss – how many items that you recall but are not in the list? Sensitivity (d’) = Z(hit rate) − Z(false alarm rate), Response time How long it takes to respond to a stimulus. Donder’s subtractive method Assume the processes are discrete and serial Condition Behavior Hypothetical Cognitive Processes 1 See fixation point Attention 2 See random letters strings Attention + vision 3 Read words Attention + vision + reading 4 Recall words Attention + vision + reading + memory COGNITIVE NEUROSCIENCE BASIC BRAIN ANATOMY  Naming system By lobe, e.g., posterior frontal cortex By function, e.g., primary motor cortex By landmark, e.g., precentral gyrus CEREBRAL CORTEX  S U B C O RT I C A L S T RU C T U R E Thalamus – relay station for sensory & motor information Hypothalamus – basic drives; eating, sex, temperature regulation, sleep Amygdala – Processing emotion, esp., fear Hippocampus – memory Cerebellum – motor control Brain stem – vital functions, e.g., breathing, heart rate Spinal cord – connect peripheral nerves, simple reflex  ACTIVATION Rationale: If brain area X supports cognitive function Y, then X will be active when Y is engaged Single-cell recording Record action potentials of a neuron EEG (electroencephalogram) Bad spatial localization Good temporal resolution ERP (event-related potential)  ACTIVATION Magnetoencephalography (MEG) Same principles as EEG Better location accuracy Still limited to outer cortex Transcranial Magnetic Stimulation (TMS) Excite or inhibit neurons E.g., inhibiting areas involved in decision making  BRAIN DAMAGE Broca’s area Left frontal lobe Broca’s aphasia (ภาวะเสียภาษา) – difficulty producing speech Patients can follow instructions but cannot produce speech. Wernicke’ area Left temporal lobe Wernicke’s aphasia – deficit in language comprehension and meaningful language production Patients produce “word salad”, fluent but incomprehensible.  BRAIN IMAGING Rationale: If brain area X supports cognitive function Y, then damage to X will impair Y Mostly to detect damage in the brain structure (anatomy) CT scan (computed tomography) X-ray technology Utilize density of body structures Computer use that data to generate pictures MRI (magnetic resonance imaging) Magnetic resonance of hydrogen atoms Better resolution  FUNCTIONAL BRAIN IMAGING Measuring indirect activity Brain activity during a task PET Metabolism of blood flow Radioactive tracer Measure gamma ray emitted from collision of positron fMRI Oxygen in blood has magnetic properties More oxygen, more active  LIMITATIONS In lesion study, the brain may find a new way to support lost function E.g., people to lost ability to recognize words by phonetic memory may compensate by using semantic memory The damaged area may be a part of a bigger system It is hard to conclude that the brain area is the only area that support the lost cognitive function Correlation does not imply causation E.g., frontal cortex activities are highly correlated with memory, but damage to the cortex does not always results in severe memory lost  LIMITATIONS A single method is not enough Need converging operations from different methods Both neuroscience and psychology inform one another