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Cognitive Psychology and Neuroscience Flashcards
- The brain:
- Approximately 2% of body weight.
- Receives 20% of blood pumped from the heart.
- Consumes 20% of the body's energy.
- Contains 100 billion neurons.
- Has 1,000,000 billion synapses.
- Contains 10^{1000000} possible circuits.
- Science as a Way of Thinking:
- Science is a dynamic method for understanding the world, not just a collection of facts.
- It acknowledges human fallibility, recognizing that beliefs can be incorrect and evolve over time.
- Overview of Module:
- Introduction to the scientific method in psychology.
- Discussion of the contrast between psychology in public discourse versus research contexts.
- Emphasis on the importance of the scientific method in psychological research.
- The Scientific Method in Psychology:
- Observation and Explanation:
- Human behavior prompts questions about why certain behaviors occur.
- This leads to the development of psychological theories and hypotheses.
- Iterative Loop of Theories:
- Theories generate predictions, allowing for refined understanding.
- Constant refinement occurs through testing hypotheses and experiments.
- Properties of Theories:
- Testable Predictions:
- Theories must provide meaningful expectations for behavior in new contexts.
- Falsifiability:
- A theory must articulate what cannot occur under its premise.
- Discovery of incompatible data necessitates theoretical revision.
- Refinement of Knowledge:
- Theories consistently evolve to align with experimental data.
- Consistent data does not guarantee a theory's correctness, only its validity for the time being.
- The Role of Paradigms in Psychology:
- Paradigms:
- Frameworks guiding research questions, methodologies, and concept definitions.
- Paradigms offer a lens to view psychological inquiry, similar to worldviews.
- Historical Examples of Paradigm Shifts:
- Miasma Theory:
- Prevailing belief that bad air and smells (miasma) caused diseases.
- Illustrated through historical events in London and practices like the plague doctor.
- Germ Theory Shift:
- Observations challenging miasma theory, such as Ignaz Semmelweis advocating handwashing.
- John Snow’s cholera mapping led to sanitation reforms, reshaping health practices.
- Key Psychological Paradigms:
- Psychodynamic Paradigm:
- Founded by Freud, focuses on internal conflicts and childhood experiences affecting behavior.
- Behaviorism:
- Championed by Watson, emphasizes observable behaviors over internal thoughts.
- BF Skinner broadened behavior definition to include self-reported feelings.
- Cognitive Paradigm:
- Emerged to study internal events as causal factors in behavior, impacting the understanding of psychological processes.
- Biological Paradigm:
- Argues that understanding cognitive processing involves biological processes such as neural activity.
- Integration of paradigms leads to a more comprehensive understanding of human psychology.
- Miasma Theory:
- Disease was believed to be caused by particles suspended in foul odors, known as miasma, emanating from rotting organic material.
- Proximity to miasma was considered a key vulnerability factor.
- Paradigm Change: Germ Theory
- Origins of the Behaviorist Paradigm:
- Freud urged us to 'look inward' and consider how the unconscious mind influenced our thoughts and behavior.
- Behaviorists encouraged us to consider how the external environment shapes our thoughts and behaviors.
- Watson's Methodological Behaviorism:
- Rejected the study of unobservable 'private' phenomena as unscientific.
- Proposed that only publicly observable phenomena, such as overt behaviors, could be studied scientifically.
- Promoted a shift in focusing on relationships between publicly observable stimuli and their behavioral consequences.
- Skinner's Radical Behaviorism:
- Broadened the definition of 'behavior' to include 'private' events (e.g., thoughts and feelings) as legitimate scientific topics of study.
- Argued that the external environment was the determinant of both observable and unobservable behaviors.
- Proposed that mental events are not the causes of behavior, but are themselves caused by the environment.
- Cognitive Paradigm:
- Established in the 1950s, it was spurred by research in artificial intelligence, linguistics, and computer stimulation of cognitive strategies.
- Placed mental events and representations at the center of psychology, suggesting that mental events could be studied as causal determinants of behavior.
- Sought to understand the processes that 'transform' stimuli into behaviors, rather than viewing the mind as a black box.
- Biological Paradigm:
- Seeks to explain cognition and behavior in terms of biological processes, such as patterns of neural activity, rather than focusing exclusively on abstract functional relationships between cognitive processes.
- Synergistic with, and extends, work within the cognitive and behaviorist paradigms.
- Overview of Psychological Research Methods:
- Psychology uses various methods to study human behavior.
- The method chosen determines whether researchers can infer correlations (associations) or causation (cause-effect relationships).
- Introspection
- Definition: Looking inward and reporting one's own mental processes.
- Example: Imagining a red square and describing its features.
- Limitations:
- Subjective and unreliable – results vary across individuals.
- Case Study Methodology
- Definition: In-depth examination of a single individual (often with rare conditions).
- Example: Phineas Gage – Frontal lobe damage linked to personality change.
- Strengths:
- Provides detailed information about rare conditions.
- Hints at potential causal links between brain and behavior.
- Limitations:
- Cannot establish causality on its own.
- Findings may not generalize to larger populations.
- Survey-Based Research
- Definition: Uses structured questionnaires for self-report data.
- Example: Measuring personality traits like extroversion using a rating scale.
- Strengths:
- Standardized and efficient for large samples.
- Captures subjective experiences directly from participants.
- Limitations:
- Self-report bias – people may not always be accurate or honest.
- Naturalistic Observation
- Definition: Observing behavior in a real-world setting without intervention.
- Strengths:
- Identifies typical behavior in context.
- Reduces self-report biases.
- Limitations:
- No control over variables – cannot determine causal relationships.
- Correlational Research
- Definition: Examines relationships between two variables.
- Example: Studying the relationship between memory performance and IQ scores.
- Types of Correlations:
- Positive (both increase together).
- Negative (one increases, the other decreases).
- No correlation (no relationship).
- Limitations:
- Correlation does not imply causation.
- Cannot determine which variable influences the other.
- Experimental Research (Causal Inference)
- Definition: Uses controlled conditions to test cause-and-effect relationships.
- Example: Testing whether wearing a hat makes people more likable.
- Key Features:
- Independent Variable (IV) – The manipulated factor (e.g., hat vs. no hat).
- Dependent Variable (DV) – The measured outcome (e.g., likability ratings).
- Random Assignment – Ensures groups are comparable.
- Strengths:
- Establishes causality by isolating the impact of the IV on the DV.
- Limitations:
- Laboratory settings may not reflect real-world behavior.
- Overview of Research Methodologies:
- Research methodologies in psychology can vary widely, influencing whether one can make theoretical inferences about mere associations or strong statements about causality.
- Introspection:
- Early psychology relied heavily on introspection, which is the process of looking inward to monitor the contents of one's own mind.
- Introspection involves observing and reporting on one's thoughts without influence from prior knowledge.
- Example exercise: Imagine a red square and describe its features. This exercise highlights how introspective analysis can be subjective and vary across individuals.
- Introspection is less relied upon in modern psychology, as more objective methods of measurement are preferred.
- Case Studies:
- Case study methodology involves obtaining in-depth biographical information about an individual, usually retrospectively through interviews.
- Often used for individuals with rare clinical disorders, case studies provide detailed insights into specific conditions.
- Survey-Based Research:
- Survey-based research combines elements of introspection and case studies through self-reports.
- Participants respond to fixed sets of questions or statements using rating scales (e.g., strongly disagree to strongly agree).
- This method allows researchers to gather direct reports on personal feelings and traits.
- Naturalistic Observation:
- In naturalistic observation, participants are observed performing tasks without specific interventions from researchers.
- This objective method minimizes self-report biases and can help establish baseline behaviors for potential behavioral interventions.
- Correlation Research Designs:
- Correlation research seeks to identify relationships among variables and measure the strength of those relationships.
- Limitations include the inability to infer causality—correlation does not equal causation.
- Experimental Designs:
- To draw causal inferences, experimental designs are employed, where participants are randomly allocated to different treatment groups.
- Independent variables are systematically manipulated to observe effects on dependent variables.
- What is psychology:
- Commonly defined as the scientific study of mind, brain and behaviour
- Why the focus on therapy?
- Sigmund Freud (1856-1939)
- Viennese neurologist
- Founder of psychoanalysis
- Foregrounded the role of the unconscious
- Id, ego, and superego
- Interpretation of dreams
- Oedipus complex
- Psychosexual development
- Talk therapy
- What else is psychology?
- Cognitive psychology
- Neuropsychology
- Biological psychology
- Developmental psychology
- Social psychology
- Organisational psychology
- Evolutionary psychology
- Mathematical psychology
- Features of science
- Scientific is grounded in observation
- Data are needed to confirm and disconfirm ideas
- Science is cumulative
- Body of knowledge that grows and is refined through time
- Science is self-correcting
- Errors or misconceptions are (eventually) excised
- Science achieves explanation and understanding
- A singular theory can account for a multitude of findings
- Critical thinking & scientific inference
- Falsification and the logic of scientific discovery
- The scientific method implies incremental refinement
- our knowledge progressively becomes a closer approximation to truth/reality
- What of competing theories?
- All swans are white Not all swans are white
- Until we observe the black swam, we should not accept the second theory.
- After we observe the black swan, we must reject the first theory
- Scientific inference requires critical thinking
- Toy problems like choosing a theory of swans are easy and clear-cut
- Real scientific inference requires exercising judgement at many levels!
- Judgements about data
- Is the evidence reliable?
- Is the measure a valid indicator of the construct?
- Does repeating the experiment achieve the same result?
Reliability and validity - Ideally, measures should be both reliable and valid
- Both are required for making legitimate inferences
- Reliability refers to how "repeatable" or consistent a measure is
- If you were to assess the same construct in the same way using the same method of measurement, do you tend to get the same results?
- Validity refers to the degree to which a measure assesses the thing it is purported to assess
- Is the construct you seek to measure actually related to the measurement?
- If the measure is not a valid reflection of the construct of interest, neither are the inferences based on the measure
- Judgements about theory
- Is the theory general?
- A scientific explanation should apply to more than just one specific case
- Can the theory be tested?
- Does the theory predict novel observations?
- Are there results that would falsify the theory?
- Judgements about theory
- Is the theory parsimonious?
- A parsimonious theory provides the simplest possible explanation that suffices to explain all relevant observations
- Principle of Ockham's razor
- Can we rule out alternative explanations?
- If multiple explanations can explains the data is there a way to distinguish them
- Judgements about alternative explanations
- Correlation vs. causation
- Because two variables are related to each other does not mean that one causes the other
- Measurement and uncertainty
- Uncertainty and quantitative measurement
- Allows us to put a numerical value on a measurement
- Quantifies our uncertainty
- “tall” is no longer subjective or relative
- Permits objective measurement by others
- Perhaps most importantly, quantitative measurement allows for comparison
- Of groups of individuals
- Of the same individual through time
- Samples and populations
- In most cases we measure something about a sample of people and seek to form generalised conclusions about the population at large
- Illustration: dice rolling
- Implications: inference is uncertain
- Sometimes a study will produce evidence for an effect when there is no true effect to be found
- False positive rate (5%)
- Sometimes a study will fail to produce evidence for an effect even though there is a true effect to find
- Summary
- Psychology is a scientific discipline with diverse avenues of inquiry
- Quantitative measurement and data-driven inference lie at the heart of (modern) psychology
- Adherence to, and effective use of scientific method requires thinking critically about the nature of evidence as well as arguments
- There is always uncertainty in scientific inference -- no one study is definitive
- Overview of Lecture Topics:
- Review of psychological paradigms and methodologies.
- Group exercise for applying theoretical concepts.
- Discussion on biases in psychological research.
- Paradigms in Psychology:
- Definition of Paradigms:
- Serve as guiding principles or lenses for understanding psychological phenomena.
- Influence interpretation of data, research questions, and methodologies.
- Relation to Theories:
- Paradigms are broader than theories, which fit within paradigms.
- Metaphor: Theories are sandcastles built in the sandbox of paradigms.
- Major Paradigms in Psychology
- Behavioral Paradigm
- Introduced by John B. Watson as a response to Freud's psychodynamic model.
- Key Beliefs:
- Humans are blank slates shaped by environmental experiences.
- Behavior is a result of learning through reinforcement.
- Key Concepts:
- Law of Effect: Behaviors followed by positive outcomes are likely to be repeated.
- Focus on observable behavior; internal thoughts deemed unscientific initially.
- Limitations:
- Cannot fully explain variability in behavior; interpretation of stimuli is often overlooked.
- Cognitive Paradigm
- Emerged in the 1950s-60s alongside advancements in computing.
- Key Beliefs:
- Focus on information processing and mental representations.
- Minds like computers; behavior results from cognitive processing of information.
- Research Focus:
- Attention mechanisms, memory encoding and retrieval, decision making.
- Contrast with Behaviorism:
- Cognitive paradigm emphasizes internal processes alongside observable behaviors.
- Biological Paradigm
- Focus on the physiological and genetic underpinnings of behavior and cognition.
- Key Beliefs:
- Understanding psychology requires knowledge of brain and body mechanisms.
- Research Methods:
- Use of imaging techniques (e.g., fMRI, EEG) and genetic studies.
- Questions Addressed:
- What brain areas are involved in specific cognitive functions?
- How do genetic differences influence behavior and mental disorders?
- Group Exercise: Applying Paradigms to Depression
- Participants divided into three groups (Behaviorist, Cognitive, Biological) to discuss:
- Underlying causes of Major Depressive Disorder (MDD).
- Treatment pathways from each paradigm's perspective.
- Relevant research questions for studying MDD.
- Bias Sources in Psychological Research
- Sampling Bias
- Importance of using representative samples for valid conclusions.
- Consequences of non-representative samples illustrated with hypothetical income-happiness study.
- Expectation Effects
- Types:
- Placebo Effect: Participants feel better when they believe they are receiving treatment.
- Hawthorne Effect: Participants change behaviour when aware they are being observed.
- Stereotype Threat: Performance affected by awareness of societal stereotypes.
- Strategies to mitigate these biases include single and double blinding methods.
- Operational Definitions
- Definition clarity is critical to ensure accurate measurement of psychological constructs.
- Issues arise when dependent variables don't accurately reflect the intended constructs (e.g., cranial capacity as a measure of intelligence).
- Conclusion:
- Recap of the significance of paradigms, methodologies, and biases in psychological research.
- Importance of critical thinking and methodological rigor in psychology.
- Measuring brain function
- Brain measurement: single-Neuron recording
Lesion Studies
- Historical method significant in understanding brain functions.
- Examines patients with brain damage (e.g., stroke or injury).
- Identifies changes in behavior or cognition linked to specific brain damage.
- Provides insights into the functions of damaged areas.
Current Techniques for Recording Brain Activity - Single Neuron Recording:
- Involves implanting electrodes into the brain.
- Measures action potentials from individual neurons.
- Primarily conducted in animal studies (e.g., rats, cats, monkeys).
- Helps determine stimuli/actions that cause specific neurons to fire.
- Electroencephalography (EEG):
- Non-invasive technique measuring electrical activity in the brain.
- Uses electrodes placed on the scalp to record brainwave patterns.
- Magnetic Resonance Imaging (MRI):
- Imaging technique that provides detailed brain structure images.
- Used for localizing brain activity based on blood flow changes.
Insights from Single Neuron Recording - Extensively studied in the visual cortex by Hubel and Wiesel.
- Revealed that many neurons respond to edges in visual stimuli, essential for constructing visual perception.
Applications in the Motor System - Used to study motor control and neuronal firing patterns in the motor cortex.
- Development of neuroprosthetics allowing control of robotic devices via neuronal activity.
- Demonstrates neuroplasticity as individuals learn to adapt their brain activity for controlling devices.
Limitations - Single neuron recording is invasive and primarily conducted in animals.
- Human applications are emerging during surgical procedures.
- Brain measurement: EEG and MRI
EEG (Electroencephalography)
- Measures summed electrical activity from action potentials of thousands of neurons in the cortex.
- Electrodes placed on the scalp, typically using a cap with around 64 sensors.
- Reveals brain activity related to sleep, alertness, and arousal through oscillatory brain waves.
2.1. Frequency Bands - Alpha Activity:
- Oscillations of 8-12 Hz.
- Increased when relaxed or sleepy; suppressed during alertness.
- Delta Waves:
- Slow waves associated with deep sleep.
2.2. Clinical Uses - Sleep studies evaluate different stages of sleep.
- Epilepsy monitoring detects abnormal spiking indicating seizures.
2.3. Event-Related Potentials (ERPs) - Reflect brain activity related to specific stimuli.
- Averages EEG data post-stimulus over multiple trials to represent processing stages.
- Useful for testing deafness in newborns; measures auditory pathway activity.
- Specific ERP peaks, like the one at 170 ms after face presentation, indicate specialized face recognition processing.
- fMRI (Functional Magnetic Resonance Imaging)
- Measures changes in blood oxygen levels, indicating brain activation.
- Active neurons increase oxygen demand, leading to more blood flow.
- Produces statistical maps showing brain activity during tasks.
- Distinct from standard MRI, which provides anatomical images.
3.1. Historical Context - First fMRI study (1992) demonstrated visual cortex activation with a flickering checkerboard pattern.
3.2. Advantages and Challenges - fMRI localizes brain functions effectively.
- Measures blood oxygen changes, not direct electrical activity of neurons, causing delays in detection timing.
- Higher costs limit its use in large-scale studies.
Overview of EEG Measurement: - Electroencephalography (EEG) allows for the detection of small electrical currents generated by neurons in the brain.
- Commonly used for measuring changes in brain activity over time related to perception, cognition, decision-making, and planning actions.
EEG Laboratory Setup: - Located at the School of Psychology, University of Queensland.
- Consists of two areas: one for the experimenter, and a separate, comfortable area for the participant.
- Participant performs computerized tasks while brain activity is monitored.
EEG Measurement Process: - Electrode sensors fitted in a cap with sixty-four sensors cover the participant’s scalp.
- Conductive electrolyte gel is used to ensure good connection between the sensors and scalp.
- EEG detects small electrical signal changes that represent brain activity in real-time.
Understanding EEG Data: - Each trace on the EEG screen corresponds to the activity from a single electrode sensor, reflecting the summed activity of vast numbers of neurons.
- Rhythmic oscillations (brainwaves) indicate fluctuating brain activity.
- Researchers focus on changes in brain activity that relate to specific tasks, despite variations in oscillation frequencies indicating alertness or cognitive load.
Experimental Tasks: - Participants may watch moving dots while auditory tones are played.
- EEG can track brain activity in anticipation of tones, even if the participant does not consciously attend to them.
- Each tone's timing is tagged in the EEG for subsequent offline analysis.
Data Analysis: - Isolation of segments (epochs) around tone presentations allows for detailed analysis.
- Averages of these epochs reveal precise brain activity changes linked to auditory processing, termed Event-Related Potentials (ERPs).
- ERPs help to identify stages of information processing, from sensory perception to cognitive evaluations.
Electrodes and Peaks: - Tone onset at time zero is the basis for tracking brain activity.
- Early peaks around 100 ms post-tone indicate initial sensory processing.
- A notable positive wave around 300 ms reflects higher-order cognitive processing, such as evaluating tone relevance.
Topography Maps and Limitations: - Topography maps illustrate activity levels across the head during different processing stages.
- While they show regions of increased activity, EEG and ERPs do not pinpoint exact brain localization.
Functional MRI Overview - fMRI measures changing brain activity during performance of different tasks in an MRI scanner.
- It helps localize brain functions such as attention, cognition, decision-making, and emotion to specific areas.
- Example: Specific nuclei in the basal ganglia, significant for voluntary movement control and affected in Parkinson's disease, can be localized with fMRI.
fMRI Scanner Mechanism - The MRI scanner utilizes a strong superconducting magnet that continuously operates.
- Participants undergo a screening procedure to ensure safety, as no metallic objects should be near the scanner.
- Participants lie on a bed that moves into the magnet, with their heads placed in a head coil that captures brain images.
- Participants wear headphones to reduce noise and can respond to tasks using a button-response pad.
- A mirror allows them to view a computer display while lying inside the scanner.
Task Performance during Scanning - Tasks are integrated into the fMRI protocol, where brain activity is measured during specific activities.
- fMRI detects changes in blood oxygen levels, which increase as active brain regions demand more energy, transported by oxygenated blood.
Data Analysis - Post-scan, collected image data is analyzed to quantify MRI signal changes that reflect variations in brain activity.
- Modern fMRI can achieve higher resolution and precision in localizing brain activity, even within specific cortical layers.
- Brain measurement is NOT mind-reading
Understanding Experimental Design
- In scientific experimentation, we differentiate between independent and dependent variables.
- The independent variable is the factor we manipulate (e.g., the task or behavior assigned to participants).
- The dependent variable is the outcome we measure, which, in this context, relates to brain activity.
Reverse Inference Problem - Reverse inference is when we try to deduce the independent variable or a conclusion about someone's thoughts based solely on brain activity observations.
- Exciting Emerging Research
- There is intriguing research suggesting potential advancements in using MRI to analyze aspects of consciousness.
- Brain plasticity and learning
Brain plasticity and connections
- Brain plasticity
- How the brain changes with learning
- Definition: the capability of the brain to alter its functional organisation as a result of experience
- Neurogenesis and synaptogenesis
- Generation of new neurons and synapses (connections)
Integration of signals - whole brain - Neuron receives many, many inputs - has only one output
- What combination of inputs will cause this neuron to "fire" and pass on it's signal?
- Brain is enormous "integrator" of information - adapts with learning (billions of neurons with millions of billions of connections)
Integration of information in the brain - Imagine this neuron represents memory of your grandmother
- When this neuron "fires" you consciously recall your grandmother
Grandmother cells - "grandmother cells" - all theoretical
- Neurons could "represent" (encode or "fire to ) a specific concept, such as your grandmother (Jerry Letvin, 1969)
- Billions of neurons can encode billions of concepts
- Memory may be represented by groups of neurons each encoding specific concepts or objects
- "Jennifer Aniston cells" found in Hippocampus
- Recording form neurons in hippocampus in epilepsy patients
- Fire specifically to pictures of Jennifer Aniston
It's all about connections - Spreading activation model - theory
- Neurons represent a specific concept (e.g. grandmother cells)
- Share connections with neurons that represent related concepts
- E.g. fire-engine --> red, truck, fire, siren
Synapses - forming and strengthening connections - Synaptogenesis
- Definitions: generation of new synapses: brain connections
Learning and memory - strengthening synapse connections - Long-term potentiation (LTP)
- Change in the structure of synapses to give stronger signal from pre- synaptic to post-synaptic neuron
Hebb's Law - "Hebbian Learning"
Graded potentials
Hebb's Law - "Hebbian Learning"
"Neurons that fire together wire together"
- Brain Reorganisation
Development of Connections and Brain Organization - Homunculus Organization
The Role of Prism Glasses - Dramatic Case of Reorganization
- The brain:
- 2% of body weight
- Recieves 20% of blood pumped from the heart
- Consumes 20% of body's energy
- 100 billion neurons
- 1,000,000 billion synapse
- 10^{1,000,000} possible circuits
- Cerebral cortex
- The outermost surface layer of the cerebrum
- Cortex= grey matter
Frontal lobe - Executive functions reasonin planning problem- solving
Parietal lobe - Primar somatosensory cortex
Occipital lobe - Posterior part of the brain, inferior to parietal lobe
Temporal lobe - Primary auditory cortex
Limbic system - Amygdala: Fear and arousal
Hippocampus - Learning and memory Forming new memories
Corpus callosum - Neuron connections between the left and right hemisphere
Phineas Gage - Railway worker
- Damaged frontal lobes
Broca's area - speech production
Broca's aphasia - Speech production Wernicke's area - language comprehension
- Wernicke's aphasia - comprehensi
- unable to understand language
Wilder Penfield
Stimulated the brain. With motor and center Cotes of the human brain
Homunculus - Brain system
- Autonomic nervous system
- Medulla hear rate, respiration etc
- Cerebellum hind brain
Motor cortex - Movement
Neurone
Neuron - Neurone send sinules at the - Cell membrane wal
- Action - potential
- Membrane - voltage depen
- Ligand - gated
- Synapes - neurons
Enzyeme
Neurone
Reflexer
Liganel - Pated ion channel
When do inputs trigger 6n action action potentia and timing ouputs
Cognative
EEG - electracephalography ERPs - event -related potentials Mri and
fMRI - function
Motor
Plasticity- How the main charge what are conns. Conedtor - lateralisation o functions to contralateral
- Motor and sensory cortex vision
- the hipocampus and the case of H. M
- Sperry and ca zzangiza 60-190191/6 25, with right hema sphere
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