Psychology as a Science and Major Perspectives

Introduction

Psychology is the scientific study of behaviour and mental processes. Unlike intuition or common sense, psychology relies on systematic observation, evidence, and critical evaluation. This chapter introduces the foundations of scientific thinking in psychology and the major theoretical perspectives that shape the field.

• Psychology as a Science: Psychology uses empirical methods to investigate questions about behaviour and mental processes, moving beyond personal opinion.

• Skeptical Thinking: Involves evaluating claims based on evidence, not popularity or authority.

• Objective Evidence: Data and observations that are not influenced by personal feelings or biases.

• Confirmation Bias: The tendency to seek or remember information that confirms existing beliefs, while ignoring contradictory evidence.

• Naive Realism: The belief that we see the world objectively, and those who disagree are biased or uninformed.

• Metaphysical vs. Scientific Claims: Metaphysical claims (e.g., about the soul) cannot be tested scientifically, while scientific claims can be empirically evaluated.

• Testable Hypotheses: Scientific claims must be stated in a way that allows for empirical testing and potential falsification.

• Major Psychological Perspectives:

  • Psychoanalysis: Focuses on unconscious motives and conflicts (Freud).

  • Behaviourism: Emphasizes observable behaviour and environmental learning (Watson, Skinner).

  • Cognitivism: Studies mental processes such as thinking, memory, and problem-solving.

  • Biological Psychology: Examines the physiological bases of behaviour.

  • Social Learning Theory: Highlights learning through observation and imitation (Bandura).

• Multiple Levels of Analysis: Behaviour can be explained at biological, psychological, social, and cultural levels. Integrating these provides stronger explanations.

• Reciprocal Determinism: Behaviour, personal factors, and environment influence each other in a dynamic way.

• The Clever Hans Example: Demonstrates the importance of controlling for unintentional cues in research.

• Role of Culture and Context: Behaviour is shaped by cultural and situational factors.

Example: Procrastination can be explained biologically (brain systems for reward), psychologically (beliefs about ability), and socially (peer influence).

Research Methods in Psychology

Introduction

This chapter covers how psychologists design studies, collect data, and draw conclusions. Understanding research methods is essential for evaluating evidence and distinguishing between correlation and causation.

• Ways of Knowing: Includes intuition, authority, and empiricism (knowledge through observation).

• Hypotheses and Operational Definitions: Hypotheses are testable predictions; operational definitions specify how variables are measured.

• Variables:

  • Independent Variable (IV): Manipulated by the researcher.

  • Dependent Variable (DV): Measured outcome.

  • Confounding Variable: An uncontrolled factor that may affect results.

• Experimental Design: Involves random assignment to conditions to infer causality.

• Correlational Research: Examines relationships between variables without manipulation. Correlations can be positive, negative, or zero.

• Correlation Strength: Determined by the absolute value of the correlation coefficient (e.g., ).

• Why Correlation ≠ Causation: Correlation may be due to a third variable or reverse causality.

• Case Studies: In-depth analysis of individuals or groups; useful for rare phenomena but limited in generalizability.

• Naturalistic Observation: Observing behaviour in natural settings without intervention.

• Self-Report Methods: Surveys and questionnaires; efficient but subject to bias.

• Reliability: Consistency of a measure.

• Validity: Whether a measure assesses what it claims to.

• Internal Validity: The degree to which a study supports causal conclusions.

• External Validity: The extent to which findings generalize beyond the study.

• Test-Retest Reliability: Consistency of results over time.

• Cross-Sectional vs. Longitudinal Design: Cross-sectional studies compare groups at one time; longitudinal studies follow the same group over time.

• Cohort Effects: Differences due to generational or historical factors.

• Attrition: Loss of participants over time in longitudinal studies.

• Ethical Principles: Informed consent, confidentiality, minimizing harm.

Example: In a study on therapy effectiveness, the IV is therapy type, the DV is anxiety reduction, and a confound could be outside therapy use.

Biological Psychology and the Nervous System

Introduction

This chapter explores the biological foundations of behaviour, focusing on how neurons communicate, the organization of the nervous system, and the functions of major brain structures.

• Neurons: Basic information-processing cells of the nervous system.

• Structure of a Neuron:

  • Dendrites: Receive signals from other neurons.

  • Soma (Cell Body): Integrates incoming signals.

  • Axon: Transmits electrical impulses away from the soma.

  • Myelin Sheath: Insulates axons, speeding up transmission.

  • Axon Terminal: Releases neurotransmitters into the synaptic cleft.

  • Synaptic Vesicles: Store neurotransmitters.

  • Neurotransmitters: Chemical messengers that cross synapses.

  • Receptors: Proteins on the receiving neuron that bind neurotransmitters.

• Action Potentials: Electrical impulses that travel down the axon. Governed by the all-or-none principle: a neuron fires fully or not at all.

• Reuptake: The process by which neurotransmitters are reabsorbed into the presynaptic neuron.

• Agonists and Antagonists:

  • Agonists: Mimic or enhance neurotransmitter action.

  • Antagonists: Block or reduce neurotransmitter action.

• Endorphins and Morphine: Endorphins are natural painkillers; morphine mimics their effects.

• Nervous System Organization:

  • Central Nervous System (CNS): Brain and spinal cord.

  • Peripheral Nervous System (PNS): All nerves outside the CNS.

  • Somatic Nervous System: Controls voluntary movements.

  • Autonomic Nervous System: Regulates involuntary functions.

    • Sympathetic: Mobilizes for action ("fight or flight").

    • Parasympathetic: Calms the body ("rest and digest").

• Reflex Arcs: Simple, automatic responses that bypass the brain.

• Limbic System: Involved in emotion and memory.

  • Amygdala: Fear and emotional salience.

  • Hippocampus: Formation of new memories.

  • Hypothalamus: Regulates bodily states and links to the endocrine system.

  • Thalamus: Sensory relay station.

• Cerebral Cortex: Outer layer of the brain, involved in higher functions.

  • Frontal Lobe: Planning, decision-making, movement.

  • Parietal Lobe: Sensory processing.

  • Temporal Lobe: Hearing, language, memory.

  • Occipital Lobe: Vision.

• Corpus Callosum: Connects the two hemispheres.

• Hemispheric Specialization: Some functions are more dominant in one hemisphere.

• Endocrine System: Glands that secrete hormones for long-term regulation.

Example: Seeing a bear triggers the amygdala (fear), activates the sympathetic nervous system (increased heart rate), and later the parasympathetic system calms the body.

Sensation and Perception

Introduction

This chapter explains how physical energy from the environment is transformed into psychological experience. It covers the processes of sensation, perception, thresholds, attention, and perceptual organization.

• Sensation: Detection and encoding of sensory information.

• Perception: Organization and interpretation of sensory input.

• Transduction: Conversion of physical energy (e.g., light, sound) into neural signals.

• Absolute Threshold: Minimum stimulation needed to detect a stimulus 50% of the time.

• Difference Threshold (Just Noticeable Difference): Smallest detectable difference between two stimuli.

• Weber’s Law: The just noticeable difference is proportional to the original stimulus intensity.

  • Formula: where is the change in intensity, is the original intensity, and is a constant.

• Signal Detection Theory: Explains how decisions are made under uncertainty, with outcomes such as hits, misses, false alarms, and correct rejections.

• Sensory Adaptation: Decreased sensitivity to constant stimulation.

• Attention: Selective focus on certain stimuli.

• Selective Attention: Focusing on specific information while ignoring others.

• Inattentional Blindness: Failure to notice unexpected stimuli when attention is elsewhere.

• Cocktail Party Effect: Ability to focus on one conversation while filtering out background noise, but still notice personally relevant information.

• Top-Down vs. Bottom-Up Processing:

  • Bottom-Up: Processing based on sensory input.

  • Top-Down: Processing influenced by expectations and prior knowledge.

• Perceptual Set: Readiness to perceive stimuli in a particular way.

• Depth Perception: Ability to perceive three dimensions using cues.

  • Binocular Cues: Require both eyes (e.g., retinal disparity).

  • Monocular/Pictorial Cues: Available to each eye alone (e.g., interposition, relative size, linear perspective).

• Rods and Cones: Photoreceptors in the retina; rods detect light/dark, cones detect colour.

• Colour Vision Theories:

  • Young-Helmholtz (Trichromatic) Theory: Three types of cones sensitive to different wavelengths.

  • Opponent-Process Theory: Colour perception is controlled by opposing neural processes.

• Sound Waves: Characterized by frequency (hertz, Hz) and amplitude (decibels, dB).

Example: Noticing the smell of bread upon entering a bakery (sensation), but not after a few minutes (sensory adaptation); hearing your name across the room (cocktail party effect).

Consciousness, Sleep, Dreams, Psychoactive Drugs, and Altered States

Introduction

This chapter explores the nature of consciousness, sleep and its stages, dreaming, psychoactive drugs, and non-drug altered states. It emphasizes the biological and psychological mechanisms underlying these phenomena.

Sleep and Biological Rhythms

• Consciousness: Awareness of self and environment.

• Circadian Rhythm: Roughly 24-hour biological cycle regulated by the suprachiasmatic nucleus (SCN).

• Sleep Pressure: Builds with time awake; counteracted by circadian alerting signals.

• Melatonin: Hormone that promotes sleepiness; affected by light exposure.

• Social Jet Lag: Mismatch between biological clock and social schedule.

• EEG: Measures brain activity during sleep.

Sleep Stages and Disorders

• NREM Sleep: Includes stages N1 (light), N2 (sleep spindles, K-complexes), N3 (slow-wave, deep sleep).

• REM Sleep: Rapid eye movement, vivid dreaming, REM atonia (muscle paralysis).

• Sleep Disorders:

  • Insomnia: Difficulty falling or staying asleep.

  • Sleep Apnea: Breathing interruptions during sleep.

  • Narcolepsy: Sudden sleep attacks, sometimes with cataplexy (loss of muscle tone).

  • Nightmares vs. Night Terrors: Nightmares are vivid bad dreams; night terrors involve intense fear and arousal, often without memory.

  • Sleepwalking, Sleep Paralysis, REM Behaviour Disorder: Various disruptions of normal sleep processes.

Functions of Sleep and Sleep Loss

• Functions: Neural efficiency, learning, memory consolidation, emotional regulation, immune and metabolic support, safety.

• Sleep Loss: Impairs attention, memory, judgment, emotional regulation, and self-monitoring. Microsleeps are brief, involuntary sleep episodes.

• Four Sleep Dimensions: Quantity, quality, timing, regularity.

• Sleep Hygiene: Practices that promote good sleep (e.g., consistent wake time, limiting caffeine).

• CBT-I: Cognitive-behavioural therapy for insomnia.

Dreams and Dream Interpretation

• Dream Research: Dreams are subjective and influenced by memory, culture, and context.

• Continuity Hypothesis: Dreams reflect waking concerns and emotions.

• Psychodynamic Approaches: Emphasize symbolism and unconscious wishes (Freud).

• Activation-Synthesis Theory: Dreams result from the brain synthesizing random neural activity.

Psychoactive Drugs and Altered States

• Psychoactive Drugs: Alter consciousness by changing synaptic communication.

• Mechanisms:

  • Agonists: Mimic or activate neurotransmitter receptors.

  • Antagonists: Block neurotransmitter action.

  • Reuptake Inhibitors: Prolong neurotransmitter action in the synaptic cleft.

  • Allosteric Modulators: Change receptor responsiveness.

• Reward Pathway and Dopamine: Dopamine is involved in reinforcement, motivation, and learning.

• Tolerance: Reduced response after repeated use.

• Withdrawal: Symptoms when use is reduced or stopped.

• Dependence: Physiological adaptation to a substance.

• Addiction: Compulsive use despite harm, craving, and loss of control.

Major Drug Categories and Risk

Additional info: Cannabis risk is higher with high THC, early use, sleep deprivation, and psychiatric vulnerability.

Non-Drug Altered States

• Hypnosis: Involves focused attention and suggestion; not mind control.

• Mindfulness: Present-moment awareness; may help with emotion regulation but is not universally beneficial.

• Expectancy Effects: Beliefs can shape subjective experience and behaviour.

Exam Preparation and Study Strategies

Introduction

Effective exam preparation involves understanding concepts, applying them to new situations, and distinguishing between similar terms. Scenario-based practice and concept mapping are recommended.

• Review lecture slides and notes for each chapter.

• Create concept maps to visualize relationships.

• Practice explaining concepts and generating examples.

• Compare and contrast similar concepts (e.g., reliability vs. validity).

• Focus on application, not just memorization.

• Pay special attention to Chapter 5 (Consciousness and Sleep), as it is heavily weighted.

Example: To distinguish between nightmares and night terrors, note that nightmares are vivid dreams remembered upon waking, while night terrors involve intense arousal and confusion, often without memory.