Foundations of Psychology: Key Concepts and Theories

Week 1 – Chapter 1 (1.1, 1.2): Psychology Science

Introduction to Psychology

Psychology is the scientific study of behavior and mental processes. It encompasses a wide range of topics, from biological bases of behavior to social influences and cognitive processes.

• What is psychology: The discipline focused on understanding mind, behavior, and mental processes.

• Scientific Method: A systematic approach to research involving observation, hypothesis formation, experimentation, and analysis.

• Biopsychosocial Model: An integrative model considering biological, psychological, and social factors in understanding health and illness.

• Empiricism and Determinism: Empiricism emphasizes knowledge through observation and experience; Determinism posits that behavior is caused by preceding factors.

• Phrenology: An outdated theory that claimed personality traits could be determined by the shape of the skull.

• Nature/Nurture: The debate over the relative contributions of genetics (nature) and environment (nurture) to behavior.

• Behaviourism: A school of psychology focusing on observable behavior and its environmental determinants.

• Cognitive psychology: The study of mental processes such as perception, memory, reasoning, and problem-solving.

• Humanistic psychology: Emphasizes personal growth, self-actualization, and free will.

Big Thinkers in Psychology

Several key figures have shaped the development of psychology as a science.

• Fechner: Founder of psychophysics, studied the relationship between physical stimuli and perception.

• Darwin: Introduced evolutionary theory, influencing comparative psychology.

• Freud: Developed psychoanalysis, emphasizing unconscious processes.

• Wundt: Established the first psychology laboratory, considered the father of experimental psychology.

• James: Promoted functionalism, focusing on the purpose of consciousness and behavior.

• Pavlov: Known for classical conditioning experiments with dogs.

• Skinner: Developed operant conditioning, emphasizing reinforcement and punishment.

• Watson: Advocated for behaviorism, focusing on observable behavior.

• Rogers: Humanistic psychologist, developed client-centered therapy.

• Hebb: Proposed the concept of neural networks and the Hebbian theory of learning.

• Penfield: Neurosurgeon who mapped the brain’s functions through electrical stimulation.

Research Methods in Psychology

Scientific Research and Design

Research in psychology relies on rigorous scientific methods to ensure validity and reliability.

• Basic and applied research: Basic research seeks fundamental knowledge; applied research aims to solve practical problems.

• Five characteristics of quality scientific research: Objectivity, reliability, validity, generalizability, and ethical standards.

• Objectivity and subjectivity: Objectivity involves unbiased observation; subjectivity includes personal perspectives.

• Generalizability: The extent to which research findings apply to broader populations.

• Informed Consent: Participants must be informed about the study and consent to participate.

• Hypothesis: A testable prediction about the relationship between variables.

• Variables: Factors that can change or be manipulated in research.

• Operational definition: Defining variables in terms of specific procedures or measurements.

• Reliability and validity: Reliability refers to consistency; validity refers to accuracy of measurement.

• Sources of bias: Factors that can distort research findings, such as experimenter bias or participant expectations.

• Single-blind and double-blind studies: Single-blind: Participants unaware of group assignment; double-blind: Both participants and researchers are unaware.

• Different types of research design:

  • Quantitative research: Uses numerical data and statistical analysis.

  • Qualitative research: Explores phenomena through non-numerical data, such as interviews or observations.

Statistical Concepts

Statistics are essential for analyzing and interpreting psychological data.

• Frequency: The number of times a value occurs.

• Normal and skewed distribution: Normal distribution is symmetrical; skewed distribution is asymmetrical.

• Central tendency: Measures that describe the center of a data set (mean, median, mode).

• Mean, median, mode:

  • Mean: Arithmetic average ($\text{Mean} = \frac{\sum x}{n}$)

  • Median: Middle value in an ordered data set.

  • Mode: Most frequently occurring value.

Biological Psychology

Genetic Basis of Behaviour

Biological psychology explores how genetics and physiology influence behavior.

• Principles of Hereditary Transmission:

  • Chromosomes: Structures containing genetic material.

  • Genes: Units of heredity that influence traits.

  • DNA: Molecule carrying genetic instructions.

  • Alleles: Different forms of a gene.

• Behavioural genomics: Study of how genes affect behavior.

• Dominant vs. recessive: Dominant alleles mask recessive ones in trait expression.

• Epigenetics: Study of changes in gene expression not caused by DNA sequence changes.

• Methylation: Chemical modification affecting gene activity.

• Genotype and phenotype: Genotype is genetic makeup; phenotype is observable traits.

• Behavioural genetics: Examines genetic and environmental influences on behavior.

Neurobiological Basis of Behaviour

The nervous system is central to understanding behavior and mental processes.

• 3 main functions of the nervous system: Sensory input, integration, and motor output.

• Central and peripheral nervous system: Central: Brain and spinal cord; Peripheral: All other neural elements.

• Somatic nervous system: Controls voluntary movements.

• Autonomic nervous system: Regulates involuntary functions.

  • Sympathetic: Prepares body for action.

  • Parasympathetic: Conserves energy, promotes rest.

• Parts of the brain: Different regions have specialized functions (e.g., occipital lobe for vision).

• Neurons and glial cells: Neurons transmit signals; glial cells support neurons.

• Dendrite and synapse/synaptic cleft: Dendrites receive signals; synapse is the gap between neurons.

• 8 neurotransmitters: Chemical messengers (e.g., dopamine, serotonin).

• Action potential of neurons: Electrical impulse enabling communication ($\text{Action Potential}$ is generated when membrane potential reaches threshold).

• Endocrine system: Glands releasing hormones affecting behavior.

• Neuroplasticity: The brain’s ability to change and adapt.

Sensation and Perception

Processes and Theories

Sensation and perception involve receiving, processing, and interpreting sensory information.

• Sensation and perception: Sensation is detecting stimuli; perception is interpreting them.

• Diagram on slide 5: Illustrates the process from sensory input to perception.

• Psychophysics: Study of relationships between physical stimuli and psychological experience.

  • Weber and Weber’s Law: The just noticeable difference (JND) is proportional to the magnitude of the stimulus ($\Delta I / I = k$).

  • Fechner: Developed methods for measuring perception.

• Absolute threshold, difference threshold, and just noticeable difference:

  • Absolute threshold: Minimum stimulus needed for detection.

  • Difference threshold: Smallest detectable difference between stimuli.

  • Just noticeable difference (JND): The point at which a change is detected.

• Signal detection theory: Explains how decisions are made under uncertainty.

• Transduction: Conversion of physical energy into neural signals.

• Sensory adaptation: Reduced sensitivity to constant stimuli.

• Subliminal information processing: Processing below conscious awareness.

• Figure ground: Differentiating objects from background.

• Gestalt principles of perceptual organization: Rules for grouping sensory information (e.g., proximity, similarity).

• Perceptual constancy: Perceiving objects as stable despite changes.

• Bottom-up and top-down processing: Bottom-up: Data-driven; top-down: Concept-driven.

• Influence on processing – attention: Attention affects perception and information processing.

Part 2: Sensory Systems

Visual System

The visual system processes light and enables sight.

• Structure of the eye: Includes cornea, lens, retina, and optic nerve.

• Myopia and hyperopia: Myopia: Nearsightedness; hyperopia: Farsightedness.

• Rods and cones: Photoreceptors for low light (rods) and color vision (cones).

• Pathway of sensory information: From retina to occipital lobe, processing visual information.

Auditory System

The auditory system enables hearing and interpretation of sound.

• Frequency: Number of sound wave cycles per second (measured in Hertz).

• Amplitude: Height of sound waves, related to loudness.

• Pitch: Perceived frequency of sound.

• Timbre: Quality or tone of sound.

• Decibel: Unit measuring sound intensity.

• Outer ear, canal, and eardrum: Structures for collecting and transmitting sound.

• Middle ear, cochlea: Transmits and converts sound to neural signals.

Vestibular System

The vestibular system is responsible for balance and spatial orientation.

• Vestibular system: Detects head movement and position, helps maintain balance.

Somatosensory System

The somatosensory system processes touch, pain, and body position.

• Senses of touch and pain: Mechanoreceptors and nociceptors detect pressure and pain.

• Acute vs. chronic pain: Acute: Short-term; chronic: Long-lasting.

• Role of brain in pain: Brain regions interpret and modulate pain signals.

Chemical Senses

Smell and taste are chemical senses that detect molecules in the environment.

• Sense of smell: Olfactory receptors detect airborne chemicals.

• Sense of taste: Taste buds detect sweet, sour, salty, bitter, and umami flavors.

• Olfactory and gustatory perception: Processes of sensing and interpreting smells and tastes.