Cognitive Psychology Overview

Cognitive Psychology: History and Overview

• Cognitive psychology is the study of mental processes enabling human function—the mind.
• The mind creates mental representations of the world and controls functions like perception, attention, memory, emotions, language, decision-making, and reasoning.
• Cognition involves mental processes—perception, attention, and memory—in understanding and interacting with the world.
• This includes recognizing, recalling, communicating, reasoning, problem-solving and making judgements.
• Cognitive tasks enable us to survive and function well, are a symbol of creativity and intelligence, and build mental world representations for interacting within it.

Early Attempts to Study the Mind

• Fechner and Weber (psychophysics): In 1854 Germany, they began to theorize on measuring mental processes. Fechner, a physicist, studied how physical differences translated into psychological experiences.
• Weber, a physician, and Fechner found our experiences don't always match objective differences. Our perception of differences relies on the starting point (reference dependence).
• Paul Broca (1861, France): Linked specific brain parts with specific mental functions, demonstrating the mind and brain's close relationship (localization of ability).
• Broca's aphasia: A language production deficiency resulting from frontal lobe damage.
• Franciscus Donders (1868, Netherlands): Early cognitive psychology experiments focused on reaction times (mental chronometry). Distinguishing between simple reaction time (responding to one stimulus) and choice reaction time (responding to multiple stimuli), determining decision-making time.
• Wilhelm Wundt (structuralism and introspection): 1879, Germany established the first psychology lab and course to study human experience structure. The father of experimental psychology, he officially called himself a psychologist.
• Structuralism: An approach explaining perception as the sum of elementary sensations.
• Analytic introspection: Trained participants described their experiences and thoughts in response to stimuli.

Hermann Ebbinghaus (Forgetting and Savings Curves)

• Studied memory. Used nonsense syllables to determine repetitions needed to recall lists without errors.
• Savings: A measure of memory retained after a learning and relearning period.
• Savings Curve: Visual representation showing rapid memory decay in the first few days after learning, then stabilizing.
• Forgetting Curves provide a sense of how much/quickly we forget. Serial Position Effect: Items at the beginning and end of a list are easier to recall than those in the middle.

William James (Psychology text and Course)

• 1875 (US): Taught the very first US psychology course at Harvard, and wrote the first US treatise on psychology (Principles of Psychology) in 1890.
• Functionalism: Focused on observable functions of the mind instead of experiments.

Behaviorism (Early-Mid 1900s)

• Behaviorism focused on observable behavior, eschewing study of the subjective mind.
• Ivan Pavlov: Discovered classical conditioning through stimulus-response pairing (conditioned and unconditioned stimuli).
• John Watson: Founded behaviorism, aiming to predict and control behavior through observable behaviors. Famous for the Little Albert study.
• B.F. Skinner: Introduced operant conditioning, emphasizing reinforcement (stimulus-response-reinforcement). Experimented by reinforcing rats to show how behavior could be maintained/increased.
• Edward Chace Tolman: Disagreed with behaviorism. His rat experiments showed that rats created cognitive maps.
• Edward Thorndike: Suggested that animal learning involved goal-directed behavior (trial and error learning) based on assuming thought processes in animals. Focused on educational psychology.

Cognitive Revolution (1950s-1960s)

• A shift in psychology towards explaining actions based on the mind.
• Influenced by computer science, inspired by the concept of information processing through stages in computers.
• Information-processing approach: Describes the mind as sequentially processing information through stages.
• Ulric Neisser coined "Cognitive Psychology" in his 1967 book, significantly marking the Cognitive Revolution.

Memory and Neuroscience

• Atkinson and Shiffrin (1968) proposed a three-stage model of memory: sensory, short-term, and long-term memory.
• Long-Term Memory: Large, long-lasting storage system with different types—episodic (life events), semantic (facts), and procedural (physical skills).

Neuroscience, Methods, and Technologies

• Neuropsychology: Studies behavior in brain-damaged individuals, comparing with non-damaged individuals.
• Electrophysiology: Examines electrical responses of nervous systems, including neurons.
• Brain Imaging: Techniques like fMRI create images of brain activity in response to cognitive tasks.
• PET (Positron Emission Tomography) and fMRI (Functional Magnetic Resonance Imaging): Used to see brain areas activated during activity.
• Functional Connectivity: Examines correlation of neural activity in different brain regions. Used methods like Resting state fMRI to determine functional connectivity of separated structures.

Localization of Function

• Localization of Function: Different brain areas perform specific jobs.
• Neuropsychology(comparison), Neuron recordings(stimulating neurons to isolate and measure activity in certain parts of the brain), and Brain imaging(looking at the pictures of brain activity with certain tasks to help find localization areas).
• Broca's Area: Involved in language production.
• Wernicke's Area: Involved in language comprehension.
• Occipital Lobe, Frontal Lobe, Temporal Lobe, Brain Stem, Cerebellum, Parietal Lobe, Motor Area, and Sensory Area

Distributed Representation

• Distributed Representation: Cognition activates many brain areas. Different brain areas are interconnected (neural networks).
• Connectome: structural map of brain network elements/connections.
• Structural connectivity: Brain "wiring diagram" created by axons (connections). Unique to individuals.
• Functional connectivity: Interaction among neurons within the connectome, determined by correlated activity.
• Dynamics of Cognition: Brain's activity and flow change constantly (even at rest). Default mode network: The brain's largest resting-state network, associated with mind-wandering, self-reflection.

Perception

• Perception: Sensory stimulation resulting in experiences.
• Senses (sight, hearing, taste, touch, smell, movement, balance, interoception).

Basic Concepts

• Percepts change with additional information. Perception is similar to reasoned problem-solving, sometimes unconsciously. Percepts occur concurrently with actions (adaptive).
• Stimulus Energy -> Sensory Receptors -> Neural Impulses -> Brain
• Kinesthetic: Body position/movement, coordination; Receptors in muscles/joints.
• Vestibular: Head position/movement (balance); Receptors in inner ear.
• Inverse Projection Problem: Determining the object from retinal images. Perceptual system solves this ambiguity.

Information Used in Human Perception (Bottom-Up vs. Top-Down)

• Bottom-Up (Data-Based): Processing starts with sensory receptor input. Features combined to create recognition.
• Top-Down (Knowledge-Based): Involves prior knowledge; percepts are actively constructed by expectations/prior knowledge.

Historical Perspectives on Perception

• Hermann von Helmholtz: Recognized ambiguous retinal images and introduced the likelihood principle (we perceive the most likely object based on stimuli). Introduced unconscious inference (perceptions as unconscious assumptions about the environment).
• Gestalt Psychologists: Proposed principles of perceptual organization, emphasizing innate mental organization.

Gestalt Assumptions and Principles

• Perception depends on Gestalt organizing principles, not just retinal stimuli.
• Role of experience is limited compared to these built-in principles (bottom-up approach). Experience influences perception but isn't the key driver.
• Apparent Movement: Perception of movement when stimuli in different locations flash with proper timing.
• Principles of perceptual organization for grouping elements (Principles of Good Continuation, Pragnanz/Simplicity, Similarity, Closure).

Regularities in the Environment (Top-Down Processing)

• Physical Regularities: Environment-specific physical properties (oblique effect demonstrates vertical/horizontal preference). Light-from-above heuristic (light often comes from above).
• Semantic Regularities: Scene schemas (knowledge of typical scene content).

Bayesian Inference

• Bayesian inference: Our outcome probability estimate depends on prior probability (initial belief) and likelihood (evidence's consistency with the outcome).

Experience-Dependent Plasticity

• Experience shapes the nervous system (e.g., perceptual systems change with experience).

Perception and Action

• Perception pathway (ventral/what): Visual cortex to temporal lobe.
• Action pathway (dorsal/where): Visual cortex to parietal lobe.
• Mirror neurons: Neurons responding during actions watched or performed. Evidence in fMRI studies.