Cognitive Psychology: Key Concepts and Brain Function

Lateralization

The tendency for the two hemispheres of the brain to specialize in different cognitive functions.

• Examples:

○ Left hemisphere → language production (Broca's area), speech perception, logical/analytical reasoning.

○ Right hemisphere → spatial attention, face recognition, visual-motor tasks, and holistic pattern recognition.

Connection: Split-brain studies (Gazzaniga, Sperry) showed lateralization in action — patients could name objects presented to the right visual field (LH), but could draw objects better when presented to the left visual field (RH).

Left hemisphere

language production (Broca's area), speech perception, logical/analytical reasoning.

Right hemisphere

Spatial attention, face recognition, visual-motor tasks, and holistic pattern recognition.

Dualism

A philosophical doctrine (Descartes) claiming the mind and body are separate entities; the mind is immaterial, while the body/brain are physical.

• Importance: Historically important but largely rejected in cognitive psychology, which views mental processes as emerging from brain activity (monism).

• Connection: Dualism delayed the scientific study of cognition because it implied the mind couldn't be studied empirically.

Empiricism

The view that knowledge is derived from sensory experience (Locke, Hume).

• Examples: Learning comes from observation, association, and experience rather than innate ideas.

• Connection: Laid groundwork for behaviorism and experimental psychology, emphasizing measurable input-output relationships.

Associationism

The idea that knowledge results from the linking of experiences and ideas in memory.

• Examples:

○ Classical conditioning (Pavlov) → association between stimulus and response.

○ "Red + fire truck" → repeated pairing builds associations in memory.

• Connection: Critical precursor to learning theories and cognitive models of memory.

Classical conditioning

Association between stimulus and response (Pavlov).

Phrenology

Early 19th-century pseudoscience claiming bumps on the skull correspond to mental faculties.

• Importance: Wrong in method but historically relevant because it suggested localization of function — that specific mental abilities could be tied to specific brain regions.

Localization of Function

The principle that specific brain areas are specialized for specific cognitive functions.

• Examples:

○ Broca's area (LH frontal lobe) → speech production.

○ Wernicke's area (LH temporal lobe) → speech comprehension.

Connection: Supported by lesion studies, modern neuroimaging (fMRI, PET). Contrasts with distributed processing models.

Broca's area

LH frontal lobe → speech production.

Wernicke's area

LH temporal lobe → speech comprehension.

Reaction Time Experiments

Measuring the time between stimulus presentation and a response as an index of mental processing speed.

• Examples: Donders' Subtractive Method — comparing reaction times across tasks to infer processing stages.

• Connection: Foundation of cognitive psychology's experimental approach.

Subtractive Method

Donders' method (1868) of isolating mental processes by subtracting reaction times of simple vs. choice tasks.

• Example:

○ Simple RT (see a light → press a button).

○ Choice RT (see red/green light → press different buttons).

○ Difference = time required for stimulus discrimination and decision-making.

Simple RT

See a light → press a button.

Choice RT

See red/green light → press different buttons.

Structuralism

Early psychological school (Wundt, Titchener) focusing on the analysis of conscious experience into basic elements (sensations, feelings, images).

• Method: Introspection — participants reported the contents of their conscious experience.

• Limitations: Highly subjective; rejected by behaviorists.

Functionalism

Early psychological school (William James, Dewey) focusing on the purpose or adaptive functions of mental processes.

• Example: Memory and attention evolved because they helped organisms survive and adapt.

• Connection: More pragmatic than structuralism; influenced applied psychology and education.

Forgetting Curves

Ebbinghaus' finding that memory retention declines rapidly after learning and then levels off.

• Example: Steep drop in recall within the first 24 hours, followed by gradual forgetting over weeks/months.

• Connection: Demonstrates the importance of rehearsal and distributed practice for long-term retention.

Human/Machine Interaction

Research on how humans interact with computers and technology; origins in WWII studies of radar operators and pilots.

• Connection: Led to the idea of the mind as an information processor — like a computer.

Signal Detection Theory

A framework for understanding decision-making under conditions of uncertainty. Distinguishes between:

○ Sensitivity (d′) → ability to detect a signal amid noise.

○ Criterion (β) → threshold for deciding "yes/no."

• Example: Radar operators deciding if a blip is an enemy aircraft or noise.

• Connection: Applied in perception, memory, eyewitness testimony.

Communications Theory

Theory from engineering (Shannon & Weaver) describing information transmission as encoding → channel → decoding.

• Connection: Inspired cognitive psychologists to model the mind as a communication system that encodes, stores, and transmits information.

Cognitive Maps

Mental representations of spatial layouts.

• Example: Tolman's rat maze experiments — rats built a "map" of the maze, not just stimulus-response habits.

• Connection: Early evidence against strict behaviorism; suggested internal mental representations guide behavior.

S-O-R Psychology (Stimulus-Organism-Response)

A refinement of behaviorism that recognizes the organism's internal processes mediate between stimulus and response.

• Contrast: Traditional behaviorism = S-R (stimulus-response). S-O-R introduces cognitive/physiological "black box" between them.

• Connection: Helps explain differences in learning/perception across individuals; precursor to cognitive psychology.

Mental Representations

Internal symbols, codes, or structures that stand for external reality in the mind.

• Examples: Cognitive maps, word meanings, images.

• Connection: Core assumption of cognitive psychology: the mind works with representations, not just raw inputs/outputs.

Modularity Hypothesis

Idea (Fodor, 1983) that the mind is composed of semi-independent, specialized modules for processing different kinds of information.

• Examples: Language module (Chomsky's "language acquisition device"), face recognition, visual processing.

• Connection: Debate in cog psych: is the mind highly modular (specialized) or more general-purpose?

Nativism

Philosophical stance (Plato, Descartes, Chomsky) that certain knowledge, structures, or abilities are innate.

• Examples: Universal grammar (Chomsky), reflexes, perceptual categories.

• Contrast: Opposite of empiricism; emphasizes biological constraints on learning.

Computer Science

Field studying computation, algorithms, and artificial systems.

• Connection: Provided models for cognition → mind as an information processor; helped shape Information Processing Theory.

Information Processing Approach

View that cognition involves sequential stages where information is transformed, stored, retrieved, and used.

• Examples: Multistore Model of Memory (Atkinson & Shiffrin, 1968).

• Connection: Core metaphor of cognitive psychology in the 1950s-70s — mind compared to computer hardware/software.

Serial Processing

Tasks are handled step by step, one after the other.

• Examples:

○ Early computer models used serial assumptions; modern models allow parallel/distributed processing.

Parallel Processing

Multiple processes occur simultaneously.

• Examples:

○ Reading aloud a word involves parallel processing (visual + phonological).

Symbol Manipulation

Cognitive processes work by manipulating mental symbols (like a computer manipulates binary code).

• Subtypes:

○ Semantic symbols → carry meaning (e.g., "dog" represents the concept of dog).

○ Syntactic program rules → rules for combining/manipulating symbols (grammar, logic).

• Connection: Tied to early AI and cognitive science theories of symbolic reasoning.

Transformation of Information

The process by which information is encoded, recoded, or converted from one representation to another.

• Example: Turning a visual image into verbal description; sensory → short-term → long-term storage.

• Connection: Core to memory models (encoding, consolidation, retrieval).

Cognitive Science

Interdisciplinary study of the mind and intelligence, combining psychology, computer science, linguistics, philosophy, anthropology, and neuroscience.

• Goal: To understand the nature of cognition and build computational models of it.

Neuron

Basic unit of the nervous system.

Cell Body (Soma)

Contains nucleus; integrates incoming signals.

Dendrites

Receive signals from other neurons.

Axon

Sends electrical impulses away from cell body.

Myelin Sheath

Insulates axon, speeds conduction.

Synapse

Junction where neurotransmitters cross between neurons.

Brainstem

Lowest part of brain, controls basic life functions (breathing, heart rate, arousal).

• Connection: Important for consciousness but not higher cognition.

Cerebellum

Structure at the back of the brain involved in motor control, balance, coordination.

• Connection: Also contributes to procedural/implicit memory (e.g., motor skill learning, piano playing).

Cortex (Cerebral Cortex)

Outer layer of the brain, responsible for higher cognitive functions.

• Divided into lobes: frontal, temporal, occipital, parietal.

• Importance: Seat of attention, memory, perception, decision-making.

Frontal Lobe

Planning, decision-making, motor control, working memory, language production (Broca's area).

Temporal Lobe

Auditory processing, memory, language comprehension (Wernicke's area).

Occipital Lobe

Visual processing.

Parietal Lobe

Sensory integration, spatial attention, touch perception.

Brodmann's Cytoarchitectonic Map

Early 20th-century mapping of the cortex based on cellular structure/density.

• Importance: Still used to designate functional regions (e.g., Broca's area = BA 44/45).

CT/CAT Scans

Imaging technique using X-rays to create structural brain images.

• Use: Identifies lesions, strokes, tumors.

• Limitation: Poorer resolution than MRI.

Electroencephalogram (EEG)

Measures electrical activity in the brain through scalp electrodes.

• Strengths: High temporal resolution (milliseconds).

• Weaknesses: Poor spatial resolution.

• Applications: Sleep research, epilepsy, cognitive tasks.

Evoked Potential

EEG signal averaged over many trials to isolate brain's electrical response to a stimulus.

• Use: Detects when/where brain processes occur.

Transcranial Magnetic Stimulation (TMS)

Non-invasive method that uses magnetic fields to disrupt or stimulate neural activity in targeted brain regions.

• Applications: Mapping brain function, treating depression.

PET Scan (Positron Emission Tomography)

Imaging method measuring glucose metabolism in brain using radioactive tracer.

• Strengths: Shows active regions during tasks.

• Weakness: Lower temporal resolution, invasive.

fMRI (Functional Magnetic Resonance Imaging)

Imaging method that measures changes in blood oxygenation (BOLD signal) during cognitive tasks.

• Strengths: High spatial resolution.

• Weaknesses: Lower temporal resolution (seconds).

• Use: Localizing brain activity during memory, perception, decision-making tasks.

Double Dissociation (in Neuropsychology)

A research method showing that two cognitive functions rely on different brain systems by demonstrating independent impairments.

• Examples:

○ Patient H.M. (anterograde amnesia) → impaired episodic memory, intact procedural skills.

○ Patient K.C. → impaired episodic memory, intact semantic memory.

○ When one function is impaired but another remains intact in Patient A, and the reverse is true in Patient B, we infer separate systems.

• Connection: Strong evidence for the fractionation of memory systems.

Memory

The set of cognitive processes by which we encode, store, and retrieve information.

• Core Stages:

1. Encoding → transforming sensory input into a mental representation.

2. Storage → maintaining information over time.

3. Retrieval → accessing stored information when needed.

• Types of Memory (broad divisions):

○ Sensory Memory: brief, modality-specific registers for raw input (iconic, echoic).

○ Short-Term / Working Memory: active, limited-capacity system for holding and manipulating info.

○ Long-Term Memory: relatively permanent store of knowledge, skills, experiences.

• Connection: Memory research is central to cognitive psychology because it demonstrates how the brain actively processes and organizes information, not just passively receives it.

Core Stages of Memory

1. Encoding → transforming sensory input into a mental representation.

2. Storage → maintaining information over time.

3. Retrieval → accessing stored information when needed.

Sensory Memory

Brief, modality-specific registers for raw input (iconic, echoic).

Short-Term / Working Memory

Active, limited-capacity system for holding and manipulating info.

Long-Term Memory

Relatively permanent store of knowledge, skills, experiences.

Multistore Model / Modal Model

A model describing memory as three separate stores — sensory memory, short-term memory (STM), and long-term memory (LTM).

• Capacity, Duration, Code:

○ Sensory registers → very brief (iconic ~ 0.3 sec; echoic ~ 2-4 sec), large capacity, raw sensory code.

○ STM → limited capacity (~7±2 items), duration ~15-30 sec without rehearsal, primarily acoustic/phonological code.

○ LTM → virtually unlimited capacity, duration possibly permanent, primarily semantic code.

• Connection: Explains serial position effect (primacy = rehearsal into LTM, recency = STM contents).

Capacity

The amount of information a memory system can hold at one time.

• Examples:

○ STM capacity ≈ 7±2 (Miller's "magic number").

○ Chunking increases effective capacity (e.g., remembering 14921776 as "1492" + "1776").

Duration

How long information persists in a memory system without rehearsal.

• Examples:

○ Sensory memory: <1 sec (iconic), a few seconds (echoic).

○ STM: ~20 seconds (Brown-Peterson task).

○ LTM: potentially lifelong (permastore studies, Bahrick, 1975).

Code

The format in which information is represented in memory.

• Examples:

○ STM → mainly acoustic (errors based on sound similarity, e.g., "B" misheard as "V").

○ LTM → mainly semantic (errors based on meaning, e.g., "big" recalled as "large").

○ Also visual coding possible (Posner letter-matching tasks).

Sensory Registers

Temporary storage for raw sensory input before conscious processing.

• Types:

○ Iconic Memory → visual sensory store; studied by Sperling's partial report technique.

○ Echoic Memory → auditory sensory store; lasts 2-4 seconds.

Iconic Memory

Visual sensory store; studied by Sperling's partial report technique.

Echoic Memory

Auditory sensory store; lasts 2-4 seconds.

Partial Report Technique

Method showing that sensory memory has large capacity but rapid decay.

Experiment: Subjects briefly saw a 3×3 grid of letters; cued by tone to recall one row. High accuracy suggested more letters were briefly available than could be reported in full.

Short-Term Memory (STM)

Limited-capacity, temporary store for information currently in use.

• Capacity: 7±2 items (Miller, 1956).

• Duration: ~15-30 sec without rehearsal (Brown-Peterson task).

• Code: Primarily acoustic but can include semantic/visual coding.

Digit Span

The number of digits a person can recall immediately in correct order; standard test of STM capacity.

• Typical: 7±2 for most adults; trained mnemonists can extend via chunking.

Chunking

Organizing information into larger, meaningful units to expand STM capacity.

• Example: 1-4-9-2-1-7-7-6 → "1492" (Columbus) + "1776" (American independence).

Decay Theory

Forgetting occurs because memory traces fade with time.

Brown-Peterson task suggests time-based decay

Interference Theory

Forgetting occurs because other information blocks retrieval.

Keppel & Underwood (1962) showed proactive interference also plays a key role.

Proactive Interference

Old information disrupts recall of new.

Retroactive Interference

New information disrupts recall of old.

Control Processes

Strategies under conscious control that regulate flow of information between STM and LTM.

Examples: Rehearsal, elaboration, imagery, retrieval cue use.

Rehearsal

Repetition of information to maintain it in STM and (sometimes) transfer it to LTM.

• Types:

○ Maintenance rehearsal → rote repetition; keeps items in STM, limited LTM benefit.

○ Elaborative rehearsal → adding meaning, connections, associations; promotes LTM storage.

Maintenance rehearsal

Rote repetition; keeps items in STM, limited LTM benefit.

Elaborative rehearsal

Adding meaning, connections, associations; promotes LTM storage.

Elaboration

Process of enriching information by relating it to existing knowledge or generating associations.

• Example: Instead of memorizing "dog-tree," imagine a dog chasing a squirrel up a tree.

• Connection: Central to Levels of Processing theory.

Imagery

Using mental pictures to encode information.

• Evidence: Bower (1970) showed interactive imagery (e.g., apple jammed into a window) improved paired-associate learning.

• Connection: Used in mnemonic strategies (method of loci, keyword method).

Use of Retrieval Cues

Memory is improved when cues present at encoding are available at retrieval.

• Examples: Context effects, state-dependent learning, mood congruency.

• Connection: Encoding specificity principle — memory performance depends on match between encoding and retrieval contexts.

Long-Term Memory (LTM)

The relatively permanent and unlimited store of knowledge, skills, and experiences.

• Capacity: Virtually unlimited.

• Duration: Potentially lifelong (Bahrick's "permastore" studies of Spanish vocab and high school classmates).

• Code: Primarily semantic (errors based on meaning, e.g., recalling "big" instead of "large"), but can also store visual and auditory codes.

• Connection: Divided into declarative (explicit) vs. non-declarative (implicit) systems.

Serial Position Effect

The pattern of memory performance showing better recall for items at the beginning (primacy effect) and end (recency effect) of a list, compared to the middle.

• Primacy: Due to rehearsal → transfer to LTM.

• Recency: Due to items still in STM.

Connection: Classic evidence for separate STM vs. LTM stores.

Primacy Effect

Enhanced recall for early items because they receive more rehearsal and enter LTM.

Evidence: Rundus & Atkinson (1970) — rehearsal frequency predicts primacy.

Recency Effect

Enhanced recall for most recent items because they are still active in STM.

Working Memory

A limited-capacity system for temporary storage and manipulation of information.

• Components:

○ Phonological Loop: Holds/verbal rehearsal of auditory information (digit span, language tasks).

○ Visuospatial Sketchpad: Temporary storage for visual/spatial material (mental rotation, imagery).

○ Central Executive: Supervisory system that allocates attention and coordinates the subsystems.

○ (Later) Episodic Buffer: Integrates info from loop, sketchpad, and LTM into a single representation.

Phonological Loop

Verbal/auditory working memory store. Includes a phonological store and an articulatory rehearsal mechanism.

• Evidence:

○ Word length effect → shorter words remembered better than longer ones (Baddeley, Thomson, & Buchanan, 1975).

○ Articulatory suppression (repeating "the, the, the") disrupts phonological loop processing.

Visuospatial Sketchpad

Holds and manipulates visual and spatial information.

• Evidence: Quinn & McConnell (1996) → visual noise interferes with visual mnemonic performance but not verbal rehearsal.

• Examples: Mental imagery, navigation, puzzle solving.

Central Executive

The attentional control system of working memory. Directs focus, switches between tasks, and integrates information.

• Connection: Associated with prefrontal cortex activity.

Episodic Buffer

Integrates info from loop, sketchpad, and LTM into a single representation.

Declarative Memory

Memory for facts and events that can be consciously recalled ("knowing that").

○ Episodic: Personal events/experiences tied to a specific time and place (e.g., your last birthday). Relies heavily on hippocampus.

○ Semantic: General knowledge, facts, concepts (e.g., Paris is the capital of France). Relies on lateral/medial temporal lobes.

Connection: Tulving argued episodic and semantic are distinct but related systems.

Episodic Memory

Personal events/experiences tied to a specific time and place (e.g., your last birthday). Relies heavily on hippocampus.

Semantic Memory

General knowledge, facts, concepts (e.g., Paris is the capital of France). Relies on lateral/medial temporal lobes.

Procedural Memory

Non-declarative memory for skills and actions ("knowing how").

• Examples: Riding a bike, typing, mirror-tracing tasks.

• Connection: Intact in amnesic patients like H.M. and Clive Wearing, even with severe episodic/semantic deficits.

Amnesia

Pathological memory loss due to brain damage or trauma.

• Types:

○ Retrograde → loss of memories formed before injury (esp. recent).

○ Anterograde → inability to form new long-term declarative memories after injury.

○ Global → combination of both.

• Famous Cases: H.M. (hippocampal removal), Clive Wearing (encephalitis), P.Z. (Korsakoff's).

Retrograde Amnesia

Loss of previously formed memories prior to brain damage.

• Pattern: Often temporally graded — distant memories better preserved than recent ones (Butters & Cermak, 1986, patient P.Z.).

Anterograde Amnesia

Inability to form new declarative memories after brain injury.

• Example: H.M. → intact STM and IQ but no ability to form new episodic/semantic memories; preserved procedural learning (mirror tracing).

Source Amnesia

Remembering a fact or piece of information but forgetting where or from whom it was learned.

• Example: Alzheimer's/amnesic patients recall new facts but cannot identify the source (Schacter et al., 1984).

• Connection: Highlights distinction between semantic and episodic memory.

Long-Term Potentiation (LTP)

A persistent increase in synaptic strength following repeated stimulation. Considered a biological mechanism for memory consolidation.

• Evidence: ECT (electroconvulsive therapy) disrupts consolidation of recent memories, supporting LTP's role.

Consolidation of Memory

The process by which newly encoded memories are stabilized and stored in LTM.

• Sleep: Plays a key role in consolidation (Antony & Paller, 2016).

• Connection: Disruption (e.g., trauma, drugs, ECT) especially impairs recent memories.