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Cognitive Psychology & Neuroscience — Comprehensive Study Notes

Historical Foundations and Major Figures

  • Introspection (late-1800s)

    • Pioneered by Wilhelm Wundt; refined by Edward Titchener.
    • Defined as systematic, trained self-observation of one’s own thoughts, sensations, and feelings.
    • Strengths
      • First attempt to treat mental events as measurable.
      • Gave psychologists a vocabulary for talking about cognition.
    • Limitations
      • Highly subjective; prone to bias and demand characteristics.
      • Cannot examine unconscious processing.
      • Lacked physiological grounding.

  • Behaviourism (≈1890 – 1950s)

    • Key figures: Ivan Pavlov, John B. Watson, B. F. Skinner.
    • Treats the mind as a “black box”; focuses on observable stimulus-response (S–R) relations.
    • Core methods
      • Classical conditioning (Pavlov’s salivating dogs).
      • Operant conditioning: reward ↑ behaviour; punishment ↓ behaviour (Skinner boxes with rats pressing levers).
    • Achievements
      • Powerful techniques for training animals and children; rigorous lab control.
    • Shortcomings
      • Could not explain language, creativity, or why identical stimuli produce different responses.
      • Ethical issues (e.g., Watson’s Little Albert fear conditioning, left un-deconditioned).

  • Cognitive Revolution (1950s – 1960s)

    • Reacted against behaviourism’s neglect of mental processes.
    • Influenced by Kant’s “transcendental method”: infer invisible causes from observable effects.
    • Ulric Neisser’s 1967 book named the field “Cognitive Psychology”.
    • Adopted the computer metaphor: mind = information-processing system, using box-and-arrow flow-charts.

  • Language Acquisition Debate

    • B. F. Skinner (1957): language learned via reinforcement.
    • Noam Chomsky (1959): children produce novel, unreinforced utterances ⇒ language ability is innate and generative.

  • Important Case Studies & Experiments

    • Edward Tolman’s mazes: rats form internal “cognitive maps” even without reward; later locate food quickly.
    • H. M. (Henry Molaison): medial temporal lobe removal stopped seizures but produced severe anterograde + graded retrograde amnesia ⇒ hippocampus essential for long-term memory.
    • Capgras syndrome: recognizes loved ones’ faces but insists they are impostors; linked to disconnection between temporal cortex (recognition) and amygdala (emotion).

Gestalt Psychology & Schemas

  • “The whole is greater than the sum of its parts.”
  • Laws of perceptual organization: similarity, proximity, good continuation, closure, simplicity.
  • Frederic Bartlett: introduced “schemas” — organized knowledge structures that shape perception and memory.

Brain Anatomy & Lateralization

  • Hindbrain

    • Medulla: breathing & heart rate.
    • Pons: relay to cerebellum, sleep & arousal.
    • Cerebellum: movement coordination & balance.

  • Midbrain

    • Orientation to visual/auditory stimuli; pain modulation.

  • Forebrain

    • Subcortical
      • Thalamus: sensory relay.
      • Hypothalamus: homeostasis, drives.
      • Limbic system
        • Amygdala: emotion, fear; damage → flat affect (e.g., Capgras).
        • Hippocampus: learning & memory (H. M.).
    • Cerebral cortex (≈3\,\text{mm} thick)
      • Frontal lobe: executive control; primary motor cortex (M1) maps body → more cortex = finer control.
      • Parietal lobe: primary somatosensory cortex; spatial attention.
      • Temporal lobe: audition, language, memory.
      • Occipital lobe: primary visual cortex (V1).

  • Hemispheric Lateralization

    • Connected by corpus callosum.
    • Split-brain studies: language mostly left, spatial functions somewhat right.

Neurons & Neural Coding

  • Structure: dendrites, soma, axon (myelin from oligodendrocytes/Schwann cells), axon terminals.
  • Resting potential ≈-70\,\text{mV}; threshold ≈-55\,\text{mV} triggers all-or-none action potential.
  • Synaptic transmission: neurotransmitters produce excitatory or inhibitory postsynaptic potentials.
  • Coding theories
    • Specificity (“grandmother cell”) vs population coding (patterns & firing rates).

Research & Measurement Methods

  • Behavioural: reaction time, accuracy, eye-tracking, self-report.
  • Neuroimaging
    • Structural: CT (low-res X-ray), MRI (high-res).
    • Functional: fMRI (BOLD oxygen), PET (radioactive glucose), EEG (temporal waves: \beta alert, \alpha relaxed, \theta drowsy, \delta deep sleep), TMS (temporary disruption via magnetic pulse).
  • Single-cell recording: electrodes in animals (e.g., feature detectors in cat V1).

Vision & Perception

  • Eye → Brain Pathway

    • Light → cornea & lens → retina (rods: low-light; cones: colour & acuity) → bipolar → ganglion → optic nerve → LGN (thalamus) → V1 → diverging “what” (ventral) & “where/how” (dorsal) streams.

  • Parallel Processing

    • Ventral “what” pathway to inferotemporal cortex: object identity; damage → visual agnosia.
    • Dorsal “where/how” pathway to posterior parietal cortex: spatial location & action; damage → optic ataxia.

  • Feature Detection

    • V1 neurons fire for specific orientations & sizes (receptive fields).
    • Motion area MT/V5; damage → akinetopsia (motion blindness).

  • Depth & Constancy

    • Binocular disparity, accommodation, interposition, linear perspective, texture gradients.
    • Perceptual constancies (size, shape, brightness) maintained via unconscious inference.

  • Binding Problem

    • Spatial maps, neural synchrony, and focused attention link distributed features; without attention → conjunction errors.

Object Recognition

  • Feature Nets & Word Recognition

    • Hierarchical detectors: features → letters → bigrams → words.
    • Activation rises with recency & frequency, explaining word-superiority effect and well-formedness.

  • Recognition-by-Components (RBC)

    • 36 geons = 3-D building blocks; view-point invariant.
    • Explains recognition from partial information and novel orientations.

  • Inferotemporal “gnostic” cells

    • Some neurons fire only for particular objects or specific viewpoints.

Face Recognition

  • Fusiform Face Area (FFA): specialized for upright faces; damage → prosopagnosia.
  • Holistic/configural processing
    • Inversion effect: accuracy plummets for upside-down faces.
    • Composite effect: hard to attend to individual facial halves when aligned.
  • Cross-race effect: better memory for own-race faces.

Attention

  • Selective Attention

    • Dichotic listening & shadowing tasks: can repeat attended channel; unattended channel limited to physical traits, but salient words (e.g., name) break through — cocktail-party effect.
    • Early vs Late Selection
      • Early: filter before semantic analysis.
      • Late: all stimuli analysed; irrelevant ones discarded.
      • Neural evidence shows flexible locus depending on perceptual load.

  • Spatial & Object-Based Attention

    • Spotlight metaphor (Posner cueing): valid spatial cues (80 % of trials) speed detection.
    • Object-based neglect: patients ignore contralateral side of an object, not just space.

  • Feature Binding & Conjunction Errors

    • Preattentive stage: parallel feature detection.
    • Focused attention stage: binds features; insufficient attention ⇒ illusory conjunctions.

  • Priming

    • Repetition & semantic priming: automatic, resource-free.
    • Expectation priming: top-down; speeds processing but consumes limited resources.

  • Divided Attention & Executive Control

    • Multitasking success depends on task similarity & total resource demand.
    • Prefrontal cortex maintains goals, inhibits habitual responses.
      • Damage ⇒ perseveration (repeating a wrong action) & goal neglect.
    • Practice → automaticity ⇒ tasks need fewer resources but produce errors like Stroop interference.

  • Inattentional & Change Blindness

    • Failure to notice visible but unattended events (e.g., gorilla video); large scene changes go unnoticed.

  • Unilateral Neglect

    • Right parietal damage ⇒ ignore left side of space/object but can attend if object is cued then rotated, showing both spatial & object components.