cognitive psych. - history & experimental methods

what is cognitive psychology?

the scientific study of the mind (how it operates, and how its operations lead to overt behavior);

study of mental operations used to navigate the world

What are cognitive processes

processes of the mind that we cannot see directly

• memory/attention/thinking

What are manifest behaviors?

Observable behaviors that can be directly measured, driven by latent processes

• reaction time/task performance

what are latent processes?

unobservable processes that drive manifest behaviors

• memory/attention/thinking

What’s the problem of a cognitive psychologist? (? → ?)

they want to understand latent processes, but can only observe manifest behaviors;

θ (latent process) → Y (manifest behaviors)

What are controlled experiments in cognitive psych?

Tests where subjects’ performance or behavior is observed under controlled conditions

What is mathematical modeling in cognitive psychology?

Using mathematical language to explain unobservable processes and understand cognitive processes.

What are neural recordings, and how are they used?

Measurements of brain activity often combined with controlled experiments/mathematical modelling

• fMRI, EEG

What is represented by X → θ → Y?

Independent variable (X) influences latent cognitive processes (θ), which in turn produce observable outcomes (Y)

How can exogenous (external) factors influence cognition?

They can alter latent processes (θ), which changes behavior (Y)

Who first theorized about human memory?

Aristotle, in De Memoria

• philosophy

What did Rene Descartes propose about the mind and body?

Mind-body interaction: the mind controls the body and vice versa

philosophy

What distinction did Ibn Sina make in cognition?

Primary cognition (unconscious sensory-perceptual processes) vs. secondary cognition (conscious reflection, metacognition)

philosophy

What was Vasubandhu’s theory of cognition?

All experience is built from transient, discontinuous mental events; cognition is a stream of distinct events.

philosophy

What is psychophysics?

study of how physical stimuli triggers sensation and perception, using mathematical principles from the physical sciences to understand psychological experiences

• PAVED THE WAY FOR MEASURING UNOBSERVABLE PROCESSES

What is the Just Noticeable Difference (JND)?

The threshold at which a change in stimulus intensity is noticed—Increases linearly with baseline level of intensity

• Weber’s Law

• ΔI = I × kw

What does Weber’s Law state?

The higher the baseline intensity (of a stimulus), the larger the change in intensity needed to notice a difference

What does Fechner’s Law (Weber-Fechner’s Law) state?

The perceived intensity of a change depends on subjective experience; small changes feel large at low intensity, large changes needed at high intensity.

What is Fechner’s constant?

A value that quantifies the relationship between a physical stimulus and perceived intensity; reciprocal to Weber’s constant

• RECIPROCAL to Weber’s constant (1/kw ) –smaller value than Weber’s constant

What is Weber’s constant (kw)?

The ratio of the smallest noticeable change in a stimulus to the original intensity.

Gabor patch

visual stimulus for studying how the visual system responds to patterns

Hemholtz’s frog experiment

Electrically stimulating frog’s calf muscle–caused the muscle to contract while a galvanometer measured time-since stimulation

• ~27ms since stimulation for calf muscle to contract

What did Hemholt’z Frog experment prove?

Neural impulses DON’T occur instantly! –neural impulses are NOT automatic

What is unconscious inference (Helmholtz)?

The brain makes automatic assumptions based on perception and past experience.

• Helmlotz

What did Christine Ladd-Franklin discover?

Human eyes vary in sensitivity to hue changes depending on baseline color intensity

• Trained under Helmlotz

What is Gestalt Psychology?

A school of psychology arguing perception is active, not passive; “the whole is other than the sum of its parts.”

we CHOOSE/SHAPE our perceptual experiences

Who is the “Father of Memory”?

Hermann Ebbighaus

What did Ebbinghaus discover?

The forgetting curve—memory retention declines rapidly, then levels off over time.

• Tested his abilities to free recall lists of nonsense words

Who invented the concept of schemas in memory reconstrution?

Frederic Bartlett

What is a memory schema?

An organized knowledge structure that shapes recall based on expectations and cultural context.

• Memory = active, constructive process, not a passive record

• culturally shaped

Federic Bartlett

What is behaviorism?

A school of psychology focused only on observable behavior (S → R), rejecting study of mental operations.

• NO SELF-REPORT

argues that mental operations CANNOT be studied— “black box”

Who popularized behaviorism?

John B. Watson

• Little Albert expriment—classical conditioning

What was the Little Albert experiment?

Behaviorism experiment that demonstrated classical conditioning in humans by conditioning fear in an infant for a white rat; this fear generalized to other furry, white objects

• rat accompanied by a loud noise that scared Albert, Albert is then showed a bunny and Albert is scared

What are the two main forms of conditioning in behaviorism?

Classical conditioning (Watson, Pavlov) and operant conditioning (B.F. Skinner).

What is classical conditioning?

Associating a neutral stimulus (NS) with an unconditioned stimulus (UCS) to elicit a conditioned response (CR).

• Conditioned response (CR) is expected when the conditioned stimulus (CS) appears after repeating S → R

UCR = involuntary/natural; eventually gets paired with UCS

• NS (later the CS) is paired with UCS

What is operant conditioning?

Learning where behavior is strengthened or weakened by consequences (reinforcement or punishment).

• Positive reinforcement

• Negative reinforcement

• Positive punishment

• Negative punishment

Who was the “Mother of Behavioral Therapy”?

Mary Cover Jones, who used conditioning to reduce phobias (Little Peter experiment).

What was the Clarks’ doll study?

Kenneth and Mamie Clark showed children associated positive traits with White dolls and negative traits with Black dolls.

What challenges to behaviorism arose?

It ignored internal knowledge acquisition and cognitive processes (e.g., Tolman’s cognitive maps, Chomsky’s language learning critique)

• we learn even when there’s no impetus to do so

What did Edward Tolman’s latent learning study show?

Rats could form cognitive maps of a maze without rewards, challenging behaviorism

What was Noam Chomsky’s critique of behaviorism?

Children produce novel words (“goed” instead of “went”), showing language isn’t learned purely through reinforcement.

Who founded the first experimental psychology lab?

Wilhelm Wundt

What method did Wundt use?

Introspection—trained participants gave detailed self-reports about experiences.

What is structuralism?

school of psychology concerned with understanding the “structure” of the mind by identifying basic elements and how they combine

• introspection & hard sciences approach

• first major school of psychology

Who invented structuralism?

Bradford Titchner

What is the structuralism theory?

the mind constructs perceptions, memories, and thoughts from lower-level sensation–EVERYTHING BEGINS WITH SENSATIONS

What are the key principles of structuralism?

Atomism, sensationalism, associationism

What is atomism?

all thoughts are composed of elementary building blocks–“atoms”

• principle of structuralism

What is Sensationalism?

the atoms of thought derive from sensory experiences

• principle of structuralism

What is Associationism?

complex thought arise from associating lower-level sensations

• principle of structuralism

What are the three parts of conscious experience in structuralism?

Sensations, images (thoughts/memories), and affections (emotions/feelings)

What are the three qualities of conscious experience in structuralism?

Quality (type of experience), intensity (strength), and duration (length)

Who combined structuralism with psychophysics?

Margaret Floy Washburn, studying animal consciousness.

• combined Weber-Fechner methods of studying perception + Titchner’s methods of introspection

What were the main criticisms of structuralism?

Relied too much on self-report

• Cannot be independently verified by another observers

  • Demand characteristics

  • No two participants will have the EXACT same experience-

• Extensive training–is this representative of day-to-day experiences?

• Limited to conscious experiences we can report

Who invented psychophysics?

Gustav Fechner

What is Positive reinforcement (operant conditioning)?

adding something pleasant to increase behavior

What is Negative reinforcement (operant conditioning)?

removing something unpleasant to increase behavior

What is Positive punishment (operant conditioning) ?

add something unpleasant to decrease behavior

What is Negative punishment (operant conditioning)?

remove something pleasant to decrease behavior