psychology exam

What is psychology?

Science of behaviour and factors that influence it

What is behaviour?

directly observable activity mental processes

•not observable: e.g., thinking, motivation

Causal Factors

Biological
Individual
Environmental

Goals of psychology

Identify/describe behaviour
identify/describe factors causing/ influencing
Replication
Change

Perspectives on behaviour

Guides to understanding
Viewpoints to understanding behaviour
Each considers different components to be important
Behaviour has diverse causes

Psychology is theoretically diverse

Biological perspective: the beginning

Mind-body dualism
Monism

Beginings of brain- behaviour connection

In support of monism

Luigi galvani

Severed leg of frog

Karl Lashley

Studied learning and memory before and after

Early schools of thought

Structuralism

Sensations as basic elements of consciousness
Wilhelm Wundt, basic elements

Functionalism

“Functions” of consciousness (the ‘whys’ not the ‘whats’)
William James, functional

Evolutionary behaviour

Legacy of darwin
Natural selection
Evolutionary psychology

Cognitive perspective - Piaget

Field of child development
Children not “miniature adults”
Stages of cognitive development

Psychodynamic Perspective - Freud

Psychological problems are result of:

Motives in part of mind we are unaware of = ‘unconscious’
Unresolved past conflicts
Defence mechanisms
Struggle between impulses and defence

Beginning: Radical Behaviourism

(Wastin; skinner)

Observable behaviour & NOT mental events
Behaviour controlled by environment
Control environment then control behaviour

Humanistic perspective

Emphasizes

Conscious motives
Freedom
Choice
Self-actualization

- Reaching one’s individual potential

Sociocultural Perspective

Culture = enduring values, beliefs, behaviours, traditions

Norms = rules that specify what is acceptable

Focus is on:

Role of culture in behaviour
Manner in which culture is transmitted
Similarities and differences between people in different cultures

Consciousness

Definition, measurement, levels and characteristics

Circadian rhythms

Brain structures and disruptions

Sleep and dreaming

Patterns, structures, typology, theories and problems

Circadian Rhythms

• A circadian rhythm is the regular fluctuation in certain

body functions from a high point to a low point within

a 24-hour period.

• Rhythmic daily cycles, e.g., wakefulness & sleep

Measuring Consciousness

• But how do we measure such states?

• Self-reports

– Direct but not verifiable

• Physiological (e.g., EEG)

– objective

• Behavioural

– Performance on tasks (e.g., rouge test)

States of consciousness

Awareness/ consciousness
Daydreaming
Altered consciousness
Unconsciousness

Structure of Sleep

• Cycle through stages roughly every 90 minutes

– Brain activity, other physiological responses change

– 3.5-7.5 cps, 1-2 s bursts , 0.5-2 cps

REM sleep

Regulated by brainstem (reticular formation)
Limbic system activity increases
Association areas near visual cortex active
Motor cortex active but signals blocked
Decreased activity in prefrontal cortex

Heart-rate increases
Breathing more rapid and irregular
Brain-wave activity increases
‘REM sleep paralysis’

Why Do We Sleep?

• Restoration Model

• Evidence?

– Adenosine

Evolutionary/circadian models

– adaptive

– survival

– conserving energy

Sleep Disorders

• Insomnia

• Narcolepsy

• REM-Sleep Behaviour Disorder (RBD)

• Sleep Apnea

• Sleepwalking

• Night Terrors (NREM)

• Nightmares (REM)

Why do we dream?

• Any stage

• Activation-synthesis theory

• Cognitive Approaches

• Freud’s Psychoanalytic Theory

– Wish fulfillment

– Gratification of unconscious desires / needs (sexual &

aggressive urges)

• Two important concepts

– Manifest content

• “Surface” story of dream

– Latent content

• Disguised psychological meaning of dream

• Can dreams predict the future?

Learning:

Pavlov

• Unconditioned stimulus (UCS)

• Conditioned stimulus (CS)

• Unconditioned response (UCR)

• Conditioned response (CR)

• Dentist, cigarette

Discrimination is the learned ability to distinguish between a conditioned stimulus and other stimuli that do not signal unconditioned stimulus.

(bell rung = salivation) (bell not rung = no salivation)

Extinction

When the CS and UCS are no longer paired and the response to the CS is weakened

Operant conditioning

Edward L. Thorndike (1913)
The law effect
Consequence

Principles of Operent conditioning

• Principle 1: Reinforcement

• Principle 2: Punishment

• Principle 3: Schedules of Reinforcement

Reinforcement versus Punishment

Increasing a response: Positive reinforcement Negative reinforcement

Decreasing a response: Positive punishment Negative punishment

Schedules of reinforcement

Continuous Vs. partial
Ratio schedule (fixed, variable)
Interval schedules (fixed, variable)

Controlled conditioning VS. Operant conditioning

Automatic (simple) vs conscious (complex)

Involuntary vs voluntary

Elicited vs emitted

Observational Learning

• Albert Bandura (1977, 1986)

• Observational (Vicarious ) learning

• Basic Processes

• Acquisition vs. performance

• Attention; Memory; Imitation; Motivation

Memory:

Human Memory: Basic Questions

How does information get into memory? encoding

How is information maintained in memory? storage

How is information pulled back out of memory? retrieval

ENCODING

Getting information into memory

Role of attention, focus awareness, selective attention = selection of input, Divided attention: cocktail party effect

Process of Encoding

§ Shulman (1972)…semantic code

– List, Synonym vs identical

Atkinson and Shiffrin (1968), information processing approach

Shepard and Metzler (1971)

Level of encoding

Craik and Lockheart (1972)

In accordance with levels of processing theory, Craik and Tulving (1975) found that structural, phonemic, and semantic encoding, which involve progressively deeper levels of processing, led to progressively better retention. (the continued possession, use, or control of something)

Self-reference effect

Encoding with respect to oneself increases memory

Sensory Memory

Brief preservation of information in original sensory form

Auditory/visual – approximately ¼-second

Short-Term Memory (STM)

Durability of storage – about 20 seconds without rehearsal

• Rehearsal – the process of repetitively verbalizing or thinking about the information

• Maintenance vs. elaborative rehearsal

Capacity of storage – magical number 7 plus or minus 2 (4 plus or minus 1?)

• Chunking – grouping familiar stimuli for storage as a single unit

Long-Term Memory

§ Unlimited vs Permanent capacity

Coding in STM vs LTM (semantic)
Flashbulb memories

- Decay vs. interference- based forgettin

Retreival and forgetting:

Retrieval: Getting Information Out of Memory

§ Using Cues to Aid Retrieval

Ineffective encoding
tip-of-the-tongue phenomenon

§ Decay

§ Reinstating the Context of an Event

Context cues – Loftus (1975)

§ Reconstructing memories

Cryptomnesia (inadvertent plagiarism – joke)

§ Interference

- Proactive

- Retroactive

Forgetting: When Memory Lapses

§ How Quickly We Forget: Ebbinghaus’s Forgetting Curve

§ Measures of forgetting

§ Retention: the proportion of material retained

Recall
Recognition
Relearning

Freud

• Psychic Mechanism of Forgetfulness (1898)

• Temporary, not permanent

• Getting safely through Oedipal

• Repression of violent and incestuous impulses

• Cannot be confirmed or rejected by research?

Frued Resurrected

§ Lund U.; Waldhauser (2011)

§ Volunteers to practice forgetting/ forgetfacts

§ EEG

Cortical regions

restrain a motor impulse and when suppress a memory

Intentional and by practice

§ Depression and recovery

Other Controversial Accounts

• Radvansky (2006)

• Performed memory tasks while crossing a room/while exiting a doorway

• Entering a doorway serves as an “event boundary”

• Passage of time vs structure of experience

Sensation and perception

Information comes in through our senses brain interprets this information

• Organs translate stimuli into nerve impulses -Transduction

Sensation - Stimulus detection process

• Organizing and giving meaning to input Perception

Sensory and perpetual processes

Reception and translation of physical energies into nerve impulses
Brain confers meaning

The science of sensation

Psychophysics

Psychophysics is the branch of psychology that quantitatively investigates the relationship between physical stimuli and the sensations and perceptions they produce.

Detectable stimulus (who/what)

Thresholds

True vs Absolute; Fechner (1860) – single point
Absolute threshold – min -> 50% (0-100% detection)
Weber’s law (JND)

𝜋 prop -> initial size (S)

Lower the absolute threshold - Higher the sensitivity

JND

If a 100 Hz tone had to be increased to 101 Hz for a subject to just notice the difference, what would you change a 1000 Hz tone to in order for that subject to notice the difference?

a. 1010 Hz

b. 1050 Hz

c. 1100 Hz

d. 1200 Hz

To solve this, you use Weber’s Law, which states:

ΔI / I = k

(where ΔI is the JND and I is the original intensity)

Step-by-Step Solution

We’re told:

At 100 Hz, the JND is 1 Hz (100 → 101 Hz)

So the Weber fraction is:

k = ΔI / I = 1 / 100 = 0.01

Now apply the same fraction to 1000 Hz:

ΔI = k × I

ΔI = 0.01 × 1000

ΔI = 10 Hz

So a person would need:

1000 Hz + 10 Hz = 1010 Hz

✔ Correct Answer: a. 1010 Hz

Signal detection theory

How certain are we that a stimulus is present?

walking alone. Did you hear something?

What criteria do we use?

Criteria fluctuate; sensitivity fluctuates; depends on other factors
Fatigue, importance of stimulus, expectation

What can signal detection theory show us?

Perception is a decision

How bold or cautious are we?

E.g., reading an X-ray to detect a tumor - Is it there?

Did you perceive a stimulus (e.g., heard a tone)

2 conditions

- Stimulus present; stimulus absent

- 4 possible outcomes

- Hit, miss, false alarm, correct rejection

Sensory process

Sensory adaptation (habituation)

Diminishing sensitivity to unchanging stimulus
Occurs in all sensory modalities

Adaptive value

Frees senses to be more sensitive to change in environment

Vision

Perceive small part of electromagnetic (EM) spectrum
Light waves measured in nanometers (billionths of meter)

- From 700 nm to 400 nm

Anatomy of visual system

Cornea

Transparent protective structure

Pupil

Adjustable opening that controls amount of light

Lens

Elastic structure for focusing
Thinner to focus on distant objects
Thicker to focus on nearby objects

Retina

Photoreceptors transduce light energy into electrical impulses

MYOPIA

Near sightedness —-- difficulty seeing far away objects
Eyeball is longer- back to front
Lens focuses light in front of retina

HYPEROPIA

Farsightedness—-------- difficulty seeing close up objects
Eyeball to short
Lens focuses light behind retina

Photoreceptors- in retina

Cones:

• For colour and detail

• Function best in high illumination

• Concentrated in centre of retina

• Fovea (in centre of retina) contains only cones

Rods

• Function best in low illumination

• 500 times more sensitive to light than cones

• Found mostly in periphery of retina - though everywhere in retina except fovea

Rods and cones synapse with bipolar cells

Cones have single line connection (one to one)
Many rods connect to single bipolar cells

Bipolar cells synapse with ganglion cells

Axons of ganglion cells form optic nerve

Create ‘blind spot’ where optic nerve exits from eye

From Light to nerve impulses

Transduction

Converting characteristics of stimulus to nerve impulses

Visual transduction

Action of photopigments
Absorption of light changes rate of neurotransmitter release
Greater rate of release = the stronger the signal passed on

Brightness and Dark Adaptation

Have ‘dual visual system’

Some animals see in daylight
Some at night
Human visual system adapted for both high & low light conditions

Dark adaptation

Progressive improvement in brightness sensitivity in low illumination
Rods not sensitive to wavelengths of red light

- Rods remain dark adapted and therefore can go from red light to dim/dark conditions

Colour vision

Trichromatic theory (YOUNG- HELMHOLTS)

•Three types of color receptors in retina

•Cones most sensitive to blue, green, red wavelengths

•Visual system combines activity from these cells

•Colours are perceived by additive mixture of impulses

•If all are equally activated - white colour is produced

Red-green colour blind individuals should not be able to perceive yellow (red + green =yellow)
Afterimages
Stare at red - look away you’ll see green (same for blue and yellow)

Opponent-process theory (Hering, 1870)

Three cone types
Each respond to two different wavelengths

- red or green

- blue or yellow

- black or white

Explains After images

• Stare at certain colour

• Neural processes become fatigued

• Have ‘rebound’ effect with receptor responding with its opponent opposite reaction

Colour Deficient vision

Trichromats

Normal colour vision

Dichromats

Deficient in one system (red-green is most common)

Monochromat

Sensitive to black and white only