Classical Conditioning: The Basics
Classical Conditioning
Pavlov’s dogs: serendipity in science
learning to associate things together
depends on existing S-R relationship
Unlearned relationship
UCS : unconditional stimulus
UCR: unconditional response
Learned relationship
CS : conditioned (neutral) stimulus
CR : conditioned response
Classical Conditioning: Acquisition & Learning phases
Acquisition Phase
when you are pairing the UCS & CS together
this is the training phase
Learning Phase
Present the CS w/o UCS
See if the response is given (salivation)
If given, then the UCR is now a CR!
Classical Conditioning:
Extinction & Biological predispositions
Extinction
occurs when CS is presented w/o UCS
learns that CS no longer is associated to UCS
the animal/person will no longer give the response when presented with the CS
Biological predispositions
salient stimuli
possible responses
taste aversion
phobias
Classical Conditioning:
Generalization & Discrimination
Generalization
occurs after conditioning has been accomplished
when the response is given to new stimuli
new stimuli are similar to the CS
Discrimination
occurs after conditioning has been accomplished
when the response is not given to new stimuli
new stimuli are seen as different from the CS
Operant Conditioning: The Basics
Operant Conditioning - BF Skinner
associate behaviors w/consequences
behaviors that are rewarded increase
behaviors that are punished decrease
Shaping
used to teach/train complex behaviors
reinforce close approximations to desired behavior
continued reinforcement is dependent upon more complex behaviors
Operant Conditioning: Reinforcement
Positive reinforcement
behavior followed by pleasurable consequence
Negative reinforcement
behavior followed by the removal of a painful or aversive stimuli
occurs before the behavior, not after as in punishment
Types of reinforcers
Primary - innately satisfying
Secondary - learned rewards
Immediate vs delayed reinforcement
Operant Conditioning: Punishment & Extinction
Punishment
always decreases the behavior it follows
is negative or aversive
Extinction
decrease in a behavior through lack of positive reinforcer
Punishment VS Negative Reinforcement
punishment decreases a behavior it follows
negative reinforcement increases a behavior because it stops when the wanted behavior occurs.
Operant Conditioning: Schedules
Schedules of reinforcement
the timing of reinforcement
the consistency of the reinforcement
Ratio schedule
reinforced after a certain number of behaviors
- piece work, commission sales
Interval schedule
reinforced after a specific amount of time has passed
Operant Conditioning: Schedules
Fixed schedules
fixed ratio
- reward every so many behaviors
fixed interval
Variable schedules
variable ratio
variable interval
Observational Learning: Learning by watching
Observational/Vicarious Learning
learning can occur by watching behavior of another
both pro-social and anti-social behaviors
Four Step Process (ARRM)
attention
retention
reproduction
motivation
Observational Learning: continued
Albert Bandura
Bobo Doll experiments
- behavior of model effects behavior of child
watching violence on TV
- associated w/increases in violent behavior in some
Applications in teaching
reducing fears
skills development
Memory
Encoding
attention, levels of processing, enriching encoding
Storage
sensory, short-term, & long-term
Retrieval
cues, context, and reconstruction
Forgetting
recall vs recognition, interference, decay
amnesia
repressed memories
Encoding
Attention
selective attention
filter
Processing levels
shallow: structural encoding (penny)
intermediate: phonemic encoding
deep: semantic (meaning)
Enriching Encoding
elaboration: linking to other information
imagery (method of loci)
Storage
Sensory Store: fleeting - not stored
iconic (visual < 1 second)
echoic (auditory, 3-4 seconds)
Eidetic Imagery: ability to hold a clear, vivid image
Short Term - working memory (20-30 sec)
limited capacity: 5-9 items; 7+/-2
stored in long term or forgotten
rehearsal and chunking
Long-term memory
unlimited capacity
stored over long periods of time
flashbulb memories
Short to Long Term Memory
The capacity of STM is about seven, plus or minus two
Is lost in approximately 15 seconds; two explanations
Decay:
Interference:
Rehearsal: essential for transferring
maintenance vs elaborative rehearsal
Serial Position effect: recall depends on item’s location
primacy and recency effects
Organization
semantic networks
associations
Schemas
framework for organizing information
Long Term Memory Strategies
Imagery
method of loci
Mnemonics
acrostics (Every Good Boy Does Fine)
acronym (ROY G. BIV)
Rhyming
days of the month
Personalize the meaning
Biological Basis for Memory
hippocampus; multiple sites
moderate arousal
The search for engrams: memory traces imbedded in neuronal changes
Long-term Potential: increase in neural responsiveness due to prior input
Retrieval & Memory Assessment
Sequential search: go right down the list
Cues: pieces of information that help locate information
activating associations: bridging connections
context cues: recall improves in the same environment
state dependent memory: recall improves with same internal state
Reconstruction
eyewitness testimony:
personal memories: very malleable
Recall
retrieve previously learned information
Recognition
identify previously learned information
Memory Failure: Storage failure
Ineffective coding
structural (shallow) or phonemic (intermediate)
Interference
proactive interference
retroactive interference
Biological Factors
aging/Alzheimer’s Disease
Korsakoff’s Syndrome
brain damage
- hippocampus, amygdala, thalamus
Forgetting: Retrieval failure
Insufficient cues
tip-of-the-tongue phenomenon
Repression
repressed painful or traumatic material
false memory syndrome
Amnesia (related to trauma or injury)
anterograde: no new memories are made
retrograde: no memories for past events
infantile
Types of Memory: Two Systems?
Declarative system - explicit memories
semantic memory
episodic memory
dated, personal experiences
Procedural Memory - implicit memories
actions
motor skills
conditioned behaviors & reflexes
Cognitive Psychology
the study of thought
a return after John Watson’s criticism
The Structure of Thought
concepts: constructs that allow classifications; shared characteristics
reliance on one or more attributes; features
Defining features: essential for category membership
Characteristic features: attributes that many, but not all, members possess
Prototype: the most typical example of a member; Colors, for example, are prototypes
Learning Concepts:
a hypothesis testing approach
conservative focusing strategy: uses one positive instance, then tests hypotheses, one at a time, to ascertain nature of the concept
Language and Thought
Behaviorists believed Thought = Speech
Piaget: Language separate from Thought
language for people, thought for objects
Whorf: linguistic relativity hypothesis: thinking depends upon language
criticized by notion that phrases can replace single words
Language: the system of sounds and symbols by which we communicate meaning
Animal communication does not meet the criteria
creativity
use a grammar
use arbitrary symbols for objects or events
none of the animal communication fulfills all these criteria
Language consists of
morphemes
phonemes
Levels
surface: what is said; connative
underlying representation: what is meant; denotative
Language acquisition
cooing: vocalizations
babbling: 6-7 months; strings of vowels and consonants; interactions
holophrases: first year; single word utterances with multiple meaning
Telegraphic speech: two word sentences: omit articles and prepositions
Theories
early behaviorists: classical and operant conditioning; gradual
Nativist: language acquisition is biological and rapid
critical periods
Nonverbal Communication
transmission of information by means other than words
Intelligence: combination of abilities that enable a person to learn from experience, to think abstractly, and to adapt successfully to the environment
History
Alfred Binet: prototype for special education
Lewis Terman: translated the test in 1916
Stanford-Binet
ratio IQ to account for age
developed by William Stern
Army Alpha and Beta: Terman
officer material
very popular: group administered
David Weschler: Weschler-Bellevue
compared person’s intelligence of their own peer group
two subsections: verbal and performance
Theories of Intelligence
Charles Spearman: two factors
"G": global
Specific Factors: performance specific to a given task
L.L. Thurstone: Primary Mental Abilities
variety of different abilities: verbal comprehension, word fluency, number, memory, space, perceptual speed, and reasoning
Raymond Cattell: Fluid and Crystal Intelligence
Robert Sternberg’s Triarchic theory:
componential intelligence: information processing
experiential intelligence: ability to combine different experiences to solve new problems; creativity
contextual intelligence: ability to function in practical social situations
Controversies
Race and Intelligence
IQ and genetics: see twin studies
environment and IQ
Motivation and Eating
Up 'til now we have mostly been concerned with "hows" of behaviour
-how we learn
-how we perceive
-how we remember
Motivation refers to the "whys" of behaviour
Definition: the desires, needs and interests that arouse and activate an organism towards a specific goal
Clark Hull's Drive Theory of Motivation
There are numerous theories that try to explain motivated behaviour -e.g. sociobiology, ethology, operant conditioning
Earlier theories of motivation - e.g. instinct theory, ethology- had pretty specific bases of motivated behaviour - e.g. genes, fixed action patterns
Hull attempted to explain motivated behaviour more generally - less emphasis on instinctive bases
Hull's concept of the "drive" was more general than the ethologist's concept
Drive: tension or arousal resulting from an unmet need
Drives need not be instinctive, just a response to some need
Defining drive in terms of need has a scientific advantage - can manipulate needs and measure leel of motivation
Important concepts for drive theory:
1. organism has needs
2. needs lead to drives
3. motivated behaviour is a form of DRIVE REDUCTION
Drive theorists proposed that this system is HOMEOSTATIC - tries to maintain a balanced state (optimal level of biological functioning)
Problems with drive theory:
1. rats prefer saccharin water over sugar water, even though it has no nutritive value
2. monkeys will solve puzzles to look at a toy train - no apparent need
3. often external motivators can override internal needs (e.g. money)
4. sex is a motivated behaviour, but it is not need based
Eating as a motivated behaviour
"drive" is hunger
Much of research driven by "drive theory"
What are the underlying factors that determine eating behaviours? - both internal and external factors are important
Internal Factors
Early researchers (1920s) thought that hunger pangs important - caused by contraction of stomach
Cannon and Washburn tested the hypothesis that the contraction of the stomach is the cue to start eating. Tested this by having Washburn swallow a balloon and measuring contractions of the stomach by looking at contractions of the balloon (changes in air pressure go out stomach via tube to measuring device)
Found that contractions of the stomach coincided with feelings of hunger. Also, inflating the balloon alleviated sense of hunger
However, people who have had stomachs removed still feel hunger. Also, cutting vagus nerve (connects stomach to CNS) in rats does not change feeding behaviour.
Blood Glucose Levels
Glucose is a simple sugar used by most cells in the body for energy - most food utlimately gets converted to glucose. decreasing glucose levels - > sense of hunger but must be able to use glucose - e.g. diabetics have alot of glucose, because they have no insulin, but still feel hungry
Liver has glucostats - receptors to monitor glucose levels - sends info to brain.
increased blood glucose levels leads to sense of satiety - a homeostatic mechanism
Also, lipostats - monitor fat levels.
Finally, presence of hormone called cholecystokinin (CCK) also influences satiety
How does the brain use signals from the rest of body
Early researchers of brain and eating were influenced by drive theory - trying to find brain mechanism that acts similar to homeostatic mechanism
Early 20th century - Frolich noted that patientswith damage to hypothalamus became obese very quickly
Rat studies - damage to specific areas of hypothalamus have different effects:
Hypothalamus can be subdivided into smaller collections of neurons called nuclei.
Selectively damaging the VENTROMEDIAL NUCLEUS of the hypothalamus (VMH) of the rat results in increased food intake and rapid weight gain.
Selectively damaging the LATERAL NUCLEUS of the hypothalamus (LH) of the rat results in rapid weight loss, as the rat doesn't eat. May have to force-feed or the animal might die.
A theory of brain mechanisms of eating:
VMH is the "stop eating" center - rat with damaged VMH cannot stop eating
LH is the "start eating" center - rat with damaged LH cannot start eating
BUT, there are some problems:
VMH-lesioned animals are very finicky eaters
After 3 weeks of excessive eating, VMH rats decrease food intake to slightly above normal levels
LH rats will eventually eat, but maintain weight at a lower level
LH rats starved before LH lesion actually eat lots and increase weight.
Alternative explanations:
Damage to LH lowers set-point (predetermined weight body attempts to maintain). Rat eats less because of lower set point -
once it is reached, rat starts eating again to maintain new, lower weight.
VMH damage appears to disrupt ability of rat to use glucose - instead it gets automatically converted into fat. No glucose remaining to feed cells of body, so rat keeps eating. Gains weight but is actually starving.
External Factors
-Meal time - ancient Romans only ate two meals a day. We eat three - if we miss a meal, we feel hungry at that meal time.
-Social Factors - eating around others increases food intake.
-Sight, smell and taste of food - green food decreases food intake. Response to this factor is not associated with obesity
-Dieting - 2 milkshake study - dieters/non-dieters - given zero or 2 milkshakes. Then allowed to eat as much ice-cream as they want. Non-dieters eat less icecream after 2 milkshakes (vs. 0 milkshakes). Dieters eat more icecream after 2 milkshakes.
They've blown their diet, so they might as well go crazy.
Theories of emotion
a chicken and egg problem - which comes first, the emotion or the Autonomic Nervous System response?
-recall, sympathetic division of ANS is activated when you are in an emotional situation - leads to increased HR, BP, sweaty
palms, etc - getting ready to flee or fight.
James-Lange Theory of emotion
-William James and Carl Lange proposed a theory that the emotional response occurs after the ANS response
-according to this theory, each emotin has its own specific pattern of ANS arousal and our brain "reads" this pattern to interpret the current emotional state
-This is a "peripheral" theory - as the peripheral nervous system is determining the emotional state of the individual.
Cannon-Bard Theory of emotion
Walter Cannon suggested the James-Lange theory was incorrect on the following grounds:
1.Different emotions are associated with similar ANS responses (e.g. fear and rage). More recently, however, it has been found that there is, in fact, specificity to the ANS response
2.Increasing ANS activity by drugs does not cause a change in emotion - does increase a sense of arousal
3.Some emotional reactoins occur before the ANS response (sadness)
4.If the peripheral nerves to the brain are cut, still get emotions (spinal cord damage)
The Cannon-Bard theory proposes that the brain controls emotion while the ANS response is merely coincidental to the emtional state. This is a "central" theory of emotion.
Attribution Theory of emotion
-Schachter and Singer - we label our "visceral" (ANS) responses cognitively - arousal is important e.g. similar visceral response to fear and sexual desire - increased HR - we attribute tis to the context (emotion is dependent on the situation)
Problems with attribution theory:
1.assumes general arousal which is labelled. But some emotions do have specific ANS responses, not predicted by attribution theory
2."vitamin" study not well-replicated. May be specific to emotions that have a very high level of ANS arousal associated with them (e.g. rating attractiveness is greater when in a state of fear - on top of suspension bridge- than when not – on solid ground).