Chapter 6 Generalization, Discrimination Learning, and Concept Formation

Modified: 2024-10-07 7:54 PM CDST

Behavioral Processes

Generalization and Discrimination

• Video: Stimulus Generalization
• APADefinition: Stimulus Generalization
  • the spread of effects of conditioning (either operant or classical) to stimuli that differ in certain aspects from the stimulus present during original conditioning. If responding is indistinguishable from that seen in the presence of the original stimulus, generalization is said to be complete (or no attention is commanded by the stimulus difference). If responding is different enough to be detected, discrimination is evident as well as generalization.
• Text Definition: The transfer of past learning to novel events and problems.
• APA Definition: Stimulus Discrimination
  • the ability to distinguish among different stimuli (e.g., to distinguish a circle from an ellipse) and to respond differently to them.
• Text Definition: The process by which animals or people learn to respond differently to different stimuli.
• Generalization Examples:
  • Think of note taking in two different classes say psychology and English literature
    • Both use same 26 letters
    • Both require student to listen and write notes
    • But, when you learn how to take notes in one class you do not have to relearn the process in another class
    • The learning generalizes
  • Now consider that music class you are taking
    • Letters are not used
    • Instead musical notes are used: whole, half, quarter, eighth, and more
    • The notebook is different: treble clef lines, base clef lines
    • Learning from psychology or English literature does NOT generalize
    • There is little similarity between the two tasks, so little generalization
  • US Motorcycle controls since 1975
    • Every new motorcycle sold in the USA since 1975 must have the layout below
    • Why?
    • For safety via GENERALIZATION
    • Most motorcycle accidents happen on new bikes and borrowed bikes

• But, old British bikes, sold in USA before 1975 have:
• Clutch lever on Right
• Front brake lever on Left
• Gearshift on Right
• Rear brake pedal on Left
• So, US bike rider, what might happen to you if you ride an old British bike?
  • It could be your last ride
  • Here is a practical application of generalization
  • Notice that automobile controls, too, are generalized by law
• Generalization Gradients
  • These graphs illustrate how animals perceive other stimuli as similar to the original conditioned stimulus



• The idealized generalization gradient above shows how the maximal responses are at the training stimulus of 582 nanometers
  • Notice how the mean responses decline in both directions from the training stimulus
• Shepard's Consequential region (p. 231)
  • Shepard argued that organisms expect to discover whether stimuli other than the training stimulus share the same consequence (reinforcement) as a stimulus whose consequence is already known.
• Watson and Rayner's Little Albert
• Albert showed fear of the white rat that had not scared him previously.
• Five days later, they showed him a rabbit.
• Again, he showed fear and burst into tears.
• He also showed fear (but not as much) to a white seal fur coat and to cotton wool.
• The conditioned emotional response (fear of white rat) transferred to other white objects.
• Watson and Rayner waited a month to see if Albert’s fears disappeared over time. They did not.
• The researchers never had a chance to attempt to decondition or extinguish Albert’s fears as he left the hospital to go home.
• A few years later one of Watson’s students, Mary Cover Jones (1924) was the first to demonstrate that it was possible to extinguish conditional emotional responses.
• Boy bitten by dog
  • One of my colleague's young son was severely bitten by his dog.
  • The boy had to go the hospital for stiches to his head.
  • About two weeks later the boy and his father were in the office.
  • Meanwhile, I had shown up with my new dog.
  • When I saw the boy I was concerned he would be scared of my dog. He was not.
  • In fact he approached and played with my leashed dog.
  • Perhaps he was unafraid because the dogs were very different in appearance.
  • His dog was a Doberman and mine was a Carolina dog (not my dog, but she looks very similar)
  • Both his father and I expected the boy to be scared of my dog.
  • Obviously, there was not stimulus generalization at play.
• Sensory preconditioning: presenting two stimuli together as a compound (tone + light)and then using one (light) as a CS, after testing with with the other (tone). Both will cause CR (p. 244)
  • Notice how tthis is similar to blocking, but backwards.
• Negative patterning (p. 246)
  • Left blinker = I'm turning left
  • Right blinker = I'm turning righ
  • Botb blinkers simultaneously = hazard of some kind:
    • Traffic tie up
    • Fog
    • I need to stop
• Variability in Training and the Generalization of Knowledge and Skills
  • Imagine playing on a baseball team
    • Half of your games are at your home stadium
    • Half are at away stadiums
    • Maybe you play at those away stadiums once a year
    • Outfielders at home stadiums have more opportunities to learn where a batted ball will land
    • Same outfielders at away stadiums do not learn as well where batted ball will land
  • Compare the above to the piano example on page 249
    • There, Stephanie's practice on different pianos helps her perform well on any piano.
  • Article about piano tuning and maintenance (not on test!)
• Representation (see p. 234)
• Look at my driver's license; it contain multiple representations:
  • Driver's license
    • Notice:
      • This is NOT me but it contains several representations of me
        • Picture
        • Date of Birth
        • D/L number (hidden)
        • Signature
      • It also contains useful descriptors
        • Height
        • Weight
        • Eye color

    

• Notice all of the different representations on my driver's license:
  • Name
  • Date of Birth
  • Address
  • Gender
  • Height
  • Eye color
  • Also notice I can drive cars, motocycles, and busses (but not those with air brakes)
• The text notes:
  • Discrete models are "useful for describing, understanding, and predicting how organisms learn about highly dissimilar stimuli" (p. 233)
  • But, "discrete-component representations fail in cases where stimuli have a high degree of physical similarity" (pp. 233-4)
• Saul Steinberg's New Yorker cover (p. 256)

• Illustrates NYC view of country
• Illustrates, via detail, which areas are more important to NYC residents
• Notice that Texas exists :-)

• How does Amazon.com Know What You Want to Buy Next? (p. 234)
• Video: Collaborative filtering
  • Notice how old movies in Amazon's newer model predicted what new movies customers wished to watch.
• Discrimination Examples
  • House cat responds to sound of electric can opener, but only near routine meal time
  • Human responds to spouse's custom ringtone but not to mom's custom ringtone
  • Copyrighted logos and Logos
    • Pepsi vs Coke (see p. 239)
  • Tuning a piano or guitar
• Discrimination Learning in the Lab
  • Determining what sound frequencies a person can detect
  • Determining what colors dogs can see
  • Determining what odors males and females can smell
    • The visual world provides us with some strong examples of the relationship between perception and sensation.
    • The odor world, however, is much more difficult for us to talk about.
    • One problem is that our language is not rich in words about odor.
    • For example, try to describe to someone how your favorite food smells. You should find that task very difficult.
    • Cain's (1982) study made that task easier for subjects.
      • Rather than ask subjects to identify odors abstractly (e.g., using words like, "oily", "foul", and "goaty"), subjects were allowed to smell common, everyday objects, and then to pick them out again while blindfolded.
      • That process revealed that the objects listed were the easiest to identify.
      • Where the brand names are listed, they were important.
      • As you read the list, you should be able to imagine a smell image of the object.
      • Women were better at identifying odors than men, but that was largely interpreted as a training difference. (Women are usually taught to recognize smells more than men.)
      • Women in our culture have more experience at identifying and discriminating odors.
      • There were a few odors, however, that men identified better.
        • They included bourbon, horseradish, and Brut aftershave.
      • The Top Ten
        1. Johnson's Baby Powder 
        2. Chocolate
        3. Coconut 
        4. Crayola crayons
        5. Mothballs 
        6. Ivory soap
        7. Vick's Vaporub 
        8. Bazooka Gum 
        9. Coffee 
        10. Caramel
    Cain, W. S. (1982). Odor identification by males and females: Prediction versus performance. Chemical Senses, 7(2), 129-142.
• Video: Discrimination Learning in the Marketplace
  • Notice how getting consumers to discriminate is more difficult has products come to resemble each other more closely.
• Video Pigeons learning discriminations
  • See page 250
  • Notice how discrimination leads to conceptual thinking, even in pigeons!
• Discrimination using Fading Technique (Terrace, see pp. 242-3)
  • Fading
    • Discrimination taught gradually
    • Pigeon first taught to peck a green key
    • Green is turned off briefly
    • Gradually, green stays off longer and longer
    • Then, dim red light replaces off (no light)
    • Red stays on longer and longer
    • Pigeon learns discrimination, but without errors
    • Also, no peak shift (see below)
• Teaching Pigeons to "Read" via Fading
  • Pigeon learns to peck when it sees card with "PECK" written on it
  • Pigeon does not peck when it sees card with "DON'T PECK written on it
  • Once again the words "PECK" and "DON'T PECK" were gradually taught via fading
• Relevance to Human Learning
  • Generalization-very important
    • Without generalization, we would have to learn EVERY new situation
    • With generalization, however, learning in one situation will transfer to similar situations
      • Think of taking notes in class (see above)
      • Borrowing someone's automobile
        • But, I ask, "Can you drive a standard transmission?"
  • Discrimination-very important too
    • Think of shoot-don't shoot situation
      • Here is a real life discrimination situation, one that can turn deadly quickly
      • Video: Two shoot/don't shoot scenarios
        • Can you see the psychology at work here?

Discrimination Learning and Stimulus Control



• Review:
  • S^D is a discriminative stimulus that signals reinforcement
  • S^Δ is a discriminative stimulus that signals nonreinforcement
• Hanson trained pigeons to peck a stimulus illuminated at 550 millimicrons (control group)
  • The solid line shows the generalization gradient, notice how the number of responses declines in both directions of illumination
• Hanson trained another group of pigeons with the same S^D but added an S^Δ at 570 millimicrons.
  • The dotted line shows the new generalization gradient, notice how the maximum number of responses is now shifted away from the S^Δ
  • Hanson called this phenomenon a peak shift
  • A cognitive interpretation is that the pigeons were attempting to make the perceptual difference between the S^D and the S^Δ larger.

Sleep Better Through Stimulus Control (p. 240)

• Identify and remove the stimuli associated with waking activities:
  • TV
  • Exam worries
  • Email worries
• Use Sleep Hygeine instead
  • Just keep stimuli associated with sleep
  • Remove: TV, laptop, tablet, phone

Concept Formation, Category Learning, and Prototypes

• Concepts: internal psychological representation of a real or abstract entity
  • Concept Attainment: Discovering relationships between class members and non-class members
    • Divan, Sofa, Love Seat, Easy Chair = ? (furniture)
    • Pants, Shirts, Dresses, Socks = ? (clothing)
    • Broaches, Belts, Shoes, Ear Rings = ? (accessories)
    • Types of Concepts
      • Conjuntive = use AND
        • To get a grade in this class you must login AND take the tests
      • Disjunctive = use OR
        • To register for this class you must have the correct preresquite course OR obtain consent of the instructor
      • Relational = "higher" "wider" etc.
        • Essay question answers with more detail earn higher scores
• Categories: A division or class of entities in the world
• Concepts and categories confusing because often the same word is used for both
  • For example, the concept of dog is your mental representation of dogs.
  • But, the category of dog is the name given to the biological entity Canidae in the mammals.
    • The AKC publishes a volume identifying all of the purebred dogs.
    • I'll bet you do not know what a Carolina Dog is.
      • I did not know either, until on found me in June 2024. She's asleep a few feet away from me as I write. :-)

    

  • So my concept of dog now includes Carolina Dog because I have seen one and have one
  • Pigeons have a concept of "peopleness"/How to explain data such as these?
    • The pigeons learned by discriminating between slides with and without people
    • But, one slide was selected as containing people
    • It showed no people but the cabin it showed had smoke coming from its chimney.
    • There were unseen people inside the cabin!
• Prototypes: the central tendency or ideal version of a category
• Video: Prototype Theory
  • Think of chairs
  • There are: office chairs, rocking chairs, overstuffed chairs, dining chairs, and on and on.
  • But your prototypical chair will likely be: made of wood, not have wheels, not have arms, and not really exist
  • Why? Because it is an ideal chair. Think of Plato, for instance. His prototypical chair only existed in his mind.
• Inductive Inference: an idea that may be true and is derived from your attempts to create a general rule from sensory data.
  • Text uses dogs. They (usually) have four legs, bark, mark their territory, and dig holes in your yard.
    • But, not all dogs do these doglike things or possess the characteristics
    • In other words, many concepts are fuzzy.
  • One of my favorite examples of conceptual fuzziness are the washing and care labels on clothing.
    • For example, "Wash in cold water." But, usually the directions neglect to say "Wash alone when new." (That's how I ended up with pink underwear, once.)

Stereotypes , Discrimination, and Racism in Generalizations About Other People

• Stereotype: A set of beliefs about the attributes of the members of a group.
  • Appropriate psychological discrimination vs Inappropriate social discrimination (p. 252)
  • Often stereotypes communicated via:
    • Family
    • Friends
    • Books
    • Movies
    • TV
    • Internet
• Confirmation bias: A tendency to ignore information that conflicts with prior beliefs and to focus on information consistent with that belief.
  • Example stereotype: Pit bulls are dangerous. That could mean:
    • All pit bulls are dangerous
    • Most pit bulls are dangerous
    • Pit bulls are more dangerous than other dog breeds
      • Note the fuzziness of this stereotype
  • Rosch notes that prototypes and stereotypes may share the same learning mechanism (p. 253)
  • Trouble with stereotypes comes from:
    • Generalizations are based on untruths or inappropriate statistics
    • When generalizations using appropriate statistics are used to justify social discrimination.
  • Remember, however, that all species are hardwired to: (pp. 254)
    • Infer contingencies between cues and outcomes
    • Obtain information that helps them better predict the future.

Generalization and the Hypocampal Region

• Experimental Neurosis
  • Pavlov's disciple, N. R. Shenger-Krestovnikova, using classical conditioning made dogs discriminate between circles and elipses
  • The circle predicted food
  • The elipse predicted shock
  • She then made the stimuli more and more alike (the elipses became more circular)
  • When the dogs could no longer discriminate, they basically gave up.
  • They no longer tried to discriminate.
• Evidence of Primary Cortex Role in Generalization (pp. 260-1)
  • Without area A1, animals can learn to respond to a tone but not to a specific tone.
• Plasticity of Cortical Representations
  • Tone-Shock pairings altered the frequency that an individual neuron responded to after only a few pairings. (pp. 261-2)
• Generalization and the Hippocampal Region (pp. 263-5)
  • Evidence from:
    • Sensory preconditioning
    • Acquired equivalence
    • Latent inhibition
  • All suggest that hippocampal region is critical for generalization to occur.
• Gluck Myers Model of Role of Hypocampus (pp. 265-6)
  • Region acts as "information gateway"
  • Unimportant or redundant information is compressed
  • Useful information is expanded
• See Steinberg New Yorker cover above
  • NYC is expanded
  • Rest of USA is compressed

Clinical Perspectives

• Schizophrenia
  • Schizophrenia is a very serious disorder in which people think in bizarre and unusual ways.
  • Common symptoms include hallucinations (e.g., false perceptions, especially auditory hallucinations--"hearing voices"),
  • delusions (thinking that one thing is something else, e.g., being absolutely convinced that a simple whiteboard eraser is a block of marijuana),
  • disorganized thinking,
  • bizarre posture (catatonia), lack of self grooming,
  • making up new words (neologisms)
  • disinterest in daily activities.
  • Hippocampal-region-dependent functions are impaired in schizophrenia (p. 268)
  • Higher-level memory processes associated with relational memory organization...are impaired in schizophrenia (p. 269)
• Altered Generalization in Autism Spectrum Disorder (ASD) (pp. 270-1)
  • Visual stimuli (e.g., a blue circle) have three features:
    • Size
    • Color
    • Shape
  • ASD children:
    • Show overselectivity
    • No preference for the one feature they focus on (tunnel vision)
  • Overselectivity may be related to:
    • Impaired social skills
    • Language deficits
    • Lack of inhibitory control
    • Ritualistic behaviors

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