Current Theoretical Approaches and Issues in Classical Conditioning

1 / 21

# Current Theoretical Approaches and Issues in Classical Conditioning - PowerPoint PPT Presentation

Current Theoretical Approaches and Issues in Classical Conditioning. Psychology 3306. Everything you know is wrong. So, the number of pairings is an important, maybe all important, variable in determining the amount of conditioning, right? Fine, then explain Kamin Blocking to me….

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about 'Current Theoretical Approaches and Issues in Classical Conditioning' - umika

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### Current Theoretical Approaches and Issues in Classical Conditioning

Psychology 3306

Everything you know is wrong
• So, the number of pairings is an important, maybe all important, variable in determining the amount of conditioning, right?
• Fine, then explain Kamin Blocking to me…
Kamin (1968)

L = Light T = Tone + = CS (shock)

Blocking is rocking
• Same number of tone shock pairings in both groups
• It is NOT just number of pairings
• The tone predicts nothing in the blocking group (nothing extra anyway)
• These results, and some others, lead to the Rescorla Wagner Model
You said there’d be no math!
• Yes, it is a math model
• Trial by trial
• Assumes you can get excitatory conditioning, inhibitory conditioning or nothing
• All based on what the CS predicts
• Let’s look at the rules
The Rules
• If the strength of the US is greater than expected then excitatory conditioning to the CS is the result
• If the strength of the US is LESS than expected, then you will get inhibitory conditioning
• The larger the discrepancy between what is observed and what is expected, the greater the conditioning
More rules
• The more salient the CS, the more conditioning you will get
• Two or more CSs together, their strength is additive
• This is, in essence, a model of surprise! The more surprised the animal, the more it learns
The model makes some groovy predictions
• Slope of the acquisition curve
• Blocking
• Conditioned inhibition
• Overexpectation
The Model:
• ΔVi – Si(Aj-Vsum)
• i = CS
• j = US
• S = Salience
• A = Value of the US
• V = amount of conditioning
• These quantities are, of course, hypothetical
An example
• OK, say a food pellet = 100
• Say salience of a light CS = .2
• Vsum = 0 (at the start of the experiment, there is no conditioning yet
OK, now for the numbers
• Trial 1
• ΔVi – Si(Aj-Vsum)
• =.2(100 – 0)
• =20
• Trial 2
• ΔVi = .2(100-20)
• =16
Continued….
• Trial 3
• ΔVi – Si(Aj-Vsum)
• ΔVi = .2(100-36)
• -12.8
• And so on….
• Less and less conditioning as time goes by
• Coo eh
• CS1 -> Light, S = .2
• CS2 -> Noise, S= .5
• 2 CSs, so two calculations per trial
• Trial 1
• ΔVLight = .2(100-0) = 20
• ΔVNoise = .5(100-0) = 50
• Trial
• ΔVLight = .2(100-70) = 6
• ΔVNoise = .5(100-70) = 15
• OK, how does blocking work?
• Well there is no strength left
• Conditioned inhibition?
• Negative for old CS
Stuff it cannot deal with
• CS preexposure
• Change S?
• Mackintosh’s attentional theory does this, S becomes an attention parameter
• Pearce Hall model
• Gallistel’s model
Types of associations
• First order conditioning is S-S
• Second order is S-S and S-R
• CS - context associations too
• US context associations
• Context Blocking
• CS CS associations in compound stimulus experiments
• Occasion setting (Holland)
Constraints on Pavlovian Conditioning
• Taste aversions
• Not just sickness
• Not the aftertaste
• Only to certain elements of the food, which depends on the species
• Special?
• Could just be a quantitative difference (Andrews and Braverman, 1975)
Form of the CR
• CR is often like the UR but not always
• Weaker
• Opposite direction
• Drug tolerance
• Compensatory CRs with opiates
• Context as CS
• Shooting gallery effect
• Could depend on drug action being in PNS or CNS (Stewart et al)
Physiological Basis
• New synapses formed in Aplysia
• Increase in transmitter release in neurons sensitive to CS (very cool)
• Just like habituation!
• What about more complex creatures
Five points about Physiology and conditioning
• 1) CR and UR pathways are often different
• 2) CR production is distributed
• 3) Conditioning is distributed
• 4) Different CRs, different brain regions
• 5) Sometimes it is individual neurons
• My conclusion then is that we have a very basic mechanism at work here