Classical conditioning: pavlov (1927) Flashcards
Pavlov: Aims
- Explain the role of conditioned reflexes in the eating behaviour of dogs.
- Explore how salivation becomes associated with new stimuli unrelated to food and properties of this association.
Pavlov: Procedure
- lab experiment
- DV was salivation collected from the salivary glands of immobilised dogs. Production of saliva could be easily measured by volume or number of drops in a cannula
- The procedure took place in a soundproof chamber to minimise the effects of extraneous variables such as noise.
- Pavlov established a baseline by measuring salivation in response to a neutral stimulus like a metronome.
- He varied presentation of so the NS was presented before (forward conditioning) or after the UCS (backward conditioning).
- Further variations were used to investigate extinction and spontaneous recovery of salivation e.g. the NS (metronome) now a conditioned stimulus (CS), was presented several times without the UCS, which produced extinction.
Pavlov: Findings
-The NS did not initially elicit a response, but the UCS elicited immediate salivation.
-After forward pairings of NS and UCS, the NS typically did elicit salivation (conditioned response, CR) after the NS was presented for a few seconds
-In one trial Pavlov recorded that salivation started nine seconds after the metronome sound
-No salivation found in response to the NS in backwards pairing
-Pavlov noted that the salivation reflex only became associated with the NS if the dog was alert ad undistracted.
-Extinction of salivation was seen (salivary volume declined after repeated presentation of the CS without the UCS) and this response to the CS spontaneously recovered on occasion.
Pavlov: Conclusion
A link is likely to be made In the brain between UCS and an NS that occurs just before the UCS
Pavlov called this signalisation, which has survival value in preparing an organism for events (e.g. a dog can learn to salivate when it hears a bell so it is prepared to eat by the time food is presented).
Pavlov: strength
-A strength of Pavlov’s research is that it had great experimental controls.
- For example, a soundproof chamber was used to reduce the possibility of external sounds distracting the dogs or providing additional stimuli.
-Also, collecting saliva externally in a cannula helped prevent loss of saliva and avoided invalid measurement. Neutral stimuli were carefully chosen and tested to ensure they did not already elicit salivation.
- These controls reduced the impact of extraneous variables, making is likely that salivation in response to the CS was due to conditioning, enhancing the internal validity of the study
Pavlov: Weakness
-A weakness is the research was conducted on dogs, reducing generalisability.
-Humans have structurally different brains from other species, and therefore respond differently to stimuli.
- In particular humans have a larger cerebral cortex than other species which permits more complex cognitive processing, including conscious choice.
-Therefore, Pavlov (and others) may have been wrong to believe his findings from animals could be generalised to humans.
Pavlov: Competing argument
In fact, studies like Little Albert (Watson and Rayner) shows that classical conditioning does take place in humans. Although humans can consciously try to overcome conditioned relaxed, this is very difficulty
Pavlov: Application
-The research helps us understand problem eating behaviours. Obesity can be partially understood in terms of conditioned responses very like those displayed in Pavlovs dogs.
-For example, Jansen et al suggests that overweight children have acquired very strong associations between cues that predict the arrival of food and the salivation response. Overeating follows exposure to these cues.
-This application of Pavlov’s research demonstrates it’s significance in developing therapies such as systematic desensitisation.
