One trial learning (OTL) & Taste Aversion• One trial learning involves a change in behaviour that occurs with

only 1 powerful experience.• Taste Aversion is a conditioned response in which a person/ animal

establishes an association between a particular food & being/ feeling ill after having it in the past

• The association is usually as a result of a single (unpleasant) experience & the particular food will be avoided in the future.

Similarity of OTL & classical conditioning

1. Both involve OTL and CC involve the pairing of the UCS & CS to elicit a CR

2. Both OTL & CC involve reflexive responses3. Both OTL & CC the learner is passive

OTL vs CC – DifferencesClassical Conditioning One Trial learning

# of associations

Time lapse between CS

& CR

Extinction

General-isation

Responses take a number of associations e.g. multiple parings of the bell & the meat powder for Pavlov’s dog

Often a large time lapse e.g. for food poisoning, the CS (contaminated food) can be presented up to 2 hours before the CR (illness)

Almost immediate. E.g. sight/smell of meat powder (UCS) results in salivation (UCR).

Can be extinguished relatively easily after presenting CS (e.g. bell) without the UCS (meat powder) for a handful of trials

CS can be easily generalised to other stimuli. E.g. dog may salivate to sound of a phone (similar in sound to bell)

A change in behaviour occurs after 1 association

Unlikely to be generalised. E.g. a taste aversion to a meat pie (result of eating a contaminated one) to other food.

Highly resistant, response is powerful i.e. feeling ill due to eating contaminated food, response will often last a life-time.

Research by Garcia & Koelling (1966) – Part 1Stage 1 Thirsty rats provided with saccharine flavoured water

paired with bright light flashed & clicking noise via 1 of 2 procedures (originally the NS).Group 1: shocked (UCS)Group 2: exposed to radiation via Xrays (UCS)

Stage 2(Post

Conditioning)

CR: Both groups avoided the Saccharine flavoured water (via smell)

They had acquired a taste aversion of Saccharine flavoured water (CS).

Research by Garcia & Koelling (1966) – Part 2Stage 1 Thirsty rats provided with water via 1 of 2 procedures

• Saccharine flavoured water was provided with no bright light flashed or clicking noise.

• Unflavoured water was paired with bright light and clicking noise

Stage 2(Post

Conditioning)

Group 1: Rats subjected to pain (UCR) via shocks (UCS) avoided water (CR) when paired with light and click (CS)But they would drink saccharine flavoured water (when there was no light/ noise)

Group 2: Rats ill (UCR) originally from radiation (UCS) would not drink (CR) saccharine flavoured water (CS)

Conclusions

• The rats had learned to avoid the UCS (shock or nausea inducing drug) by avoiding the water paired with this!

• Rats associated stimuli in ways that foster survival