Blue Gouramis

Highly Territorial But Needs to Mate

3. What are the CS and US?

Conclusions

• 4. Pavlovian CRs are usually highly adaptive

Darwin’s Finches

4. What are the CS and US?

Taste Aversion

Conclusions

• 1 (again). Conditioned behaviour is “evoked” by the CS, it is not “chosen” at the time by the organism

• 5. What constitutes a pairing depends on the response system (no optimal ISI)

5. What are the CS and US?

Paired versus Unpaired

Diagnostic tool

Conclusions

• 6. Effects of CS-US pairings must be compared to a proper control group

• 7. Slow development of the CR may predict disease

6. What are the CS and US?

sniff, social contact, approach

Recall: The US also affects the Form of the CR

•Unconditioned Stimulus– food vs. water outcome

•Conditioned Stimulus– social vs. nonsocial signal

Stimulus Substitution Examples (the CS takes the place of the US)

• Pavlov: UR = Salivation, CR = Salivation

• Cocaine: UR = Activity, CR = Activity

• Cyclophosamide: UR & CR = immune suppression.

• Autoshaping: CR for water = Closed beak, CR for grain = Open beak

Critical Point

• US difference is readily explained by stimulus substitution

• CS difference is not!!!!!!!!!!!!!!!!!!

7. What are the CS and US?

(shock)

(tone)

After one or two pairings…

(CS)

Blood pressure

Heart Rate

Stress Hormones

Hypoalgesia

Freezing

(CR’s)

Conditioned Suppression

Suppression Ratio

a = responses during the CS

b = responses prior to the CS

a(a + b)

After 10 Tone-Shock trials: a = 3; b = 20. 3/(3+20) = 0.13

On first Tone-Shock trial: a = 30; b = 30. 30/(30+30) = 0.50

Rayner with “Little Albert”

Timberlake Behavior Systems Theory

The CS and US engage the same “behavior system” – e.g., defensive, sexual

The form of the CR depends on the length of the delay between CS and US.

Overt CR is flexible – depends on the interval

Activity/Arousal

Approach SexualEncounter

Escape FreezeFlight/Flinch

USCS

Conclusions

• 8. Effects of CS-US pairings can be measured directly or indirectly by their effects on another behavior

• 9. Form of CR changes with ISI

• 2. (Again) Although the CR is evoked, there are many situational factors that determine its form