3. What are the CS and US? (shock) (tone)
Dec 18, 2015
After one or two pairings…
(CS)
Blood pressure
Heart Rate
Stress Hormones
Hypoalgesia
Freezing
(CR’s)
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
Conclusions
• 4. Effects of CS-US pairings can be measured directly or indirectly by their effects on another behavior
Conclusions
• 1. Conditioned behaviour is “evoked” by the CS, it is not “chosen” by the organism [Reminder]
• 7. What constitutes a pairing depends on the response system (no optimal ISI)
Stimulus Substitution (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
However…
• Fear conditioning: CR = freezing, UR = activity
• CS can determine form of CR: Lever licked, UR = eat pellet
However…
• Fear conditioning: CR = freezing, UR = activity
• CS can determine form of CR
• Interval between CS and US also matters– Long delay: General search CR– Short delay: Focal search CR
Timberlake Behavior Systems Theory
The CS and US engage the same “behavior system” – e.g., appetitive, sexual, defensive
The form of the CR depends on the length of the delay between CS and US.
Overt CR is flexible – depends on situation