W7: Learning 1: Associative Learning Flashcards
Why are Classical and Operant conditioning important to understand?
Classical and Operant conditioning are basic fundamental forms of learning. Fundamental types of learning are very similar across specifics, allows cross-species comparisons. Helps us understand stimulus-response, habits drug use and to develop AI.
What is the relationship between memory and learning?
Long-term memory =>Non-declarative (implicit) => Other (conditioning.
Experimental paradigms
Classical and Operant conditioning are experimental paradigms that have lead to highly influential frameworks for associative learning.
Classical conditioning
Stimulus-response association
Operant condition
Action-outcome association
Stimuli-action-reward
Stimuli: auditory cue, visual stimuli, olfactory stimuli (food, bell)
Action: ringing the bell, bringing food.
Reward: food
Classical/Pavlovian Conditioning
Pairing two stimuli: Conditioned stimulus (CS) + Unconditioned stimulus (US).
US: associated with a “hardwired” response.
Response becomes associated with CS through conditioning.
The CS and US can be temporally segregated or overlapping. Typical time scales for time intervals of 100’s milliseconds.
Unconditioned Response/Stimuli
US elicits a corresponding UR. US are controlled by experimenter. UR are measured.
Unconditioned: indicates that the response to this type of stimulus is hardwired/innate, it doesn’t have o be learned.
US: Food, loud noise (aversive stimuli) UR: salivation, food eaten, avoidance behaviour (for aversive stimuli) (measurable)
What is a conditioned Stimulus (CS)
CS is previously neutral (light, tone), consistently paired with US. After learning-triggers a CR (usually similar to UR)
What is aversive conditioning ?
(little albert)
US can also be aversive. (eye-blink condition, electrical shocks). Important to understand the formation of phobias, anxiety disorders and protection mechanisms.
Often single-trial learning, Temporal correlation as a proxy for causation.
Aversive stimuli: the little albert experiment: Watson & Raynor, 1920.
Extinction: Experimental data
After acquisition and extinction procedure was performed over several days. Each day the CS was presented without the US. Reduction in responding to CS is called extinction.
Spontaneous recovery
For S1 there was a 8 day resting period between the last extinction session and the test trials. For S2 the last extinction session was immediately before the test trials. Note that the response to S1 is suddenly back again. “Spontaneous recovery”
What happens during extinction
CR decrease. Unlearning seems not to be main reason due to spontaneous recovery (not completely erased) Extinction is a new learning.
Excitatory association reinforce response. Inhibitory association prevent response. When both are equally strong, cancel each other out.
Spontaneous recovery: Inhibitory association becomes weaker. Excitatory association more persistent.
Why is Extinction Learning?
Environments change over time: food may be available sometimes, but not always. Not fully erasing enables some flexibility in line with changing world!
If associations are wrong and no longer valid – may want to get rid of learning!
= Phobias – Addiction
Generalization
ability to response with CR to a new stimulus CS 2 (shares resemblance with original CS)
Important learning mechanism to avoid overtraining to specific examples and prepare for real-life situations (sirens in different countries.
