Chapter 4: Classical Conditioning Flashcards
What is appetitive conditioning?
Any conditioning where the stimulus is pleasant.
What does Aristotle have to do with classical conditioning?
Rules of Association: stimuli that are similar in time and space get associated with one another.
What is fear conditioning?
Exposure to shock (US) produces escape/avoidance behavior (UR). It is a type of aversive conditioning.
What is aversive conditioning?
When a conditioned stimulus leads to a conditioned response. This conditioned response reflex helps avoid a noxious unconditioned stimulus.
What is the context test in fear conditioning?
When placed in a context where the rat was previously shocked, the rat doesn’t explore much and shows “freezing” behavior.
What is the tone test in fear conditioning?
When tone is played, the rodent freezes. Meaning that the tone was conditioned to signal the shock in the conditioned stimulus of the box.
How does eyeblink conditioning work?
- US = puff of air
- CS = tone
- UR = blink
- CR = blink (but earlier)
The conditioned response prepares to avoid US
How are the UR and CR different in the eyeblink conditioning test?
The CR is not the same as UR, it takes place before the US and can even be different in speed or form.
What is the temporal progression of the eyeblink response?
- Day 1: CS causes no CR
2. Day 3-5: CR emerges as a slow squeezing shut of the eye prior to the US
What is the conditioned compensatory response? Give an example.
The conditioned compensatory response results in a CR that is different from the UR. For example, a dog that gets injected with adrenaline will have an increased HR. But eventually, being put in the context of an adrenaline shot will decrease HR that will maintain homeostasis against the adrenaline injection.
Explain extinction in classical conditioning?
Breaking the association between the CS and US can extinguish the new CS CR reflex, comparable to habituation. But it never fully disappears. It just conditions a new response to the CS -> “don’t respond”.
What three things can make the CS more effective again? That is, recovery or spontaneous recovery. What does this suggest?
- Stress
- New Context
- Passing of Time
This suggests that there is a distinct ensemble of neurons that activates during extinction and during recovery which survives extinction.
What are the four factors governing Classical Conditioning?
- Timing
- Blocking
- Latent Inhibition
- Associative Bias
What is trace eyeblink conditioning.
Harder to learn, when there is a interstimulus interval (ISI) between CS and US. Optimal ISI is 400 ms.
What is delay eyeblink conditioning?
Best type of learning, occurs when two stimuli that are superimposed, animal learns that at the end of the end of this CS, the US will happen.
What happens when the CS and US are engaging different modalities?
It may be hard to divide attention between two things. (Cross-modal vs unimodal conditioning)
What’s the difference between forward and backward conditioning?
Forwards conditioning means that the CS happens and then the US happens. This is the more effective way to learn since CS predicts US. Backwards conditioning is where CS happens after US. It can work initially and lead to conditioning inhibition (since CS does not predict US). Which means that the CS means nothing.
What is blocking?
When an animal is trained to 2 CS (e.g. tone and light) preceding US (e.g., shock). Both tone and light produce only modest CR (less significant than if only one or the other were trained. Also, when an animal is pre-trained with light, and then trained with light AND tone, the animal will not respond to tone alone. Meaning that when the CS is redundant to what is known, no learning occurs.
What is compound conditioning?
Conditioning in which two or more cues are present together, usually simultaneously, forming a compound CS.
What is overshadowing?
An effect seen in compound conditioning when a more salient cue within a compound acquires more association strength than does the less salient cue and is thus more strongly associated with the US.
What is latent inhibition?
If you pre-expose a group to CS without a US, then later pairings with the US will be inhibited because one stops paying attention to the CS. Meaning, it takes a lot longer for animals that are pre-exposed to be conditioned.
What is associative bias?
Louder, stronger, neutral stimulus (NS) are more likely to become conditioned CS. The NS will also have more chance to become the CS if it is in the same modality as the CR.
What is the CS Modulation (Attentional Approaches) to CC?
Attention to the stimulus is critical for learning. This explains why repeated exposure with no consequences decreases CS-US association (latent inhibition).
What is the US Modulation Theories? (Rescorla Wagner)
Based on learning from errors, we learn best when there is a discrepancy between what is predicted and what actually occurs (explains blocking).
What is error-correction learning?
Learning through trial and error to reduce the discrepancy (error) between what is predicted and what actually occurs.
What is associative weight in the R-W Theory?
In the Rescorla–Wagner model of conditioning, a value representing the strength of association between a conditioned stimulus (CS) and an unconditioned stimulus (US).
What is a positive error? Give an example?
CS predicts nothing or too little, but US occurs or is very strong (R-W model predicts increase association).
What is a negative error?
CS predicts US but no US occurs (R-W model predicts decrease in association).
What is the equation for prediction error?
Prediction Error = Actual US - Expected US
What is the equation for adjustment?
Change in stimulus weight = Learning Rate x Prediction Error
Draw how brain substrates moderate learning.
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How does the removal hippocampus affect CS modulation.
Removal of hippocampus does not alter basic classical conditioning, but it does eliminate the effect of latent inhibition. It also disrupts other paradigms that depend on changes in the processing of CS.
What is the hippocampus important for in CC? (4)
- Context fear in fear conditioning
- Trace conditioning
- (maybe) affects US modulation (in cerebellum)
- (maybe) affects CS modulation
What proteins affect learning?
CREB-1 (when activated, promotes growth of new synapses), CREB-2 (when deactivated, promotes growth of new synapses). Long term learning depends on activation/deactivation of these proteins.
What is the cerebellum?
A brain region that lies below the cerebral cortex in the back of the head. It is
responsible for the regulation and coordination of complex voluntary muscular
movement, including classical conditioning of motor-reflex responses.
What are the two main regions of the cerebellum?
- Cerebellar cortex (contains large, drop shaped, densely branching neurons called Purkinje cells).
- Interpositus Nucleus: one of the cerebellar deep nuclei from which the CR output is generated in classically conditioned motor responses.
What is the pathway of a CS?
When a tone and a light occur, the stimulus goes into the pontine nuclei (in the brain stem) which have a distinction for different types of stimuli (visual, auditory, etc.). This signal then goes into the cerebellar deep nuclei region with mossy fibers. This then passes into the granule cell in the cerebellar cortex and mets the parallel fibers whcih branch into the cerebellar cortex and purkinje cells where the CR output pathway begins. It passes into the interpositus region and results in the eyeblink.
What is the pathway of a US?
An airpuff activates neurons in the inferior olive (structure in lower part of the brainstem) which activates the interpositus nucleus which leads to the UR. But a second branch of the pathway, projects up to the cerebellar cortex through the climbing fibers. Each of these fibers wraps around a Purkinje cell and have a strong excitatory effect on them. To produce an eyeblink response, the cells project into the deep nuclei where they form an inhibitory synapse with the interpositus nucleus. To produce a response, output from the neurons in the interpositus nucleus travel down to the eye muscles to generate a blink.
What is the inferior olive?
Located in the brainstem, a nucleus of cells that conveys information about
aversive stimuli, such as an airpuff US, up to both the interpositus nucleus and the cerebellar cortex.
What confirms the facts that the cerebellum is only responsible for conditioned responses and not for unconditioned responses?
The lack of substantial
interpositus activity in a US-alone trial (despite a strong
eyeblink UR).
What happens to the CS-CR circuit in a well-trained animal?
Purkinje cells decrease their firing in response to the tone CS-US pairing due to a weakening in the strength of the parallel fiber synapses on the Purkinje cells. This is called a long-term depression (LTD). Purkinje cells inhibit the interpositus nucleus, and so when they are turned off, the inhibition is removed and the interpositus is free to fire.
Draw how is blocking explained on the neurological level?
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