L4- Learning and the Brain Flashcards
What is Prediction Error?
What does it represent?
It is [Actual Outcome - Expected Outcome]
It is the extent to which the organism was unable to predict the correct outcome US (surprise).
It is assumed to drive new learning.
How does dopamine influence learning?
Neurons that release dopamine become more active when an animal experiences a reward and a few dopamine neurons respond to punishment.
Do dopamine neurons increase their activity when a conditioned stimulus is presented (when an animal is anticipating a reward)?
What does this imply?
Yes, they increase in activity.
They seem to be involved in learning.
What is Single Cell Recording?
When you measure activity from just a single cell, rather than measuring activity in the entire brain.
What is an action potential?
The change in electrical potential associated with the passage of an impulse along the membrane of a muscle cell or nerve cell.
A neuron that is not engaged will not show any activity.
True or False
Why?
False
Even if a neuron is not engaged it will spontaneously fire action potentials at a baseline rate. If they don’t do that they tend to die.
This is why you see dots even with no CS
A conditioned animal’s neurons will respond to both the CS and the reward.
True or False
Why?
False
An animal neurons that has been conditioned seems to only respond to the CS (if it has been conditioned to expect a reward after) and not the reward itself.
The dopamine neurons only fire if there is a surprise.
This test was done by Shultz
What happens to dopamine neurons during extinction (if the animal is presented with the stimulus but received no reward)?
The neuron goes silent when the animal should have received the reward.
Do dopamine neurons respond to reward or prediction error?
Prediction Error
In Shultz test, what part of the text is the Associative strength of CS (V) and what part is Prediction Error (λ - V)
Just after CS = (V)
Just after the expected response is Prediction Error = (λ-V)
What is Control (Unovershadowing)?
When Phase one of the experiment the CS is not paired with the US and then in phase 2 the second CS is paired with both the first CS and the US.
It delivers a strong CR
Is the activity of dopamine neurons consistent with either the Hull-Spence Model or the Rescorla Wagner Model?
Consistent with the Rescorla Wagner Model.
What is the catastrophic interference problem of associative and connectionist models?
Most models ‘suffer’ from catastrophic interference (new learning erases old learning)
e.g. model learns A-B association, then learns A-C association, it would forget A-B association entirely.
Humans and animals, on the other hand, remember both A-B and A-C and can both be recalled.
What is Synaptic Plasticity?
It is how learning is thought to occur in part.
Synapses between neurons gradually become more efficient at transmitting a neural signal the more they are used.
This happens because the dendrite (receiver of another neuron) creating more receptors that become more efficient at accepting the neurotransmitters)
Memories are stored in one part of the brain at a time.
True or False
Why?
False
Memories are stored in multiple parts of the brain at the same time to avoid ‘catastrophic interference’ (completely forgetting information).
What is the difference in memory and interference between the Hippocampus and Neocortex?
Hippocampus: Learns quickly, it stores memories temporarily. Because of its rapid synaptic plasticity, it suffers from interference. (learns associations fast, forgets fast)
Neocortex: Memories are gradually acquired in the neocortex, where they are stored permanently. Its synaptic plasticity is slower but more stable. (learns slower, more stable)
- Your memory of ‘where you parked your car today’ is a memory that is stored in which part of the brain?
- Your memories of what your ‘best parking strategy’ is stored in which part of your brain?
- Hippocampus
- Neocortex
What is Episodic Memory?
A type of long-term memory that involves conscious recollection of previous experiences together with their context in terms of time, place, associated emotions, etc.
Remember what, where and when
What type of memory will you be unable to form if you damage your Hippocampus?
Episodic
What is Procedural Memory?
A type of implicit memory (unconscious memory) and long-term memory which aids the performance of particular types of tasks without conscious awareness of these previous experiences.
Tying shoes, riding a bike, reading, gaming
Damage to the Hippocampus will mean you can no longer form procedural memories.
True or False
False
It will only stop you from forming episodic memories
- What is Retrograde Amnesia?
- What does it negatively affect?
- Where you forget memories that happened right before the Hippocampus was damaged.
-
Episodic Memory, Autobiographical Memory, Declarative Memory.
* Newer memories far more likely to be lost than old ones*
What were Haist, Gore and Mao (2001) findings on memory when using fMRI scans during their experiment on presenting healthy adults with famous faces from different decades?
That they could recall names of all celebrities equally well regardless of the decade.
However, their hippocampus was most active when presented with recent celebrities.
Faces of celebrities from the past activated the entorhinal cortex.
Memory Structure: Hippocampus -> Entorhinal Cortex -> Neocortex
Where are memories stored?
Memories are postulated to be stored in the synapses between neurons that fire simultaneously to recreate the experience.
