LECTURE FOURTEEN Flashcards
1
Q
BEHAVIORISM
A
- Focus on observable behavior
- Mostly focused on learning
- What is learning?
- Associating stimulus with response
- Associating concepts with other concepts (semantic
network) - Associating inputs with outputs (machine learning)
2
Q
FORMING ASSOCIATIONS
A
- Key with learning is to associate things together
- From classical conditioning to elaborative encoding
- Hebbian learning
- Neurons that fire together wire together
- Correlative, associative learning
- Note this type of basic associative learning is very sensitive to correlation – but not cause
3
Q
CLASSICAL CONDITIONING
A
- Unconditioned stimulus (UCS)
Some stimulus that elicits a natural behavior response - Unconditioned response (UCR)
The response elicited from the UCS - Conditioned stimulus (CS)
Some stimulus that doesn’t elicit the UCR originally (neutral stimulus), but will after training - Conditioned response (CR)
The same initial UCR now elicited by the CS after training
4
Q
CLASSICAL CONDITIONING (CC)
A
- Pair CS (bell) with UCS (food) to elicit UCR (salivation)
- CS (bell) becomes associated with UCS (food)
- After repeated pairings, CS (bell) now elicits CR
(salivation) - CS now associated with UCS (triggers CR because UCS
triggers UCR)
5
Q
ASPECTS OF CC
A
- Aspects of conditioning:
- Acquisition – learn CS/CR association
- Extinction – remove UCS – now CS/CR association
weakens - Recovery – restoration of CS/CR association (can be
elicited by repairing UCS with CS, or spontaneous) - Generalization – stimuli similar to CS can also elicit CR
- Discrimination – stimuli different to CS do not elicit CR
- Note that generalization and discrimination are in
contest for any CS
6
Q
OPERANT CONDITIONING
A
- No longer passive association – now the animal must
“do” something (“operate”) - Basic procedure
- Animal performs some action
- Animal is rewarded for this action – behavior reinforced
- Animal is punished for this action – behavior undermined
- Reinforced behaviors become more common and sought out, undermined become less frequent and avoided
7
Q
PLEASURE
A
- Electrical stimulation of certain brain regions leads to acute pleasurable feeling; rewarding sensation
- Reward circuit in the limbic system
- Mesolimbic dopamine pathway
- VTA to nucleus accumbens
- Rats (and people…) will compulsively “press the lever”
when it stimulates this area - Appears like addiction
- Rats will forego food (and starve) in favor of stimulation
8
Q
REWARD CIRCUIT
A
- Purpose of the reward circuit
- Provide behavioral sense of reward upon fulfilling unmet biological need
- “Reinforcers”
- Food, sex, comfort/safety, belongingness
- Can be more abstracted; money, high fives, Instagra followers
- Tightly linked with learning and memory
- Hippocampus, amygdala
- Must learn/remember what you did to achieve reward
- People, places, objects, activities, actions all become associated with reward
9
Q
LEARNED HELPLESSNESS
A
- What if, no matter what the animal does, they are
punished? - Learned helplessness
- Punishment regardless of action
- No way to avoid punishment
- After some time, animal will no longer “try”
- Animal has learned that it is helpless
10
Q
LEARNED HELPLESSNESS THEORY OF DEPRESSION
A
- Is this what is happening in depression?
- Bad things happen to a person and are judged as completely outside their control
- Chronic, un-relievable stress is like unavoidable punishment
- Nothing the person does avoids punishment
- Natural response? Stop trying and accept it – learned helplessness
- Note this is much more than sadness - “Why bother”
- How to treat? Cognitive therapy and/or drugs that promote learning/unlearning (plasticity and neurogenesis)
- Antidepressants and psychedelics both have this in common
11
Q
DRUGS AND BEHAVIORISM
A
- Drugs are “natural reinforcers” – DoA operate directly on brain’s reward system
- Thus, the drug reward is both a reinforcer for
operant conditioning and an UCS in classical conditioning - Drugs themselves then become CS and sought after
12
Q
DRUG ADDICTION
A
- Implications of behavioral drug addiction viewpoint:
- Addiction is a learned behavior
- Context of drug use becomes CS – triggers CR, cravings, desire to take drugs
- Treatment from a behavioral perspective:
- Eliminate CS contexts – go to rehab
- Eliminate CR – block or interfere with drugs from having their rewarding effects in the brain
- Chantix, naltrexone, etc.
- Once drug use is extinguished, must watch for
spontaneous recovery of learned association (relapse)
13
Q
ADDICTION IN GENERAL
A
- These same principles hold true for any
addiction, not just drugs. - Gambling addiction
- Food addiction (particularly sugar)
- Social media addiction
- All involve learning, all involve some sort of reward
14
Q
PROGRAMMING
A
- Two main methods for programming computers
- Algorithms
- Line by line coding (standard programming)
- Explicit instructions on how to analyze things
15
Q
LEARNING IN HUMANS
A
- For adult humans:
- Learning typically involves a “teacher” or some sort of
desired outcome that can easily be checked against - Supervised learning
- Biologically relevant learning involves reinforcement
- Do something clearly biologically relevant (e.g., eat food, have sex), get a reinforcing effect in the brain (reward circuit)
16
Q
LEARNING IN MACHINES
A
- How do (some) neural networks learn?
- Provide input and desired output (training data set)
- Use a learning algorithm (Hebbian, back-propagation, etc.) to change connection weights to get the right answer
- Provide input without desired output and evaluate accuracy of the model (testing data set)
- With enough good training data, network can learn to generalize to new stimuli!
- Reinforcement learning – “right answer” is reinforced (not explicit)
17
Q
DEEP LEARNING NETWORKS
A
- Neural networks with more than one hidden layers = deep networks
- Take a longer time to learn and process info
- Massive amounts of computational power needed to train
- Can perform complex analyses (like object recognition!)
18
Q
DEEP NETWORKS
A
- This sounds like vision in the brain!
- Network provides emergent solution to
complex problem - If we can “peek into” hidden layers it’s like
opening the black box of cognition
19
Q
DEEP DREAMING
A
- Take a network that has learned to classify objects
- Peek into hidden layers to see how it is doing it
- Network has learned to identify animals (but
nothing else) - Show it a picture of something without animals
- It “sees” everything as animals
- Recurrent connections and feedback
- Things become more and more animal like
20
Q
INCEPTIONISM
A
What if you only feed in static?
And then feed that back in…
And then feed it back in again…
21
Q
AI ART
A
- Currently, multiple programs using image recognition
software to generate images - Train network with many labeled pieces of art
- Generate new piece through a written prompt
- Good at some things…bad at others (text!) but improving
22
Q
SO WHAT DOES THIS ALL HAVE TO DO WITH THE MEMORY AGAIN
A
Conditioning (classical and operant) and associative
learning is not explicit memory
* Can be demonstrated in all animals
* Does not require sense of self….probably
* Can be remembered without being consciously
recognized (esp. classical conditioning)
* Does not require effortful encoding and elaboration –
just repetition
Part of implicit memory
* Memory for skills, procedures, and basic learning
associations
23
Q
ANTEROGRADE AMNESIA
A
- Inability to form new explicit memories
- Implicit memory still intact – can form new
procedural memories and use old procedures: However, no explicit memory of learning a new
procedure - Damage to the hippocampus (subcortical):
- Surgery
- Korsakoff’s Syndrome (alcoholism complications)
- Viral infection
24
Q
WHAT IS IMPLICIT MEMORY
A
- Any change in mental processes or behavior as a result of experience that is not explicit memory
- Probably not a single system
- many brain processes for storing experience have built up over evolutionary history
- explicit memory may be just the most recent “layer”
- Types of implicit memory
classical conditioning
operant conditioning?
perceptual fluency
25
PRIMING
* Brief exposure to a stimulus aids subsequent
processing of that stimulus (or related stimuli)
* Pairwise priming
* Implicit priming
* Masked priming
* Semantic priming
* Block priming
26
EXPLICIT MEMORY
* Variable tasks
* Effortful recollection
* Able to communicate
* Complex consequences and prediction
* Adapt to changing situations
27
IMPLICIT MEMORY
* Stereotyped tasks
* Automatic access
* Unable to communicate
* Simple consequences and conditioning
* Automatize frequent tasks
