Lecture 19 - Learning 1 Flashcards
(17 cards)
What is the phylogenetic distribution of learning?
Skinner box = animal in controlled environment, present stimuli and record responses
Rats most common animal to study learning
However, other organisms e.g. goldfish (Mackintosh, 1971), octopus (Zerrella et al.) and ants (Dupuy et al.)
Other examples e.g. snails, paramecia (single-celled organism), plants
How did Arzi et al. show that humans can learn new information during sleep?
Sleep lab – presented with pleasant or unpleasant smell
1200 Hz tone -> deodorant
400 Hz tone -> rotten fish
Measured how much people sniffed during their REM or nREM sleep
Significantly more sniffs of deodorant
Sniffing behaviour transferred itself to the tones
In REM and nREM sleep
Learning in sleep persists into wakefulness (only when learning effect established in nREM sleep)
What is learning?
No generally-accepted definition
A relatively permanent change in behaviour as a consequence of experience
The problem of behavioural silence e.g. might not go on to change behaviour as a result of experience
Why do we learn?
Reflex are fast and automatic, so don’t (necessarily) need the brain/to learn about them
However, many organisms live in environments that have predictive relationships between events (e.g. fire has a predictive relationship with smoke, light, heat). Can use predictive relationship to change behaviour due to anticipation
But predictive relationships may change (e.g. finding food in summer vs winter)
To survive animals must modify their behaviour as a consequence of their experience with the environment
What is habituation?
“The relatively persistent waning of a response as a result of repeated stimulation which is not followed by any kind of reinforcement” (Hinde, 1970)
What did Whitlow (1975) show about habituation?
Subjects = rabbits
Response = vasoconstriction (blood volume) in the ear in response to low or high tone presented for 1s
Stimuli = 530 or 4000 Hz tones, counterbalanced
When same stimulus presented 30s later, vasoconstriction was lower than first stimuli
Stimulus-specific habituation effect (went away after 150s)
What did Cross et al. show about habituation?
Subjects = neonatal rats split into two groups: (a) Mozart group; (b) Schoenberg group
Stimuli = 12 hours per day exposure to vocal and non-vocal selections of Mozart or Shoenberg’s music for 52 days
Response = choice of entering a compartment of a box playing novel Mozart or Shoenberg’s music (15 days after exposure phase)
Acquisition of musical preference (Mozart group sent longer in Mozart box, same for Schoenberg)
Interpretation: avoidance of some aversive aspect of the music habituated with exposure
What did Domjan show about habituation?
Subjects = water-deprived rats, split into two groups: group S and group W
Stimuli = group S: 30 min access to sweetened water, then 30 min water per day; group W: 30 min access to just water per day
Response = consumption (in ml) each day across 20 days
Group W consumed a lot of normal water; group S avoided sweetened water at first but increased consumption over time and corresponding reduction for normal water
Shows how learning and innate behaviour can work together to be adaptive:
Rats are cautious about novel flavours – sensible, reduces chance of poisoning (neophobic response)
With experience, diet can be widened, through habituation
What is classical conditioning?
First reported by Pavlov (1927)
Conducted many experiments along with a team of scientists
Many more classical-conditioning experiments continue to be conducted by psychologists and neuroscientists across the world to this day
Most don’t explore salivation in dogs, but they do use the terminology he developed
What is the unconditioned stimulus (US)?
A biologically significant stimulus (e.g. food or water or pain)
What is the unconditioned response (UR)?
The response evoked by the US
What is the conditioned stimulus (CS)?
A previously neutral stimulus (e.g. bell or light) that acquires a response by being paired with the US
What is the conditioned response (CR)?
The response evoked by the CS
How is classical conditioning involved in learning?
The behaviour of Pavlov’s dogs changed in a relatively permanent fashion (the dog acquired a CR) as a consequence of experience (the pairing of the CS with the US)
This is appetitive conditioning (the US, food, is pleasant)
Aversive conditioning, where the US is unpleasant…
Using Pavlov’s terminology we can describe very different learning experiments that use different responses or stimuli with the same language
What did Martin and Levey (1991) show about classical conditioning?
Blocks of colour (blue or red) presented
Cornea air puff after blue block or nothing after red block
Conditioned Response (CR) – blinking (whether this would be elicited by blue block)
At first relatively little evidence of blinking during the lights (CS)
Blinking elicited by the CS that predicted the air puff (US)
Very functional. Eyelid responses anticipate irritations and protect the eye
What did Smith and Roll show about classical conditioning?
Examples of conditioning thus far have paired the CS and US often and closely together in time
Experimental group training:
Rats allowed to drink sucrose solution (CS) then given 1 dose of X radiation to make them feel nauseous (US). Interval between CS and US varied between groups
Control group training:
Same as above, but X rays not delivered when button was pressed (US never happened)
Final test – choice between sucrose solution and water in both groups
Conditioning when:
There is a substantial interval between CS and US – taste-aversion learning persisted for half a day
There was only one CS-US pairing
Is this a “special” form of conditioning?
Maybe - being able to acquire an aversion quickly and over a long interval is functional, and maybe an adaptive specialisation
How do we learn to like the right-hand side of space and how to detect a lie?
People typically have a more positive attitude towards the side of their body the same as their dominant hand
Cassanto = cartoon animals presented and told positive or negative aspects about them. Drew nice animals in right hand box and negative in left in right handed and vice versa
People come to implicitly associate good things more strongly with the side of space that they interact with more fluently (dominant side)
Politics example = move dominant hand more when making positive statements
Detect lies if you know which people’s dominant hand is
