Habituation and classical conditioning

Question 1

What are 3 possible definitions of learning?

Answer 1

Acquisition of information/skills
Acquisition of knowledge - internal representations
Long-lasting change in behaviour as result of experience

Question 2

How can memory be viewed?

Answer 2

As ability to REMEMBER things or mental record of experiences
It is the PROCESS by which we code, store and retrieve info about our experiences

Question 3

How and memory and learning connected?

Answer 3

Form a very integrated system - when we learn something we need to be able to store and retrieve it

Question 4

What is reflexive behaviour and what are 4 key examples?

Answer 4

Series of fixed patterns of behaviour that guarantee adaptive responses to particular stimuli:
Grasp reflex - palmar grasp reflex when item placed in infant palm, involuntary flexion; after 6 months replaced by voluntary grasping
Walking - when soles of feet touch flat surface even newborns will place one foot in front of the other
Moro reflex - present up to 4 months, response to sudden loss of support - spreading out arms, unspreading arms, crying all involved
Babinski reflex - When sole of foot stroked the big toe moves upwards and other toes fan out, absence of descending inhibition (in an older child this is abnormal, should curl toes instead)

Question 5

What did Descartes assume about reflexes?

Answer 5

Work in a very simple mechanistic fashion, no learning involved as response so immediate

Question 6

What is the Bell-Magendie law?

Answer 6

Describes reflex arcs - anterior spinal nerve roots contain only motor fibres while posterior are only sensory, so in this way impulses can only be conducted in one direction
By this law, if reflexes do depend on the simple arc, they should be invariant i.e. occur whenever the eliciting stimulus present - reflexes would result in FIXED AND AUTOMATIC behaviour

Question 7

What actually happens with reflex responses?

Answer 7

In many circumstances responses are not simply fixed and automatic - learning can override the primitive reflex response e.g. through habituation
Interneurons/association neurones are key to understanding this

Question 8

What do we see in habituation?

Answer 8

For example, a new and intense sound produces a startle response in a rat, measurable by degree of movement - intensity of the jumps made
Rat actually stops responding when stimulation is repeated, and we see reduction in magnitude and frequency of the response as trials continue

Question 9

What is the importance of DISHABITUATION?

Answer 9

Provides evidence against idea that habituation is simply overstimulated and fatigued muscles/neurones
- An unexpected stimulus e.g. light rather than the loud sound will restore the reflexive response when the sound is then played again

Question 10

What does dishabituation indicate?

Answer 10

Reflex arc alone cannot account for habituation - evidence of modulatory inhibition from upper levels of NS (transmitted through interneuron)
We call this NON-ASSOCIATIVE LEARNING

Question 11

What was Leaton’s experiment into the temporal course of habituation?

Answer 11

Leaton (1976) presented tone to rats and measured startle response - phase 1 (days 1-11) was one trial every 24hr (long-term habituation), phase 2 was 240 trials once every 3 seconds (day 12, short-term habituation) and phase 3 (days 13-15, spontaneous recovery) was one trial every 24 hr
Results indicated larger habituation effect on phase 2 as startle responses significantly reduced - magnitude increased again in phase 3 but not to same level as in phase 1

Question 12

What did Leaton’s experiment suggest?

Answer 12

Massed presentations of eliciting stimulus result in full short term habituation which vanishes after a rest time (Spontaneous recovery)
Long-term habituation is more likely with widely spaced stimulus presentations and is retained for long periods
Provides some insight into how organisms store and retrieve info - temporal course constitutes simple model for short and long term retention of information processes; reflexes changed via experience and learning, startle reflex essentially diluted due to memory formation

Question 13

What are the key components of classical conditioning?

Answer 13

Neutral stimulus i.e. tone (only response is a head turn)
Biologically relevant stimulus i.e. food (response is salivation)
After learning i.e. pairing tone with presentation of food, the tone becomes a CONDITIONED STIMULUS because it provokes the salivation response even in absence of food i.e. provokes the CONDITIONED RESPONSE

Question 14

What is meant by excitatory classical conditioning?

Answer 14

When conditioned stimulus has positive relationship with unconditioned stimulus i.e. CS comes to predict the occurrence of the US, leading to the conditioned response

Question 15

What is meant by inhibitory classical conditioning?

Answer 15

If CS prevents occurrence of CR the CS is known as an inhibitory CS or conditioned inhibitor
E.g. if dog trained to salivate to tone (CS) and then a light is presented simultaneously with the tone but no food given. The tone will signal absence of food after repeated trials - the key is that excitatory conditioning does need to have occurred first to allow conditioned inhibitor to mean anything

Question 16

What are the 2 types of excitatory learning?

Answer 16

Appetitive and aversive

Question 17

What is appetitive conditioning?

Answer 17

A form of associative learning by which new rewards are learned and are imbued with motivational salience - neutral stimuli acquire a new motivational significance through association with reward
e.g. if use food as US, see normal alimentary behaviour in response, can use approaching response to measure learning during CS presentation e.g. associating a light with presence of food
Initially rat won’t enter feeder much following light, but after repeated trials associating it with food, responses increase

Question 18

What is aversive conditioning?

Answer 18

Use of something unpleasant or punishment to stop an unwanted behaviour
e.g. taste aversion conditioning - animal drinks flavoured solution (CS) but is then poisoned producing mild sickness (US); when subsequently offered the CS again it will avoid drinking it
It is the reduced consumption of solution that is a reliable index of associative learning

Question 19

What is another example of aversive conditioning?

Answer 19

In flatworms - shock (US) administered causing flatworm to shrink up
When US paired with light (CS), repeated exposure eventually results in shrinkage occurring just in response to light

Associations only form when stimuli close enough together

Question 20

What question can be asked about inhibitory conditioning?

Answer 20

In inhibitory conditioning, nothing follows the stimulus i.e. the tone doesn’t signal anything of biological relevance
The question is, has any learning actually occurred - is the tone just meaningless or is it actively signalling absence of something?

Question 21

What was the experiment conducted by Wasserman, Franklin and Hearst?

Answer 21

Pigeon in a box with an illuminated disk, which acquires CS properties when associated with food - approaching and pecking disk indicates excitatory learning
Group 1 - light associated with food
Group 2 - light and food presented randomly so no association
Group 3 - food NEVER associated with light (inhibitory learning condition)
Measured time spent close to light - in group 1 it was 10/10 seconds, group 2 was 5/10 seconds so no learning and random behaviour, while group 3 was no seconds - implies inhibitory conditioning did occur and they learned the association with absence of food

Question 22

What is the problem of silent learning?

Answer 22

Inhibitory CS often provokes response opposite to response elicited by excitatory CS, but sometimes inhibitory properties of CS are not evident - some behaviours are not as obvious as withdrawal from an illuminated disk, some may appear as ABSENCE of a behaviour so it isnt clear whether there has been learning or not

Question 23

What is the purpose of a summation test?

Answer 23

To find whether an animal has learned something after inhibitory training
Control group = tone is excitatory CS, producing 10ml saliva; light is neutral as no inhibitory training –> no effect, presence of neutral stimulus doesn’t affect magnitude of excitatory response i.e. same amount of saliva due to tone in presence/absence of light
Experimental group = Tone is excitatory CS, but light is inhibitory CS after inhibitory training –> inhibits salivation, counteracts excitatory response and when light shown with tone only 5ml saliva produced

Question 24

What is a retardation test?

Answer 24

For example, light becomes an inhibitory stimulus signalling absence of food
When try to pair inhibitory CS with food, it should take longer to make association if inhibitory learning has indeed occurred (have to change inhibitory neural connections)
Pre-existent inhibitory link RETARDS the acquisition of an excitatory link

Question 25

What does associative learning theory suggest?

Answer 25

Nodes/neurones respond to stimuli from the environment, and learning involves formation of connections and associations between the mental representation nodes of CS and US so when CS activated after training the internal representation of the US is activated by association even when not physically present
In the case of inhibitory learning an inhibitory link is established

Question 26

What is meant by extinction?

Answer 26

Equivalent to the process of forgetting; following conditioning, presentations of CS alone i.e. without any reinforcement severely reduce magnitude of conditioned response - e.g. the tone seems to become less of a good predictor of food and the salivation response weakens until responding stops altogether after several extinction trials

Question 27

How does extinction relate to phobias?

Answer 27

The connection between CS and reinforcement doesn’t disappear - allowing time to relapse after extinction restores the CR so the association has not been forgotten
Response spontaneously recovers back to original level, and it is this that is an issue in desensitisation therapy - leaving time after extinction and phobic response will return in full

Question 28

What is the current view of extinction?

Answer 28

Instead of eliminating the original learning, it seems to involve acquisition of new meaning for the CS i.e. new learning has occurred and the tone now has two meanings, one excitatory and one inhibitory, which can explain why later responses do decrease gradually (summative effect) i.e. with subsequent spontaneous recoveries return to less and less of original level of response

Question 29

What was Guttman and Kalish’s generalisation/discrimination experiment?

Answer 29

Pigeons trained to peck disc of light (580nm), and once they had learned this, test trials were given with different light stimuli
Generally picked lights close to the 580nm light trained with i.e. they had learned about that one stimulus and generalised from that to similar stimuli
We see similar generalisation in phobias
For light that was vastly different, pigeons were able to discriminate and didn’t choose them

Question 30

When can animals learn to discriminate between similar stimuli?

Answer 30

When those stimuli are repeatedly presented with differential outcomes
e.g. a tone of 1000Hz associated with food while 900Hz paired with absence of reward
Initially we see generalisation of stimuli, with 900Hz being associated with food initially
Discrimination does occur rapidly, however, after only a couple of trials (doesn’t happen this fast in natural settings)

Question 31

How does classical conditioning influence behaviour in response to chemotherapy treatment?

Answer 31

Chemo typically results in nausea and vomiting
This reaction to the treatment can be generalised to the clinical setting i.e. hospitals alone can trigger the nausea (hospital becomes a CS)
In particularly vulnerable patients, hospital context may become aversive and merely thinking about it may produce ANTICIPATORY nausea and vomiting - challenging as may lead patient to withdraw and avoid hospital and their treatments

Question 32

How can we assess the psychological impact of side effects of chemotherapy and figure out how to avoid them?

Answer 32

Using rat context conditioning models - knowing the factors that prevent context conditioning in the animal model would help to develop chemotherapy protocols that will not provoke anticipatory symptoms e.g. patients now given anti-sickness meds alongside their treatment