Lecture 2 Flashcards
What is the simplest unit of unconditioned behaviour?
a reflex
what is a reflex?
a stereotyped pattern of movement of a part of the body that can be reliably elicited by presenting the appropriate stimuli
can involve only one gland or set of muscles
What is a startle response?
a defensive reaction to a sudden, unexpected stimulus - involves the automatic tightening of skeletal muscles as well as various hormonal & visceral changes
what is an orienting response?
we automatically position ourselves to facilitate attending to a stimulus - can involve a relatively major body movement, such as when we automatically turn in response to unfamiliar noise behind us
what is reflexive behaviour commonly considered as?
an automatic and invariant consequence of the eliciting stimulus - however we know that the responses don’t occur with the same vigour every time
is elicited behaviour flexible or inflexible?
flexible
why is reflexive behaviour modifiable?
so we can focus on relevant stimuli and not react to unimportant stimuli
if a stimulus is relevant we tend to
not habituate
if a stimulus is irrelevant we tend to?
habitiuate
what are the two things that regulate our reflex responses
habituation & sensitisation
what is the habituation effect
a progressive decrease in the vigour of an elicited response that may occur with repeated presentations of the eliciting stimulus
what is the sensitisation effect
an increase in the vigour of elicited behaviour that may result from repeated presentation of the same stimulus
what are the general principles of habituation
- the course of habituation -
- the effects of time -
- relearning effects
- effects of stimulus intensity
- effects of stimulus frequency
- effects of over learning
- stimulus generalisation
- effects of exposure to a second stimulus
discuss 2. the effects of time to habituation
following habituation, if the stimulus is withheld for some period the response will recover. Cases in which significant spontaneous recovery does & does not occur are called short and long term habituation
discuss 1. the course of habituation
decrements in responding from trial to trial
discuss 3. relearning effects
while habituation may disappear over a long period of time, it should proceed more rapidly in a second series
discuss 4. effects of stimulus intensity
habituation is stronger when stimulus intensity is weaker
discuss 5. effects of stimulus frequency
high versus low stimulus frequency and decline in responding
discuss 6. effects of overlearning
further learning can occur when there is no longer any change in observable behaviour (below-zero habituation) to increase long-term retention to habituation
discuss 7. stimulus generalisation
the transfer of habituation from one stimulus to new but similar stimuli is generalisation
discuss 8. effects of exposure to a second stimulus
this may result in the recovery of a previously habituated response (dishabituation)
What are the general principles of sensitiation
- sensitisation effects are influenced by the same stimulus intensity and time factors that govern habituation phenomenon
- sensitisation may also be short term (decay as a result of time without stimulation) or long-term
- unlike habituation, sensitisation is not stimulus-specific e.g. shell shocked soldier
Why does repeated exposure to certain stimuli sometimes result in habituation and sometimes in sensitisation?
intensity of the stimulus: a low intensity stimulus typically results in habituation, while a high intensity stimulus typically results in sensitisation
the evolutionary/adaptive significance of the stimulus
are habituation & sensitisation associative/non-associative learning?
non-associative,
Discuss sexual arousal as unconditioned desires
-a number of animals exhibit complex unconditioned display reactions bc of certain stimuli e.g. Japanese quail courting display
What did Farris (1967) sought to investigate about conditioned sexual desires - what was the results
the extent to which courting displays could be classically conditioned by pairing a previously neutral stimulus (low intensity buzzer) with the presentation of the unconditioned stimulus (female quail)
effects began to appear at 5th pairing - all components of courting was elicited by the birds by the buzzer alone after 32 pairings
Discuss the study of behaviour in humans
- 7 males subjects
- US pictures nude women
- CS picture of knee-length, black fur lined boots
- boots 30 second, nude slides 10 seconds
- arousal assessed by measuring penile erection
What did the study in sexual arousal in humans find
- initially, none of Ss showed arousal to boots. After 30 pairings, 5/7 men showed arousal to boots.
- response generalised - 5 responded to different types of boots
- end of experiment, arousal to boots was extinguished by repeatedly showing boots by themselves
What are the implications of the sexual arousal/classical conditioning experiment
shows that conditioning of this kind could have an important role in the development of abnormal behaviours such as fetishes
-classical conditioning may therefore play an important role in channeling sexual behaviour
Discuss generalisation and Pavlov’s experiment
found that conditioning resulted in salivation not only to the one CS
- after conditioning dogs salivated not only to the 1000-Hz tone but also to tones of 1100 Hz, 1200 Hz and so on
- greatest salivation to tones most similar to training stimulus
What is stimulus generalisation
transfer of effects of conditioning to similar stimulus - after conditioning with one particular CS, other similar stimuli can also elicit CRs, despite not being paired with the US
What is stimulus discrimination
tendency for a response to be elicited more by one stimulus than another… this can be deliberately trained
Discuss a stimulus discrimination training example
Two types of trials randomly presented e.g. 2000-Hz tone & 1900 Hz tone. As result of training, the 2000-Hz tone has become an excitatory CS (or CS+) b/c it predicts the presentation of food, + the 1900-Hz tone has become an inhibitory CS or (CS-) b/c it predicts the absence of food.
What chemical is associated with habituation?
calcium
-decreased calcium will decrease the release of neurotransmitter from the presynaptic sensory neuron. This will cause a decrease excitation in postsynaptic motor neuron which will decrease the gill withdrawal reflex.
what is the difference between habituation & sensitisation and classical conditioning
h & s - non-associative single-stimulus
cc - associative, multiple stimulus’
