classical conditioning: object learning
- associating one feature of an object with another
- each of 2 stimuli must be able to be manipulated independently
fear conditioning
- Watson and Rayner: little Albert
- conditioned fear has generalized to other similar stimuli
- aversive US: often mild, brief, shock delivered
amygdala and fear
- amygdala nuclei can be modulated by brain structures known to influence emotions (e.g hippocampus, PFC, hypothalamus)
- ACC - anterior cingulate cortex - involved in many higher level functions (attention, decision-making, anticipation of reward)
eyeblink reflex: reticular formation
- spine to brain connectivity
- critical to arousal - ascending reticular activating system (ARAS)
- regulates consciousness, respiration, cardiac rhythm
- movement control through connections to cerebellum/spinal cord
eyeblink reflex: red nucleus
- located in midbrain
- motor control, notably reaching
eyeblink reflex: pontine nuclei
- ventral part of pons
- sleeping, respiration, error connection
pons
- part of brainstem
- fibers from cortex travel to nuclei in pons
- cerebellar peduncles = key pathways for info travelling from cortex and brainstem to cerebellum
cerebellum
CR depends on cerebellum
- involved in motor learning
1. balance
2. walking, cycling
- axons (climbing fibers) enter CB and instruct learning by signaling occurrence of movement errors
- signals are believed to correct future movement
eyeblink conditioning
- bio/neural memory stored in localized brain region
- neural circuitry for eyeblink reflex lies in brainstem + cerebellum
- UR (eyeblink) elicited by puff of air to eye mediated by trigeminal nucleus neurons projecting from brainstem
eyeblink conditioning
- CS input targets brainstem pontine nucleus, then ascends via mossy fibers to CB
- US signals relayed to CB via climbing fibers
- CS + US signals meet in CB - climbing fibers (US) act as teachers
- output mediated by neurons projecting from:
1. interposed nucleus to red nucleus to cranial motor nuclei
2. CR develops in interposed nucleus - refer to notebook schema
sign tracking
e.g. squirrel can predict availability of acorns on the basis of the leaves and shape of the tree
goal tracking
- tracking goal object
- e.g. food, sex, etc.
- individual differences = genetic
- correlations to impulsivity, vulnerability, sensitization
reward system: dopaminergic pathway
- principally involves reward
- formed by projections (axons) of midbrain dopamine neurons
- when rewarding stimuli is experienced, dopaminergic-mesolimbic system is activated
- effect: release of dopamine to targeted nuclei (nucleus accumbens)
taste preferences and aversions
- each time you eat = conditioning trial
- food cues come to signal: what when how much we eat
- taste preference is learned; if flavour paired with nutritional fulfillment or other positive consequences
- taste aversion is learned; if ingestion of novel flavour is followed by aversive consequence (throwing up)
excitatory Pavlovian conditioning
- organisms learn relationship between CS + US
- CS is paired with US and CR comes to resemble UR
- CS elicits or excites the produced CR; CS comes to predict the CR
- learning induces CS neural activity related to US neural activity but in absence of US
effectiveness of conditioning: is there a better procedure for Pavlovian conditioning?
NO, but there are different approaches…
- delayed, simultaneous, trace and backward condition produce strong conditioned responding
- different behavioural and neural mechanisms are engaged by different procedures
- trace + delayed conditioning can have the same CS-US interval
- backward conditioning produces mixed results
- trace conditioning: CS is turned off a short time before US occurs
temporal learning hypothesis
learning involves not only what to expect, but when to expect it
inhibitory Pavlovian conditioning
- learning to predict the absence of US
- unpredictable aversive stimuli is more stressful than predictable aversive stimuli
- inhibitory conditioning prereq: US must occur periodically; US should have excitatory context, signal for absence of event (CS)
inhibitory conditioning procedures
trial A
- stimulus labeled C+ precedes US
- provides excitatory context for development of conditioned inhibition
trial B
- stimulus labeled C+ is presented wit C-
- US does not occur, CS = conditioned inhibitor
repeated trislas of CS+ followed by US + CS+/CS- without US
- CS- gradually gains inhibitory properties
negative CS-US contingency/correlation
- just CS that is negatively correlated with US
- US is less likely to occur after CS than at other times; US = periodically presented by itself; never occurs with CS+/CS-
- unlike Pavlov, where US always occurs at end of CS+
- each CS is followed by predictable absence of US
measuring conditioned inhibition: bidirectionality
bidirectional response system:
- response systems can change in opposite directions from baseline
behavioral response can be bidirectional
- conditioned excitation results in a change in one direction
- conditioned inhibition results in a change in opposite direction
many responses are not bidirectional
- conditioned excitatory stimulus can elicit freezing
- conditioned inhibitor won’t produce activity
measuring conditioned inhibition: compound-stimulus test/summation test
- measure how the presentation of a cS- disrupts or suppresses responding that would normally be elicited by CS+
- panic attack s suppressed with presence of trusted person as safety measure
retardation of acquisition test
- used to measure conditioned inhibition
- if stimulus actively inhibits a response, it is especially difficult to turn that stimulus into a conditioned excitatory CS
- if CS was previously establish as a conditioned inhibitor, rate of excitatory conditioned is delayed
- conditioned inhibition can be difficult to distinguish from other behavioural processes
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Introduction to Learning44
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The Nature of Elicited Behaviour55
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Classical Conditioning23
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Classical Conditioning Mechanisms14
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Classical Conditioning Foundations0
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Schedules of Reinforcement and Choice Behaviours54
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Instrumental Conditioning: Motivational Mechanisms63
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Stimulus Control of Behaviour20
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Comparative Cognition: Memory Mechanisms41
