Psychology of Learning Exam 2

Three simple types of learning

Habituation, sensitization, perceptual learning

Habituation

decreasing responses to a frequent but innocuous stimulus; a decrease in the strength or occurrence of a behavior due to repeated exposure; ubiquitous (found throughout the animal kingdom); with more repetitions of the stimulus, longer-lasting effects can become relatively permanent; pattern of experience matters (spaced works better than massed); generally stimulus specifcity

Sensitization

increasing a responses to a noxious/arousing stimulus; increase in the strength or occurrence of a behavior due to exposure to an arousing or noxious stimulus; increase resonding to the start stimulus after the shock; ubiquitous; more generalization and less stimulus specificity

Perceptual learning

becoming better at processing/recognizing a frequent stimulus

Acoustic startle response in mice habituation example

mice become startled from a loud noise (innate defensive reflex) but becomes less reactive after hearing the same sound multiple times during a length of time

Stimulus Specificity

Generally, responses only decrease to the habituating stimulus, for very similar stimuli, however, there can be some generalization

Dis-habituation

a novel/arousing stimulus can temporarily recover responses to the habituation stimulus; this fades quickly though

Spontaneous recovery

when repeated stimulus stops, behavior gradually returns to normal; time for recovery depends on several factors

Why do innocuous stimuli work better than strong ones?

If a stimulus is too strong, the less chance there is of habituation occurring; weak stimuli is better for habituation and ensures useless stimuli is ignored but painful/important stimuli gains more attention; with very strong stimuli, sensitization occurs

Groves and Thompson 1970

Dual Process Theory- proposed that habituation and sensitization reflect differential activation of two different systems: a low threshold reflex pathway that weakens with repeated use (S-R system) and a high threshold pathway that, when activated, increases responses globally (state system)

What does dual-process theory tell us about habituation and sensitization?

A weak stimulus will increase reflex pathway activation, stimulus-specific decline in responsiveness (weakens S-R connection); a noxious stimulus will increase reflex and state system activation, generalized increase in responsiveness

Opponent process theory

There are two things in life that motivate you, the fear of pain and the desire for pleasure

What are aplysia californica and why are they important?

The '“sea hare” has only 20,000 neurons in its CNS; the neurons are also very large; these features have made aplysia popular to understanding the neural mechanisms of learning and memory

Gill-withdrawal reflex

in aplysia, if you touch the tail, siphon or gill, the gill contracts within the mantle and time to relaxation is measured

synaptic depression

repeated touch depletes sensory neuron of transmitter (neural mechanism of habituation in aplysia); in long-term habituation, some sensory motor synapses are actually pruned away

habituation and sensitization in aplysia

H: gentle touch to siphon, gill withdrawal reflex occurs, continue touching every minute for a while and progressively duration of withdrawal shortens

S: gentle touch to siphon followed by aversive shock to tail, the next touch will produce a much longer withdrawal duration

synaptic facilitation

Tail shock activates interneurons that release serotonin; the serotonin modulates sensory neurons to release more transmitters on next activation; in long-term sensitization, new sensory motor synapses are added

Hebbian Plasticity

“neurons that fire together wire together”; describes how the connection between two neurons changes based on their simultaneous activity

What happens in stroke learned non-use?

Stroke can cause loss of sensation without loss of motor control; patients can end up ignoring and not using the desensitized limb which seems to be a maladaptive instance of competitive hebbian plasticity: the lack of sensory input from the limb causes it to lose attention and resources relative to the healthy limb

Constraint induced movement therapy

In this type of therapy, the “good” limb is restrained, forcing the use of the desensitized limb.

this gives a chance for the use of the damaged limb and can improve behavioral performance and expands cortical representations for the limb

Unconditioned stimulus (US)

stimulus that naturally and automatically elicits a reflexive or innate response (UR) without prior learning

Unconditioned response (UR)

unlearned reflexive or innate response elicited by the UCS without prior learning

Conditioned Stimulus (CS)

an originally neutral stimulus that, after association with the US, elicits a conditioned response (CR)

Conditioned Response (CR)

learned response elicited by a conditioned stimulus

Classical conditioning

begins with an innate and unlearned response, then a neutral stimulus is repeatedly presented before the reflex is triggered, producing a new learned response; classical conditioning helps an organism prepare for the future and represents an association between the CS and the US

apetitive conditioning

when the arrival of the unconditioned stimulus is a positive event (i.e. food)

Aversive conditioning

when the arrival of the unconditioned stimulus is a negative event (i.e. shock)

Conditioned emotional response (CER)

when the conditioned response is an emotional response (i.e. fear and anxiety; little albert experiment)

Classical excitatory conditioning

Conditioned stimulus elicits a response that is similar or identical to the unconditioned response

Classical inhibitory conditioning

Conditioned stimulus elicits a response that is different or opposite to the unconditioned response

Acquisition

the establishing and strengthening of the conditioned response

Extinction

Process in which the conditioned stimulus is presented in the absence of the unconditioned stimulus; causes the conditioned response to weaken and eventually disappear; breaking the association between the conditioned stimulus and the unconditioned stimulus can extinguish the new CS—>CR reflex; however, extinction doesn’t erase the CS-US connection, it just inhibits it

stimulus generalization

stimuli similar to the initial conditioned stimulus elicit a conditioned response; this aids in survival

Discrimination

conditioned response occurs to one stimulus but not to another

Positive contingency

the presence of one stimulus does not occur without the other; CS and US are in some way correlated with each other, such that one predicts the other; CS is consistently followed by the US; —> classical excitatory conditioning, CS elicits a response similar to or identical to UR

Negative contingency

the presence of one stimulus does not occur with the other; CS and US are in some way correlated with each other such that one predicts the absence of the other; CS is consistently followed by the absence of the US; —> classical inhibitory conditioning; CS elicits a response different or opposite to UR

Variables of the CS-US relationship that affect conditioning

CS-US order, interval, correlation, and number of trials

Forward delay conditioning

CS is presented first before introducing and adding the US

Forward trace conditioning

CS is presented and then stops and after some time the US is presented

Simultaneous CS-US order

onset of CS and US are at the exact same time

Backward CS-US order

US onset followed by the CS

Variables about stimuli that affect conditioning

Intensity of stimulus, familiarity/previous experience

Why is intensity of stimuli important

Intensity = strength + salience; Kamin’s 1965 Study

Latent inhibition

pre-exposure to the conditioned stimulus repeatedly; then pair the conditioned stimulus with the unconditioned stimulus; learning is inhibited