Class Notes (1,033,555)
CA (592,181)
McGill (36,154)
PSYC (3,969)
PSYC 211 (290)
Lecture 16

PSYC 211 Lecture Notes - Lecture 16: Lateral Geniculate Nucleus, Parahippocampal Gyrus, Supplementary Motor Area

22 pages64 viewsFall 2017

Department
Psychology
Course Code
PSYC 211
Professor
Jonathan Britt
Lecture
16

This preview shows pages 1-3. to view the full 22 pages of the document.
PSYC 211
Chapter 12
Encounters with the environment alters behaviour by modifying the nervous system
Learning - the process by which experiences change our nervous system and hence our behaviour
Changes = memories
Experiences are not stored; experiences change the way we perceive, perform, think, and plan
o This is done by physically changing the structure of the nervous system, altering neural
circuits that are active in perception, performance, thought, and planning
4 basic forms of learning
o Perceptual Learning - the ability to learn to recognize stimuli that has been perceived before
Primary function: the ability to identify and categorize objects and situations
Unless we learn to recognize something, we cannot learn how we should behave with
it
Each sensory system is capable of perceptual learning; we can learn to recognize
objects by sight, smell, touch; we can recognize words people say, the sound of their
voices, the way they walk, etc.
Perceptual learning appears to be accomplished primarily by changes in the sensory
association cortex (ex: learning to recognize visual stimuli involves changes in the
visual association cortex)
o Stimulus-response learning - the ability to learn to perform a particular behaviour when a
particular stimulus is present
Involves the establishment of connections between circuits involved in perception and
movement
Behaviour could be an automatic response (ex: defensive reflex) or it could be a
complicated sequence of movements
Two major categories of learning: classical conditioning and instrumental/operant
conditioning
Classical Conditioning - Pavlov
A form of learning in which an unimportant stimulus acquires the properties of
an important one - involves an association between two stimuli
An initially neutral stimulus - has little effect on behaviour - becomes able
to elicit a reflexive, species-typical behaviour
Involves:
automatic, species-typical behavioural responses
Association between 2 stimuli
Unconditioned response (UR) - occurs unconditionally, without any special
training
Ex: a puff of air toward the eye will automatically cause the eye to blink
Unconditioned Stimulus (US) - the stimulus that produces the unconditioned
response
Ex: the puff of air toward the eye
When a neutral stimulus is paired with the unconditioned stimulus, (ex: a tone is
paired with a puff of air to the eye) it will cause the animal to blink before the
puff of air is administered - unconditioned response occurs at the sound of the
tone, not at the administration of the air
Conditioning
find more resources at oneclass.com
find more resources at oneclass.com
You're Reading a Preview

Unlock to view full version

Only half of the first page are available for preview. Some parts have been intentionally blurred.

PSYC 211
Conditional stimulus (CS) elicits (the tone) the conditional response (CR) (the
blink)
Changes (synaptic) in the brain upon classical conditioning
Assume:
US (puff of air) is detected by a single neuron in the somatosensory
system
CS (tone) detected by a single neuron in the auditory system
The response (eye blink) is controlled by a single neuron in the
motor system
If a tone is presented by itself, the animal exhibits no behavioural reaction
because the synapse connecting the tone-sensitive neuron with the
neuron in the motor system is weak
When an action potential reaches terminal button of synapse T
(tone), the EPSP that it produces in the dendrite of the motor
neuron is too small to make that neuron fire
If a puff of air is presented to the eye (without any pairing of other
stimulus) the eye will react by blinking
Reaction occurs because there is a strong synapse between the
somatosensory neuron and the motor neuron that causes a blink
To establish classical conditioning, first present the tone (CS) quickly
followed by the puff of air (US)
After repeated pairings, the tone will eventually elicit the blink by itself
Hebb - proposed a rule that might explain how neurons are changed by
experience in a way that would cause changes in behaviour
Hebb's rule - cellular basis of learning involves strengthening a synapse
that is repeatedly active when the postsynaptic neuron fires
If a stimulus repeatedly becomes active around the same time that
the postsynaptic neuron fires, changes will happen in the structure
or chemistry of the synapse that will strengthen it
If the tone is presented first, then weak synapse T becomes active
If the puff is presented immediately after, then strong synapse P
(puff of air) becomes active and makes the motor neuron fire
The act of firing then strengthens any synapse with the motor
neuron that has just been active (synapse T)
After several pairings of the stimuli and after several increments of
strengthening, synapse T becomes strong enough to cause the
motor neuron to fire by itself = learning
Instrumental/operant/reinforcement conditioning - Skinner
Involves:
behaviours that have been learned
An association between a response and a stimulus
Flexible form of learning - permits organism to adjust its behaviour according to
the consequences of that behaviour
When a behaviour if followed by favourable consequences - reinforcing
stimuli - the behaviour tends to occur more frequently
When a behaviour is followed by unfavourable consequences - punishing
stimuli - the behaviour tends to occur less frequently
find more resources at oneclass.com
find more resources at oneclass.com
You're Reading a Preview

Unlock to view full version

Only half of the first page are available for preview. Some parts have been intentionally blurred.

PSYC 211
Reinforcement causes changes in the nervous system that increases the
likelihood that a particular stimulus will elicit a particular response
Process of reinforcement learning - Skinner's box
When a hungry rat is first placed in an operant chamber - Skinner's box -
the rat will likely not press the lever
But if rat presses lever and is immediately rewarded with food, the
likelihood of its making another response increases
Reinforcement causes the sight of the lever to serve as the stimulus that elicits
desired behaviour (pressing the lever)
Without the presence of the lever, there will be no behaviour - a rat won't
just start waving it's paw in the air
Sight of the lever is required
Process of reinforcement strengthens a connection between neural circuits
involved in perception (sight of the lever) and those involved in movement (act
of lever pressing)
Brain contains reinforcement mechanisms controlling this process
o Motor Learning - learning to make a new response
A component of stimulus-response learning
Cannot occur without sensory guidance from the environment (internal and external)
The more novel the behaviour, the more neural circuits in the motor systems of the
brain must be modified
A particular learning situation can involve varying amounts of all 3 types of learning
Ex: if an animal is taught to make a new response whenever presented with a
stimulus its never seen before, it must learn to recognize the stimulus
(perceptual learning) make a response (motor learning) and a connection must
be established between the two new memories (stimulus-response learning)
If it is taught to make a response it has already learned whenever presented
with a new stimulus, only perceptual and stimulus-response learning occurs
o Perceptual learning, Stimulus-Response learning, and Motor learning consist primarily of
changes in the sensory system, between a sensory system and the motor system, or in the
motor system (respectfully)
o Relational Learning - learning the relationships among individual stimuli
Ex: to become familiar with the contents of a room:
First, learn to recognize each of the objects
Learn the relative locations of the objects with respect to each other
As a result, our perceptions of the objects and their locations relative to us tell
us exactly where we are in the room
Episodic learning - remembering sequence of events that we witness - requires us to
keep track of and remember not only individual evens but also the order in which they
occur
Synaptic Plasticity
Learning involves synaptic plasticity - changes in the structure or biochemistry of synapses that
alter their effects on postsynaptic neurons
Long-Term Potentiation
Long-term increase in the excitability of a neuron to a particular synaptic input caused by repeated
high-frequency activity of that input
find more resources at oneclass.com
find more resources at oneclass.com
You're Reading a Preview

Unlock to view full version


Loved by over 2.2 million students

Over 90% improved by at least one letter grade.