PSYC20007 Lecture Notes - Lecture 4: Visual Search, Peptic Ulcer, Spacetime
14 Jun 2018
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Lecture 4 - Tuesday 15 August 2017
PSYC20007 - COGNITIVE PSYCHOLOGY
LECTURE 4
LEARNING & KNOWLEDGE
TODAY
•1. Learning involves attention
•Not all of information is important for achieving a particular goal
•Trade off between salience and validity
•The nature of selective attention determines the mental representations we form about the
world
•2. How does our existing knowledge inform our learning and interpretation of the world?
•Learning about causes
•Explanations
•Occam’s Razor
•It may not be immediately obvious yet, but much of what I will discuss today will reflect heavily
on the concepts and categories lecture from last week. The section on learning will draw parallels
to how we learn categories and learn to attend to particular features. The second part of the
lecture on knowledge will be related to applying our existing concepts and knowledge to a given
problem.
LEARNING INVOLVES ATTENTION
•In the pursuit of some goal, organisms must overcome initial fascination (attention) to salient but
irrelevant attributes.
•Organisms must figure out what is relevant for achieving a particular goal.
•Eg. how the bees dance in order to tell the other bees the angle they should fly to find food.
SELECTIVE ATTENTION
•Note what is transmitted by the bees’ dance and what is not:
•Emphasis on location and distance
•No information about:
•Terrain, weather, predators, etc
•Bees have evolved a method for transmitting information to others that captures only the most
relevant (valid) information
•This makes it very easy for other bees to learn where to find food
•If only everything were so simple....
HOW DO WE KNOW ATTENTION IS IMPORTANT FOR LEARNING?
•There are four experimental effects which show us that attention is important for learning
•Trade offs between salience and validity
•Blocking
•Highlighting
•Learning rules of different complexity
SALIENCE
•Salience: how much does the cue grab your attention all other things being
equal?
•In the absence of validity, high salience cues will attract attention
•Low salience cues will not attract attention
•Salience is a property readily illustrated by pop-out visual search displays.
•In the next slide, I want you to find the odd-one out; raise your right hand
if the odd one is on the right; raise your left hand if the odd one is on the
left.
Lecture 4 - Tuesday 15 August 2017
PSYC20007 - COGNITIVE PSYCHOLOGY
SALIENCE & VALIDITY
•(8) In a Posner cuing task, only one of the
arrows correctly predicts the location of
the light.
•The probability with which the arrow
predicts the location might vary from
perfect validity (p = 1.0) to less-than-
perfect validity (p = .80) to chance (p = .
50)
•The subject’s task is to learn which of these cues
to attend to respond to the light as quickly as
possible
•(9) The first block has training blocks 1-10.
•Plotting a cue with high salience and fixed
validity, and another cue with low salience.
•Assume t below salience cue doesn’t tell you
anything useful.
SELECTIVE ATTENTION: VALIDITY vs
SALIENCE
→ Kruschke & Johansen (1999)
•(10) there’s a trade off between them. Increasing
utilisation of one cue decreases utilisation of other
cues, because we can’t attend to everything.
•Utilization is like validity but concerns how much
people will learn about or use a cue on which to base
their response.
•They interact: a high salience cue needs to be
balanced by a high validity cue.
SUMMARY THUS FAR
•(11) Attention is driven not only by salience but by how much it captures our attention; by both
salience and validity.
•Attention determines what we learn
•Blocking
•Highlighting
•Unidimensional rules
CLASSICAL CONDITIONING
•(12) In classical conditioning, subjects – human or animal - learn to associate a new stimulus to
an outcome that was previously only activated by a different stimulus (the unconditioned
stimulus). The outcome is initially referred to as the unconditioned response. After pairing the new
stimulus with the unconditioned stimulus and evoking the unconditioned response a few times,
the new stimulus (now called the conditioned stimulus) begins to evoke the same response on its
own, which is in that case referred to as the conditioned response.
•Pavlov had learned then when a bell was rung in subsequent time with food being presented to
the dog in consecutive sequences, the dog will initially
salivate when the food is presented. The dog will later come
to associate the ringing of the bell with the presentation of
the food and salivate upon the ringing of the bell.
Lecture 4 - Tuesday 15 August 2017
PSYC20007 - COGNITIVE PSYCHOLOGY
EVIDENCE FOR ATTENTION
1. BLOCKING
•(13) A is the red light, B is the bell, C is the alarm,
D is the blue light
•A.B is the red light + the bell C.D is the alarm +
the blue light
•B.D is the bell + the blue light, new combo, what
will happen? Should be 50/50. But this isn’t what
happens! It will usually go to the RHS, the side
indicated by the blue light.
•(14) The mouse learns that the red light
is predictive of reward X. So by adding
the bell to the red light, the mouse learns
nothing; it still knows the red light is
predictive of the reward X.
2. HIGHLIGHTING
•(15) New mice learn immediately that red light +
bell = reward. Test BD of alarm + bell, we
predict that because they’ve seen B twice as often
as they’ve seen D they will go to the LHS but it
goes to the right. This is selective attention.
•(16) A and B are already paired with X;
it has already split its attention between A
and B. Whenever it sees A with D it shifts
its attention to D because D is novel and
will predict the new outcome.
•2 hypoths:
•1. when things are paired, they will
become associated.
SIMPLE LEARNING THEORY vs ATTENTIONAL
LEARNING THEORY
•(17) Simple Learning Theory
•Suppose there are a large number of potential cues and a large number
of potential outcomes or actions
or categories.
•Consider, for instance, language
learning.
Document Summary
Learning involves attention: not all of information is important for achieving a particular goal, trade off between salience and validity, the nature of selective attention determines the mental representations we form about the world, 2. The section on learning will draw parallels to how we learn categories and learn to attend to particular features. The second part of the lecture on knowledge will be related to applying our existing concepts and knowledge to a given problem. How do we know attention is important for learning: there are four experimental effects which show us that attention is important for learning, trade offs between salience and validity, blocking, highlighting, learning rules of different complexity. Kruschke & johansen (1999: (10) there"s a trade off between them. Summary thus far: (11) attention is driven not only by salience but by how much it captures our attention; by both salience and validity, attention determines what we learn, blocking, highlighting, unidimensional rules.
