Transcript Learning

Implicit Learning I
Dr Magda Osman
Room 2.25
Office hours Mondays & Tuesday
What is learning?

Learning
Learning is the process by which relatively permanent changes occur in
behavioural potential as a result of experience

As opposed to memory
Memory is the relatively permanent record of the experience that underlies
learning.
What is implicit learning?

Implicit learning

e.g. of hidden „grammar rules”
Learning new skills in patients with amnesia

Automatic processing (fast, inflexible)


Implicit memory: memory without any sensation of
remembering


Changes in performance (e.g. Word-stem completion task,
anagram solution)
Performance of people with amnesia on indirect tests of memory
The case for implicit learning I

We sense that we can learn things intuitively – without effort


Language, is a good example in which we are able to acquire a lot of
information very quickly – does this suggest implicit learning?
We can train animals to learn to do many things, they don’t
seem to be conscious of what they know – they must be using
a form of implicit learning, right?

Therefore, by extension if there are basic learning mechanism that
animals have, then perhaps we have a basic unconscious systems as
well?
The case for implicit learning II

We can apply knowledge without thinking


We are able to acquire complex information quickly – so, doesn’t this
mean that we can learn implicitly?
There seem to be different types of learning, some which are
harder to implement than others

Implicit and explicit learning refer to different states of
consciousness, if these states exist, then surely there are different
learning mechanism that generate them?
What does implicit learning imply?

Implicit is unconscious learning, that is, processes that operate
independently of consciousness (Reber & Reber, 2001)

Knowledge that is stored in memory that cannot later be recalled or
recognized, but can exert influence over behaviour

Implicit learning relies on knowledge and representations that are
encoded and stored differently from explicit knowledge.
(Claparede (1911) – amnesic was pricked by concealed needle in
their hand, days later they refused to shake the physician’s hand
“You never know what people carry around”)
Newell & Shanks (in press)
Examples of implicit learning

Priming/subliminal perception

Perceptual motor learning/Rule learning

Clinical Dissociations
How can we know when a process is
unconscious?

Necessary to demonstrate a dissociation between a
behavioural measure of performance and measures
of awareness.

Two stages of information processing: encoding & retrieval:

Amnesics show difficulty in retrieving the details (declarative
knowledge),

but that doesn’t mean to say they weren’t conscious at the time of
learning (encode the experience – as procedural knowledge)

To demonstrate the encoding process as unconscious, you need to
demonstrate that at the moment the stimulus was presented, the
individual’s awareness of the stimulus was absent
How can we know when a process is
unconscious?

Problems with definition of consciousness and
detection threshold (at encoding)

Cheesman & Merikle (1984)

Subjective threshold – discriminative responding for
which individuals CLAIM they are guessing, but are NOT
responding at chance level

Objective threshold – discriminative responding for which
individuals are ACTUALLY responding at chance level
Subliminal priming - what does it mean to
learn without attention?

Presentation of stimuli subliminally – without conscious
detection

Demonstrations of unconscious detection rests on two
different points:




Accessibility of information at encoding (retrieval)
Availability of information stored after it was presented
Some say that unconscious detection = the inaccessibility of information
at encoding (Brody, 1989) – but can you know?
Others say that unconscious detection = availability to consciousness is
greater than accessibility (Erdelyi, 1986, 2004)
Subliminal priming

Market researcher James Vicary (1957) reported a study
involving 700 cinema goers in the states.

The two messages shown during the film were “Eat Popcorn” and “Drink
Coca-Cola”. A message was flashed for 3msc of a second every five
seconds – in lab tests this was claimed to be too fast for conscious
attention.



People Claimed this was too fast for conscious awareness.
Companies claimed that over a six-month period sales of popcorn
rose 57% and sales of Coca-cola rose 18.1%.
This was the beginning of the concept of subliminal advertising.

However, these impressive results were never replicated, and in 1962
Vicary admitted the study was a hoax.
Subliminal priming/Masked Priming


Subliminal priming:
stimuli too short (20-110ms with masking)/ or too
low intensity to reach conscious level
But in both case processing of incoming stimuli is said
to occur

Classic demonstrations


Semantic priming (Marcel’83)
Affective priming (Zajonc’80)
13
Simple Lexical Decision with
subliminal priming
BREAD
TABLE
kurtka
PHOUD
BUTTER
Word
Nonword
14
Subliminal Priming
Prime
Mask
Target
TABLE
XXXXXX
PHOUD
BREAD
XXXXXX
BUTTER
HORSE
XXXXXX
BALLOON
20ms
20-200ms
1000ms
15
Masked Priming

Find that the masked stimulus (prime) influences the
speed of judgment of word/non-word discrimination
TABLE

PHOUD
Incongruent trials – slow responses
BREAD

XXXXXX
XXXXXX
BUTTER
Congruent trials (semantically related trials) – speed responses
HORSE
XXXXXX
BALLOON

Congruent trials (semantically unrelated trials) – baseline

Opstal et al (2010) Opstal et al (2011)
16
Priming

Bargh, Chen, & Burrows (1996) study


Priming Old Age and Walking to the Elevator
Primes were presented at a supraliminal level
(conscious level)
Repetition Priming

Jacoby et al (1989) Judgments of fame effect


Based on the effect reported by (Claparede (1911)
- Mere exposure to names of people will make them seem
famous (people can’t figure out why the names are familiar so
judge them as famous)

Jacoby et al’s (1989)

Exposure phase –non-famous names: Sebastian Weisdorf, Valerie Marsh, Adrian
Marr either 1 or 4 times

Test phase –non-famous names & famous names – judgement of fame

Manipulation – test administered directly after exposure, or a day after.
Repetition Priming




Jacoby et al’s predictions
were:
Famous names – judged accurately,
New names – judged innacurately,
Old non-famous names [1x] more
inaccuarte than [4x]
0.7
0.6
0.5
Famous
New
1x
4x
0.4
0.3
0.2
0.1



Famous names – judged accurately,
New names – judged more accurately
compared to Old non-famous names [1x]
Old names [4x] judged inaccurately
0
Immediately
One day
Is diverted attention, still a lack of attention?

Attention and consciousness are highly
correlated phenomena – so lack of attention
towards the to-be-learnt object is still classed as
implicit learning (e.g. dual task paradigm)

E.g. Mulligan (1997, 1998)

Asked people to memorize word lists, while repeating back stings of
numbers varying length
Later recall for words learnt while repeating long lists was impaired,
but on indirect test (stem completion, e.g. Fisherma_?) show that
people did learn the words.

Perceptual-motor/rule learning
Logic of Experiments
1.
Present people with simple/complex stimuli that
follow a rule
2.
Include a training period
3.
Include a test period
1.
2.
Explicit (or direct) measures of knowledge
Implicit (or indirect) measures of knowledge
Explicit measures:
Implicit measures:
1. Ask questions that directly relate to
information that was presented during
training
1. Ask people to report their confidence or how
much they like the stimulus they are presented
2. Ask people what they think they learnt
2. Produce stimuli that don’t follow the
pattern/rule that you were exposed to in training
Artificial Grammar Learning
Reber (1967)
Present people with stimuli that
follow a complex rule

Training period: MTTV
Try to remember as many of these strings of letters as
possible

Test period: Which is grammatical?
VXM or VMR? BPPQ or BQF?
How did you decided which is grammatical
What is the grammar?
General findings

People show above chance accuracy (54%-69%) in discriminating
between grammatical and non-grammatical letter strings. But are
unable to report how they make their discriminations (Reber, 1967–
replicated (Brooks, 1978; Dienes, Broadbent & Berry, 1991; Saffran, 2001),

People can transfer their ability to discriminate to letter strings they
haven’t seen before, but without knowing. (Dienes & Altmann, 1997)

Cross modal transfer (from one sensory form to another)– people learnt
letter string but at test were able to discriminate between sequences of
musical tones (Altman, Dienes, & Goode, 1995)

If during training people are made aware that there is a grammar, their
ability to later discriminate declines. (Reber, 1967; Reber, Kassin, Lewis,
& Cantor, 1980)
But….

E.g. People may not learn rules, but just pairs of letters (bigrams) that the
grammar allows. People trained on grammatical pairs were just as good as
people trained with complete strings
(Dulany, Carlson, & Dewey, 1984; Perruchet & Pacteau, 1990; Shanks, 2004)

Grammaticality is conflated with familiarity, people only tend to rate
grammatical strings if they feel that they are familiar to them. When looking at
unfamiliar letter strings only, discrimination for grammaticality was at chance
(Kinder & Assmann, 2000; Johnstone & Shanks, 2001)

Familiarity – is a fluency effect (the easier something is to process, the more
familiar it seems), when told to deliberately ignore the fluency of processing
the letter strings, discrimination for grammaticality was at chance
(Kinder, Shanks, Cock, &Tunney, 2003)
Measures of explicit knowledge not exhaustive, and not inclusive
of what the individual may have actually learnt.
Serial Reaction Time Task
Nissen & Bullemer (1987)
 Present people with stimuli that
follow a rule. E.g. deterministic
sequence: 13423413241

Training period: Block of trials
in which people perform the
task

Test period:



Transfer task
Indirect Measures
Direct Measures
General findings

People show dissociation between the ability to perform the sequence
and accuracy of their knowledge of the sequence (Hartman et al, 1989;
Nissen & Bullemer, 1987; Willingham et al, 1989)

Learning through observation impairs performing the sequence, but
not knowledge of the sequence (Kelly & Burton, 2001; Kelly et al, 2003)

Process dissociation in free generation tasks show that when people
are told to explicitly avoid generating the sequence, they still generate
the sequence (Cleeremans & Jiménez, 1998)

Dual Task studies show that you can learn the sequence even when
having to complete a secondary task at the same time – like tone
counting (Cohen et al, 1990; Frensch, Lin, & Buchner, 1998; Hsiao &
Reber, 2001)
But…

Learning of the sequence is affected if you have to discriminate between high
and low tones and indicate the result using foot-tapping, or a highly visual
demanding task.
(Heuer & Schmidtke, 1996; Rowland & Shanks, 2004)

Poor discrimination between old and new sequences was improved from
guessing to well above chance, by introducing performance related pay to
motivate individuals to respond accurately.
(Johnstone & Shanks, 1999)

Usually, only partial elements (6-items) of the sequence are presented for later
recognition tests, when trained for a long time, and then presented whole (12items) old or new strings people were faster to respond to old than new, and
were able to discriminate old items from new
(Shanks & Johnstone, 1999; Shanks & Perruchet, 2003)
Theoretical Question
Given that there are so many different forms of
knowledge:
1.
Are there multiple types of learning
processes/mechanisms
2.
Is there one single learning
process/mechanism
Implicit learning = rule abstraction
1.
2.
3.
4.
Learning is a sophisticated process that tracks and exacts
patterns and forms them into rule without any conscious
effort
As a result, what becomes processed are the deep underlying
structures (e.g. language learning, intuitive reasoning)
From this we can make accurate predictions and generalize
and transfer knowledge (e.g. cross modal transfer)
We do not need to consciously attend to information for it to
be learnt.
Implicit learning = exemplar based
1.
2.
3.
4.
5.
Given that we don’t always know what to expect in our
environment,
we often begin by learning by example,
when we have enough examples that are stored in memory,
we can begin to make predictions by comparing how similar
new examples are to the ones we have in memory.
We do not need to attend to information to learn it implicitly
There is no implicit learning

TAP – transfer appropriate processing

1.
2.
3.
(Morris et al, 1977) – learning the properties of the words (semantic
or phonemic), when tested based on either properties, when training
& test matched, performance was better.
Our cognitive system is designed to find short cuts. We
often begin by learning chunks of information, which makes
it easier to store information in memory
From this simple rules can be formed which enable us to
make predictions.
Attention is absolutely necessary for learning
(Shanks & St John, 1994; Shanks, 2004)
Describe the different
methodological approaches used
to investigate implicit learning