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Some provocative questions Does natural selection still work in our highly artificial society? What will the homo sapiens be like in another 200.000 years? (Why are there mental illnesses, if adaptationism is so powerful in evolutionary psychology?) Freud, Sigmund

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some provocative questions
Some provocative questions
  • Does natural selection still work in our highly artificial society?
  • What will the homo sapiens be like in another 200.000 years?
  • (Why are there mental illnesses, if adaptationism is so powerful in evolutionary psychology?)
freud sigmund
Freud, Sigmund
  • What do Freud and Evolutionary psychology have in common?
    • The Unconscious
the realm of unknown implicit knowledge and learning

The realm of unknown: implicit knowledge and learning

Budapest Semester in Cognitive Science

Cognitive Psychology

Day 2.

but before anything else
But before anything else
  • Provo is a picturesque region of France.
  • Corman was a pretender to the throne of Provo.
  • He was tired of waiting.
  • He thought arsenic might work.

Try to remember these!

look at these pictures
Look at these pictures

Now look carefully at these pictures. You will need to recall them later.

memory

Maintenance Rehearsal

Sensory

Memory

Working or

Short-term

Memory

Encoding

Long-term

memory

Attention

Sensory

Input

Retrieval

Memory
  • How come?
  • Malfunctions
  • Experimental data
  • The Atkinson-Schifrin-model
famous anterograde amnesiac hm
Famous Anterograde Amnesiac: HM
  • Severe epilepsy, treated with surgery to bilaterally remove medial temporal lobes, including hippocampus
  • Operation 9/1953, 27 years old
anterograde amnesia
Anterograde Amnesia
  • Inability to acquire new information
    • “Memento”
    • Does not affect short-term memory and general knowledge from the past
    • It is difficult to learn new facts
    • Affects memory regardless of modality (visual, auditory, tactile, etc). Spares skilled performance
try to recall as many items as you can
Cat

Apple

Banana

Hammer

Toothpick

Parrot

Table

Blackberry

Fly

Chair

Screw

Pigeon

Orange

Knife

Bed

Dog

Fork

Rat

Try to recall as many items as you can!
slide12

Primacy effect

Recency effect

peterson s stm task
Peterson’s STM Task
  • Test of memory for 3-letter nonsense syllables
  • Participants count backwards for a few seconds, then recall
  • Without rehearsal, memory fades
voices of dissent again
Voices of dissent - again
  • Two systems? Dissocition studies:
    • STM & LTM tests differ:
      • Non-word repetition test
      • Word list learning
      • Presentation rate
      • Meaningfulness
    • Can there be a clear division line?
  • Is there an alternative path – crossing out STM entirely?
memory15

Maintenance Rehearsal

Sensory

Memory

Working or

Short-term

Memory

Encoding

Long-term

memory

Attention

Sensory

Input

Retrieval

Memory
memory16

Maintenance Rehearsal

Sensory

Memory

Working or

Short-term

Memory

Encoding

Long-term

memory

Attention

Sensory

Input

Retrieval

Memory
there is more than we can tell
There is more than we can tell…
  • Eidetic pictures of children

How many stripes did you see on the cat?

sensory memory store

Sensory

Memory

Sensory

Input

Sensory Memory Store
  • Function - holds information long enough to be processed for basic physical characteristics
  • Capacity - large
    • can hold many items at once
  • Duration - very brief retention of images
    • .3 sec for visual info
    • 2 sec for auditory info
sensory memory store19
Sensory Memory Store
  • Visual or iconic memory was discovered by Sperling in 1960
  • It is only conscious in part – not all of it
  • Sensitive to eye movement
  • Bright background following it (mask)
sperling s experiment
Sperling’s Experiment
  • Presented matrix of letters for 1/20 seconds
  • Report as many letters as possible
  • Subjects recall only half of the letters
  • Was this because subjects didn’t have enough time to view the entire matrix? No
  • How did Sperling know this?
sperling s experiment21

High

Medium

Low

Sperling’s Experiment
  • Sperling showed people can see and recall ALL the letters momentarily
  • Sounded low, medium or high tone immediately after matrix disappeared
    • tone signaled 1 row to report
    • recall was almost perfect
  • Memory for image fades after 1/3 seconds or so, making report of entire display hard to do
sperling s iconic memory experiment
Sperling’s Iconic Memory Experiment

G V U

L S J

N A Z

A M K

X F Q

O U N

slide23
Is the fading effect evolutionarily adaptive?
    • Would we not be better off like Funes, the famous rememberer of Borges’ short story?
      • Theories of forgetting: lack of encoding, decay, interference, retrieval failure (cue)
    • Why is forgetting adaptive?
  • What is the role of consciousness?
    • Can short presentations of stimuli be effective – and have a lasting effect?
      • N.B.: you can not consciously recall the letters!
long lasting effects of short exposures to stimuli
Long lasting effects of short exposures to stimuli
  • Facial expressions
    • 18-30 ms presentation
    • Unconscious effect
    • Judged neutral faces to be more pleasant
    • Höschel et al. 2001

Priming studies

eidetic memory
Around 15% of children

Lasts around 40 seconds

More susceptible to interference

More likely to create false memories!

Leads to the question – how much trace do non-conscious events leave in normal population?

Eidetic memory
subliminal ads
Subliminal ads
  • Subliminal is defined in two ways
    • Embedded figures of text, not obvious to superficial examination (picture ads)
    • Short exposure times (television or movies)
the question of subliminal advertisements
The question of subliminal advertisements

Wilson Bryan Key: Subliminal Seduction and Media Sexploitation

james vicary priming
James Vicary - priming
  • 1957 – subliminal advertising
    • Eat popcorn
    • Drink Coca-Cola
  • Embedded in a film (0,03s cuts) increased sales by 20-60%
  • However he never published this finding
    • Later in an interview he claimed that this was a fabrication
    • No one could reproduce it in its original
critique
Critique
  • Moore: weak effects and strong effects
    • Weak effects – over emotions – improbable because of the competition with various supraliminal stimuli
    • Strong effects – over buyer behaviour – improbable because of the control over one’s behaviour
slide31
Subliminal advertising is banned in most English-speaking countries
  • Yet many self-help audiotapes containing subliminal messages are sold
    • Self-esteem, weight loss, memory enhancement
  • even though many studies failed to find evidence that they work
    • mind you: these are double blind studies!
    • Also they contain far too long sentences to be processed linguistically – see priming studies (Greenwald, 1992) – Brand names?
placebo
Placebo
  • Most companies deny that they use subliminal ads
    • Yet 74% of people believe in it
    • 71% of those who believed in it thought it works as well
  • Rosenthal effect? (Cassandra-type or self-fulfilling prophecy)
new evidence
New evidence
  • Revival after 2000 – new studies
  • Cooper and Cooper (2002)
    • Subliminally primed people with pictures of Coca Cola cans and the word thirsty
    • Their self-rated thirst rose
  • Dijksterhuis et al (2005)
    • Subliminally primed drink&cola and neutral words
    • Exp group drank more, but no difference is what
slide34
Karremans et al (2006)
    • Self-rated thirst
    • Primed with Lipton Ice or neutral words (Npeic Tol – same letters) for 23 ms
      • In pilots they found that usually the prime can not be guessed – not conscious
    • Allegedly, they were supposed to partake in a detection task
      • BBBBbBBBBB – how many small bs?
    • Choice between Lipton Ice tea (Coke being too sweet or too popular – brand loyalty) and Spa Rood
direct emotional priming
Direct emotional priming
  • Strahan et al. (2005)
    • Subliminal priming will only affect people’s choices if they are goal-relevant
    • It affects attitude to bevarages, BUT only if the person is thirsty! Higher evaluation
  • Bargh (1996)
    • Trait priming – the person is only going to be rude after the priming, IF (and only if) given the possibility
memory36

Maintenance Rehearsal

Sensory

Memory

Working or

Short-term

Memory

Encoding

Long-term

memory

Attention

Sensory

Input

Retrieval

Memory
long term memory

Maintenance Rehearsal

Sensory

Memory

Working or

Short-term

Memory

Encoding

Long-term

memory

Attention

Sensory

Input

Retrieval

Long-Term Memory
  • Capacity unlimited
  • Thought by some to be permanent
  • Encoding transfers info from STM to LTM –semantically organized basis
  • Anterograde amnesia
amnesia
Amnesia
  • Types of amnesia
    • Anterograde
    • Retrograde
retrograde amnesia
Retrograde amnesia
  • Temporal gradient:
    • early memories are better remembered than memories before trauma (Ribot’s law)
    • Recently formed memories continue to undergo neurological change: memory consolidation
  • Retrograde amnesia often becomes less severe over time
    • Most remote memories are likely to return first
  • Does not affect overlearned information (e.g. skills)
anterograde amnesia40
Anterograde Amnesia
  • Inability to acquire new information
    • Think of movie “Memento”
    • Does not affect short-term memory
    • Does not affect general knowledge from the past
    • But, it is difficult to learn new facts
    • Affects memory regardless of modality (visual, auditory, tactile, etc). Spares skilled performance
    • Hyper-specific memory for those skills that are learned after onset – learning is expressed only in context in which it was encoded
our hero anew hm
Our hero anew: HM
  • Severe epilepsy, treated with surgery to bilaterally remove medial temporal lobes, including hippocampus
  • Operation 9/1953, 27 years old
spared implicit learning in anterograde amnesia
Spared (implicit) learning in anterograde amnesia
  • Claparede study (1911).
    • Patient never remembered having met Claparede (doctor) before
    • Claparade offers handshakes with pinprick
    • Next time, no explicit memory of event (or doctor)
    • Still, patient refuses to shake hands and offers explanation: “sometimes pins are hidden in people’s hands”
  • Korsakoff patients & Trivia questions
    • Given feedback, then retested. No conscious memory for items but better performance. “I read about it somewhere”. (Schacter, Tulving & Wang, 1981).
slide43
H.M
  • General knowledge intact but “stuck in time”.
    • Did not learn words introduced after 1953: “jacuzzi”, “granola”, “flower-child”
  • Was able to form some memories
    • Initially couldn’t learn how to get to his new home. Took many years to learn his own house
    • However it is not true that he was simply incapable of learning at all
hm able to mirror trace
HM able to mirror trace

improvement in H.M. for mirror tracing task (without conscious recollection of previous training episodes)

 the medial temporal lobes are not necessary for all types of long-term memory.

Milner, 1965

a taxonomy of memory systems
A Taxonomy of Memory Systems

LONG TERM MEMORY

EXPLICIT

(declarative)

IMPLICIT

(non-declarative)

SEMANTIC

(facts)

EPISODIC

(events)

PRIMING

(perceptual,

conceptual)

PROCEDURAL

(skills & habits)

ASSOCIATIVE

LEARNING

(classical & operant conditioning)

Medial Temporal Lobe

Cortex

Striatum

Amygdala/ Cerebellum

implicit and explicit memory
Implicit and explicit memory
  • Implicit memory:

past experiences influence perceptions, thoughts & actions without awareness that any information from past is accessed

  • Explicit memory:

conscious access to info from the past

(“I remember that..” )

-> involves conscious recollection

slide49
Proof for dissociation in brain injured
  • Can the same be shown for healthy adults?
healthy amnesiacs
Healthy amnesiacs?
  • Visual search task with repeated items
  • Search the letter T!
  • Effect of midazolam / similar to LTM deficit
healthy amnesiacs51
Healthy amnesiacs?
  • Relational implicit memory / repeated spatial configurations
  • Non/relational implicit memory / motor acceleration
priming demonstration
Priming Demonstration
  • Unscramble the following words:
  • O R E S
  • L T E P A
  • K T A L S
  • TSME
  • L O B S O M S
  • ELAF
  • ROSE
  • PETAL
  • STALK
  • STEM
  • BLOSSOM
priming demonstration53
Priming Demonstration
  • ELAF = LEAF
  • Why not respond FLEA?
  • Because flower parts were primed (flower power)
slide54

Explicit & Implicit Memory Tests

Look at the following words. I will test your memory for these words in various ways.

memory test
Memory Test
  • Explicit test of memory: recall
    • Write down the words you remember from the list in the earlier slide
memory test57
Memory Test
  • Explicit test of memory: recall
    • Write down the words you remember from the list in the earlier slide
  • Implicit test of memory: word fragments
    • On the next slide, you will see some words missing letters, some “word fragments” and some anagrams. Guess what each word might be.
implicit memory test priming
Implicit memory test - PRIMING

Subjects presented with target words.

Subsequent recognition phase: Targets and distractors.

Right answers measured:

Fragment Completion A--a--in

Word Stem Completion Bri---

Implicit memory is evidenced when Ss complete or identify more studied than non-studied words.

Reaction-time measured (does not exclude correctness)

Perceptual Identification

Lexical Decision

Degraded Word Naming

Implicit memory evidenced by faster RTs for studied words

Assassin

grsfersd

Assassin

Ardenisk

priming across modalities
Priming across modalities
  • Look at the picture . Then when the instructor says a word, write it down.
what about amnesiacs in im tests
What about amnesiacs in IM tests?
  • Graf, Squire, & Mandler (1984):
    • Study words: cheese, house, …
    • Explicit memory test: cued recall. Complete fragment to a word from study list:

ch _ _ _ _

    • Implicit memory test: word stem completion. Complete fragment to form any word: ch _ _ _ _
incidental learning
Incidental learning

Graf, Squire & Mandler, (1984)

Presented amnesic patients and controls with word lists - S’s made pleasantness ratings.

Test stimuli for Cued Recall and Stem Completion identical -

E.g. BRI--

only instructions differed.

slide65

Gradedness in time

Forgetting: Tulving et al (1982):

S’s learn list of uncommon words (e.g. Toboggan).

Test = standard recognition, fragment completion (_O_O_GA_)

Repetition priming effect equal for recognised and non recognised words

Fragment completion performance unchanged after 1w

modality shifts
Modality shifts
  • Jacoby & Dallas (1981)
  • Targets presented visually at learning, but spoken at test
  • No effects on recognition memory
  • Significantly reduced priming effects in implicit test.
  • Roediger & Blaxton (1987)
  • Changed typescript between learning and test:
  • No effects on recognition memory
  • Significantly reduced priming effects in implicit test.
slide67
Explicit Memory:Sensitive to retention interval / Dividing attention
  • Implicit Memory: sensitive to manipulations of surface features (e.g. modality shifts).
two systems a unitary one
Two systems & a unitary one?
  • Stochastic Independence (Sherry & Schacter, 1987)
  • If Implicit and Explicit memory effects represent the function of separable memory systems, there should be no correlations between measures of Implicit and Explicit memory.
  • Tulving et al: (1982) No correlation between recognition and fragment completion.
  • Unitary system
  • If implicit memory is one system then there ought to be correlations between different measures of that systems performance.
  • BUT: No correlations - so lots of different implicit memory systems?
dissociation
Dissociation
  • Major symptoms (Steinberg, 1997)
  • Amnesia – holes of memory
    • Few days to several years
  • Depersonalization – detached from oneself- alien
  • Derealization – surroundings are unreal
  • Identity Confusion – unnoticeable to environment
  • Indentity Alteration – can be noticed
  • Linked to early childhood trauma – usually sexual abuse
    • Explanation – because of the harassment the body is no longer percieved as a safe home – escaping is only possible in the mind
    • Sexual abuse – causes DID in 80% of cases
      • ??? In Hungary there are hardly any – supposedly 1% should be
      • Post-traumatic stress disorder is very rarely detected
dissociative identity dosirder
Dissociative Identity Dosirder

DID: Dissociative Identity Disorder (DSM-IV)

  • Key symptom is “inter-identity amnesia” - One identity claims amnesia for events experienced by other identities.
slide71
Rafaele et al (2002): Tested 31 DID patients on 3 implicit memory tests. Also tested 25 controls and 25 DID “simulators”
  • Material learned as one personality and tested as another
  • Equal implicit memory effects in all three groups for both data driven and conceptually driven implicit memory tasks.
  • “What we did find in both our implicit and explicit memory studies was a dissociation between objective memory performance and patients’ subjective reports: that is, although patients indicated no subjective recollection of the encoding phase performed by a different identity states at all, their test scores indicated normal memory functioning”
  • Thus (according to Rafaele et al) - DID patients suffer from a lack of “memory meta-awareness”.
transitory amnesia
Transitory amnesia
  • Psychogenic amnesia
    • Following a traumatic event, complete loss of memory for a few days
    • The case of M.F.
    • he was at the Gare de l’Est for 5 days – was going to go on Tuesday, but suddenly discovered that on the train ticket he bougt Saturday was printed.
    • After his divorce and suicidal thoughts he lived in his car – which provided him with protection and body
    • Too embarassed to confess he’s unemployed, he lies constantly to his new partner
lack of consciousness

Lack of consciousness

Coma, vegetative state and locked-in syndrome

disorders of consciousness
Disorders of consciousness
  • Vegetative State
  • Minimally conscious state
  • Locked-in syndrome
  • Often no motor responses
slide76
Arousal = opening of eyes, reaction to immediate stimuliAwareness of environment and self= Awareness of the self versus the other
vegetative state
Vegetative state
  • Patients seem to be awake – but there is no indication of will, voluntary action.
  • Wakefulness is present, but awareness is not
  • Terri Schiavo – judicial murder?
  • What is death?
    • Brain death
    • Devastation of neocortex
      • Permanent cessation of ‘‘those higher functions of the nervous system that demarcate man from the lower primates
  • Permanent (after 3-12 months)
  • Some Alzheimer’s diseases, anencephalic neonates
minimally conscious state
Minimally Conscious State
  • The border between VS and MCS is blurred
  • inconsistent, erratic responsiveness
  • Non-reflex bahaviour
    • To qualify, they have to show clearly discernible evidence of consciousness
      • Following simple commands consistently (3/4!!)
      • Yes/no answers – regardless of accuracy
      • Intelligible verbalization
      • Purposeful behaviour (reaction to own name)
locked in syndrome
Locked-in syndrome
  • (maladie de l'emmuré vivant, Eingeschlossensein)
  • Damage to the ventral part of the midbrain (pons) – a trajectory to muscle movements
  • Patients are fully aware of their environment, but are unable to move
    • They can move their extraorbital muscles – basically the eyes – and sometimes face muscles
  • Can communicate using dasher and eye tracking
    • Jean-Dominique Bauby
comatose patients
Comatose patients
  • Anoxic coma – very little chance to wake up
  • Traumatic coma- better prognostics
  • Stroke -
  • How do you know if you should switch the machine off?
  • Those who do not start to wake up after 2-4 weeks have very bad prognosis
glasgow coma scale
Glasgow Coma Scale
  • Best eye response (E)
  • There are 4 grades starting with the most severe:
  • No eye opening
  • Eye opening in response to pain. (Patient responds to pressure on the patient’s fingernail bed; if this does not elicit a response, supraorbital and sternal pressure or rub may be used.)
  • Eye opening to speech. (Not to be confused with an awaking of a sleeping person; such patients receive a score of 4, not 3.)
  • Eyes opening spontaneously
glasgow coma scale82
Glasgow Coma Scale
  • Best verbal response (V)
  • There are 5 grades starting with the most severe:
  • No verbal response
  • Incomprehensible sounds. (Moaning but no words.)
  • Inappropriate words. (Random or exclamatory articulated speech, but no conversational exchange)
  • Confused. (The patient responds to questions coherently but there is some disorientation and confusion.)
  • Oriented. (Patient responds coherently and appropriately to questions such as the patient’s name and age, where they are and why, the year, month, etc.)
glasgow coma scale83
Glasgow Coma Scale
  • Best motor response (M)
  • There are 6 grades starting with the most severe:
  • No motor response
  • Extension to pain (adduction of arm, internal rotation of shoulder, pronation of forearm, extension of wrist, decerebrate response)
  • Abnormal flexion to pain (adduction of arm, internal rotation of shoulder, pronation of forearm, flexion of wrist, decorticate response)
  • Flexion/Withdrawal to pain (flexion of elbow, supination of forearm, flexion of wrist when supra-orbital pressure applied ; pulls part of body away when nailbed pinched)
  • Localizes to pain. (Purposeful movements towards painful stimuli; e.g., hand crosses mid-line and gets above clavicle when supra-orbital pressure applied.)
  • Obeys commands. (The patient does simple things as asked.)
how to decide on coma
How to decide on coma
  • Brain responses
    • active and passive odball paradigm
    • Mismatch negativity (MMN) – novelty of stimulus
      • -150-250 ms onset
    • P300 ellicited by infrequent stimuli
      • Called P3a if it is task irrelevant stimuli
    • Tone-evoked usually
self referential stimuli
Self-referential stimuli
  • Own-name effect – coctail party effect in
    • dichotic listening tasks
    • RSVP - No attentional blink for own name, but a significant attentional blink for the stimulus after
    • Slows judgements – such as two digits having the same parity - considerably
comatose patients87
Comatose patients
  • Subjects own name (SON) – ellicits involuntary orientation, attention and P300
  • Deviant tones – probability of 0,14 (other tones)
  • Novel tones – probability of 0,03 (own name)
slide89
The combination of P300 and MMN is the best predictor of awakening from coma
  • The predictions are somewhat more reliable in anoxic coma cases
p300 an interesting story
P300 – an interesting story
  • Difficult: diurnal and age-related changes
  • Schizophrenia – reduced P300 component
    • Impaired controlled information processing
  • Hypnosis : altered consciousness
  • Alcoholics also show decreased P300 – not clear if it is addiction or alcohol itself
  • LIE DETECTION – Brain fingerprinting in MERMER by Lawrence Farwell
    • "Memory and Encoding Related Multifaceted Electroencephalographic Response"
brain fingerprinting
Brain Fingerprinting
  • Known and relevant events produce a different P300 than unknown and irrelevant ones (remember the odball)
  • information present/absent judgement
    • Details of a crime unknown but to the culprit presented – if there are none, not applicable…
    • Can be applied to alibi defense as well (time!)
    • Pictures, words, phrases
  • 6-10 crime-related, 6-10 life-related (related basline) and 12-20 irrelevant stimuli (unrelated baseline)
  • Accuracy is reported to be over 99%
  • Admissible in US court
  • Harrington v. State, Case No. PCCV 073247.
constructing memories
Constructing memories
  • Recall the sentences from the beginning of the lesson! Write them down.
constructing continuity
Constructing continuity
  • Korsakoff patients – typical case
    • Confabulation – making sense of airy nothing
slide95

Implicit learning

based on: Zoltán Dienes Conscious and unconscious mental processes

slide96

Implicit learning

People learn to make decisions on a task more accurately or more quickly without being able to justify their decisions adequately.

OR:

The learning process by which people come to acquire implicit (unconscious) knowledge.

Consider:

Acquisition of natural language, social skills, musical appreciation, many practical skills

implicit
Implicit?
  • Unconscious (knowledge or learning?)
  • Incidental
  • Non-intentional
  • Non-verbalizable
slide98

Four common paradigms for investigating implicit learning:

  • Artificial grammar learning
  • Dynamic control tasks (complex systems)
  • Probabilistic Category Learning
  • Serial reaction time (SRT) task
slide99

1. Artificial grammar learning

Artificial Grammars:

Subjects “trained” on grammatical sequences, then presented with grammatical vs non-grammatical sequences.

slide100

Artificial Grammars: Reber (1967)

Group A: Learn “grammatical” letter sequences

Group B: Learn random letter sequences (using same letters)

Both groups then shown 44 letter sequences, 22 of which were gramatical, 22 of which were random.

Group A successfully categorised 79% of the sequences

Group B were at chance

Effect lasts for years (Allen & Reber, 1980)

When questioned about the nature of the grammar, subjects generally claim to be guessing and are unable to report any knowledge of the rules

Many replications (but effects tend to be smaller)

abstract or episodic
Abstract or episodic
  • Abstract knowledge:
    • Summarizes information across a series of learning episodes
    • Does not code detail
  • Episodic knowledge
    • Codes detail
  • If memory is affected by similarity to originally taught sequences, it should be episodic
    • Transfer experiments! – various successful ones.
slide102

How Implicit is Implicit Learning?

  • Underlying abstract rules
  • REBER himself thought so
  • against evidence from category learning – rules are ususally explicit when used
  • 2. Exemplar-based accounts
  • Vokey and Brooks (1992)
  • similarity and grammaticality controlled
  • some items similar (differing in one letter), but ungrammatical
  • some items grammatical but differing in three letters
slide103
3. Fragment-based accounts

Those who learned bigrams or trigrams performed as well as those who learned the entire strings

Grammaticality has no effect at all? Is it all conscious memory then?

slide104

Dienes and Scott (2005)

  • In test phase, subjects rated confidence in judgment and rated the basis of the judgment:
  • Guess – judgment has no basis whatsoever, may as well have flipped a coin
  • Intuition – have some confidence in judgment, but have no idea why it’s right
  • Rules – judgment based on rules acquired from the training phase I could state
  • Memory – judgment based on memory for training strings or parts of training strings
slide106

The most direct way of testing for conscious knowledge is to test for higher order thoughts(Dienes, Altmann, Kwan, & Goode 1995)

slide107

Independent variables:

  • In the training phase, urged to search for rules or just memorize exemplars.
  • Rule search should encourage the development of conscious structural knowledge.
  • In the test phase, classify with full attention or while performing a demanding secondary task (random number generation).
  • Secondary task should interfere with the application of conscious structural knowledge.
slide108

When there was an implicit basis: No effect of learning condition nor secondary task on percentage correct

When there was an explicit basis: A secondary task disrupted correct classification in the rule search condition

slide109

2. Dynamic control tasks

Subjects interact with a simulated system, e.g. the sugar production factory (Berry & Broadbent 1984)

On each trial, hire and fire workers to try to maintain the level of sugar production at a target value.

Underlying equation (unknown to subjects) links current sugar production to number of workers and past sugar production.

Donald Broadbent

1926-1993

slide110

2. Dynamic control tasks

  • Berry and Broadbent (1984)
  • Training on the task improved ability to control the system but not ability to answer questions about how the system worked
  • +Trying to consciously work out the rules impairs learning!!!
  • Other dynamic control tasks include:
  • Interacting with a person, trying to make them friendly
  • Controlling a traffic system
3 probabilistic category learning
3. Probabilistic category learning
  • The weather prediction task
  • One or more cards presented in a random spatial order
  • Amnesic patients learn it
  • Basal ganglia dysfunction (Parkinson, Huntingdon)

High predictability (75%)

low predictability (58%) cards

how implicit is this
How implicit is this?
  • How do people solve the task?

(1)  One-Cue Learning.

Basing responses on the presence or absence of a single card (e.g., "I predicted rain whenever I saw the triangle card.").

(2)  Multi-Cue Learning.

Basing responses on the combinations of cues present on a given trial (e.g., "I noticed that triangles and diamonds usually meant rain, and the circles and squares meant sunny."5).

(3)  Singleton Learning.

Learning the correct response to singleton patterns (A = 0001, B = 0010, C = 0100, D = 1000), in which only a single card appears, and guessing on the remaining trials (e.g., Memorizing the single cards, "The single cards were the easiest, so I concentrated on those.").

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4. Serial reaction time task

(Nissen & Bullemer, 1987)

On each trial a light goes on

Just press corresponding button

Unbeknownst to subject, sequence of lights is rule governed

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Violates rules

Rule governed

Subjects are sensitive to the presence of the sequence even when they deny knowing that there was a sequence

conclusion
Conclusion
  • We are unaware of pretty much of what is going inside in our own minds
    • Leaves the question of „how much” open
    • Though we have different models, we have no way of telling what is under the tip of the iceberg – the only certainty seems to be that there is something