Unconscious memory

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Unconscious memory
Zoltán Dienes Conscious and unconscious mental
processes
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Unconscious memory You use memory but you are not
aware of using memory Types of conscious
memory Recollection Remember target event and
details of you yourself in spatiotemporal
context. (And you are aware of remembering.) Fami
liarity You know you have come across the target
item before but you cant remember context. You
are aware of knowing the target item is old.
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Implicit and explicit tests Warrington and
Weiskrantz (1970) gave amnesics and normals a
list of words to study (including e.g.
patio). On a recognition test, amnesics
performed worse than normals On stem
completion e.g. Pat - - Subjects were better at
words they had seen before, and this priming was
not significantly different between amnesics and
controls
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Schacter (1987) Explicit memory tests   Make
specific reference to, and require recollection
of, a specific learning episode.   Implicit
memory tests   Do not refer to prior episodes but
are facilitated by them
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Does performance on implicit tests reflect
unconscious memory? Problem You COULD solve stem
completion by use of conscious memory
Larry Jacoby
Conscious and conscious memory in
opposition Jacoby use opposition logic.
Exclusion test Complete the stem with the first
word that comes to mind BUT NOT one from the
list Conscious and unconscious memory work in
opposition any tendency for above-baseline
priming is plausibly due to unconscious memory
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Inclusion task conscious and unconscious memory
act in concert Results from exclusion and
inclusion combined allows an estimate of the
amount of the conscious memory process and the
amount of the unconscious memory process (Process
Dissociation Procedure PDP)
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Memory processes producing experiences that dont
seem like memory  Unconscious memory and the
illusion of loudness.   Jacoby et al 1988
(JEPLMC) Previously heard and new sentences
presented in a background of white noise of
varying loudness.   gt Background noise judged as
less loud for old rather than new
sentences   Subjects told about the effect and
told to avoid it are unable to do so Subjects
experience the effect as a perceptual one.
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Unconscious memory and the illusion of
truth Begg, Anas, Farinacci (1992), Experiment
4 (JEPG)   1. Learning phase Subjects
presented with obscure statements (like house
mice can run an average of four miles an hour)
labelled as true or false. Half the subjects
performed a simultaneous mental arithmetic task
(divided attention condition).   2. Test phase
presented with new and old sentences, rate extent
to which each is felt to be true.   Sleeper
effect Unconscious memory can make a statement
seem true.
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Recollection of source would enable a subject to
rate a statement as false if it was labelled
false (note conscious and unconscious memory are
put in opposition Exclusion) and to label it as
true if labelled true (conscious and unconscious
memory act together Inclusion).   Proportion
test items rated true old new C U Label
true false Full attention .78 .40 .46 .38 .19 D
ivided attention .72 .50 .47 .21 .16
PDP estimate of conscious process
PDP estimate of unconscious process
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In other experiments, false rated as more true
than new items, e.g. experiment 1
old new C U label true false .66 .59 .4
5 .07 .18
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Mere Exposure effect (Zajonc, 1968) - Simple
exposure to meaningless shapes enhances subjects
attitude towards the shapes - Strength of the
effect is often not correlated with recognition
accuracy Some evidence for a negative
relationship with explicit recognition - Longer
the delay between exposure and testing, larger
the effect - Subliminal rather than supraliminal
exposure produces stronger effects     -gt Our
conscious experiences are partly reconstructions
based on unconscious processes
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Mandler et al 1987 (JEPLMC 13 646-648) 1)  
Irregular shapes flashed for 1 or 2 ms 2)  
Subjects shown pairs of shapes, one new, one old
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Information processing under general
anaesthesia 1)   Do therapeutic suggestions
improve recovery? Evans Richardson 1988 (The
Lancet Aug 27 1988, p. 491)   40 hysterectomy
patients randomly assigned to 1)   Control
group. Heard silence. 2)   Experimental
group. You will not feel sick, you will not
have any pain . . The operation seems to be
going very well and the patient is fine . . .
No patient could recall anything.
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  Control Experimental Post-operative stay
(days) 8.4 7.1 sig Periods of High
temperature 3.9 2.2 sig Nurses assessment Of
recovery Better than expected - 14 1 6
16 sig nausea (0-100) 43 28 ns pain
distress (0-100) 20.8 18.2 ns
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2) standard implicit memory tests Roorda-Hrdlick
ova et al (1990) Control group (43
patients) Listened to tape of seaside sounds
after first incision. Experimental group (38
patients) Seaside sounds plus the words Yellow
banana green pear Repeatedly for 15 minutes  
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No patient could recall anything that happened
during anaesthesia.  Asked to name first three
vegetables, colours, and fruit that came to
mind. Mean number of hits Experimental
group 2.35 Control group 0.79 p lt .001