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When one item is made distinct from the other items in a list, memory for the distinctive item is improved, a finding known as the isolation or von Restorff effect (after von Restorff, 1933). Although demonstrated numerous times with younger adults and children, this effect has not been found with older adults (Cimbalo & Brink, 1982). In contrast to the earlier study, we obtained a significant von Restorff effect for both younger and older adults using a physical manipulation of font colour. The effect size for older adults was smaller than that obtained for younger adults, confirming a prediction of Naveh-Benjamin's (2000) associative deficit hypothesis, which attributes age-related differences in memory performance to older adults' reduced ability to form associations. The findings are consistent with related research in which older adults demonstrate similar--but smaller--benefits for distinctive information to those for younger adults.
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Short article
Age-related differences in the von Restorff
isolation effect
Tamra J. Bireta
The College of New Jersey, Ewing, NJ, USA
Aime
´
e M. Surprenant and Ian Neath
Memorial University of Newfoundland, St. John’s, Newfoundland, Canada
When one item is made distinct from the other items in a list, memory for the distinctive item is
improved, a finding known as the isolation or von Restorff effect (after von Restorff, 1933).
Although demonstrated numerous times with younger adults and children, this effect has not been
found with older adults (Cimbalo & Brink, 1982). In contrast to the earlier study, we obtained a
significant von Restorff effect for both younger and older adults using a physical manipulation of
font colour. The effect size for older adults was smaller than that obtained for younger adults, con-
firming a prediction of Naveh-Benjamin’s (2000) associative deficit hypothesis, which attributes
age-related differences in memory performance to older adults’ reduced ability to form associations.
The findings are consistent with related research in which older adults demonstrate similar—but
smaller—benefits for distinctive information to those for younger adults.
Keywords: Ageing; Distinctiveness; Free recall; Isolation effect; von Restorff.
Normal ageing is typically associated with declines
in memory performance across a wide variety of
tasks and for many different types of informat ion
(Zacks, Hasher, & Li, 2000). Explanations for
these changes in memory performance usually
cite a deficit in some process involved in memory
formation/retrieval (e.g., forming associations;
Naveh-Benjamin, 2000) or a deficit in a general
cognitive factor (e.g., processing speed; Salthouse,
1996). None of these theories, however, propos e
that memory mechanisms operate in a fundamen-
tally different manner in older adults. Consistent
with this assumption, younger and older adults
usually show similar benefits from experimental
manipulations that improve memory, including
generation (Taconnat & Isingrini, 2004), and
levels of processing (Troyer, Ha
¨
fliger, Cadieux, &
Craik, 2006). One factor that may be an exception
Correspondence should be addressed to Tamra J. Bireta, Psychology Department, Social Sciences Building, The College of New
Jersey, 2000 Pennington Rd., Ewing, NJ, 08628, USA. E-mail: tbireta@tcnj.edu
This research was supported, in part, by National Institute on Aging Grant AG021071 awarded to AMS and IN. Portions of this
paper are based on a dissertation presented by TJB to the faculty of the Graduate School of Purdue University. We thank
E. J. Capaldi, J. S. Nairne, and R. W. Proctor for comments and discussions. Part of this work was presented at the 47th Annual
Meeting of the Psychonomic Society, Houston, Texas, November 2006.
# 2007 The Experimental Psychology Society 1
http://www.psypress.com/qjep DOI:10.1080/17470210701626608
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to this rule is distinctiveness: The available data
suggest that the benefit of distinctiveness may be
reduced—or even absent—for older adults.
There are two purposes of the research reported
here: (a) to examine age-related differences in
the effects of distinctiveness and (b) to ev aluate
the hypothesis that an associative deficit in older
adults (Naveh-Benjamin, 2000) underlies age-
related deficits in memory.
When a particular item is made distinct from
other items in a list, memory for the distinctive
item is improved. This is known as the von
Restorff effect or the isolation effect (von
Restorff, 1933). Recall of the distinctive item is
typically compared to that of a control item that
is consistent with the background items .
Isolation effects can be achieved with both physical
manipulations (e.g., size, colour, or font type) and
semantic changes (e.g., meaningfulness or cat-
egory). Numerous studies have demonstrated the
robustness of this effect using various stimul i and
methodologies (for a review, see Hunt, 1995),
and the isolation effect is reliably obtained in
college-age adults as well as in chil dren (Howe,
Courage, Vernescu, & Hunt, 2000). The size of
the isolation effect depends on several fa ctors,
including the manner in which the isolate differs
from the other items in a list. Large effects are
obtained using size, colour, and spacing manipula-
tions, and isolati on effects increase in magnitude as
the difference between the isolate and the other list
items increases (Gumenik & Levitt, 1968; see also
Hunt, 1995).
Despite the la rge liter ature on isolation effects
in children and young adults, only one published
study has examined the isolation effect in older
adults. Cimbalo and Brink (1982) displayed lists
of nine consonants to younger and older adults
for immediate written serial recall, with the
isolate lists containing a consonant in a larger
font in the fifth position. Younger, but not older,
adults recalled the isolates better than the control
items. The authors argued that older adults
noticed the size difference, but suggested that
the lack of an isolation effect reflected a deficit in
using structural information to organize the list.
The isolate, then, “may have been considered as
analogous to noise, something to be ignored” by
the older adults (p. 76).
Most current theories of ageing and memory,
including theories based on inhibition, reduced
resources, and slower speed of processing, predict
that older adults will show lower overall perform-
ance than younger adults on most episodic
memory tasks (Zacks et al., 2000). They lack,
however, a specific reason why older adults
might show a reduced or nonexistent benefit for
the isolate. In contrast, the associative deficit
hypothesis (Naveh-Benjamin, 2000) offers a
specific explanation for age-related differences in
the isolation effect. Naveh-Benjamin argued that
it is important to distinguish between memory
for a single unit and memory for associations
among units. Associations between two units can
include two items, an item and its context, two
contextual features, or “the representation of two
mental codes” (p. 1170). He proposed that the
reason older adults show poorer memory in most
episodic memory tasks is that older adults have
difficulty “merging different aspects of an episode
into a cohesive unit” (p. 1185).
Naveh-Benjamin and colleagues (Naveh-
Benjamin, 2000; Naveh-Benjamin, Hussain,
Guez, & Bar-On, 2003; Naveh-Benjamin, Guez,
Kilb, & Reedy, 2004) have demonstrated that an
important predictor of when older adults will
show worse performance than younger adults is
whether the task requires memory for units
versus memory for the association between units.
For example, compared to younger adults, older
adults recognized fewer wordnonword and
wordword pairs despite similar levels of perform-
ance for recognition of the individual items
(Naveh-Benjamin, 2000). This type of associative
deficit was replicated using pictorial stimuli
(Naveh-Benjamin et al., 2003) and face/name
pairs (Naveh-Benjamin et al., 2004). This view
has also been successful in accounting for older
adults’ reduced memory for contextual details
(for a meta-analysis, see Spencer & Raz, 1995)
using the idea that older adults can remember
individual units (i.e., the items or the contextual
features), but suffer when they must also remem-
ber associations amongst them (i.e., which
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contextual feature went with which items). Naveh-
Benjamin (2000, Exp. 3) ruled out the possibility
that older adults simply lack information about
contextual details in general by presenting words
in different fonts, followed by tests for the
words, fonts, and wordsfont relations. Older
adults showed equivalent memory for the words
and for the fonts, but a large deficit in recalling
the word font relations.
According to the associative deficit hypothesis,
age-related differences in the isolation effect are
due to the difficulty that older adults have in
associating contextual features with items such as
the colour in which a word was presen ted. The
association of the contextual element (colour) to
an item is necessary for an isolation effect to
occur because it is this contextual element that
causes the isolate to have increased distinctiveness
at retrieval (due either to items being placed in
different categories, e.g., Hunt & Lamb, 2001,
or cues uniquely specifying the isolate, e.g.,
Nairne, 2006). If older adults do not associate
contextual elements to items as well as younger
adults, then a smaller or nonexistent isolation
effect should be found for older adults.
The current experiment was designed to compare
isolation effects in younger and older adults and to
test a prediction of the associative deficit hypothesis
that older adults will show reduced isolation effects.
Participants viewed lists of 12 unrelated nouns, with
the isolate lists consisting of one item in a red font
and all other items in a black font. Immediately fol-
lowing presentation, participants recalled the items
using free written recall. In addition, two different
presentation rates were used to determine whether
older adults would show greater isolation effects
when given an increased opportunity to encode
the information.
Method
The design of the current experiment differed
from the Cimbalo and Brink (1982) study in the
following ways: First, the list items were presented
one at a time rather than simultaneously to ensure
that all items were given equal opportunity to be
encoded. Second, presentation time was held
constant across lists for a given participant rather
than varied unpredictably. Third, the isolate
manipulation involved a perceptually obvious
manipulation of colour rather than a slight size
difference (1 mm) between controls and isolates.
Finally, the test was free rather than serial recall,
a task that typically yields larger isolation effects
(e.g., Kelley & Nairne, 2001).
Participants
A total of 80 younger adults (M ¼ 19.3 years,
range 1826) and 80 older community-dwelling
adults (M ¼ 70.1 years, rang e 6089) participated
in this experiment. The younger adults were
Purdue University undergraduates who partici-
pated in exchange for course credit. The older
adults were paid $10 per hour and were recruited
from the community. The education levels of
older adults ranged from high sch ool to gradu-
ate/professional degrees, with 79% of the partici-
pants completing at least some college
coursework (highest level of education was a
high-school degree for 21% of the older adults;
some college for 15%; a college degree for 21%;
some gradu ate or professional education for 3%;
and a graduate or professional degree for 40%).
All participants reported themselves to be in
good health, and none reported using any medi-
cations that migh t interfere with cognitive
functioning.
All participants were admin istered a 20-item
vocabulary test adapted from Salthouse (1993)
and a computerized memory span task based
upon the reading span test in Kane et al. (2004)
in order to obtain an estimate of each participant’s
overall level of cognitive function ing. Typical
results obtained: There was a slight difference in
favour of the younger adults for memory span
(younger M ¼ 7.6, SD ¼ 1.1; older M ¼ 6.7,
SD ¼ 1.0), t (158) ¼ 5.35, p , .01, but older
adults did significantly better on the vocabulary
test (younger M ¼ 7.9, SD ¼ 3.4; older M ¼
13.6, SD ¼ 5.2), t(158) ¼ 8.24, p , .01.
Materials
The stimuli were 241 nouns selected from Clark
and Paivio (2004). The nouns selected were of
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AGEING AND THE ISOLATION EFFECT
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medium to high imageability (M ¼ 6.03, range
4.006.90 out of 6.90), familiarity (M ¼ 5.97,
range 4.216.92 out of 7.00), and frequency
(M ¼ 1.75, range of 1.00 to 2.00 using log
ThorndikeLorge frequency; M ¼ 1.70, range of
1.00 to 2.77 using log KuceraFrancis frequency).
Design
Age (younger, older) and presentation rate (1.5 s,
3 s) were between-subjects variables, and the
isolation manipulation of list type (isolate,
control) and serial position (112) were within-
subjects variables. Participants viewed the to-be-
remembered items one at a time in the middle of
a computer screen and were asked to read each
word silently. Each list contained 12 different
items, with each item presented for either 1.5 or
3 s and no delay between items. The items on
each list were randomly selected without replace-
ment from the 241 stimuli; thus no word was
repeated within or across lists for any individual.
All of the items in the control lists were presented
in black against a white background. In the isolate
lists, the 7th item was presented in red, and the
other 11 items were black. The isolate always
appeared in the 7th serial position to maximize
the possibility of obtaining an isolation effect for
older adults. First, fewer trials are required to
obtain reliable data than if all positions are
tested, and, second, effect sizes are likely to be
larger in middle serial positions than in earlier
and later positions (because of the absence of
primacy and recency effects). There were 20
trials in total: 10 control lists and 10 isolate lists.
List type on any given trial was random.
Procedure
Participants were told that they would see 12
words one at a time followed by the cue “please
recall the words”. They were asked to recall as
many words as possible by writing the words
down on a response sheet that contained trial
numbers and 12 numbered lines per trial. They
were informed that they could recall the items in
any order and could take as much time as necess-
ary. To proceed to the next list, the participant
clicked on a button labelled “next trial”.
Participants were tested one at a time, and the
experimenter remained in the room to ensure
compliance with the instructions.
Results
As Figure 1 illustrates, older adults clearly showed
a von Restorff isolation effect regardless of the
presentation rate. When questioned after the
experiment, all of the younger adults and all but
2 of the 80 older participants reported awareness
of the isolate.
Free recall
The data were first analysed with a 2 (age: younger,
older) ! 2 (presentation rate: fast, slow) ! 2 (list
type: control, isolate) ! 12 (serial position: 112)
Figure 1. Recall of control and isolate lists as a function of group
and serial position. The top panel shows fast presentation, and
the bottom panel shows slow presentation.
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analysis of variance (ANOVA). For this and all sub-
sequent analyses, alpha was set to .05. Younger
adults recalled more list items than older adults
(5.28 out of 12 vs. 3.99), yielding a main effect of
age, F(1, 156) ¼ 60.12, MSE ¼ 26.24. More
words were recalled with the slower presentation
rate than with the faster rate (5.05 vs. 4.22), result-
ing in a main effect for presentation rate, F(1, 156)
¼ 25.13, MSE ¼ 26.24. Overall, lists containing
the isolate were not recalled differently from
control lists (4.63 vs. 4.64), F(1, 78) , 1. Typical
primacy and recency effects were obtained, resulting
in a main effect of serial position, F(11, 1716) ¼
121.96, MSE ¼ 4.45.
The difference in recall between younger and
older adults increased from earlier to later serial
positions (collapsed across presentation rates),
with a significant interaction between age and pos-
ition, F (11, 1716) ¼ 4.66, MSE ¼ 4.45. This
occurred primarily because of the increased
recency effects that younger adults displayed with
fast than with slow presentation. List type inter-
acted with position, reflecting the isolation effect
in which the item in the 7th serial position was
better recalled in the isolate lists than the control
lists (4.94 vs. 3.33), F(11, 1716) ¼ 10.35,
MSE ¼ 2.24. Slow presentation resulted in a
memory advantage over fast presentation for
earlier, but not for later, serial positions, yielding
a significant interaction between position and
presentation rate, F(11, 1716) ¼ 4.91, MSE ¼
4.45. There were no other significant interactions.
Isolation effect
To examine the effects of age on the isolation
effect, additional analyses were performed on
recall of just the items occurring in the 7th serial
position. A 2 (age: younger, older) ! 2 (presen-
tation rate: fast, slow) ! 2 (list type: control,
isolate) ANOVA yielded main effects for all vari-
ables. More items were recalled by younger than
older adults (5.18 vs. 3.09), F(1, 156) ¼ 82.76,
MSE ¼ 4.19, and with slow than fast presentation
(4.54 vs. 3.73), F(1, 156) ¼ 12.81, MSE ¼ 4.19,
and the isolates were recalled more often than
control items (4.94 vs. 3.23), F(1, 156) ¼ 78.03,
MSE ¼ 2.69. Younger adults demon strated a
larger difference between isolates and controls
(6.26 vs. 4.09) than did older adults (3.63 vs.
2.56), resulting in a significant interaction
between age and list type, F(1, 156) ¼ 9.21,
MSE ¼ 2.69. A t test confirmed an isolation
effect for older adults, with the means for isolates
(3.63) and controls (2.56) differing significantly,
t(80) ¼ 4.29. No other interactions were signifi-
cant. The lack of a significant three-way inter-
action between age, presentation rate, and list
type, F(1, 156) ¼ 0.62, MSE ¼ 2.69, suggests
that the difference in the size of the isolation
effect for younger compared to older adults does
not depend on presentation rate.
Participant variables
The sample of older adults included many who
had graduate or professional degrees. One possible
concern is that the von Restorff effect that was
observed was driven by a subgroup of highly
educated and potentially higher performing older
participants. The older participants were divided
into two groups based on level of education. The
closest we could come to a median split that
resulted in groups with equivalent ages was to
define the “high education” group as those with
at least some graduate school (N ¼ 34, M ¼
70.41, range 60 to 82) and the “low education”
group as everyone else (N ¼ 46, M ¼ 69.85,
range 60 to 89). Both groups showed a significant
von Restorff effect, t(32) ¼ 4.02 and t(44) ¼ 2.41
for the “high” and “low”, respectively, although the
high education group had a larger isolation effect
than the low education group (2.56 vs. 3.91 com-
pared to 2.56 vs. 3.41). However, the age-related
difference remains even when the high education
group was compared to the younger adults
(4.09 vs. 6.26). Thus, high levels of education in
older adults reduces, but does not eliminate, the
age-related differences seen in the magnitude of
the isolation effect.
Because our sample included a wide range of ages
forolder adults, it was possible to examine differences
in the isolation effect between the youngold (ages
6074, N ¼ 59) and the oldold (ages 7589, N
¼ 21). Each age group showed a significant isolation
effect: 3.78 isolates versus 2.69 controls for the
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youngold, t(19) ¼ 2.53, compared to 2.19 isolates
versus 3.19 controls for the oldold, t(57) ¼ 3.97.
The magnitude of the isolation effect did not
differ, t(78) ¼ 0.15. Thus, the benefit of the isolate
appears relatively stable across older age.
Output order
One possible explanation for the higher recall of
the isolate may be that it is output earlier than
the control item, which reduces output interfer-
ence. To check for this, mean output position for
recalling the item from the 7th position (when it
was recalled) in both the control and isolate lists
was calculated (see Figure 2). A 2 (age: younger,
older) ! 2 (presentation rate: fast, slow) ! 2
(item type: control, isolate) ANOVA was con-
ducted on average output position for isolates
and controls. Of most importance, isolate items
were not output at earlier positions than control
items, F(1, 56) , 1. However, older adults
output the 7th items (collapsed across control
and isolate lists) significantly earlier than did
younger adults (position 3.7 vs. 4.4), resulting in
a main effect of age, F(1, 156) ¼ 14.22, MSE ¼
2.48. This is due to the fewer total number of
items recalled by older adults than by younger
adults. The isolated items were also output
earlier with fast presentation compared to slow
presentation (3.7 vs. 4.3), F(1, 156) ¼ 12.27,
MSE ¼ 2.48. Again, this effect occurred as a
result of the fewer items recalled with fast than
with slow presentation. There were no significant
interactions. This analysis was repeated on nor-
malized data, which takes into account the
differential levels of recall; again, no evidence of
early output of the is olated item was observed.
GENERAL DISCUSSION
Younger adults demonstrated better memory for
isolated items than did controls in lists of homo-
geneous background items, replicating the well-
known isolation effect (von Restorff, 1933). In con-
trast to the results obtained by Cimbalo and Brink
(1982), the results of the current study clearly
demonstrate a significant isolation effect for older
adults. Because of the numerous methodological
differences between the Cimbalo and Brink study
and the current experiment, it is not clear why the
effect was not obtained in their study. However,
their combination of serial recall, simultaneous
presentation, and a relatively small difference
between isolate and control items may all have con-
tributed to the difference. The current study used a
more typical methodology and found that older
adults are affected by distinctiveness in a qualitat-
ively similar way to younger adults.
Although the older adults showed a signi ficant
isolation effect, it was smaller than that of the
younger adults. These results support the predic-
tions of Naveh-Benjamin’s (2000) associati ve
deficit hypothesis. According to this view, older
adults show poorer memory in most episodic
memory tasks due to difficulty “merging different
aspects of an episode into a cohesive unit” (p.
1185). In the current experiment, memory for
each list requires associations amongst the items
and/or associations between each item and the
surrounding context, both of which will be
deficient for older adult s. This v iew, therefore,
correctly predicts overall lower performance for
older adults. Further, because older adults are
not able to assoc iate contextual elements with
specific items as well as younger adults, th ey are
not able to use these contextual features as retrieval
cues as effectively. The weaker association between
the unique colour information and the item will
reduce the isolation effect because it is this contex-
tual element that causes the isolate to have
increased distinctiveness at retrieval.
Figure 2. Proportion of responses for isolates and controls (7th
position) by output position.
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The finding of a reduced isolation effect for older
adults could also be explained by accounts that pos-
tulate processing differences between younger and
older adults, as processing differences have been
shown to affect the magnitude of the isolation
effect (e.g., Fabiani, Karis, & Donchin, 1990). For
example, one view states that distinctive processing,
defined as “processing the difference in the context
of similarity”, is more difficult for older adults (see
Smith, 2006, p. 279). This difficulty arises from the
need to process information about the item as well
as information about the relationships between the
items, which draws upon cognitive resources that
are limited for older adults. According to this view,
older adults are less likely to engage in distinctive
processing when the task requires a large amount
of cognitive resources. Therefore, in a task such as
the one in the current study that requires a large
amount of cognitive resources, older adults would
be less able to engage in the distinctive processing
that results in the isolation effect.
Most current accounts of the isolation effect
attribute it to the increased distinctiveness at
retrieval for the isolate relative to the background
items (e.g., Hunt & Lamb, 2001; Kelley &
Nairne, 2001; Nairne, 2006). Research in other
areas has found that older adults do benefit from
enhanced distinctiveness at retrieval, albeit to a
lesser extent than younger adults (e.g., Ma
¨
ntyla
¨
& Ba
¨
ckman, 1992; Smith, 2006), and it would
therefore be surprising if older adults did not
show an isolation effect. Contrary to the only
other published study, the result s reported here
show that older adults do show a typical isolation
effect, and, in parallel with findings in other
areas, the effect is reduced for older adults.
Original manuscript received 4 April 2007
Accepted revision received 27 July 2007
First published online day month year
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8 THE QUARTERLY JOURNAL OF EXPERIMENTAL PSYCHOLOGY, 0000, 00 (0)
BIRETA, SURPRENANT, NEATH
... 6 Many isolation paradigms have been developed since the phenomenon was first described: the isolated item can be different from others by differing physically (a different color or font size), semantically (meaningfulness or category) or even a taboo word presented in a list of neutral words. 7 In all cases, people demonstrate superior recall of these items when isolated. 3,8,9 Therefore, the Von Restorff effect has been demonstrated numerous times in children and adults and, although it was first considered absent in elders, 10 subsequent studies showed it is also present in older ages, albeit with a smaller effect size. ...
... 3,8,9 Therefore, the Von Restorff effect has been demonstrated numerous times in children and adults and, although it was first considered absent in elders, 10 subsequent studies showed it is also present in older ages, albeit with a smaller effect size. 7,11 Other studies have also reported the effect in a healthy elderly population, but failed to observe the effect in Alzheimer's Disease (AD) patients. 13 In all these studies, the paradigm used was the free recall of word lists, a task highly susceptible to isolation effects. ...
... We hold that the isolation effect displayed by older adults can be observed across different methodologies used to investigate this phenomenon, regardless of whether the isolated word is emotionally distinct (as in this study), or differs semantically 11 or physically from the remaining items. 7,12 In addition, we also investigated the presence of the Von Restorff effect in clinical samples with memory impairment (amnestic MCI and AD patients). Only one study studied this effect in an AD population. ...
Article
Full-text available
The Von Restorff (isolation) effect refers to a stimulus that is more likely to be remembered amongst other stimuli in memory tasks. It has been demonstrated with different age ranges and methodologies. Objective: To investigate: a) the presence of the isolation effect in elders tested with the new Brazilian Portuguese version of the Rey Auditory Verbal Learning Task (RAVLT) in which a word with potential emotional weight (mother) was introduced; b) whether isolation effects persist in memory disorders of different degrees of severity (Mild Cognitive Impairment [MCI]; Alzheimer's Dementia [AD]). Methods: The RAVLT was administered to 287 consecutive volunteers. Individuals underwent medical and neuropsychological evaluation and were further sub-grouped into normal controls (n=114), MCI (n=87) and AD (n=86) patients. One-way analysis of variance (ANOVA) and Chi-squared tests were performed. Post-hoc Tukey analysis was conducted to assess significance of group differences. Results: There were significant group effects on the learning curve. A W-shape - instead of the classical U-shape - was found for the serial position curve in all groups. Conclusion: The new Brazilian version of the RAVLT exhibited the Von Restorff effect, where this phenomenon was evident not only in older adults but also patients with MCI and AD, providing further psychometric measures for inter-group analyses.
... Hence, these ads entail deviation from regular advertising messages through schemadiscrepant information. This deviation affects recipients' memory, which is theoretically known as isolation effect (Bireta et at., 2008). This effect suggests that a particular object that has been previously made distinct from other items is better memorised than a conventional object. ...
... We expect this effect to be culturally invariant because the isolation effect merely suggests that schema incongruence reflexively triggers cognitive processing (Bireta et al., 2008). However, cognitive processing does not yet comprise any judgment of the deviant stimulus. ...
... With respect to memory, both visual metaphors increase recall, and this effect occurs regardless of the recipients' cultural disposition. This result can be explained by the isolation effect suggesting that schema-incongruent information induces an extended elaboration process (Bireta et al., 2008). As cognitive processing does not comprise any judgment of the deviant stimulus, the recipients' value system (i.e., culture) is not involved in memory formation. ...
... 76). More recent studies have reported isolation effects in older adults, but the effects were smaller in magnitude than the effects found in college-age adults (Bireta, Surprenant, & Neath, 2008;Geraci, McDaniel, Manzano, & Roediger, 2009). Bireta et al. (2008) argued that older adults lack the cognitive resources needed for Bprocessing the difference in the context of similarity^(p. ...
... More recent studies have reported isolation effects in older adults, but the effects were smaller in magnitude than the effects found in college-age adults (Bireta, Surprenant, & Neath, 2008;Geraci, McDaniel, Manzano, & Roediger, 2009). Bireta et al. (2008) argued that older adults lack the cognitive resources needed for Bprocessing the difference in the context of similarity^(p. 351; see also Smith, 2011). ...
Article
An item that is conceptually or physically different from other items in a series is often remembered well. This isolation effect has been found independent of the position of the isolated item in the list, suggesting that special attention to or processing of the isolated item is not a necessary precondition of the effect. Three experiments are reported that challenge this conclusion. In Experiment 1a, we compared memory for conceptually isolated items to memory for the same items in unrelated and homogeneous lists. Under moderately distracting conditions, isolation effects were observed with midlist but not with early isolates. In fact, early isolation impaired memory for the conceptually distinct items relative to the same items in homogeneous lists. Experiment 1b replicated this memory impairment for early conceptual isolates and extended it to nondistracting conditions. In Experiment 2, we focused on early isolation, manipulating the type of isolation and whether or not participants performed judgments of learning (JOLs). An early isolation effect was observed for numbers isolated in lists of words (and vice versa), but not for conceptual isolates. Performing the JOL task reduced the size of the early isolation effect. These results suggest that number/word stimulus contrasts are coded automatically and support an isolation effect independent of list position. However, conceptual contrasts require relational processing and will only support an early isolation effect when such processing occurs. The results of Experiments 1a, 1b, and 2 suggest that attentional resources during list presentation and a favorable retrieval environment combine to support good memory for distinctive events.
... The typical outcome is that memory for the word table will be better when participants receive the isolation list than when participant receive the control list. Although, as noted by Hunt (1995), many studies that use the isolation paradigm place the critical isolated item late in the isolation list (e.g., the 7th item in a 12 item list, Bireta, Surprenant, & Neath, 2008), key evidence regarding the question of salience comes from studies in which the critical item occurs early in the list. For instance, von Restorff (1933) purposely placed the critical items early in the list (e.g., serial Positions 2 and 3) because at this point the list context has not yet been established. ...
... In late isolation lists, the nature of the list structure supports processing the difference between the late isolate and the already established list context. Consistent with this proposal, a number of studies have demonstrated a late isolation effect for older adults using a variety of stimulus types, including items isolated on a semantic dimension (Badham & Maylor, 2013;Bireta et al., 2008;Geraci, McDaniel, Manzano, & Roediger, 2009;R. E. Smith, 2011;Vitali et al., 2006; see R. E. Smith, 2011 for discussion of Cimbalo and Brink (1982) experiment in which older adults did not demonstrate the late isolation effect). ...
Article
The isolation paradigm is often used for studying the effects of distinctiveness on memory. Within this paradigm the isolated item can appear early or late in the list. Most prior studies using the isolation paradigm with older adults placed the isolated items late in the study list, however, Smith (2011) used an early isolation list and found that older adults showed an early isolation effect when the dimension of isolation was more readily detected (numbers vs. letters) but did not show an isolation effect when the dimension of difference was more subtle (category membership). The current experiments replicate these findings and demonstrate judgments of learning are elevated for the isolated item in the former case, but not in the latter case, for young and older adults. (PsycINFO Database Record
... For example, the inconsistency effect is broadly similar to the von Restorff or isolation effect, in which participants show superior memory for an isolate word that differs from other study list words on some dimension (e.g., the word table in a list of vegetables). Several reports suggest that the magnitude of the memory enhancement for the isolate is attenuated in older adults compared to the young (e.g., Bireta, Surprenant, & Neath, 2008;Cimbalo & Brink, 1982;Geraci, McDaniel, Manzano, & Roediger, 2009). Similarly, while young adults remember atypical actions better than typical actions in scripted textan inconsistency effectthe magnitude of that effect has been shown to be reduced in older adults (Hess, 1985;Hess, Donley, & Vandermaas, 1989). ...
Article
Full-text available
The present study examined age-related differences in the inconsistency effect, in which memory is enhanced for schema-inconsistent information compared to schema-consistent information. Young and older adults studied schema-consistent and schema-inconsistent objects in an academic office under either intentional or incidental encoding instructions, and were given two recognition tests either immediately or after 48 hr: A yes/no item recognition test that included modified remember/know judgments and a token recognition test that required determining whether an original object was replaced with a different object with the same name. Young and older adults showed equivalent inconsistency effects in both item and token recognition tests, although older adults reported phenomenologically less rich memories of schema-inconsistent objects relative to young adults. These findings run counter to previous reports suggesting that aging is associated with processing declines at encoding that impair memory for details of schema-inconsistent or distinctive events. The results are consistent with a retrieval-based account in which age-related difficulties in retrieving contextual details can be offset by environmental support.
Article
This study contrasted two explanations of the von Restorff effect – distinctive processing and retrieval cue efficacy, which differ in their assumptions about encoding processes. A homonym, kiwi, was used as the critical word and manipulated to either be synonymous with background items, or made an isolate by orienting participants towards its alternate meaning. The orientation was done at either the encoding or retrieval stages. Experiments 1a and 1b showed that even without distinctive processing at encoding, the von Restorff effect could still occur at retrieval in the presence of an effective retrieval cue. Experiments 2 and 3 eliminated the von Restorff effect through equating cue overload between the control and isolation lists. The results support the retrieval cue efficacy account and suggest that it is not necessary to have distinctive processing to obtain the isolation effect.
Thesis
Le travail de recherche présenté dans cette thèse considère la mémoire humaine comme un système unique et non abstractif qui reflète l’ensemble de nos expériences sous forme de traces épisodiques multimodales. Les objectifs de cette thèse sont multiples, mais le principal est de montrer qu’un effet robuste de la mémoire, l’effet de distinctivité, peut émerger aussi bien dans les tâches implicites que dans les tâches explicites et que cet effet s’expliquerait en termes de mécanismes spécifiques (activation et intégration multimodales) et non pas en termes de systèmes mnésiques sous-jacents.Trois séries d’expériences ont été élaborées. Dans une première série, nous avons manipulé l’information contextuelle extrinsèque associée à ces concepts. Une tâche de catégorisation nous a permis de démontrer que l’effet de distinctivité pouvait se manifester avec une tâche implicite de mémoire.Dans une deuxième série d’expériences, nous avons manipulé la distance entre des images à catégoriser dans une phase d’encodage. Ainsi, les images apparaissaient soit plus éloignées les unes des autres, soit plus proches. Suite à une récupération implicite, nous avons mis en évidence que notre hypothèse de distinctivité spatiale était validée, c’est-à-dire que les items spatialement plus distinct lors de l’encodage sont associés à des performances supérieures en phase test.Dans la troisième série d’expériences, nous avons mis en évidence que lesperformances liées à l’effet de distinctivité dans les tâches implicites et explicites de mémoire variaient selon différents niveaux d’intégration des dimensions sensorielles. Cette idée a été testée en rappel libre, en décision lexicale et en reconnaissance.Au final, nos résultats expérimentaux suggèrent que les performances issuesdes tâches implicites et explicites peuvent être expliquées au sein du même système mnésique unique. Ainsi, les processus d’intégration seraient à l’origine de ce phénomène.
Article
One experiment examined age-related differences in memory for distinctive information. Although a facilitative effect of orthographically distinctive words was obtained for the two groups of age, the bizarreness effect was only obtained in free recall for young adults but not for the oldest group (over age 70). The results are discussed in relation to Hunt's (2006) theory of distinctiveness which predicts that fluctuations in the degree item-specific and relational processing will influence the effects on memory.
Article
The isolation effect is the finding that memory is improved for items that are distinctive. The isolation effect has led advertisers to suggest that their advertisements should be designed to "stand out" from other advertisements. The current study examined semantic and physical isolation effects for print advertisements. Participants viewed a slideshow containing four advertisements for trashcans. Each advertisement contained a different brand name and feature for the trashcan pictured in the advertisement. In Experiment 1, one of the four advertisements included a product feature rated as highly distinctive (semantic isolate) relative to the product features appearing in the other advertisements. The isolated advertisement in Experiment 2 included a product feature of a different font size and color (physical isolate) than the product features appearing in the other advertisements. Participants were tested on the brand names and features from the advertisements. Unlike previous experiments on isolation effects in advertising, participants were required to remember which feature was presented with which brand. Participants demonstrated an isolation effect, with better recall of the features from the distinctive advertisements than the regular advertisements. This benefit, however, did not reliably extend to memory for the brand names associated with the isolate. These findings demonstrate that the robust nature of the isolation effect is not limited to laboratory settings; rather, the effect is more generalizable and occurs in real-world situations as well.
Article
In over 100 years of scientific research on human memory, and nearly 50 years after the so-called cognitive revolution, we have nothing that really constitutes a widely accepted and frequently cited law of memory, and perhaps only one generally accepted principle. The purpose of this monograph is to begin to rectify this situation by proposing 7 principles of human memory that apply to all memory. These principles are qualitative statements of empirical regularities that can serve as intermediary explanations and which follow from viewing memory as a function. They apply to all types of information, to all memory systems, and to all time scales. The principles highlight important gaps in our knowledge, challenge existing organizational views of memory, and suggest important new lines of research.
Article
Full-text available
The isolation effect is a well-known memory phenomenon whose discovery is frequently attributed to von Restorff (1933). If all but one item of a list are similar on some dimension, memory for the different item will be enhanced. Modern theory of the isolation effect emphasizes perceptual salience and accompanying differential attention to the isolated item as necessary for enhanced memory. In fact, von Restorff, whose paper is not available in English, presented evidence that perceptual salience is not necessary for the isolation effect. She further argued that the difference between the isolated and surrounding items is not sufficient to produce isolation effects but must be considered in the context of similarity. Von Restorff's reasoning and data have implications for the use of distinctiveness in contemporary memory research, where distinctiveness is sometimes defined as perceptual salience and sometimes as a theoretical process of discrimination. As a theoretical construct, distinctiveness is a useful description of the effects of differences even in the absence of perceptual salience, but distinctiveness must be used in conjunction with constructs referring to similarity to provide an adequate account of the isolation effect and probably any other memory phenomena.
Article
Full-text available
The authors reviewed the evidence of age differences in episodic memory for content of a message and the context associated with it. Specifically, the authors tested a hypothesis that memory for context is more vulnerable to aging than memory for content. In addition, the authors inquired whether effort at encoding and retrieval and type of stimulus material moderate the magnitude of age differences in both memory domains. The results of the meta-analysis of 46 studies confirmed the main hypothesis: Age differences in context memory are reliably greater than those in memory for content. Tasks that required greater effort during retrieval yielded larger age differences in content but not in context memory. The greatest magnitude of age differences in context memory was observed for those contextual features that were more likely to have been encoded independently from content. Possible mechanisms that may underlie age differences in context memory-attentional deficit, reduced working memory capacity, and failure of inhibitory processing are discussed.
Chapter
Younger adults often perform better than older adults do on memory tests. Researchers interested in these age-associated performance differences have at times drawn concepts from the "mainstream" research (that is, research that focuses on younger adults) and applied these concepts to explain why older adults frequently do not remember as well as younger adults. This chapter looks at attempts to explain age differences in episodic memory as a function of relational and item-specific processing, and in some cases both kinds of processing. The focus is on studies comparing intentional retrospective memory in healthy younger (generally less than 30 years of age) and older adults (generally 60 years of age and older). The chapter primarily addresses three questions. First, are there age-related differences in item-specific processing? Second, are there age-related differences in relational processing? And finally, are there agerelated differences in distinctive processing? The chapter concludes by relating three of the four points concerning distinctiveness raised by R. Reed Hunt to the literature on memory and aging.
Article
An associative hypothesis to explain and predict older adults' deficient explicit episodic memory performance was outlined and tested. The hypothesis attributes a substantial part of older adults' deficient memory performance to their difficulty in merging unrelated attributes-units of an episode into a cohesive unit Although each of the components can be memorized to a reasonable degree, the associations that tie the attributes-units to each other grow weaker in old age. Four experiments are reported that provide (a) a converging validity to the hypothesis by demonstrating this associative deficit for both interitem relationships and intraitem relationships and (b) a discriminant validity to the hypothesis by contrasting and testing competing predictions made by the associative hypothesis and by alternative hypotheses. The implications of these results to older adults' episodic memory performance arc discussed.
Article
In monotonen Reihen artgleichen Materials, wie sie die klassische Gedächtnispsychologie verwendet hat, wirken intensive Kräfte, die die entstandene Lernwirkung aufzuheben tendieren. Reihenglieder, die nicht in so monotoner Häufung gegeben werden, erreichen deshalb weit höhere Reproduktionswerte als Glieder in Häufungsstellung. Indessen beruht die untersuchte Schädigung nicht einfach auf der Nachbarschaft vieler einander artgleicher Glieder, sondern auf Bereichsbildung und auf Absorption der Glieder in Bereichen, die durch gleichmäßigen Reihenverlauf begünstigt wird. Prüfung des Wiedererkennens anstatt der Reproduktion führt zu demselben Ergebnis, jedoch anscheinend in schwächerer Form. — Rückwirkende und vorwärtswirkende Hemmung sind Nebenformen im Prinzip der gleichen Schädigung. Dem niederen Grade, mit welchem die Bereichswirkung bei Prüfung des Wiedererkennens wirksam zu werden scheint, dürfte Ausbleiben einer vorwärtswirkenden und rückwirkenden Hemmung bei derselben Prüfungsart entsprechen.
Subjects were instructed to use either rote or eleborative strategies to memorize words in a Von Restorff paradigm. When instructed to use rote strategies, subjects displayed a higher Von Restorff effect and a lower recall performance than when instructed to use elaborative strategies. Furthermore the amplitude of the P300 component of the event-related brain potential predicted subsequent recall only when subjects used rote strategies. When subjects used elaborative strategies, the relationship between P300 amplitude and subsequent recall was not observed. These results confirm and expand, in a within-subjects design, the results reported by Karis, Fabiani and Donchin (1984) who capitalized on different strategies used by different subjects. These results also lend support to a 3-phase model of the Von Restorff effect.
Article
Adult age differences in the consistency effect were examined in 3 experiments. The consistency effect refers to items inconsistent with expectations being better remembered than items consistent with expectations. Younger and older adults walked into an office room and viewed objects that varied in their consistency with expectation. Immediate and delayed recognition tests on item information (i.e., distractors were defined by their semantic identity) revealed that both age groups recognized unexpected items better than expected items. However, when recognition of token information was requested (i.e., distractors were defined by their physical appearance), younger adults, in contrast to older adults, exhibited consistency effects. Also, under divided attention, young adults revealed the same pattern of data as did elderly adults under full attention. The results are discussed in terms of capacity-related differences in distinctive encoding.
Article
College students (n = 36) and elderly persons (n = 28 females, eight males; 60–83 years old) were compared on an immediate-memory task involving an outstanding item in the center of the array. The college students remembered the outstanding item well, the elderly did not. Both groups displayed better overall performance for the list containing the outstanding item. The results are discussed in terms of differences in processing strategies.
Article
Two studies were conducted to determine the relative importance of processing speed and knowledge as predictors of performance in simple verbal tasks within samples of young and old adults. Eight different criterion tasks were investigated, and performance on each was found to be significantly related both to speed of processing and to quantity of word knowledge. It was also discovered that although young adults were faster than old adults and that old adults were equal or superior to young adults in relevant knowledge, the same regression equations could be used to predict criterion performance in both groups. These results therefore suggest that any age-related compensation that exists in these tasks is rather weak, in the sense that speed and knowledge appear to have the same importance in young and old adults, and only the average levels of the predictors differ as a function of age.