REFERENCE No. RES-000-22-0144
FULL REPORT
Mechanisms of Flashbulb Memories: A Cross-Sectional and Longitudinal Study
BACKGROUND
Flashbulb memories are particularly vivid and long lasting autobiographical memories that are
accompanied by high levels of confidence in their accuracy. It has been customary to study these
memories via unexpected and dramatic public events. For example, in the Brown and Kulik’s (1977)
seminal study, participants reported to have very detailed memories of their personal circumstances
when they first heard about the assassination of President John F. Kennedy even though 13 years had
passed from this dramatic event.
Two contrasting views exist on flashbulb memories. According to Brown and Kulik (1977)
flashbulb memories are created by a special encoding mechanism that retains crucial details of the
current unusual and emotional circumstances such as activity, location, informant, other people, etc. As
a result, memory trace is virtually unsusceptible to any decay or reconstruction for many years. In
contrast, Neisser (1982) has argued that flashbulb memories are ordinary memories that have been
preserved by frequent rehearsal, and are not necessarily veridical. For example, Neisser and Harsh
(1992) interviewed 44 people about their flashbulb memories of the Challenger explosion one day after
the event and again after 2 1/2 years. The comparison of participants' memory scores revealed a high
degree of inaccuracy in reports obtained 2 1/2 years after the initial interview.
In the past 10-15 years, evidence has started to accumulate in support of both positions with some
studies showing good test-retest consistency and others showing significant inconsistencies and
distortions. Several views have been put forward to explain possible reasons for these contradictory
findings. According to Winningham et al.’s (2000) consolidation hypothesis most of the forgetting
occurs in the first few days of the original event. After this the memory traces consolidate into a
relatively permanent narrative account. Therefore, those participants who have been interviewed within
the first few days after the event should exhibit poorer consistency across test-retest sessions than those
who were initially tested after several weeks from the original event.
In contrast, Schmolck, et al. (2000) suggested that it is the length of the delay interval between
the test and the re-test, rather than the one between the event and the initial test, that is a crucial factor in
determining the outcome of any particular study. For example, in their study on the verdict of O.J.
Simpson’s murder trial, the consistency was quite good in a group with a test-retest delay of 15 months
but major distortions were observed in a group with a 32-month delay. One possible confound in this
study was the announcement of a second verdict (this time from O.J. Simpson’s civil trial) 16 months
after the initial verdict. Therefore, according to Horn (2001) “the question of whether flashbulb
memories decay over time is still open” (p.180).
Another “open” question in this area refers to the effects of age on flashbulb memories. There are
only two published studies that examined the effects of age on the test-retest consistency of flashbulb
memories with contradictory findings (Cohen, Conway & Maylor, 1994; Davidson & Glisky, 2002).
Perhaps the most important unanswered question refers to special status of flashbulb memories. One
way to prove the special nature of flashbulb memories is to show that ordinary autobiographical
memories of mundane and less emotional events are not as consistent, detailed and vivid as flashbulb
memories. There are only a handful of studies that have compared the consistency of flashbulb
memories with those of some baseline control event (e.g., Bohannon, 1988; Christianson, 1989; Larsen,
1992; Weaver, 1993). However, the choice of the control events has been criticised by Brewer (1992)
who argues that a proper comparison should involve a control event that asks participants to recall their
personal circumstances of hearing some mundane personal news. In addition, it is essential that this
personal news is same for all participants. So far, however, none of the studies have tested participants’
memories for such control events and compared them to flashbulb memories.
REFERENCE No. RES-000-22-0144
2
AIMS AND OBJECTIVES
The aim of the present project was to address the important questions outlined above by
conducting a large-scale cross-sectional and longitudinal study on people’s flashbulb memories of
terrorist attack on New York on September 11, 2001. This unfortunate event provides a unique
opportunity to study flashbulb memories. In terms of surprise, emotional shock and media coverage it
surpassed even the assassination of John F. Kennedy, which has been reported to elicit the highest
incidence of flashbulb memories (Brown & Kulik, 1977; Conway, 1995).
With this in mind, Lia Kvavilashvili seized the opportunity of having access to a subject pool of
healthy community living older people (maintained by her previous ESRC funded project on memory
and ageing -R000222575), and conducted initial telephone interviews with 84 participants aged over 61.
Data were also collected from a group of 84 younger participants. In order to test the Winningham et
al.’s (2000) consolidation hypothesis, half of the participants were tested on 12 and 13 of September (a
short delay between the event and an initial test), and half on 21 and 22 September (a longer delay
between the event and an initial test). In order to further examine the possibility of rapid forgetting in the
first few weeks after the event half of the participants in each of these groups were re-tested two weeks
after their initial test in September 2001. Thus, all the initial data collection for the project was
completed by October 2001.
The ESRC funding was obtained to conduct a crucial follow up phase of the project. This would
involve re-testing the original sample of 168 volunteers (called 2001 sample) after a long delay in 2003,
and then again after one year from the first re-test in 2004. It would also involve an additional large
scale study on a new sample of young and old participants (called 2003 sample) that would examine the
consistency of memories for unimportant control personal event from 2003 to 2004. Memories for the
death of Princess Diana would also be obtained in 2003 and 2004 to examine the consistency between
the memories that are 6 and 7 years old.
The successful completion of this follow up phase allowed us to address all six research
objectives outlined in the original proposal. These are presented below and, where appropriate, minor
changes in the timing of tests are noted:
(1) To evaluate the consistency of flashbulb memories by comparing young and old participants’
initial flashbulb memory reports of September 11 with those taken 18 months and 30 months after
the event.
In the ESRC supported project we examined the test-retest consistency over the longer time delays by
conducting the first re-testing after almost 2 years from September 11 (in July-August 2003), and the
second re-testing after almost three years (in July-August 2004). Having longer delays enabled us to
better evaluate Schmolck et al.(2000) claims that major distortions occur in flashbulb memories after
long delay intervals.
(2) To test the Winningham et al. (2000) consolidation hypothesis in order to resolve the previous
contradicting findings concerning the consistency of flashbulb memories.
(3) To test the special encoding mechanism hypothesis by comparing the retention of flashbulb
memories with that of a control event, consisting of hearing the news of a relatively unsurprising
and less important personal event.
In the original proposal, we aimed for a 18 month interval between the initial test for memory of the
control event in spring 2003 and the re-test in autumn 2004. In the actual project, the test-retest delay for
the control event was only one year. If the consistency of flashbulb memories was reliably higher after
the delay of 2 years than for the control event after only one year this would provide the stronger
evidence in support of special encoding mechanism hypothesis.
(4) To examine the potential role of several key variables in the formation of flashbulb memories in
order to compare the contrasting models of flashbulb memories proposed by Conway et al.
(1994) and Finkenauer et al. (1998).
REFERENCE No. RES-000-22-0144
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(5) To study the age effects on flashbulb memory and the factors that may be responsible for
producing the age deficit found by Cohen et al. (1994).
(6) To study the forgetting rates of flashbulb memories by (i) examining the stability of flashbulb
memory descriptions over increasing time delays, and (ii) by comparing the flashbulb memory
descriptions of two events that happened relatively recently versus a long time ago.
METHOD
MATERIALS:
(1) Flashbulb Memory Questionnaire
In all conducted studies, Flashbulb Memory Questionnaire, modelled after Conway et al. (1994), was
administered to young and old participants in the form of Telephone Interviews and participants’
responses were recorded by researchers as closely to verbatim as possible. Initially, participants had to
provide a short but detailed narrative description about their personal circumstances in which they first
heard the news of the target event (e.g., the terrorist attack in New York). This was followed by
participants answering specific questions about the time (when did you hear about the news), the place
(where were you at the time), the activity (what were you doing), the source of the news (how did you
find out), and others present (if not alone then indicate who else was present). Finally, participants had
to provide ratings on several 10-point rating scales assessing such background variables as levels of
surprise, emotion, vividness, etc. (1=not at all, 10=extremely surprised, emotional, etc). Participants also
rated their confidence in the accuracy of their memory description and answers to each of the 5 specific
questions.
(2) Screening Tests
All participants were administered three tests over the telephone to assess their cognitive status and, in
case of older participants, to screen for any signs of cognitive decline or early dementia. The following
tests were used:
The Telephone Interview for Cognitive Status (TICS) consists of 11 items with a maximum score
of 41 (cut off score 30). The TICS correlates highly with scores on Mini Mental Sate Examination
(MMSE; Folstein, et al., 1975), and has 94% sensitivity and 100% specificity in discriminating patients
with Alzheimer’s disease from normal controls (Brandt, et al., 1988). The Isaacs Set Test (IST) is a
verbal fluency test requiring participants to produce as many exemplars of 4 categories (colours,
animals, fruit, cities) as possible within a given time (15 seconds per category) with a maximum score of
40) (Isaacs & Kennie, 1973). A short version of Wechsler Similarities Test (WST) (Wechsler, 1980)
requires participants to explain in what ways word pairs orange-banana, dog-lion, boat-plane, coat-dress
and eye-ear are similar (maximum score of 10).
The IST and WST were used as screening tests because in the study of Rouch-Leroyer et al.,
(1998) 18.5% of old people, who scored below the cut off points on both of these tests (less than 25 on
IST and less than 6 on WST), were diagnosed with dementia after two years. Together with TICS these
tests allowed us to exclude some older participants with signs of cognitive decline without the necessity
of going to their homes for conducting more conventional tests as MMSE. We can therefore recommend
these test to other ageing researchers in similar circumstances.
PARTICIPANTS:
There were 3 different samples of young and old participants named after the year in which they
were first tested (2001 sample, 2003 sample and 2004 sample). In all samples, older participants were
healthy community residing adults who did not report any hearing problems at the initial telephone
interview. Young and old participants also did not report having experienced any of the following:
serious head injury, stroke, mental health and/or memory problems diagnosed by a physician. For all
participants, English was their first language.
REFERENCE No. RES-000-22-0144
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(1) 2001 sample – In this sample, there were 168 participants (84 young and 84 old) when they
were first recruited and tested in 2001. Out of these, 135 participants (64 young and 71 old) were
available for testing in summer 2003. This is a remarkably low drop out rate (20%) given that almost
two years had passed from the original test in 2001. Young participants mean age was 33.41 (SD=9.79,
range 20-56) and for old participants it was 71.44 (SD=5.09, range 61-81). However, the data of four old
participants were excluded on the basis of their scores on either TICS, or IST and WST. All four
participants had very low scores on free recall of 10 words (item 5 on TICS) further justifying their
exclusion from the sample.
(2) 2003 sample - Participants in 2003 sample were recruited by door-to-door distribution of
leaflets in the local community, advertising in the local newspapers, libraries and the University of 3rd
age. Most successful method was advertising in the Guardian job section for voluntary work. In total,
there were 89 young (mean age=37.72, SD=8.08, range 22-50) and 96 old participants (mean age=67.42,
SD=5.39, range 60-82). However, the data of two old participants were excluded on the basis of their
below cut off scores on TICS and WST.
(3) 2004 sample – In total, 85 new participants (47 young and 38 old) were recruited and tested in
summer 2004. The recruitment methods were same as for 2003 sample. Young participants mean age
was 34.21 (SD=9.56, range 22-50) and for old participants it was 67.61 (SD=6.74, range 60-80).
Table 1 shows the final participant numbers in each of these three samples in summer 2003 and summer
2004. This table shows that the participant drop out rate in 2001 sample and 2003 sample from summer
2003 to summer 2004 was remarkably low (5 % and 11%, respectively).
TABLE 1
The number of participants tested in 2003 (panel a) and in 2004 (panel b) as a function of age group
(young, old) and the sample of participants (2001 sample, 2003 sample, 2004 sample).
(a) Participants tested in 2003
____________________________________________________________________________
AGE GROUP
Young
Old
SAMPLE
TOTAL
_____________________________________________________________________________
The 2001 sample
64
67
131
The 2003 sample
89
94
183
TOTAL
153
161
314
______________________________________________________________________________
(b) Participants tested in 2004
____________________________________________________________________________
AGE GROUP
Young
Old
SAMPLE
TOTAL
_____________________________________________________________________________
The 2001 sample
59
65
124
The 2003 sample
75
88
163
The 2004 sample
47
38
85
TOTAL
181
191
372
______________________________________________________________________________
REFERENCE No. RES-000-22-0144
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PROCEDURE:
(1) 2001 sample – In this sample, young and old participants, who had been tested pre-project in
2001, were re-tested on their memories of September 11 once in summer 2003 and once again in
summer 2004. In summer 2003, at the end of their interview they were administered three screening
tests described above. In addition, all participants received a small payment (£10 of Boots vouchers) in
return of their time and commitment to the project shortly after their interview in summer 2003.
(2) 2003 sample – In May/June 2003, the study was advertised as memory and ageing study, and
participants were asked to take part in several telephone interviews on their memories of personally
experienced events. Participants were informed that they had a good chance to win £100 in a prize draw
run shortly by the research team. It was emphasised, in order to take part, participants had to own and be
familiar with using a mobile phone as they would be contacted via their mobile on one or two occasions.
Having a mobile phone was essential for the design as it would ensure that at the time of receiving a
phone call about the control event (i.e., not winning a prize) participants were in a variety of locations.
After the first interview consisting of administering the cognitive screening tests all participants received
a phone call (predominantly on their mobile phones) informing them that they did not win a prize in the
prize draw. This was the control event for which participants memory was tested in subsequent
interviews. The design of the study was identical to the one used for flashbulb event. Half of the
participants were contacted after a short delay from receiving the news about the prize draw (on the 2nd
and 3rd day) and half after a longer delay of 10 and 11 days. Within each group half of the participants
were re-tested after two weeks from their initial re-test for the control event. After completing
interview(s) concerning their memories of the control event, all participants completed one additional
interview concerning their memories of September 11 and the death of Princess Diana. The order of
these events was counterbalanced. Like in the 2001 sample, participants received £10 of Boots vouchers
in summer 2003. Finally, in summer 2004 participants completed two more interviews. In one interview
they were re-tested on their memory for the control event after 11-12 months from their original
interview in 2003. The second interview concerned flashbulb memories of September 11 and the Death
of Princess Diana. The actual prize draw was run after all the data was collected and two participants
won £100 each as advertised at the beginning of the study.
(3) 2004 sample – Young and old participants in this sample were tested only in July/August
2004. In addition to the screening interview they completed a telephone interview concerning their
memories of September 11 and the death of Princess Diana. The order of these events was
counterbalanced. These participants served as a control group for assessing the effects of repeated
testing, if any, in 2001 and 2003 samples. Obviously, we could only assess if repeated testing had any
effects on phenomenal characteristics of memories such as vividness, amount of details and specificity.
RESULTS
Results are presented separately for each research objective:
(1) The consistency of flashbulb memories after a long delay of 23-24 months
(a) Consistency of answers to 5 specific questions:
Participants’ answers to each of the five questions (about time, place, activity, others present and source)
at the re-test were assigned a score of ‘0’, ‘1’, or ‘2’ depending on how consistent they were with the
respective answers provided at the initial test. For example, ‘0’ would indicate completely inconsistent
or ‘don’t remember’ answer and ‘2’ exactly the same answer. Following Neisser and Harsh (1992), the
Weighted Attribute Score (WAS) was calculated for each participant. The scores of ‘0’ to‘2’ were
assigned for ‘place’, ‘activity’ and ‘source’, and an additional bonus point was given if a participant’s
cumulative score for ‘time’ and ‘others present’ was 3 or more (out of a total possible 4). The resultant
score can vary from 0 to 7.
REFERENCE No. RES-000-22-0144
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The mean Weighted Attribute Scores for young and old people from the 2001 sample were 5.29
(SD=1.44) and 4.99 (SD=1.74), respectively. These means are markedly higher than those reported by
Neisser and Harsh (1992) and Schmolck et al. (2000) in their samples of young participants (M= 2.95
and M=3.30, respectively). Does this mean then that no forgetting occurred over the period of two years
as Brown and Kulik (1977) would suggest?
This suggestion was tested using the half of the 2001 sample who were first re-tested two weeks
after their initial test in September 2001. In this group, the mean Weighted Attribute Scores after two
weeks from initial test were near ceiling for both young and old participants (6.52 and 6.14,
respectively). After a delay of almost two years they dropped to 5.19 and 4.92, respectively, and this
drop was statistically significant (F(1,66)=58.36, p<.0001).
This result convincingly shows that flashbulb memories are not totally immune to forgetting as
suggested by Brown and Kulik (1977). However, the results also show that the retention rates are far
better than those reported by Neisser and Harsh (1992) and Schmolck et al. (2000). This finding is
further supported by the data concerning the consistency of memory descriptions.
(b) Consistency of memory descriptions:
Memory descriptions in 2003 were compared to the initial descriptions provided by participants in
September 2001, and were coded into six categories: 0=can’t remember, 1= major distortion, 2=minor
distortion, 3= less specific, 4=more specific, and 5=same. The percentages of young and old participants
whose memory descriptions were coded into these six categories are presented in the panel (a) of Table
2. This Table shows that in both groups only about 8% to 9% of memories were coded as major
distortions in sharp contrast to 40% reported by Schmolck et al.(2000).
TABLE 2
The percentages of young and old participants whose memory descriptions were coded as ‘don’t
remember’, ‘major distortion, ‘minor distortion’ ‘less specific’, ‘more specific’, and ‘same’. The raw
numbers are presented in the brackets. Panel (a) shows the data on flashbulb memories of September 11
in the 2001 sample. Panel (b) shows the data on non-flashbulb control event in the 2003 sample.
(a) Consistency of flashbulb memory descriptions in the 2001 sample with a delay of 23-24 months
________________________________________________________________________________
TYPE OF MEMORY
Can’t
Major
Minor
Less
More
Same
Remember Distortion Distortion
Specific Specific
TOTAL
_________________________________________________________________________________
Young
0%
(0)
8%
(5)
22%
(14)
14%
(9)
44%
(28)
12%
(8)
100%
(64)
Old
3%
(2)
9%
(6)
25%
(17)
30%
(20)
30%
(20)
3%
(2)
100%
(67)
TOTAL
1.5%
8%
24%
22%
37%
7.5%
100%
(2)
(11)
(31)
(29)
(48)
(10)
(131)
__________________________________________________________________________________
REFERENCE No. RES-000-22-0144
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TABLE 2 (cont.)
(b) Consistency of control non-flashbulb memory descriptions in the 2003 sample with a delay of 11-12
months
________________________________________________________________________________
TYPE OF MEMORY
Can’t
Major
Minor
Less
More
Same
Remember Distortion Distortion
Specific Specific
TOTAL
_________________________________________________________________________________
Young
9%
(7)
11.5%
(9)
11.5%
(9)
62%
(49)
1%
(1)
5%
(4)
100%
(79)
Old
20%
(18)
3%
(3)
12%
(11)
56%
(51)
3%
(3)
6%
(5)
100%
(91)
TOTAL
15%
(25)
7%
(12)
12%
(20)
59%
(100)
2%
(4)
5%
(9)
100%
(170)
__________________________________________________________________________________
(2) Winningham et al.’s (2000) consolidation hypothesis
The results did not support this hypothesis. The mean Weighted Attribute Scores of participants who
were first tested 1 or 2 days after the attack (M=5.09, SD=1.59) were not significantly worse from the
scores of participants who were tested 10-11 days after the event (M=5.17, SD=1.63) (F<1). This
finding has important methodological implications by showing that the timing of initial testing is NOT a
primary determinant of the test-retest consistency of flashbulb memories.
(3) How special are flashbulb memories?
In order to answer this question we compared the consistency scores for September 11 in the 2001
sample to the consistency scores of control event in the 2003 sample. As predicted, flashbulb memories
were significantly more consistent (mean WAS=5.13) than memories of the control event (mean
WAS=3.20) even though the test-retest delay was almost twice as long (23-24 months) than for control
memories (11-12 months); F(1,298)=98.13, p<.0001, effect size - partial eta squared=.25.
Interestingly, consistency scores were also reliably higher for flashbulb memories after only two
weeks from the initial test (mean WAS=6.31 ) than for the control event (mean WAS=5.70) in half of
the 2001 and 2003 samples who were first re-tested two weeks from their initial test, F(1,142)=12.17,
p=.001, partial eta squared=.08. Moreover, the drop in the consistency scores over the one year was
twice as large for the control event in the 2003 sample, with partial eta squared=.53, than for the
flashbulb event over two years in the 2001 sample, partial eta squared=.26.
There were also reliable qualitative differences between the flashbulb and control memories that
emerged for the memory descriptions. Panel (b) of Table 2 shows the percentages of participants in 2003
sample whose non-flashbulb memory descriptions were coded into the categories of ‘same, ‘more
specific’, ‘less specific, ‘minor distortion’ etc. The most striking differences between the flashbulb and
control events emerged for the categories ‘more specific’ and ‘less specific’. While at the re-test after
two years a substantial number of the flashbulb memories of young and old people were ‘more specific’
(44% and 30% respectively), only 1% and 3% of control memories were classed as ‘more specific’ at
the re-test after one year. In contrast, while the majority of control memories were ‘less specific’ (62%
and 56% in young and old, respectively) only 14% and 30% of young and old people’s flashbulb
REFERENCE No. RES-000-22-0144
8
memories were classed as ‘less specific’. Taken together, these findings provide strong support to the
idea that flashbulb memories are indeed different from ordinary non-flashbulb memories.
(4) Which variables correlate with flashbulb memory consistency scores?
The mean ratings of participants’ initial reactions to terrorist attack in 2001 as well as the ratings of
confidence in memory accuracy and the rehearsal in summer 2003 are presented in the upper and lower
panels of Table 3. Out of all the variables, listed in Table 3, only self-rated confidence in memory
accuracy was correlated with Weighted Attribute scores in both young (r=.33, p<.01) and old (r=31,
p<.02) participants. This finding was somewhat unexpected given that several studies have obtained
positive correlations between the accuracy and such key variables as surprise, importance or emotional
impact and rehearsal (e.g., Conway et al., 1994; Finkenauer et al., 1998). However, there are a growing
number of studies that have also failed to establish correlations between accuracy scores and these
variables (e.g., Davidson & Glisky, 2002; Otani et al., 2005; Weaver, 1993).
TABLE 3
Mean ratings of background variables made by the young and old participants in the 2001 sample
(standard deviations in brackets). Panel (a) shows the ratings obtained at an initial test in September
2001. The lower panel shows the ratings obtained in summer 2003 after a delay of 23-24 months. All
ratings were made on 10-point rating scales (1=not at all, 10=extremely).
(a) Ratings obtained in September 2001
____________________________________________________________________________
AGE GROUP
Young
Old
_____________________________________________________________________________
Surprise
8.63 (1.80)
8.77 (2.07)
Emotion
4.80 (2.36)
4.95 (2.71)
Importance (personal)
6.28 (2.50)
5.66 (3.21)
Importance (national)
8.83 (1.28)
8.54 (1.43)
Thinking about Sept.11
7.30 (1.99)
7.27 (1.81)
Vividness
8.05 (1.97)
8.55 (1.97)
______________________________________________________________________________
(b) Ratings obtained in July-August 2003
____________________________________________________________________________
AGE GROUP
Young
Old
_____________________________________________________________________________
Confidence
8.48 (1.46)
8.19 (2.17)
(in memory description)
Confidence
8.64 (1.24)
8.86 (1.51)
(in specific questions)
Thinking about Sept. 11
5.70 (1.90)
5.69 (1.78)
Thinking about personal
2.75 (1.40)
3.28 (1.72)
circumstances of hearing
the news
Vividness
8.12 (1.61)
8.28 (2.01)
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(5) Effects of age on flashbulb memories
In the 2001 sample, there were no age effects in the consistency of flashbulb memories for Weighted
Attribute scores. There was a small reliable age effect in the consistency for memory descriptions, eta
squared=.05. This was due to the older group reporting a different level of specificity (either less or
more specific) than the younger group rather than the older group producing more memory descriptions
with major and minor distortions (see Table 2). Unexpectedly, similar pattern was also obtained for the
consistency of memories for the control event in the 2003 sample. Taken together, these findings are in
sharp contrast with the prevalence of marked age effects observed in the laboratory with non-personal
materials such as lists of words, or pictures.
(6) Stability and forgetting rates of flashbulb memories over long time delays
The rich data set obtained by repeated testing of 2001 and 2003 samples allow us to address this issue
from several different angles. Here we highlight the most important points that emerged from this
analysis.
(a) The 2003 sample – participants in this sample were tested for their memories of September 11 and
the death of Princess Diana in summer 2003 and summer 2004. This enabled an investigation of later
stages of forgetting of flashbulb memories. The mean Weighted Attribute Scores for September 11 were
not different from those for Princess Diana (4.81 and 5.10 respectively). Interestingly, these means were
not statistically different from the mean consistency score for September 11 in 2001 sample when they
were re-tested in 2003 (M=5.13). These findings indicate that the significant drop in consistency occurs
within the first two years with no further drop in subsequent years.
(b) The 2001 sample – participants in this sample were re-tested on their memories of September 11 in
summer 2003 and summer 2004. The new Weighted Attribute Scores were calculated by comparing
participants’ answers to 5 specific questions in 2004 to those provided in September 2001. The mean
consistency scores obtained in 2004 were not reliably worse than those obtained in 2003 indicating that
no further drop in consistency occurred during one year from 2003 to 2004. If anything, the percentage
of memory descriptions coded as major distortions in the young group dropped from 8% in 2003 to
1.6% in 2004 indicating that 4 participants reverted back to their original memories. A particularly
interesting finding about memories classed as ‘major distortions’ is that they were not about events that
had never happened. Instead, in these cases people appeared to remember another occasion in which
they heard of September 11 again, later on the same or next day. This provides support for the so called
Wrong Time Slice Hypothesis. This is illustrated in Table 4 by the three flashbulb memory descriptions
of September 11 from one participant in the 2001 sample. This participant first learned about September
11 from Carol in general office, and then went upstairs to watch it on TV. In his second report, taken
two weeks from the first test, he also mentions that he bumped into Ciaran on his way up to watch the
TV. In 2003, this participant incorrectly remembers that it was Ciaran who first told him about
September 11.
(7) Additional findings
The project resulted in the rich data set from which we have reported only the most important findings
that directly address the research objectives outlined in the original proposal. Additional findings that
are worth mentioning here refer to the absence of any effects of repeated testing either on
phenomenological characteristics of memories (vividness, amount and specificity of details) or their
test-retest consistency. In addition, in terms of phenomenological characteristics, 7-year old memories of
the Death of Princess Diana taken in 2004 were no different from memories of September 11 in the 2001
sample taken immediately after the event (in September 2001). This replicates and extends our earlier
findings (see Kvavilashvili et al., 2003).
REFERENCE No. RES-000-22-0144
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TABLE 4
Example memory descriptions from the data of one young participant from the 2001 sample
_____________________________________________________________________________
Initial test on 12 September, 2001:
“I was in the departmental office and Carol said have you heard the news, there’s been a terrorist
attack in America, they are watching it on the TV upstairs”.
Retested 2 week later:
“I heard about it in the general office and Carol said something’s going on in America, there’s
been some aircraft crashing and I went upstairs to look at the TV and bumped into Ciaran on the
stairs”.
Retested in August 2003:
“I was in the stairwell on my way to Psychology, CP Snow. I think Ciaran came out and said
‘have you heard about this thing in NY an aeroplane has crashed into the WTC.’. I said ‘Is it a
terrorist attack?’. I’m pretty sure it was before the 2nd plane crashed and it was about lunchtime.
I then went upstairs to the top floor and watched a live feed and saw the 2nd plane crash. I stayed
there for 1.5 hours- maybe more”.
Retested in August 2004:
I was going into the Psychology department and I bumped into Ciaran who said ‘A plane has
flown into WTC’. Then I went upstairs and watched it on TV in 2H255.
___________________________________________________________________________________
FUTURE RESEARCH PRIORITIES
The present project provided us with answers to some important questions of flashbulb memory as well
as with interesting insights into various theoretical and methodological issues of studying flashbulb
memories. It also generated a new set of questions and hypotheses that we want to pursue in the future
(e.g., age effects on the consistency of control memories, the role of memory descriptions in the
consistency of answers to specific questions, variables involved in the formation of flashbulb memories,
etc.). Given that the project has resulted in a pool of 292 volunteers (122 young and 170 old), willing to
take part in similar studies run in the Department, it should be possible to examine these questions in the
future.
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