REST AND EYEWITNESS MEMORY RECALLR.

REST AND EYEWITNESS MEMORY RECALL
R. Edward Geiselman, Ph.D.
To maximize the completeness and accuracy of memory recall, it is logical
to assume that an eyewitness should be ready emotionally, physiologically,
and cognitively to participate in an investigative interview. Toward
achieving complete and accurate recall, there are several factors commonly
studied within the field of eyewitness psychology that would suggest an
eyewitness should be interviewed as soon as possible following an event.
These factors include ordinary forgetting, contextual changes, mood changes,
and post-event influences (see 1, for a review of these factors). Perhaps the
most obvious factor in favor of delaying an interview is the extreme level of
stress experienced by some eyewitnesses soon after the event. In recognition
of these possibly counteracting factors, I have recommended to detectives
that a decision about when to conduct a full investigative interview must be
made on a case-by-case basis. If the witness is in apparent shock, is incoherent,
sweating, or pacing, then obtain some basic elements from the witness
to begin the investigation and return for a full investigative interview later.
Otherwise, conduct the full interview as soon as possible before the retrieval
environment has changed and memory has faded.
However, the eyewitness’s level of stress at the time of an interview may
not be the only factor worthy of consideration in favor of delaying the full
investigative interview. The eyewitness’s level of rest at the time of an interview
may also be a significant factor. It is somewhat common, for example,
in cases of officer involved shootings that the officer involved would be
without sleep for more than 24 hours prior to participating in a full investigative
interview (2, 3). The purpose of the present research report is to present
some previously unpublished data from past research projects which suggest
that an eyewitness’s level of rest at the time of recall is related to the eyewitness’s
ability to recall information accurately in detail.
2 / GEISELMAN: RESEARCH NOTE: REST AND EYEWITNESS MEMORY RECALL
The data come from three research projects (four experiments, five comparisons)
conducted between 1995 and 2001 in which a range of methodologies
was employed and a range of performance criteria was measured. In the
first project, Geiselman et al. (4) staged a realistic classroom disruption and
altercation where the students believed the event to be authentic, and the
measure of eyewitness performance was photo array identification accuracy.
In the second project, Geiselman et al. (5) showed a videotape of a staged
robbery, and the measure of eyewitness performance was the completeness
and accuracy of the descriptions of the persons involved. In the third project,
Geiselman et al. (6) showed a videotape of a purse snatching, and the measure
of eyewitness performance was photo array identification accuracy. In
each of these studies, the eyewitnesses were administered the same comprehensive
questionnaire just prior to the test of their recollections. One of the
many items on the questionnaire was, “How well rested are you right now?”
The participants responded to this item on a 5-point rating scale.
While none of the three research projects was designed specifically to
examine the relationship between rest at the time of test and memory recall
performance, the participants’ responses on the question about rest were
found to be significantly related to the memory measures in each study. In
the Geiselman et al. (4) Experiments 1 and 2, the Point-Biserial correlation
between the participants’ ratings of rest at the time of test and photo array
identification accuracy was .40, p < .001 (Experiment 1, sample size = 238)
and .44, p < .001 (Experiment 2, sample size = 111). In the Geiselman et al.
(5) Experiment 2, the Pearson correlation between participants’ ratings of
rest at the time of test and the number of elements included in the participants’
verbal descriptions of the perpetrator was .38, p < .001 (sample size =
160). From the same experiment, the Pearson correlation between the ratings
of rest and the accuracy rate (percent correct) for the elements in the descriptions
of the perpetrator was .51, p < .001. In the Geiselman et al. (6) experiment,
the Point-Biserial correlation between participants’ ratings of rest at
the time of test and photo array identification accuracy was .43, p < .001
(sample size = 100). In sum, across these three research projects, participants’
ratings of rest at the time of test were consistently related to the memory-
recall measures.
AMERICAN JOURNAL OF FORENSIC PSYCHOLOGY, VOLUME 28, ISSUE 2, 2010 / 3
It is important to note that these observations from each of the three
projects are correlational in nature. Level of rest at the time of test was not
manipulated systematically in any of the experimental designs such that a
causal connection could be drawn between level of rest and eyewitness recall
performance. Nonetheless, the present observations based on over 600 eyewitnesses
are consistent with the idea that allowing an eyewitness to rest before
being interviewed is an important consideration. This relationship is
worthy of further study in experiments where causality can be established.
Based on the present observations in relatively low-stress situations, it is reasonable
to expect that a well-rested eyewitness would exhibit more complete
and more accurate recall than would a less-rested eyewitness (especially in
higher-stress situations).
Obtaining the needed rest prior to a full investigative interview could be
difficult to achieve in some situations such as officer involved shootings.
Klinger (3) reports that 46% of officers involved in shootings experience
difficulty sleeping within the first 24 hours and approximately one-third of
the officers still experience difficulty sleeping after one week. In addition,
the decision to possibly delay the full investigative interview to allow for rest
must be made based on surface indicators of officer stress only. It is well
documented within the field of eyewitness psychology that police officers
show the same deleterious effects of heightened stress on memory performance
as civilians (7). Artwohl (8) cautions that some officers might appear
quite calm shortly after participating in a shooting and may prefer to give a
full interview at that time. Nevertheless, “often it is best for officers to sleep
first and give their statement later. This does not preclude their providing
enough brief information during an immediate on-scene ‘walk-through’ to
get the investigation started.” The present observations concerning rest and
memory recall from the three Geiselman research projects are consistent with
Artwohl’s assessment and recommendation.
How might rest contribute to more complete and accurate eyewitness recall?
One hypothesis is that REM (rapid eye movement) sleep plays an important
role in the consolidation of memories and therefore recall should be
more complete following sleep (see 9, for a review). Recent research also
suggests that sleep deprivation may contribute to the generation of false
memories (10). Interestingly, the generation of false memories caused by
4 / GEISELMAN: RESEARCH NOTE: REST AND EYEWITNESS MEMORY RECALL
sleep deprivation has been found to be largely reversed with the administration
of caffeine, “indicating that adenosinergic mechanisms can contribute to
the generation of false memories associated with sleep loss” (11). In light of
these research data showing positive effects of rest and negative effects of
sleep deprivation, the expression “let me sleep on it” appears to have some
validity as it applies to eyewitness memory recall performance.
If a full investigative interview is delayed to allow for rest, investigators
should consider using the cognitive-interview protocol to conduct the interview
(12). The cognitive-interview protocol contains techniques for reconstructing
the sensory and emotional context that existed at the time of the
event as well as techniques for enhancing memory retrieval following some
forgetting. These techniques also have been found to circumvent certain
post-event influences (13). Therefore, a cognitive interview could help to
counter any negative effects on memory recall caused by a delay of the full
investigative interview to allow for rest.

Hasil (Bahasa Indonesia) 1:

REST AND EYEWITNESS MEMORY RECALLR. Edward Geiselman, Ph.D.To maximize the completeness and accuracy of memory recall, it is logicalto assume that an eyewitness should be ready emotionally, physiologically,and cognitively to participate in an investigative interview. Towardachieving complete and accurate recall, there are several factors commonlystudied within the field of eyewitness psychology that would suggest aneyewitness should be interviewed as soon as possible following an event.These factors include ordinary forgetting, contextual changes, mood changes,and post-event influences (see 1, for a review of these factors). Perhaps themost obvious factor in favor of delaying an interview is the extreme level ofstress experienced by some eyewitnesses soon after the event. In recognitionof these possibly counteracting factors, I have recommended to detectivesthat a decision about when to conduct a full investigative interview must bemade on a case-by-case basis. If the witness is in apparent shock, is incoherent,sweating, or pacing, then obtain some basic elements from the witnessto begin the investigation and return for a full investigative interview later.Otherwise, conduct the full interview as soon as possible before the retrievalenvironment has changed and memory has faded.However, the eyewitness’s level of stress at the time of an interview maynot be the only factor worthy of consideration in favor of delaying the fullinvestigative interview. The eyewitness’s level of rest at the time of an interviewmay also be a significant factor. It is somewhat common, for example,in cases of officer involved shootings that the officer involved would bewithout sleep for more than 24 hours prior to participating in a full investigativeinterview (2, 3). The purpose of the present research report is to presentsome previously unpublished data from past research projects which suggestthat an eyewitness’s level of rest at the time of recall is related to the eyewitness’sability to recall information accurately in detail.2 / GEISELMAN: RESEARCH NOTE: REST AND EYEWITNESS MEMORY RECALLThe data come from three research projects (four experiments, five comparisons)conducted between 1995 and 2001 in which a range of methodologieswas employed and a range of performance criteria was measured. In thefirst project, Geiselman et al. (4) staged a realistic classroom disruption andaltercation where the students believed the event to be authentic, and themeasure of eyewitness performance was photo array identification accuracy.In the second project, Geiselman et al. (5) showed a videotape of a stagedrobbery, and the measure of eyewitness performance was the completenessand accuracy of the descriptions of the persons involved. In the third project,Geiselman et al. (6) showed a videotape of a purse snatching, and the measuresaksi mata kinerja adalah foto array identifikasi akurasi. Dalammasing-masing studi, saksi mata yang diberikan yang lengkap yang samakuesioner sebelum ujian kenangan mereka. Salah satubanyak item atas kuesioner ini, "seberapa baik beristirahat Apakah Anda sekarang?"Peserta menanggapi item ini pada skala peringkat 5-titik.Sementara tidak ada proyek-proyek penelitian tiga dirancang secara khusus untukmeneliti hubungan antara lain pada saat pengujian dan memori ingatkinerja, para peserta tanggapan pada pertanyaan tentang sisa yangditemukan secara signifikan berhubungan dengan langkah-langkah memori dalam studi masing-masing. Dalamkorelasi Geiselman et al. (4) percobaan 1 dan 2, titik-Biserialantara peserta peringkat istirahat pada saat tes dan foto arrayidentifikasi akurasi adalah.40, p <.001 (1 percobaan, ukuran sampel = 238)dan.44, p <.001 (2 percobaan, ukuran sampel = 111). Dalam Geiselman et al.(5) percobaan 2, Pearson korelasi antara peringkat pesertaberistirahat pada saat pengujian dan jumlah elemen masing-masing pesertaDeskripsi verbal pelaku adalah.38, p <.001 (sampel ukuran =160). dari percobaan sama, Pearson korelasi antara peringkatistirahat dan tingkat akurasi (persen benar) untuk elemen-elemen di Deskripsipelaku adalah 51, p <.001. Dalam Geiselman et al. (6) percobaan,the Point-Biserial correlation between participants’ ratings of rest atthe time of test and photo array identification accuracy was .43, p < .001(sample size = 100). In sum, across these three research projects, participants’ratings of rest at the time of test were consistently related to the memory-recall measures.AMERICAN JOURNAL OF FORENSIC PSYCHOLOGY, VOLUME 28, ISSUE 2, 2010 / 3It is important to note that these observations from each of the threeprojects are correlational in nature. Level of rest at the time of test was notmanipulated systematically in any of the experimental designs such that acausal connection could be drawn between level of rest and eyewitness recallperformance. Nonetheless, the present observations based on over 600 eyewitnessesare consistent with the idea that allowing an eyewitness to rest beforebeing interviewed is an important consideration. This relationship isworthy of further study in experiments where causality can be established.Based on the present observations in relatively low-stress situations, it is reasonableto expect that a well-rested eyewitness would exhibit more completeand more accurate recall than would a less-rested eyewitness (especially inhigher-stress situations).Obtaining the needed rest prior to a full investigative interview could bedifficult to achieve in some situations such as officer involved shootings.Klinger (3) reports that 46% of officers involved in shootings experiencedifficulty sleeping within the first 24 hours and approximately one-third ofthe officers still experience difficulty sleeping after one week. In addition,the decision to possibly delay the full investigative interview to allow for restmust be made based on surface indicators of officer stress only. It is welldocumented within the field of eyewitness psychology that police officersshow the same deleterious effects of heightened stress on memory performanceas civilians (7). Artwohl (8) cautions that some officers might appearquite calm shortly after participating in a shooting and may prefer to give afull interview at that time. Nevertheless, “often it is best for officers to sleepfirst and give their statement later. This does not preclude their providingenough brief information during an immediate on-scene ‘walk-through’ toget the investigation started.” The present observations concerning rest andmemory recall from the three Geiselman research projects are consistent withArtwohl’s assessment and recommendation.How might rest contribute to more complete and accurate eyewitness recall?One hypothesis is that REM (rapid eye movement) sleep plays an importantrole in the consolidation of memories and therefore recall should bemore complete following sleep (see 9, for a review). Recent research alsosuggests that sleep deprivation may contribute to the generation of falsememories (10). Interestingly, the generation of false memories caused by4 / GEISELMAN: RESEARCH NOTE: REST AND EYEWITNESS MEMORY RECALL
sleep deprivation has been found to be largely reversed with the administration
of caffeine, “indicating that adenosinergic mechanisms can contribute to
the generation of false memories associated with sleep loss” (11). In light of
these research data showing positive effects of rest and negative effects of
sleep deprivation, the expression “let me sleep on it” appears to have some
validity as it applies to eyewitness memory recall performance.
If a full investigative interview is delayed to allow for rest, investigators
should consider using the cognitive-interview protocol to conduct the interview
(12). The cognitive-interview protocol contains techniques for reconstructing
the sensory and emotional context that existed at the time of the
event as well as techniques for enhancing memory retrieval following some
forgetting. These techniques also have been found to circumvent certain
post-event influences (13). Therefore, a cognitive interview could help to
counter any negative effects on memory recall caused by a delay of the full
investigative interview to allow for rest.