Encyclopedia of Psychology and Law

eyewitnesses (aged 17 to 81 years). The witnesses indi-

vidually viewed a video reconstruction of a robbery at

a savings bank. No weapons were seen in the video,

although the culprit indicated to the clerk that he had a

gun. The critical aspect of this video for the purposes of

the study was the length of exposure to the culprit’s

face in the video. Two versions of the video were cre-

ated. In one version, the culprit’s face (full-frontal and

profile view) was visible for 45 seconds, and in another

version, the culprit’s face (full-frontal and profile view)

was visible for 12 seconds. No other details differed,

and the videos were of the same duration (1 minute 40

seconds). About 35 to 40 minutes after witnessing the

robbery, witnesses in the long-exposure group made

more correct identifications of the robber when he was

present in the lineup. They also provided more correct

descriptions of the robber under the long-exposure con-

dition. A longer exposure did not appear to inflate false

identifications when the culprit was absent from the

lineup in the Aberdeen study.

One additional finding from the comparison of wit-

nesses exposed to a target for a shorter or longer dura-

tion in the Aberdeen study could be of use to

investigators. Witnesses in the long-exposure condi-

tion were more confident in their identification deci-

sions than were witnesses in the short-exposure

condition. However, they were confident even when

they were inaccurate. In other words, confidence was

nota reliable indicator of accuracy under long expo-

sure. This effect was most marked in the culprit-absent

conditions. This finding becomes more meaningful

when the implications for assessing witness credibility

are examined. When deciding whether or not a given

witness is likely to be reliable, a police officer or a

juror may rely on that witness’s verbal expression of

their confidence. To summarize, the research suggests

that the likelihood of a witness making an accurate

identification is increased if he or she has seen the per-

petrator’s face for a longer period of time. However, an

extended exposure could make witnesses more confi-

dent in their identification ability even when they are

wrong. Therefore, while a longer exposure increases

the chances of an accurate identification, investigators

should not rely too heavily on witness confidence as an

indicator of accuracy.

So far it has been proposed that the extent of time

of exposure to a face could be useful information when

assessing the potential of an eyewitness to aid an inves-

tigation and the administration of justice. One of the

limitations of prior research on exposure duration is

that it has been assumed that a witness who is exposed

to a perpetrator for a longer time will be paying more

attention to the face and processing it more “deeply,”

thereby providing a stronger and more accessible

memory trace. However, this assumes that there is

nothing else at the scene of the crime to attract one’s

attention. This is typically not the case. For example,

research has shown that when a perpetrator is holding

a weapon, a witness’s attention may be drawn to that,

and consequently, the witness may spend less time

looking at the face (referred to as the weapon-focus

effect). It is important in future research to identify

various situational factors that alter the relationship

between degree of exposure and memory for an event.

Amina Memon

See also Confidence in Identifications; Confidence in

Identifications, Malleability; Eyewitness Memory;

Eyewitness Memory, Lay Beliefs About; Retention

Interval and Eyewitness Memory; Weapon Focus

Further Readings

Memon, A., Hope, L., & Bull, R. H. C. (2003). Exposure

duration: Effects on eyewitness accuracy and confidence.

British Journal of Psychology, 94,339–354.

Pedersen, A., & Wright, A. (2002). Do differences in event

descriptions cause differences in duration estimates?

Applied Cognitive Psychology, 16,769–783.

Read, J. D. (1995). The availability heuristic in person

identification: The sometimes misleading consequences of

enhanced contextual information. Applied Cognitive

Psychology, 9,91–121.

EXTREMEEMOTIONALDISTURBANCE

A number of states in the United States provide

by statute that defendants charged with murder or

attempted murder may seek to mitigate the charges

against them by claiming, and proving, that when they

intentionally murdered or attempted to murder their

victim, they did so under the influence of an extreme

mental or emotional disturbance (EED) for which

there was a reasonable explanation or excuse. Typically,

such statutes provide that the reasonableness of such

explanation or excuse shall be determined from the

viewpoint of a person in the defendant’s situation at

the time of the crime, under the circumstances as the

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