Hypermnesia in the eyewitness to a crime

Abstract

Forty students served as subjects in two groups of witnesses to which a surprise filmed crime was shown. All subjects gave free recall statements about the crime. Following either a directed thinking interval or a diversionary task to block rehearsal, witnesses gave two additional statements. Hypermnesia for hits and memory intrusions was observed, but d' scores did not show hypermnesia. The witnesses fell into two groups: "good" witnesses who had ascertained the correct schema and "bad" witnesses who were obviously on the wrong track. While most witnesses showed short-term hypermnesia for correct responses (hits), the good witnesses showed a significant increase in memory intrusions (false alarms) during the third recall trial (p < .01). Only with correct-schema witnesses did d' scores above the guessing level occur. Witnesses who had ascertained the correct schema but who were interrogated too often tended to make things up to suit the demands for detail, with a resultant increase in memory intrusions and lower d'.

Recall, recognition, and confidence patterns in eyewitness testimony

“…The ®rst recall revolved around actions and in the second trial subjects repeated the narration, ®lling it in mainly with peripheral details. As in the work of Eugenio et al (1982), errors increased somewhat, basically a ecting details, and, more so in central than in peripheral information. Moreover, the level of attention paid to the event did not seem to be responsible for the e ect, as the intentional group had more errors in details than did the incidental group.…”

“…Repetition improves net recall (Dunning and Stern, 1992;Scrivner and Safer, 1988;Turtle and Yuille, 1994), but can also produce errors and intrusions (Eugenio et al, 1982). Therefore, it seems appropriate to ascertain whether the e ects are the same for actions and details in both central and peripheral information.…”

Repeated testing in eyewitness memory: a means to improve recall of a negative emotional event

“…After completing the ®rst recall trial, participants were provided with a 5-minutè think' period (Erdelyi and Becker, 1974;Eugenio et al, 1982), during which they were instructed to`think back on the scene you witnessed . .…”

“…Because hypermnesia is a more robust phenomenon when pictures, rather than words, are used as stimuli (Erdelyi and Becker, 1974;Payne, 1986Payne, , 1987, it is not surprising that it is obtained using dynamic pictorial stimuli such as crime ®lms. However, a limitation of Scrivner and Safer's study, as well as other studies addressing the eects of repeated testing on eyewitness memory (e.g., Dunning and Stern, 1992;Eugenio et al, 1982;Turtle and Yuille, 1994), is that they did not expose a control group of participants to a non-violent event. Without such a comparison, it is impossible to know whether the increase in amount recalled over attempts is greater than, less than, or the same as it would be in the absence of arousal.…”

“…Although Burke et al (1992) found no bene®t of repeated testing for remembering details of an event, other research suggests that eyewitnesses do remember more over multiple recall attempts (Dunning and Stern, 1992;Eugenio, Buckhout, Kostes and Ellison, 1982;Scrivner and Safer, 1988;Turtle and Yuille, 1994). Furthermore, the gains in recall tend not to be accompanied by an increase in the number of errors (Dunning and Stern, 1992;Scrivner and Safer, 1988;Turtle and Yuille, 1994; but see Eugenio et al, 1982). For example, Scrivner and Safer (1988) evaluated the eects that repeated testing has on eyewitnesses' recall of a violent event.…”