The influence of the period of retention on the reliability of episodic memory in the context of testimony

Valentina Baić,Marija Tasić,Milan Oljača

doi:10.5937/nabepo26-35280

Abstract

The paper presents a study that aimed to examine the reliability of episodic memory by varying the retention time from the moment of initial observation of two incidents to the moment of communicating what was actually remembered. Ninety (90) students aged 21-26 from the University of Criminal Investigation and Police Studies participated in the research (50 males and 40 females). The interval of retention presented an independent variable on four levels: immediately after watching a recording, after 1 month, after 3 months and after 6 months. The accuracy of recall, or remembering one aspect of the incident (characteristics of the event, characteristics of the perpetrators and characteristics of the victim) was a dependent variable. Results suggest that memory accuracy declines dramatically after a month, but also after three and six months, when the downward trend in memory accuracy is less pronounced. Regarding the degree of confidence in memory accuracy, the pattern of results is practically identical to that of memory accuracy. As a whole, the results indicate that the retention interval strongly affects both accuracy and certainty in memory accuracy, regardless of the type of crime and the characteristics being evaluated.

Highlights

The results indicate that the retention interval strongly affects both accuracy and certainty in memory accuracy, regardless of the type of crime and the characteristics being evaluated
An inaccurate witness statement is sometimes the consequence of a deliberate lie about the target event (Vrij et al, 2017), while a wrong/mistaken statement can be the result of wrong perception, poor memory, or of a number of factors (Gustafsson et al, 2019), such as factors relating to the criminal incident itself (Bornstein et al, 2012), factors connected with the eyewitness (Deffenbacher et al, 2004; Pozzulo & Warren, 2003; Wise & Safer, 2004) and factors that come to light after a criminal incident (Morgan et al, 2013; Shapira & Pansky, 2019)
The main conclusion of this research was that a high degree of memory accuracy is present immediately after watching the video-audio recording, and that such accuracy falls after one month and after three months, whereby the effect of the decline in memory accuracy is big in terms of effect size

Summary

Introduction

During the first half of the 20th century studies on human memory were mainly based on memorising meaningless syllables, based on the work of Ebbinghaus. Alongside many variables which influence the accuracy of an eyewitness statement (Blackwell-Young, 2008), eyewitnesses’ memory depends to a large degree on the conditions in which their interview is carried out, the way in which they are interviewed, the way in which questions are formulated, the type and order in which questions are asked, and from how much time has passed from the moment when the event was observed to the moment when the witness testified in the police or the prosecutor’s office (Evans & Fisher, 2011) Research shows that it is most optimal for the witness to be examined as soon as possible, and no later than four months from the moment the criminal event is observed (Penrod & Cutler, 1995; Shepard, 1983). This study examines the effects of several variables such as period of retention, memory accuracy, and confidence in memory accuracy

Methods

Results

Conclusion