[“Does the tainted truth effect on memory occur following a description of a scene?]

by

ACKNOWLEDGEMENT

I would take this opportunity to thank my research supervisor, family and friends for their support and guidance without which this research would not have been possible.

DECLARATION

I, [type your full first names and surname here], declare that the contents of this dissertation/thesis represent my own unaided work, and that the dissertation/thesis has not previously been submitted for academic examination towards any qualification. Furthermore, it represents my own opinions and not necessarily those of the University.

Signed __________________ Date _________________

ABSTRACT

Existing research shows that the postevent misinformation effect on eyewitness memory can be successfully reduced by retrospective warnings. Exploring potential costs of such warnings, we investigated whether warned eyewitnesses might overcorrect for misinformation influence from the postevent source. Across three experiments, warned participants recognized relatively fewer event items that were truthfully described in a postevent narrative ("tainted" event items) than did unwarned participants. This tainted truth effect was obtained for peripheral but not for central event items (Experiments 1-3); it persisted when the warning took the form of an explicit source-monitoring instruction (Experiment 2) and when the accessibility of the postevent information was increased (Experiment 3). Overall, the effect was stronger with a socially framed warning than with more direct, explicitly phrased warnings. The findings suggest that the tainted truth effect is due to more careful monitoring for information from a suspicious postevent source rather than mere memory impairment.

TABLE OF CONTENTS

DECLARATION3

ABSTRACT4

CHAPTER 1: INTRODUCTION6

CHAPTER 2: LITERATURE REVIEW9

The Present Research: Warnings And Overcorrection In The Eyewitness Misinformation Paradigm11

Witness12

Remembering Faces13

Change of Appearance: Facial Characteristics13

Disguise14

Children15

Identification Procedures16

CHAPTER 3: METHODOLOGY18

Design18

Materials18

Procedure20

REFERENCES21

CHAPTER 1: INTRODUCTION

Existing research shows that the postevent misinformation effect on eyewitness memory can be successfully reduced by retrospective warnings. Exploring potential costs of such warnings, we investigated whether warned eyewitnesses might overcorrect for misinformation influence from the postevent source. Across three experiments, warned participants recognized relatively fewer event items that were truthfully described in a postevent narrative ("tainted" event items) than did unwarned participants. This tainted truth effect was obtained for peripheral but not for central event items (Experiments 1-3); it persisted when the warning took the form of an explicit source-monitoring instruction (Experiment 2) and when the accessibility of the postevent information was increased (Experiment 3). Overall, the effect was stronger with a socially framed warning than with more direct, explicitly phrased warnings. The findings suggest that the tainted truth effect is due to more careful monitoring for information from a suspicious postevent source rather than mere memory impairment.

The susceptibility of human memory to external influences has stirred considerable, sometimes heated, debate among researchers, clinicians, and practitioners, partly because it can have profound implications for real-life issues, such as the reliability of eyewitness testimony, or the possibility of recovering long-forgotten memories of distressing past experiences (e.g., Roediger & McDermott, 2000). Responding to the potentially disconcerting consequences of memory's fallibility, researchers have investigated ways of reducing their impact, especially the distorting effects of postevent misinformation (e.g., a postevent narrative containing false details) on eyewitness ...