Perceptual Load Affects Eyewitness Accuracy and Susceptibility to Leading Questions.

Gillian Murphy,Ciara M. Greene

doi:10.3389/fpsyg.2016.01322

Abstract

Load Theory (Lavie, 1995, 2005) states that the level of perceptual load in a task (i.e., the amount of information involved in processing task-relevant stimuli) determines the efficiency of selective attention. There is evidence that perceptual load affects distractor processing, with increased inattentional blindness under high load. Given that high load can result in individuals failing to report seeing obvious objects, it is conceivable that load may also impair memory for the scene. The current study is the first to assess the effect of perceptual load on eyewitness memory. Across three experiments (two video-based and one in a driving simulator), the effect of perceptual load on eyewitness memory was assessed. The results showed that eyewitnesses were less accurate under high load, in particular for peripheral details. For example, memory for the central character in the video was not affected by load but memory for a witness who passed by the window at the edge of the scene was significantly worse under high load. High load memories were also more open to suggestion, showing increased susceptibility to leading questions. High visual perceptual load also affected recall for auditory information, illustrating a possible cross-modal perceptual load effect on memory accuracy. These results have implications for eyewitness memory researchers and forensic professionals.

Highlights

Selective attention is what allows us to focus on what is relevant and ignore irrelevant, potentially distracting information
Perceptual Load Affects Eyewitness Memory for reviews of recent studies challenging the load hypothesis). This theoretical approach builds directly on a large body of research in the field of selective attention, in particular efforts to resolve conflicting accounts of when in the attentional process distracting information is filtered out of awareness. Much of this evidence comes from research using variations of the Eriksen flanker task (Eriksen and Eriksen, 1974) in which interference from a peripheral distractor letter is reduced when the central task—a search array containing other letters—imposes high perceptual load
We argue that perceptual load is very different to a weapon focus effect as it is the content of the entire scene that maxes out all available attention capacity

Summary

INTRODUCTION

Selective attention is what allows us to focus on what is relevant and ignore irrelevant, potentially distracting information. This theoretical approach builds directly on a large body of research in the field of selective attention, in particular efforts to resolve conflicting accounts of when in the attentional process distracting information is filtered out of awareness (see Murphy et al, 2016 for a review) Much of this evidence comes from research using variations of the Eriksen flanker task (Eriksen and Eriksen, 1974) in which interference from a peripheral distractor letter is reduced when the central task—a search array containing other letters—imposes high perceptual load. There is evidence that real world situations which place high demands on attention can result in reduced memory accuracy and increased suggestibility to leading questions This is true for when individuals are presented with attention-grabbing stimuli such as a weapon (the “weapon-focus effect”; Pickel, 1998; Saunders, 2009) and when they are instructed to perform a divided-attention task during encoding (Reinitz et al, 1994; Lane, 2006). In the research reported here, we explored three key questions. (1) Are eyewitness reports for high load events less accurate than for low load events? (2) Does high load induce spatial narrowing, so that peripheral details are especially affected by load? (3) Are high load memories more susceptible to the effects of leading questions than low load memories?

Method

Results

DISCUSSION