5.1. Introduction

Many recent studies have investigated the relationship between emotion and attention. The role of emotional information in attentional processing, particularly negative emotional information, is of special interest. Two different styles of attention to threatening information have been reported across individual properties: a vigilant processing mode in dysphoric populations and an avoidant processing mode in non-dysphoric normal populations.

Attentional bias effects in emotionally disturbed populations have been widely investigated, particularly in clinically guided anxiety, phobia, or depression research. Generally, in these populations, processing an emotionally negative, irrelevant stimulus can interfere with the ongoing processing of purposefully attended stimuli through the capture of attentional resources. This vigilant processing style is associated with emotionally disturbed populations such as the anxious or the depressed but, while less frequent, has also been reported in normal individuals in whom emotions have been induced either by social events or laboratory manipulation.

An avoidant processing style, in which negative information is simply ignored or controlled during actual target processing performance, has been observed in normal populations. This has not been as thoroughly investigated as attentional processing of negative information in disturbed populations, and the purpose of this series of experiments was to measure the impact of emotional stimuli on attention in normal individuals.