The Influence of Emotional Stimuli on Attention Sharing in a Dual Modality ERP Paradigm: Effects of Varying Interstimulus Intervals

The Influence of Emotional Stimuli on Attention Sharing in a Dual Modality ERP Paradigm: Effects of Varying Interstimulus Intervals

A large and growing body of evidence demonstrates that attention is preferentially allocated to stimuli with emotional content. Emotionally negative stimuli serve as a mechanism of biological preparedness to enhance attention. In agreement with this idea, previous studies looking at the influence of emotional pictures on tone processing showed that the ERP measures of cognition was reduced when participants were exposed to an emotional picture with intermittent auditory startle probes We hypothesized that if an auditory oddball (attention capturing) stimulus was placed in the same perceptual time frame as a preceding emotional picture, the auditory stimulus would then share attention resources with the visual stimulus. To this end, we employed a dual sensory modality task, wherein emotionally negative pictures were contrasted with emotionally neutral pictures and each picture was immediately followed by a tone in an auditory oddball paradigm. We have observed the influence of the emotional pictures at a short (600 ms) and long (2000 ms) interstimulus (picture-tone) interval. We find that only the short (600 ms) interstimulus interval alters attention resources to the subsequent tone. Combined, these results suggest that shared attention resources only occur at the short interstimulus interval. Here, the visual LPP to negative pictures likely serves as an ERP counterpart of the early stages of selective attention (if this longer interval will alter the attention), implying that an emotionally arousing or emotionally negative stimulus results in further automatic stimulus evaluation.