Emotional sounds modulate early neural processing of emotional pictures

Antje B M Gerdes,Anita Kusay,Florian Bublatzky,Matthias J Wieser,Michael M Plichta,Georg W Alpers

doi:10.3389/fpsyg.2013.00741

Abstract

In our natural environment, emotional information is conveyed by converging visual and auditory information; multimodal integration is of utmost importance. In the laboratory, however, emotion researchers have mostly focused on the examination of unimodal stimuli. Few existing studies on multimodal emotion processing have focused on human communication such as the integration of facial and vocal expressions. Extending the concept of multimodality, the current study examines how the neural processing of emotional pictures is influenced by simultaneously presented sounds. Twenty pleasant, unpleasant, and neutral pictures of complex scenes were presented to 22 healthy participants. On the critical trials these pictures were paired with pleasant, unpleasant, and neutral sounds. Sound presentation started 500 ms before picture onset and each stimulus presentation lasted for 2 s. EEG was recorded from 64 channels and ERP analyses focused on the picture onset. In addition, valence and arousal ratings were obtained. Previous findings for the neural processing of emotional pictures were replicated. Specifically, unpleasant compared to neutral pictures were associated with an increased parietal P200 and a more pronounced centroparietal late positive potential (LPP), independent of the accompanying sound valence. For audiovisual stimulation, increased parietal P100 and P200 were found in response to all pictures which were accompanied by unpleasant or pleasant sounds compared to pictures with neutral sounds. Most importantly, incongruent audiovisual pairs of unpleasant pictures and pleasant sounds enhanced parietal P100 and P200 compared to pairings with congruent sounds. Taken together, the present findings indicate that emotional sounds modulate early stages of visual processing and, therefore, provide an avenue by which multimodal experience may enhance perception.

Highlights

In everyday life people are confronted with an abundance of different emotional stimuli from the environment
As the analysis focused on visual event-related potentials (ERP) only, these trials were not considered for further analysis
Audiovisual pairs with pleasant sounds and pictures were rated as more pleasant than pleasant pictures only, t(21) = 3.47, p < 0.01, whereas unpleasant sounds with unpleasant pictures were rated as marginally more unpleasant than unpleasant pictures only, t(21) = 1.89, p < 0.10—see Table 1

Summary

Introduction

In everyday life people are confronted with an abundance of different emotional stimuli from the environment. The identification and evaluation of an emotional facial expression is biased toward the valence of simultaneously presented affective prosodic stimuli and vice versa (de Gelder and Vroomen, 2000; de Gelder and Bertelson, 2003; Focker et al, 2011; Rigoulot and Pell, 2012) Such interactions between emotional face and voice processing even occur when subjects were asked to ignore concurrent sensory information (Collignon et al, 2008) and were shown to be independent of attentional resources (Vroomen et al, 2001; Focker et al, 2011). The processing of emotional cues can even alter responses to non-related events coming from a different sensory modality which may indicate that an emotional context can modulate the excitability of sensory regions (Dominguez-Borras et al, 2009)

Results

Discussion

Conclusion