Context counts! social anxiety modulates the processing of fearful faces in the context of chemosensory anxiety signals

Abstract

During emotion perception, context is an important source of information. Whether contextual cues from modalities other than vision or audition influence the perception of social emotional information has not been investigated. Thus, the present study aimed at testing emotion perception and regulation in response to fearful facial expressions presented in the context of chemosensory stimuli derived from sweat of anxious individuals. In groups of high (HSA) and low socially anxious (LSA) participants we recorded the startle reflex (Experiment I), and analysed event-related potentials (ERPs; Experiment II) while they viewed anxious facial expressions in the context of chemosensory anxiety signals and chemosensory control stimuli. Results revealed that N1/P1 and N170 amplitudes were larger while late positive potential (LPP) activity was smaller for facial expressions presented in the context of the anxiety and the chemosensory control stimulus as compared to facial expressions without a chemosensory context. Furthermore, HSA participants were highly sensitive to the contextual anxiety signals. They showed enhanced motivated attention allocation (LPP, Study II), as well as larger startle responses toward faces in the context of chemosensory anxiety signals than did LSA participants (Study I). Chemosensory context had no effect on emotion regulation, and both LSA and HSA participants showed effective emotion regulation (Study I and II). In conclusion, both anxiety and chemosensory sport context stimuli enhanced early attention allocation and structural encoding, but diminished motivated attention allocation to the facial expressions. The current results show that visual and chemosensory information is integrated on virtually all levels of stimulus processing and that socially anxious individuals might be especially sensitive to chemosensory contextual social information.

Keywords: chemosensory anxiety signals; context; emotion perception; emotion regulation; event-related-potentials; social anxiety; startle reaction.

Figure 1

Trial timing in Experiment I (upper half of figure) and Experiment II (lower half). Note that Experiment 1's dotted lines indicate the intervals in which startle probes were delivered. Within each trial only one of these probes was administered.

Figure 2

In Experiment I, HSA participants (dashed lines) showed larger startle magnitudes than LSA participants (sold lines) toward the anxious facial expression presented in the context of the chemosensory anxiety signal during startle position C. Furthermore, for HSA participants startle responses did not differ between startle probes A, B, and C, while for LSA participants startle responses were smaller during startle probe B, and probe C, than probe A, indicating startle habituation in LSA, but not in HSA participants. ^*0.040.

Figure 3

Effects of chemosensory context on the N1 (upper left), P1 and N170 (lower left) and LPP (right) potential. Faces presented in the context of chemosensory signals elicited larger N1 and P1 potentials (central scalp locations), and larger N170 potentials (occipital and parietal scalp locations), but smaller LPPs (recorded at all electrode locations). ^*N1 = 0.041; ^*P1 = 0.004; ^*N170 = 0.046; ^*LPP = 0.009.

Figure 4

High socially anxious individuals showed larger N170 (left) and LPPs (right) in response to anxious facial expressions presented without a chemosensory context. Note that the N170 effect was located in its maximum over left parietal and occipital electrodes positions and the LPP effect was maximal at right lateral electrode positions. ^*N170 = 0.024; ^*LPP = 0.003.

Figure 5

High socially anxious individuals (HSA) showed larger LPPs in response to faces presented in the context of chemosensory anxiety signals (right side) than did low-socially anxious individuals (LSA). There were no differences between HSA and LSA participants for faces presented in the context of chemosensory sport stimuli (left side). Note that LPP effects were maximal over left lateral electrode positions. ^*LPP right side = 0.001.