No influence of eye gaze on emotional face processing in the absence of conscious awareness

Nathan Caruana,Marwa El Zein,Christine Inkley,Kiley Seymour

doi:10.1038/s41598-019-52728-y

Nathan Caruana, Marwa El Zein + Show 2 more

Open Access

https://doi.org/10.1038/s41598-019-52728-y

Copy DOI

Abstract

The human brain has evolved specialised mechanisms to enable the rapid detection of threat cues, including emotional face expressions (e.g., fear and anger). However, contextual cues – such as gaze direction – influence the ability to recognise emotional expressions. For instance, anger paired with direct gaze, and fear paired with averted gaze are more accurately recognised compared to alternate conjunctions of these features. It is argued that this is because gaze direction conveys the relevance and locus of the threat to the observer. Here, we used continuous flash suppression (CFS) to assess whether the modulatory effect of gaze direction on emotional face processing occurs outside of conscious awareness. Previous research using CFS has demonstrated that fearful facial expressions are prioritised by the visual system and gain privileged access to awareness over other expressed emotions. We hypothesised that if the modulatory effects of gaze on emotional face processing occur also at this level, then the gaze-emotion conjunctions signalling self-relevant threat will reach awareness faster than those that do not. We report that fearful faces gain privileged access to awareness over angry faces, but that gaze direction does not modulate this effect. Thus, our findings suggest that previously reported effects of gaze direction on emotional face processing are likely to occur once the face is detected, where the self-relevance and locus of the threat can be consciously appraised.

Highlights

The human brain has evolved specialised mechanisms to enable the rapid detection of threat cues, including emotional face expressions
FMRI studies using continuous flash suppression (CFS) have shown that amygdala responses elicited by fearful faces – that are suppressed from awareness – are similar to those elicited by consciously perceived fearful faces[36,45]
Would a fearful face with direct gaze gain access to awareness earlier than an angry face with direct gaze, despite the angry face presenting a more relevant threat signal to the observer? Some behavioural evidence from studies using the Garner Interference task show that when expressed emotions are unambiguous, the emotion is encoded before gaze interferes[15], suggesting that the effect of gaze may occur at later stages of cognitive processing

Summary

Introduction

The human brain has evolved specialised mechanisms to enable the rapid detection of threat cues, including emotional face expressions (e.g., fear and anger). Gaze direction is an important contextual cue known to influence judgments of emotional expression, those that signal threat to the observer (i.e., anger and fear). This is arguably because gaze direction contextualises the relevance and locus of the threat to the observer[9,10,11]. FMRI studies using CFS have shown that amygdala responses elicited by fearful faces – that are suppressed from awareness – are similar to those elicited by consciously perceived fearful faces[36,45] These findings support suggestions of a ‘low road’ pathway which operates without awareness to prioritize the detection of threatening stimuli. No study has yet assessed whether the fast integration of gaze and emotion cues occurs outside of awareness leading to the faster detection of Threat + stimuli

Objectives

Methods

Results

Conclusion