Psychology

Human cognitive neuroscience seminar

Speakers: Renzo Lanfranco (University of Edinburgh)

Topic: Cognitive biases in the unconscious processing of emotions

Abstract: Do we need perceptual awareness to detect emotions? Recent studies have suggested that certain emotional facial expressions (most commonly, fear) have preferential access to awareness. This is typically demonstrated using breaking continuous flash suppression (bCFS), which measures how long it takes a stimulus to break through interocular suppression into awareness: Faster breakthrough is taken to indicate prioritised unconscious processing. In bCFS, however, observers decide for themselves how long to view a stimulus before reporting it; this raises the concern that differential report-related decision criteria, rather than perceptual differences, underlie the different breakthrough times found for different expressions. Although many studies have tried to control for criterion effects by making the reported feature orthogonal to the valence of the stimulus, it is impossible to know what decisional factors are at play when observers set their own stimulus exposure durations.

In this presentation, I will describe four experiments in which participants were shown different facial expressions, suppressed by CFS, for a range of pre-specified durations. Importantly, observers could not decide how long to view a stimulus before giving a response; after each trial, they reported the location (left or right) and valence (emotional or not) of the face. Detection sensitivity to both features increased with exposure duration, but we found no differences between fearful, angry, happy and neutral faces. We did find reduced sensitivity to inverted (compared to upright) faces, demonstrating the efficacy of this method. Furthermore, we found that criterion measures (bias) for reporting emotional valence did differ across expressions, supporting the idea that previous findings of differential breakthrough times are due to decisional factors. Observers use different criteria to decide on various emotions’ presence, but different emotions do not enjoy differential conscious access.

Contact

The seminars are organised by the Human Cognitive Neuroscience research group. For further information, or if you would like to join the e-mail list for these seminars, please email Ed Silson.

Ed Silson

Human cognitive neuroscience

 

Apr 26 2018 -

Human cognitive neuroscience seminar

2018-04-26: Cognitive biases in the unconscious processing of emotions

Room S1, Psychology Building, 7 George Square, Edinburgh, EH8 9JZ