Abstract
The presentation of a rapidly changing high-contrast mask to one eye renders visual stimuli presented to the other eye invisible for several seconds (so called continuous flash suppression; CFS). Some emotional expressions (i.e. fearful faces) 'break-through' CFS and thereby enter conscious awareness more quickly than other emotional expressions. Here, we ask whether break-through is determined by the subjective experience of the stimulus, or by its low-level visual properties. We took advantage of a visual illusion where the top half of one face appears to fuse perceptually with the bottom half of another, when aligned spatially and presented upright. Using the emotional version of the composite face illusion (CFI) in conjunction with CFS, we explored whether the presence of illusory emotion can direct processing resources. Unsuppressed emotional (happy, fearful, neutral) lower face halves were aligned with suppressed neutral upper face halves, and the time it took for the upper face halves to break through suppression was measured. Although the suppressed face halves were physically identical, we predicted that the illusory emotion induced by the CFI could lead to some stimuli emerging more quickly than others. First, we validated the CFI in our stimuli, showing that the neutral upper face halves were perceived as more fearful or happy in the presence of a fearful or happy lower face half, respectively. In the CFS task, across 32 observers, we found a large significant effect of inversion, whereby the upper face halves were responded to more quickly when the stimulus configuration was presented upright rather than inverted. There was also a small effect of emotion, which did not interact with inversion. We take this as evidence to suggest that the low-level properties of the unsuppressed face region likely impact on breakthrough time, but that the illusory perception of emotion does not direct processing resources.
Meeting abstract presented at VSS 2018