A leftward bias however you look at it: Revisiting the emotional chimeric face task as a tool for measuring emotion lateralization

Abstract

(2016) 'A leftward bias however you look at it : revisiting the emotional chimeric face task as a tool for measuring emotion lateralization.', Laterality., 21 (4-6). pp. 643-661. Further information on publisher's website: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractLeft hemiface biases observed within the Emotional Chimeric Face Task (ECFT) support emotional face perception models whereby all expressions are preferentially processed by the right hemisphere. However, previous research using this task has not considered that the visible midline between hemifaces might engage atypical facial emotion processing strategies in upright or inverted conditions, nor controlled for left visual field (thus right hemispheric)visuospatial attention biases. This study used novel emotional chimeric faces (blended at the midline) to examine laterality biases for all basic emotions. Left hemiface biases were demonstrated across all emotional expressions and were reduced, but not reversed, for inverted faces. The ECFT bias in upright faces was significantly increased in participants with a large attention bias. These results support the theory that left hemiface biases reflect a genuine bias in emotional face processing, and this bias can interact with attention processes similarly localized in the right hemisphere.3

Laterality and (in)visibility in emotional face perception: Manipulations in spatial frequency content.

“…These results are in line with findings of a meta-analysis which suggested that free-viewing laterality tasks, such as the ECFT task, are reliable and easy to administer tool for the assessment of RH integrity (Voyer, Voyer, & Tramonte, 2012). The LVF/RH bias consistently found in ECFT does not appear to differ according to stimulus valence (Bourne, 2010(Bourne, , 2011Christman & Hackworth, 1993;Innes, Burt, Birch, & Hausmann, 2016;Workman, Peters, & Taylor, 2000). Given also that studies consistently report left hemiface biases using only expressions of happiness (Bourne & Gray, 2011;Levy et al, 1983), this is taken as strong evidence against the Valence-Specific Hypotheses in favour of the RH Hypothesis.…”

Inducing the use of right eye enhances face-sex categorization performance.

“…As in previous bubbles (e.g., Dupuis-Roy et al, 2009, 2018Gosselin & Schyns, 2001;Ince et al, 2016), eye-tracking (Butler et al, 2005), and chimeric faces studies (Butler et al, 2005;Innes, Burt, Birch, & Hausmann, 2016), there appeared to be a slight bias for the use of the left-eye region from the observer's perspective compared with the right-eye region (see Figure 2a). We showed that this bias is statistically significant by averaging z scores in two regions of interest (ROI)-the right-eye and the left-eye anatomically defined ROIs-for each individual unsmoothed CI and compared average ROI scores with a two-tailed paired t test (M and 3).…”

Emotion Perception from Face, Voice, and Touch: Comparisons and Convergence

“…Single amygdala neurons respond to facial emotions [23], in particular expressions of the eye region [24]. Whereas cortical face processing [25] and its emotion modulation [26] appear preferentially lateralized to the right hemisphere, the lateralization of subcortical emotion effects is still unclear.…”