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

Abstract

It is widely agreed that hemispheric asymmetries in emotional face perception exist. However, the mechanisms underlying this lateralization are not fully understood. In the present study, we tested whether (a) these asymmetries are driven by the low spatial frequency content of images depicting facial expressions, and (b) whether the effects differed depending on whether the emotional facial expressions were clearly visible or hidden (i.e., embedded in low spatial frequencies). The manipulation sheds light on the contribution of cortical and subcortical routes to emotional processing mechanisms. We prepared both unfiltered (broadband) and 'hybrid' faces. Within the latter, different bands of spatial frequency content from images of two different expressions were combined (i.e., low frequencies from an emotional image combined with high frequencies from a neutral image). We presented these broadband and hybrid images using the free-viewing emotional chimeric faces task (ECFT) in which two images are presented above and below fixation and asked participants to report which of the two mirror reversed images appeared more emotional. As predicted, the results showed that only broadband expressions produced the well-known left visual field/right hemisphere (LVF/RH) bias across all basic emotions. For hybrid images, only happiness revealed a significant LVF/RH bias. These results suggest that low spatial frequency content of emotional facial expressions, which activates the magnocellular pathway in subcortical structures and bypassing cortical visual processing, is not generally sufficient to induce an LVF bias under free-viewing conditions where participants deny explicitly seeing the emotion, suggesting that the LVF bias in ECFT is primarily cortically mediated.

Emotion lateralization in a graduated emotional chimeric face task: An online study.

“…We hypothesized an overall LVF/RH bias for easily recognized chimeric faces (emotional intensity of 100%) across all six basic emotions, regardless of emotional valence, which is in line with the overall RH bias reported previously (Bourne, 2010;Hausmann et al, 2021;Sackeim & Gur, 1978; for a review, see Gainotti, 2019). In line with Carbary et al (2001Carbary et al ( , 2002, we also predicted that the ECFT bias decreases as the emotional facial expressions become less emotionally distinct.…”

The impact on emotion classification performance and gaze behavior of foveal versus extrafoveal processing of facial features.

“…Indeed, even isolated face parts (eyes, mouth) are better recognized and more strongly represented in right inferior occipital gyrus when they were presented at typical, rather than reversed, visual field locations (de Haas et al, 2016). There are also left visual-field advantages for many aspects of face perception, including emotion perception (e.g., Adolphs, 2002; Burt & Perrett, 1997) and recent evidence indicates that low spatial frequencies are not generally sufficient to induce a left visual field bias in emotion perception under free-viewing conditions (Hausmann, Innes, Birch, & Kentridge, 2019). These issues deserve further investigation.…”

Left Hemisphere Dominance for Negative Facial Expressions: The Influence of Task

“…Three major theories of hemisphere asymmetries in emotion processing-the RHH, VSH, and AWH-predict right hemisphere dominance for negative facial expressions of disgust, fear, and sadness. This is observed in many studies (e.g., Bourne, 2010;Kumar and Srinivasan, 2011;Rahman and Anchassi, 2012;Innes et al, 2016;Damaskinou and Watling, 2018;Kajal et al, 2020;Hausmann et al, 2021), however, some studies observe left hemisphere dominance for one or more of these expressions (Prete et al, 2014b(Prete et al, , 2015aBurt and Hausmann, 2019;Bublatzky et al, 2020;Lai et al, 2020;Stanković and Nešić, 2020). The present research investigated whether tasks that require identifying the linguistic category of facial expressions are more likely to produce left hemisphere dominance than tasks that do not require this information.…”

“…Critically, despite the important differences between the theories, the RHH, VSH, and AWH are similar in that they all predict right hemisphere dominance for the negative facial expressions of sadness, fear, and disgust. This effect is observed by many studies (e.g., Bourne, 2010;Kumar and Srinivasan, 2011;Rahman and Anchassi, 2012;Innes et al, 2016;Damaskinou and Watling, 2018;Kajal et al, 2020;Hausmann et al, 2021). Nonetheless, some studies have observed left hemisphere dominance for one or more of these expressions under particular experimental conditions (Prete et al, 2014b(Prete et al, , 2015aBurt and Hausmann, 2019;Bublatzky et al, 2020;Lai et al, 2020;Stanković and Nešić, 2020).…”

“…Studies of hemisphere asymmetries in facial expression processing have employed a wide variety of tasks. Some studies ask subjects to decide which of two faces is more emotional (Bourne, 2010;Innes et al, 2016;Hausmann et al, 2021) or more like a particular emotion (Jansari et al, 2011;Rahman and Anchassi, 2012); others ask whether a face is emotional or not (Najt et al, 2013;Stanković and Nešić, 2020), a positive or negative expression (Lichtenstein-Vidne et al, 2017;Kajal et al, 2020), or the same or different expression compared to another (Mattavelli et al, 2013(Mattavelli et al, , 2016Flack et al, 2015;Sliwinska and Pitcher, 2018). Of note, none of these tasks require subjects to explicitly identify different facial expressions (i.e., respond whether an expression is happy, angry, and sad, etc.…”