Unseen facial and bodily expressions trigger fast emotional reactions

Abstract

The spontaneous tendency to synchronize our facial expressions with those of others is often termed emotional contagion. It is unclear, however, whether emotional contagion depends on visual awareness of the eliciting stimulus and which processes underlie the unfolding of expressive reactions in the observer. It has been suggested either that emotional contagion is driven by motor imitation (i.e., mimicry), or that it is one observable aspect of the emotional state arising when we see the corresponding emotion in others. Emotional contagion reactions to different classes of consciously seen and ''unseen'' stimuli were compared by presenting pictures of facial or bodily expressions either to the intact or blind visual field of two patients with unilateral destruction of the visual cortex and ensuing phenomenal blindness. Facial reactions were recorded using electromyography, and arousal responses were measured with pupil dilatation. Passive exposure to unseen expressions evoked faster facial reactions and higher arousal compared with seen stimuli, therefore indicating that emotional contagion occurs also when the triggering stimulus cannot be consciously perceived because of cortical blindness. Furthermore, stimuli that are very different in their visual characteristics, such as facial and bodily gestures, induced highly similar expressive responses. This shows that the patients did not simply imitate the motor pattern observed in the stimuli, but resonated to their affective meaning. Emotional contagion thus represents an instance of truly affective reactions that may be mediated by visual pathways of old evolutionary origin bypassing cortical vision while still providing a cornerstone for emotion communication and affect sharing.affective blindsight ͉ electromyography ͉ emotional body language ͉ motor resonance ͉ emotional contagion ͉ face

From affective blindsight to emotional consciousness

“…These measures primarily include eye blink (Hamm et al, 2003), skin conductance (Anders et al, 2004(Anders et al, , 2009, pupil dilation and facial electromyography (Tamietto et al, 2009). Eye blink recording samples the startle reflex and gets potentiated after fear conditioning to unseen visual cues (Hamm et al, 2003).…”

“…Eye blink recording samples the startle reflex and gets potentiated after fear conditioning to unseen visual cues (Hamm et al, 2003). Skin conductance and pupil dilation are measures of autonomic arousal induced by sympathetic system activity, and have been reported to increase during passive exposure to facial as well as bodily expressions of emotions projected to the blind field of patients GY and DB (Tamietto et al, 2009). Lastly, electromyography has been used to assess the presence of emotional contagion in patients with affective blindsight (Tamietto et al, 2009).…”

“…Skin conductance and pupil dilation are measures of autonomic arousal induced by sympathetic system activity, and have been reported to increase during passive exposure to facial as well as bodily expressions of emotions projected to the blind field of patients GY and DB (Tamietto et al, 2009). Lastly, electromyography has been used to assess the presence of emotional contagion in patients with affective blindsight (Tamietto et al, 2009). Emotional contagion refers to the spontaneous and automatic tendency to mimic the facial expressions seen in others and, consequently, to converge emotionally (Dimberg, 1982;Dimberg, Thunberg, & Elmehed, 2000;Hatfield, Cacioppo, & Rapson, 1994;Tamietto et al, 2009).…”

“…Thus, it has been proposed, and later on verified with different neuroimaging methods, that considerable post-lesion and experience-dependent plasticity has taken place in GY's brain (Bridge et al, 2008;Tamietto et al, 2012). Although we will discuss the neural underpinnings of affective blindsight in a dedicated section below, it has become increasingly clear that affective blindsight is not such a rare phenomenon, for it has been reported in more than 20 different patients studied by at least five independent research teams in several different countries (Anders et al, 2004(Anders et al, , 2009Bertini et al, 2013;Cecere et al, 2014;de Gelder & Hadjikhani, 2006;de Gelder et al, 1999de Gelder et al, , 2002de Gelder et al, , 2005de Gelder et al, , 2014Hamm et al, 2003;Heywood & Kentridge, 2000;Morris et al, 2001;Pegna et al, 2005;Rossion et al, 2000;Tamietto & de Gelder, 2008;Tamietto et al, 2009Tamietto et al, , 2012Van den Stock et al, 2011). These patients suffered different lesions to the visual cortex at different ages, but for the large majority in adulthood, and two of them had bilateral cortical blindness.…”

“…The phenomenon, referred to as ''affective blindsight'', denotes the uncanny ability of such patients to respond correctly, or above chance level, to emotionally salient visual stimuli presented to their blind fields (Anders et al, 2004(Anders et al, , 2009Bertini, Cecere, & Ladavas, 2013;Cecere, Bertini, Maier, & Ladavas, 2014;de Gelder & Hadjikhani, 2006;de Gelder, Morris, & Dolan, 2005;de Gelder, Pourtois, van Raamsdonk, Vroomen, & Weiskrantz, 2001; de Gelder, Pourtois, & http://dx.doi.org/10.1016/j.concog.2015.05.007 1053-8100/Ó 2015 Elsevier Inc. All rights reserved. Weiskrantz, 2002;de Gelder, Tamietto, Pegna, & Van den Stock, 2014;de Gelder, Vroomen, Pourtois, & Weiskrantz, 1999;Hamm et al, 2003;Heywood & Kentridge, 2000;Morris, DeGelder, Weiskrantz, & Dolan, 2001;Pegna, Khateb, Lazeyras, & Seghier, 2005;Rossion, de Gelder, Pourtois, Guerit, & Weiskrantz, 2000;Tamietto & de Gelder, 2008;Tamietto, Pullens, de Gelder, Weiskrantz, & Goebel, 2012;Tamietto et al, 2009;Van den Stock et al, 2011). As is the case for the original phenomenon of ''blindsight'' (Pöppel, Held, & Frost, 1973;Weiskrantz, Warrington, Sanders, & Marshall, 1974), the ''blind'' component in affective blindsight refers to the patients' statement of not seeing or consciously perceiving the emotional stimuli, while the ''sight'' component reflects their residual ability to respond, discriminate or display spontaneous expressive and physiological responses that are appropriate to the specific emotional content of the visual signals they are presented with.…”