The Body Action Coding System II: muscle activations during the perception and expression of emotion

Abstract

Research into the expression and perception of emotions has mostly focused on facial expressions. Recently, body postures have become increasingly important in research, but knowledge on muscle activity during the perception or expression of emotion is lacking. The current study continues the development of a Body Action Coding System (BACS), which was initiated in a previous study, and described the involvement of muscles in the neck, shoulders and arms during expression of fear and anger. The current study expands the BACS by assessing the activity patterns of three additional muscles. Surface electromyography of muscles in the neck (upper trapezius descendens), forearms (extensor carpi ulnaris), lower back (erector spinae longissimus) and calves (peroneus longus) were measured during active expression and passive viewing of fearful and angry body expressions. The muscles in the forearm were strongly active for anger expression and to a lesser extent for fear expression. In contrast, muscles in the calves were recruited slightly more for fearful expressions. It was also found that muscles automatically responded to the perception of emotion, without any overt movement. The observer's forearms responded to the perception of fear, while the muscles used for leaning backwards were activated when faced with an angry adversary. Lastly, the calf responded immediately when a fearful person was seen, but responded slower to anger. There is increasing interest in developing systems that are able to create or recognize emotional body language for the development of avatars, robots, and online environments. To that end, multiple coding systems have been developed that can either interpret or create bodily expressions based on static postures, motion capture data or videos. However, the BACS is the first coding system based on muscle activity.

Emotional faces guide the eyes in the absence of awareness

“…Why did participants look towards fearful faces, but avert their gaze away from angry faces, in the absence of awareness? As mentioned in the Introduction, under awareness these two threat-related emotions have differential perceptual consequences (Kret et al, 2013b; Marsh et al, 2005; Springer et al, 2007; Huis In 't Veld et al, 2014) and may be mediated by different neural pathways (Luo et al, 2007). In the absence of awareness, before this study, there had been only circumstantial evidence for differential processing of angry and fearful faces according to the time they take to break into awareness (Yang et al, 2007; Milders et al, 2006; Troiani et al, 2014; Jusyte et al, 2015; Zhan et al, 2015).…”

“…Angry faces indicate direct threats (a person with an angry expression looking directly at the observer) leading to avoidance (Schmidt et al, 2012; Marsh et al, 2005) or freezing (Roelofs et al, 2010) responses. When looking at angry faces observers show a stronger startle reflex (Springer et al, 2007), stronger activation of the torso muscles (Huis In 't Veld et al, 2014), widening of the pupils (Kret et al, 2013b), and higher activation in brain areas associated with defense preparation (Williams et al, 2005; Pichon et al, 2009; Kret et al, 2011) than when looking at fearful faces. Threat processing is considered to evolve along two distinctive neuronal pathways, a fast sub-cortical and a slower cortical route (LeDoux, 1998).…”

Is it the real deal? Perception of virtual characters versus humans: an affective cognitive neuroscience perspective

“…This suggests that it is important to animate human-like virtual characters and program robots with human-like motion data. Several EMG studies by Huis in ‘t Veld et al (2014a , b ) suggested that specific muscle groups are used for the bodily expressions of emotion in humans. This information, together with motion capture data could be used to improve modeling of biological movements for virtual agents and robots.…”

Emotion Regulation through Movement: Unique Sets of Movement Characteristics are Associated with and Enhance Basic Emotions

“…A few used Laban movement analysis or its most known components: Effort and Shape (Levy and Duke, 2003 ; Gross et al, 2010 , 2012 ; Crane and Gross, 2013 ). Yet others characterized the movements based on the specific muscles that are activated (Huis In 't Veld et al, 2014a , b ), or used kinematic variables such as movement duration, velocity, acceleration, joints displacement (range of motion), and joint coordination (Pollick et al, 2001 ; Sawada et al, 2003 ; Roether et al, 2009 ; Gross et al, 2010 , 2012 ; Barliya et al, 2013 ). Although these studies were able to discriminate among the different emotions expressed in movement, they used different coding schemes, making it difficult to compare outcomes across studies and to build a comprehensive description of the associations between certain motor characteristics of body movements and specific emotions (Gross et al, 2012 ).…”