Abstract
AbstractErotic scenes and images of mutilated bodies are emotional stimuli that have repeatedly shown to evoke specific neurophysiological responses associated with enhanced attention and perceptual processing. Remarkably however, only a handful of studies have investigated human motor reactions to emotional activation as a direct index of physical approximation or withdrawal. Given the inconclusive results of these studies, the approach-avoidance distinction, one of the most salient concepts in human motivational research, remains a broadly exploited hypothesis that has never been empirically demonstrated. Here, we investigate postural responses elicited by discrete emotional stimuli in healthy young adults. We discover that both positive and negative affective pictures induce a significant posterior deviation from postural baseline equilibrium. Further, we find that neutral pictures also evoke posterior deviation, although with a less pronounced amplitude. Exploring the dynamical evolution of postural responses to emotional pictures at high temporal resolution, we uncover a characteristic profile that remains stable for stimuli from all three affective categories. In contrast, the postural response amplitude is modulated by the emotional content of the stimulus. Our observations do not support the interpretation of postural responses to affective picture-viewing as approach-avoidance behavior. Instead, our findings indicate the involvement of a previously unrecognized motor component of the physiological mechanism underlying human orienting responses.
Highlights
Postural displacements in response to emotional activation have recently been proposed as a direct and objective index of approach–avoidance behavior in humans
Because forward movement decreases the actual distance between the subject and the affective stimulus, whereas backward leaning increases the subject–stimulus distance, it is reasonable to argue that postural sway can be used as an objective measure of approach–voidance behavior that is not influenced by experimental instructions
Subjects exhibit a marked negative center of pressure (COP) deviation from baseline in the A-P axis during the presentation of pictures pertaining to all three affective categories
Summary
Postural displacements in response to emotional activation have recently been proposed as a direct and objective index of approach–avoidance behavior in humans. A series of empirical studies has examined the pulling or pushing of levers as a possible motor index of approach–avoidance behavior In this framework, a faster pull of the lever (arm flexion) in the presence of a positive compared to a negative stimulus is assumed to indicate approach, whereas a faster push of the lever (arm extension) in the presence of a negative compared to a positive stimulus is believed to represent avoidance Because forward movement decreases the actual distance between the subject and the affective stimulus, whereas backward leaning increases the subject–stimulus distance, it is reasonable to argue that postural sway can be used as an objective measure of approach–voidance behavior that is not influenced by experimental instructions. The authors aimed at exploring postural behavior induced by sustained emotional states, rather than assessing phasic responses to discrete emotional stimuli
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
