A freezing‐like posture to pictures of mutilation

Abstract

Postural sway and heart rate were recorded in young men viewing emotionally engaging pictures. It was hypothesized that they would show a human analog of "freezing" behavior (i.e., immobility and heart rate deceleration) when confronted with a sustained block of unpleasant (mutilation) images, relative to their response to pleasant/arousing (sport action) or neutral (objects) pictures. Volunteers stood on a stabilometric platform during picture viewing. Significantly reduced body sway was recorded during the unpleasant pictures, along with increased mean power frequency (indexing muscle stiffness). Heart rate during unpleasant pictures also showed the expected greater deceleration. This pattern resembles the "freezing" and "fear bradycardia" seen in many species when confronted with threatening stimuli, mediated by neural circuits that promote defensive survival.

Sustained and transient modulation of performance induced by emotional picture viewing.

“…In the present study, however, we observed potentiation of an interference effect during a non-emotional, simple visual detection task performed when the affective stimulus was not being displayed. In this context, it is noteworthy that Azevedo et al (2005) revealed a gradual slowing down of heart rate when subjects viewed the same unpleasant pictures as employed in the present study (the gradual slowdown appeared to asymptote around the 5-6th picture presentation). These results suggest a gradual instatement of an emotional state, which may underlie the interference effect observed in the present study.…”

“…Moreover, humans evoke robust physiologic reactions when viewing mutilation pictures ). More importantly, in a recent experiment from our group (Azevedo et al, 2005), male subjects viewed the exact same sequence of mutilation and neutral pictures as in the present study while posturographic and electrocardiographic recordings were acquired. The results revealed a freezing-like state consisting of immobility, rigidity and bradycardia when viewing unpleasant relative to neutral pictures.…”

Biomechanical organization of gait initiation depends on the timing of affective processing

“…Neural processing of unpleasant and threatening items proceeds in a stereotypical manner; the initial response is typically postural immobility, during which the organism is hypervigilant (e.g. [2,16,17]). This response is then followed by overt action patterns.…”

“…Posturographic studies have revealed that potent emotional triggers may activate innate behavioral tendencies, such as freeze, fight, or flight responses [2][3][4]. These responses may play into the neural control of balance, where they become visible as automatic postural adjustments.…”

Emotional scenes and facial expressions elicit different psychophysiological responses

“…A significant rise of the skin conductance level can be found for both positive and negative stimuli when compared to neutral ones (e.g., Azevedo et al, 2005;Bradley et al, 2001Bradley et al, , 2005.…”