Physiological and neural responses to witnessing animal suffering and connection
Poster No:
737
Submission Type:
Abstract Submission
Authors:
Byeol Kim Lux1, Melanie Kos2, David Ward1, Tor Wager1
Institutions:
1Dartmouth College, Hanover, NH, 2Temple University, Philadelphia, PA
First Author:
Co-Author(s):
Introduction:
Witnessing suffering can be a potent stressor. Nonhuman animals exhibit inflammatory responses and depressive behavior when exposed to counterparts' suffering (Sial et al., 2015). In humans, observing pain activates brain regions associated with physical pain (Krishnan et al., 2016). Despite this, the psychological and physiological costs of causing distress to animals and the benefits of fostering compassion remain largely unexplored. This study aims to uncover neurobiological responses to witnessing animals' suffering and connection, using diverse modalities, including 3T fMRI and physiological measures (N = 88). This poster explores the variations in heartbeat and skin conductance during the viewing of animal videos and the associated brain representations linked to autonomous activity. These results indicate the activation of the sympathetic nervous system, eliciting fight-or-flight responses triggered by the perceived threat of witnessing suffering.
Methods:
The fMRI experiment was conducted over two-day sessions. During the fMRI scans, participants viewed a 30-minute aversive video depicting animal treatment in the food industry, such as slaughterhouses, or a positive video showing the intelligence of farm animals engaging in games and forming meaningful connections with humans. They viewed either of the two types of video in each session, and the order of videos was counterbalanced. Following the movie runs, a 10-minute resting state fMRI run was conducted. Additionally, we measured heart rate and skin conductance during the MR scans.
Results:
To examine the impact on heartbeat and skin conductance during the viewing of two distinct videos, we compared interbeat-interval (IBI) and skin conductance. We found a significant decrease in IBI, signifying an increased heart rate (Figure 1; paired t-test, t = 2.026, p = 0.046, df = 84), and a significant higher in skin conductance level (SCL) (t = -3.757, p < 0.001, df = 50) when participants viewed negative clips versus positive ones. Moreover, the skin conductance response (SCR) exhibited a higher standard deviation during the negative session compared to the positive one (t = -3.232, p = 0.002, df = 50). These observed rapid heartbeats and increased skin conductance levels indicate an activated sympathetic nervous system and escalated physiological arousal in response to negative stimuli. The greater variability of skin conductance implies that they experienced more momentary arousal fluctuations. Subsequently, we explored whether the physiological responses persisted during the resting state after the movie-watching. Notably, the significantly lower IBI endured in the resting state even after exposure to the negative clips (t = 2.955, p = 0.004, df = 85). Transitioning to an examination of brain representations linked to autonomous activity, we analyzed activation patterns during video viewing, focusing on associations with IBI and SCL. We found that increased activity in specific areas–the pre-supplementary motor area, ventral anterior insula (vaIns), and posterior orbitofrontal cortex (pOFC)–when heart rate was higher during the negative session compared to the positive one (Figure 2, False Discovery Rates corrected q< 0.05). Notably, prior research has associated the vaIns and pOFC with interoceptive awareness and emotional processing, providing context for our observed neural responses (Craig, 2009, Kringelbach, 2005).
·Figure 1.
·Figure 2.
Conclusions:
The physiological arousal induced by negative movie viewing, coupled with the continual elevated heart rate, persisted even after the viewing. These findings suggest that participants underwent stress-inducing arousal while viewing animal suffering. Also, we identified the neural representations linked to the heightened heart rate during negative movie watching compared to positive movie watching. These results mark an initial step in uncovering the impact of witnessing animal suffering and animal connection on our body and brain.
Emotion, Motivation and Social Neuroscience:
Emotional Perception 1
Modeling and Analysis Methods:
fMRI Connectivity and Network Modeling
Neuroanatomy, Physiology, Metabolism and Neurotransmission:
Cortical Anatomy and Brain Mapping
Novel Imaging Acquisition Methods:
BOLD fMRI 2
Keywords:
Cognition
Computational Neuroscience
ELECTROPHYSIOLOGY
Emotions
FUNCTIONAL MRI
NORMAL HUMAN
1|2Indicates the priority used for review
Provide references using author date format
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