Hyperactivity in the Hippocampus During Threat Processing was Associated With Levels of Depression

Abstract Introduction Threat-related information is preferentially processed, facilitating quick and efficient responses. However, the impact of extended sleep deprivation on perception of and response to threatening information is not well known. Sleep loss may increase amygdalar activity and negative mood, potentially facilitating threat processing. However, it also reduces cognitive function, possibly impairing ability to respond. The present study assessed the extent to which extended sleep deprivation modulates threat processing using a threat expectation paradigm. Methods Twenty-one participants underwent one baseline night of sleep followed by 62hrs total sleep deprivation (TSD) and one recovery night of sleep (12hrs). Threat expectation task performance was assessed at baseline, at multiple time points during TSD, and following recovery sleep. To control for circadian influence, performance at three 1100 sessions (baseline, 52hrs into TSD, and recovery) were compared. The threat expectation task involved determining whether a presented face was fearful (i.e., signaled threat) or neutral. Faces were presented at three expectation levels: 80%, 50%, and 20% chance of viewing a fearful face. Results Overall, responses were faster (F=9.77, p=0.001) and more accurate (F=11.48, p=0.001) when the type of face (fearful or neutral) was expected. Accuracy significantly decreased over TSD (t=7.71, p<0.001) and recovered following subsequent sleep. Fear bias was calculated for accuracy (accuracy for fearful face minus neutral face). Under conditions of high expectation (80%) of viewing a fearful face, fear bias increased across TSD (t=-1.95, p=0.07). Although accuracy to both fearful and neutral faces significantly declined across TSD (both p<0.001), decline for neutral faces was greater, thus increasing fear bias. Importantly, the increased bias toward fear was still evident compared to baseline following a 12-hour recovery sleep opportunity, (t=-1.93, p=0.07). Conclusion Extended sleep deprivation, common in operational environments where there is also high expectation of encountering threat, impairs cognitive control and is thought to enhance amygdala activity. These data show that, consequently, cognitive resources become biased toward biologically adaptive behaviors (i.e., threat processing) at the expense of attending and responding more broadly to all stimuli. This behavior is not reversed with a single extended sleep opportunity. Support (if any) Department of Defense Military Operational Medicine Research Program (MOMRP)

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How Multi-Sensory Animal Embodiment in Virtual Reality Influences Environmental Threat Processing and Conservation Behaviors

10.21203/rs.3.rs-957911/v1 ◽

2021 ◽

Author(s):

Daniel Pimentel ◽

Sriram Kalyanaraman

Keyword(s):

Virtual Reality ◽

Charitable Giving ◽

Small Scale ◽

Virtual Reality Simulation ◽

Experiment Study ◽

Loggerhead Sea Turtles ◽

Differential Processing ◽

Environmental Threats ◽

Environmental Threat ◽

Threat Processing

Abstract Efforts to mitigate environmental threats are often inversely related to the magnitude of casualty, human or otherwise1–3. This “compassion fade” can be explained, in part, by differential processing of large- versus small-scale threats: it is difficult to form empathic connections with unfamiliar masses versus singular victims4. Despite robust findings, little is known about how non-human casualty is processed, and what strategies override this bias. Over four experiments, we show how embodying threatened megafauna – Loggerhead sea turtles (Caretta Caretta) – in virtual reality can offset and reverse compassion fade. After observing compassion fade during exposure to mass non-human casualty in virtual reality (Study 1; N=60), we then tested a custom multi-sensory virtual reality simulation facilitating embodiment of a threatened Loggerhead (Study 2; N=98). Afterwards, a field experiment (Study 3; N=90) testing the simulation with varied number of victims showed embodiment offset compassion fade. Lastly, a fourth study (N=25) found that charitable giving among users embodying threatened wildlife was highest when exposed to one versus many victims, though this effect was reversed if victims were of a different species (Dolphins). The findings demonstrate how animal embodiment in virtual reality alters processing of environmental threats and non-human casualty, thereby influencing biodiversity conservation outcomes.

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Inter-individual differences in trait anxiety shape the functional connectivity between the bed nucleus of the stria terminalis and the amygdala during brief threat processing

NeuroImage ◽

10.1016/j.neuroimage.2017.10.054 ◽

2018 ◽

Vol 166 ◽

pp. 110-116 ◽

Cited By ~ 24

Author(s):

Leonie Brinkmann ◽

Christine Buff ◽

Katharina Feldker ◽

Paula Neumeister ◽

Carina Y. Heitmann ◽

...

Keyword(s):

Individual Differences ◽

Functional Connectivity ◽

Trait Anxiety ◽

Stria Terminalis ◽

Bed Nucleus ◽

Threat Processing

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Coping styles and threat processing

Personality and Individual Differences ◽

10.1016/s0191-8869(02)00287-8 ◽

2003 ◽

Vol 35 (4) ◽

pp. 843-861 ◽

Cited By ~ 16

Author(s):

Pedro Avero ◽

Kimberly M Corace ◽

Norman S Endler ◽

Manuel G Calvo

Keyword(s):

Coping Styles ◽

Threat Processing

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The distinctive neural circuitry of complex posttraumatic stress disorder during threat processing

Psychological Medicine ◽

10.1017/s0033291719003921 ◽

2020 ◽

pp. 1-8

Author(s):

Richard A. Bryant ◽

Kim L. Felmingham ◽

Gin Malhi ◽

Elpiniki Andrew ◽

Mayuresh S. Korgaonkar

Keyword(s):

Posttraumatic Stress Disorder ◽

Posttraumatic Stress ◽

Stress Disorder ◽

International Classification Of Diseases ◽

Complex Posttraumatic Stress Disorder ◽

Cross Sectional ◽

Amygdala Activation ◽

Threat Processing ◽

Dorsolateral Prefrontal ◽

Classification Of Diseases

Abstract Background There is controversy over the extent to which the new International Classification of Diseases (ICD-11) diagnosis of complex posttraumatic stress disorder (CPTSD) is distinct from posttraumatic stress disorder (PTSD). This study aimed to conduct the first investigation of distinctive neural processes during threat processing in CPTSD relative to PTSD. Method This cross-sectional functional magnetic resonance study included 99 participants who met criteria for PTSD (PTSD = 32, CPTSD = 28) and 39 trauma-exposed controls. PTSD was assessed with the Clinician-Administered PTSD Scale (CAPS). CPTSD was assessed with an adapted version of the International Trauma Questionnaire. Neural responses were measured across the brain while threat or neutral faces were presented at both supraliminal and subliminal levels. Results During supraliminal presentations of threat stimuli, there was greater bilateral insula and right amygdala activation in CPTSD participants relative to PTSD. Reduced supraliminal right dorsolateral prefrontal cortex activation and increased subliminal amygdala and insula activation were observed as common dysfunction for both CPTSD and PTSD groups relative to trauma controls. There were no significant differences in terms of subliminal presentations and no differences in functional connectivity. Dissociative responses were positively associated with right insula activation (r = 0.347, p < 0.01). Conclusions These results provide the first evidence of distinct neural profiles of CPTSD and PTSD during threat processing. The observation of increased insula and right amygdala activation in CPTSD accords with the proposal that CPTSD is distinguished from PTSD by disturbances in emotion regulation and self-concept.

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