scholarly journals Distributed and Multifaceted Effects of Threat and Safety

2021 ◽  
pp. 1-22
Author(s):  
Dinavahi V. P. S. Murty ◽  
Songtao Song ◽  
Kelly Morrow ◽  
Jongwan Kim ◽  
Kesong Hu ◽  
...  
Keyword(s):  
Temporal Evolution ◽  
Brain Regions ◽  
Anterior Insula ◽  
Important Goal ◽  
Bed Nucleus ◽  
Threat Processing ◽  
Fmri Study ◽  
Response Profiles ◽  
Anxious Apprehension ◽  
The Brain

Abstract In the present fMRI study, we examined how anxious apprehension is processed in the human brain. A central goal of the study was to test the prediction that a subset of brain regions would exhibit sustained response profiles during threat periods, including the anterior insula, a region implicated in anxiety disorders. A second important goal was to evaluate the responses in the amygdala and the bed nucleus of the stria terminals, regions that have been suggested to be involved in more transient and sustained threat, respectively. A total of 109 participants performed an experiment in which they encountered “threat” or “safe” trials lasting approximately 16 sec. During the former, they experienced zero to three highly unpleasant electrical stimulations, whereas in the latter, they experienced zero to three benign electrical stimulations (not perceived as unpleasant). The timing of the stimulation during trials was randomized, and as some trials contained no stimulation, stimulation delivery was uncertain. We contrasted responses during threat and safe trials that did not contain electrical stimulation, but only the potential that unpleasant (threat) or benign (safe) stimulation could occur. We employed Bayesian multilevel analysis to contrast responses to threat and safe trials in 85 brain regions implicated in threat processing. Our results revealed that the effect of anxious apprehension is distributed across the brain and that the temporal evolution of the responses is quite varied, including more transient and more sustained profiles, as well as signal increases and decreases with threat.

scholarly journals Dynamic Threat Processing

2019 ◽  
Vol 31 (4) ◽  
pp. 522-542 ◽  
Author(s):  
Christian Meyer ◽  
Srikanth Padmala ◽  
Luiz Pessoa
Keyword(s):  
Skin Conductance ◽  
Real Life ◽  
Brain Regions ◽  
Anterior Insula ◽  
Related Factors ◽  
Bed Nucleus ◽  
Context Sensitive ◽  
Threat Processing ◽  
Skin Conductance Responses ◽  
The Right

During real-life situations, multiple factors interact dynamically to determine threat level. In the current fMRI study involving healthy adult human volunteers, we investigated interactions between proximity, direction (approach vs. retreat), and speed during a dynamic threat-of-shock paradigm. As a measure of threat-evoked physiological arousal, skin conductance responses were recorded during fMRI scanning. Some brain regions tracked individual threat-related factors, and others were also sensitive to combinations of these variables. In particular, signals in the anterior insula tracked the interaction between proximity and direction where approach versus retreat responses were stronger when threat was closer compared with farther. A parallel proximity-by-direction interaction was also observed in physiological skin conductance responses. In the right amygdala, we observed a proximity by direction interaction, but intriguingly in the opposite direction as the anterior insula; retreat versus approach responses were stronger when threat was closer compared with farther. In the right bed nucleus of the stria terminalis, we observed an effect of threat proximity, whereas in the right periaqueductal gray/midbrain we observed an effect of threat direction and a proximity by direction by speed interaction (the latter was detected in exploratory analyses but not in a voxelwise fashion). Together, our study refines our understanding of the brain mechanisms involved during aversive anticipation in the human brain. Importantly, it emphasizes that threat processing should be understood in a manner that is both context-sensitive and dynamic.

scholarly journals Dynamic threat processing

2017 ◽  
Author(s):  
Christian Meyer ◽  
Srikanth Padmala ◽  
Luiz Pessoa
Keyword(s):  
Skin Conductance ◽  
Real Life ◽  
Brain Regions ◽  
Anterior Insula ◽  
Related Factors ◽  
Bed Nucleus ◽  
Threat Processing ◽  
Skin Conductance Responses ◽  
The Right ◽  
Mri Study

AbstractDuring real-life situations, multiple factors interact dynamically to determine threat level. In the current functional MRI study involving healthy adult human volunteers, we investigated interactions between proximity, direction (approach vs. retreat), and speed during a dynamic threat-of-shock paradigm. As a measure of threat-evoked physiological arousal, skin conductance responses were recorded during fMRI scanning. Whereas some brain regions tracked individual threat-related factors, others were also sensitive to combinations of these variables. In particular, signals in the anterior insula tracked the interaction between proximity and direction where approach vs. retreat responses were stronger when threat was closer compared to farther. A parallel proximity-by-direction interaction was also observed in physiological skin conductance responses. In the right amygdala, we observed a proximity by direction interaction, but intriguingly in the opposite direction as the anterior insula; retreat vs. approach responses were stronger when threat was closer compared to farther. In the right bed nucleus of the stria terminalis, we observed an effect of threat proximity, whereas in the right periaqueductal gray/midbrain we observed an effect of threat direction and a proximity by direction by speed interaction (the latter was detected in exploratory analyses but not in a voxelwise fashion). Together, our study refines our understanding of the brain mechanisms involved during aversive anticipation in the human brain. Importantly, it emphasizes that threat processing should be understood in a manner that is both context sensitive and dynamic.

Sensitivity to Faces with Typical and Atypical Part Configurations within Regions of the Face-processing Network: An fMRI Study

2018 ◽  
Vol 30 (7) ◽  
pp. 963-972 ◽  
Author(s):  
Andrew D. Engell ◽  
Na Yeon Kim ◽  
Gregory McCarthy
Keyword(s):  
Face Processing ◽  
Brain Regions ◽  
Domain Specific ◽  
Face Area ◽  
Fmri Study ◽  
The Face ◽  
Occipital Face Area ◽  
Typical Configuration ◽  
The Brain ◽  
Processing Network

Perception of faces has been shown to engage a domain-specific set of brain regions, including the occipital face area (OFA) and the fusiform face area (FFA). It is commonly held that the OFA is responsible for the detection of faces in the environment, whereas the FFA is responsible for processing the identity of the face. However, an alternative model posits that the FFA is responsible for face detection and subsequently recruits the OFA to analyze the face parts in the service of identification. An essential prediction of the former model is that the OFA is not sensitive to the arrangement of internal face parts. In the current fMRI study, we test the sensitivity of the OFA and FFA to the configuration of face parts. Participants were shown faces in which the internal parts were presented in a typical configuration (two eyes above a nose above a mouth) or in an atypical configuration (the locations of individual parts were shuffled within the face outline). Perception of the atypical faces evoked a significantly larger response than typical faces in the OFA and in a wide swath of the surrounding posterior occipitotemporal cortices. Surprisingly, typical faces did not evoke a significantly larger response than atypical faces anywhere in the brain, including the FFA (although some subthreshold differences were observed). We propose that face processing in the FFA results in inhibitory sculpting of activation in the OFA, which accounts for this region's weaker response to typical than to atypical configurations.

scholarly journals Distributed and multifaceted effects of threat and safety

2021 ◽  
Author(s):  
Kelly Morrow ◽  
Dinavahi V P S Murty ◽  
Jongwan Kim ◽  
Songtao Song ◽  
Kesong Hu ◽  
...  
Keyword(s):  
Stria Terminalis ◽  
Functional Magnetic Resonance ◽  
Magnetic Resonance Study ◽  
Bed Nucleus ◽  
Aversive Events ◽  
Fmri Study ◽  
Anticipatory Processing ◽  
Small Set ◽  
The Impact ◽  
The Brain

Sustained anticipation of unpredictable aversive events generates anticipatory processing that is central to anxiety. In the present functional Magnetic Resonance Study (fMRI) study, we examined how sustained threat is processed in the human brain. We used a relatively large sample (N = 109) and employed a Bayesian multilevel analysis approach to contrast threat and safe periods. Our analyses demonstrated that the effect of sustained threat is heterogeneous and distributed across the brain. Thus, the impact of threat is widespread, and not restricted to a small set of putatively emotion-related regions, such as the amygdala and the bed nucleus of the stria terminalis. Both transient and sustained, and increased and decreased responses during threat were observed. Our study reveals that transitioning between threat and safe states, and vice versa, leads to a widespread switch in brain responding that involves most of the brain.

scholarly journals Neural Substrates Underlying Learning-Related Changes of the Unconditioned Fear Response

2013 ◽  
Vol 7 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Kimberly H. Wood ◽  
Dystany Kuykendall ◽  
Lawrence W. Ver Hoef ◽  
David C. Knight
Keyword(s):  
Associative Learning ◽  
Pavlovian Conditioning ◽  
Emotional Response ◽  
Negative Relationship ◽  
Neural Substrates ◽  
Brain Regions ◽  
Anterior Insula ◽  
Fmri Signal ◽  
Posterior Insula ◽  
The Brain

The ability to predict an impending threat during Pavlovian conditioning diminishes the emotional response that is produced once the threat is encountered. Diminution of the threat response appears to be mediated by somewhat independent associative learning and expectancy-related processes. Therefore, the present study was designed to better understand the neural mechanisms that support associative learning processes, independent of expectancy, that influence the emotional response to a threat. Healthy volunteers took part in a Pavlovian conditioning procedure during which trait anxiety, expectation of the unconditioned stimulus (UCS), skin conductance response (SCR), and functional magnetic resonance imaging (fMRI) signal were assessed. The results showed no evidence for associative learning that was independent of expectation. Threat-related SCR expression was diminished on predictable trials vs. unpredictable trials of the UCS (i.e. conditioned UCR diminution). Similar to SCR, conditioned UCR diminution was observed within the left dorsolateral PFC, dorsomedial PFC, ventromedial PFC, and left anterior insula. In contrast, potentiation of the threat-related fMRI signal response was observed within left dorsolateral PFC, inferior parietal lobule (IPL), and posterior insula. A negative relationship was observed between UCS expectancy and UCR expression within the dorsomedial PFC, ventromedial PFC, and anterior insula. Finally, the anticipatory fMRI signal responses within the PFC, posterior cingulate, and amygdala showed an inverse relationship with threat-related activation within the brain regions that showed UCR diminution. The current findings suggest that the PFC and amygdala support learning-related processes that impact the magnitude of the emotional response to a threat.

An fMRI Study on the Differences in the Brain Regions Activated by an Identical Audio-Visual Clip Using Major and Minor Key Arrangements

NeuroImage ◽  
2009 ◽  
Vol 47 ◽  
pp. S186
Author(s):  
J.H. Sohn ◽  
J.M. Lee ◽  
I.H. Kim ◽  
C.K. Lee ◽  
Y.K. Kim ◽  
...  
Keyword(s):  
Brain Regions ◽  
Fmri Study ◽  
The Brain

scholarly journals SAT-605 Characterization of Dual Projection Patterns of Refeeding-Activated Neurons in the Parasubthalamic Nucleus

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Gabor Wittmann ◽  
Nicholas Cosentino ◽  
Ronald M Lechan
Keyword(s):  
Food Intake ◽  
Nucleus Tractus Solitarius ◽  
Brain Regions ◽  
Central Nucleus ◽  
Free Access ◽  
Target Area ◽  
Sprague Dawley ◽  
Bed Nucleus ◽  
Alexa Fluor ◽  
The Brain

Abstract We have observed that following a fast, animals terminate their food intake within 2h after refeeding accompanied by a pattern of neuronal activation as identified by c-fos immunostaining that involves a number of brain regions associated with the regulation of food intake including the nucleus tractus solitarius (NTS), parabrachial nucleus (PBN), central nucleus of the amygdala (CEA), hypothalamic arcuate and paraventricular nuclei, and bed nucleus of the stria terminalis. We also observed striking c-fos activation in the posterior-lateral hypothalamus called the parasubthalamic nucleus or PSTN, raising the possibility that it may also be an important anorectic center in the brain. To establish how the PSTN is integrated into the CNS, we performed dual-label retrograde tract tracing studies to characterize whether refeeding-activated PSTN neurons project to one, or more than one target area in the CNS. Adult, Sprague-Dawley rats received dual stereotaxic injections of Alexa Fluor 488- and Alexa Fluor 555-conjugated cholera toxin β subunit (CTB; 0.1%, 0.5–1 µl volume) into the 1) PBN and NTS, 2) PBN and CEA and 3) NTS and CEA. After 7–12 days, the animals were fasted for 24 h and then given free access to food for 2 h before euthanasia by transcardial perfusion with 4% paraformaldehyde. Brains with successful dual injections were further processed for c-fos immunohistochemistry. The results showed that 26.5±3.8% of PSTN neurons projecting to the PBN also project to the CEA, and 34.6±7.6% of PSTN neurons that project to the CEA also project to the PBN. In addition, 20.2±2.7% of PSTN neurons that project to the PBN also project to the NTS, and 38.1±9.7% of PSTN neurons that project to the NTS also project to the PBN. Furthermore, 35.0±12.5% of PSTN neurons that project to the CEA project to the NTS and 37.1±4.0% of PSTN neurons that project to the NTS project to the CEA. Finally, up to 15% of the neurons with dual projections to the PBN and CEA contained c-fos after refeeding; up to 18% of the neurons with dual projections to the PBN and NTS contained c-fos; and up to 30% of neurons with dual projections to the NTS and CEA contained c-fos. We conclude that a large number of PSTN neurons have more than one projection site within the brain, thus the PSTN appears to have the capability of simultaneously communicating information about appetite to several, major feeding-related sites within the brain, presumably to terminate feeding.

A Parametric Approach to Orthographic Processing in the Brain: An fMRI Study

2000 ◽  
Vol 12 (2) ◽  
pp. 281-297 ◽  
Author(s):  
M. -A. Tagamets ◽  
Jared M. Novick ◽  
Maria L. Chalmers ◽  
Rhonda B. Friedman
Keyword(s):  
Data Analysis ◽  
Healthy Adult ◽  
Brain Activation ◽  
Brain Regions ◽  
Orthographic Processing ◽  
Matching Task ◽  
Parametric Approach ◽  
Fmri Study ◽  
Different Types ◽  
The Brain

Brain activation studies of orthographic stimuli typically start with the premise that different types of orthographic strings (e.g., words, pseudowords) differ from each other in discrete ways, which should be reflected in separate and distinct areas of brain activation. The present study starts from a different premise: Words, pseudowords, letterstrings, and false fonts vary systematically across a continuous dimension of familiarity to English readers. Using a one-back matching task to force encoding of the stimuli, the four types of stimuli were visually presented to healthy adult subjects while fMRI activations were obtained. Data analysis focused on parametric comparisons of fMRI activation sites. We did not find any region that was exclusively activated for real words. Rather, differences among these string types were mainly expressed as graded changes in the balance of activations among the regions. Our results suggests that there is a widespread network of brain regions that form a common network for the processing of all orthographic string types.

scholarly journals Mass spectrometry imaging identifies abnormally elevated brain l-DOPA levels and extrastriatal monoaminergic dysregulation in l-DOPA–induced dyskinesia

2021 ◽  
Vol 7 (2) ◽  
pp. eabe5948
Author(s):  
Elva Fridjonsdottir ◽  
Reza Shariatgorji ◽  
Anna Nilsson ◽  
Theodosia Vallianatou ◽  
Luke R. Odell ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Side Effects ◽  
Mass Spectrometry Imaging ◽  
Brain Regions ◽  
Stria Terminalis ◽  
Brain Areas ◽  
Bed Nucleus ◽  
Neuronal Signaling ◽  
Cortical Areas ◽  
The Brain

l-DOPA treatment for Parkinson’s disease frequently leads to dyskinesias, the pathophysiology of which is poorly understood. We used MALDI-MSI to map the distribution of l-DOPA and monoaminergic pathways in brains of dyskinetic and nondyskinetic primates. We report elevated levels of l-DOPA, and its metabolite 3-O-methyldopa, in all measured brain regions of dyskinetic animals and increases in dopamine and metabolites in all regions analyzed except the striatum. In dyskinesia, dopamine levels correlated well with l-DOPA levels in extrastriatal regions, such as hippocampus, amygdala, bed nucleus of the stria terminalis, and cortical areas, but not in the striatum. Our results demonstrate that l-DOPA–induced dyskinesia is linked to a dysregulation of l-DOPA metabolism throughout the brain. The inability of extrastriatal brain areas to regulate the formation of dopamine during l-DOPA treatment introduces the potential of dopamine or even l-DOPA itself to modulate neuronal signaling widely across the brain, resulting in unwanted side effects.

The Neural Basis of Personal Goal Processing When Envisioning Future Events

2010 ◽  
Vol 22 (8) ◽  
pp. 1701-1713 ◽  
Author(s):  
Arnaud D'Argembeau ◽  
David Stawarczyk ◽  
Steve Majerus ◽  
Fabienne Collette ◽  
Martial Van der Linden ◽  
...  
Keyword(s):  
Brain Regions ◽  
Posterior Cingulate Cortex ◽  
Personal Goals ◽  
Neural Basis ◽  
Event Simulation ◽  
Ventral Medial Prefrontal Cortex ◽  
Fmri Study ◽  
Future Events ◽  
Self Knowledge ◽  
The Brain

Episodic future thinking allows humans to mentally simulate virtually infinite future possibilities, yet this device is fundamentally goal-directed and should not be equated with fantasizing or wishful thinking. The purpose of this fMRI study was to investigate the neural basis of such goal-directed processing during future-event simulation. Participants were scanned while they imagined future events that were related to their personal goals (personal future events) and future events that were plausible but unrelated to their personal goals (nonpersonal future events). Results showed that imaging personal future events elicited stronger activation in ventral medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC) compared to imaging nonpersonal future events. Moreover, these brain activations overlapped with activations elicited by a second task that assessed semantic self-knowledge (i.e., making judgments on one's own personality traits), suggesting that ventral MPFC and PCC mediate self-referential processing across different functional domains. It is suggested that these brain regions may support a collection of processes that evaluate, code, and contextualize the relevance of mental representations with regard to personal goals. The implications of these findings for the understanding of the function instantiated by the default network of the brain are also discussed.

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