Traces of fear in the neural web — Magnetoencephalographic responding to arousing pictorial stimuli

Rockstroh, Brigitte; Elbert, Thomas

doi:10.1016/j.ijpsycho.2010.01.012

Cited by 20 publications

(27 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reported findings are consistent with the idea that severe trauma leads to immediate, enduring changes in brain function and to the genesis of a trauma network [2], [7]. Such a trauma network may function as a rapid threat detection mechanism, which triggers a defensive reaction, although conscious stimulus appraisal might not have yet occurred [57].…”

Section: Discussionsupporting

confidence: 86%

“…Due to spreading activation between nodes, excitement of a single element is sufficient to activate the whole network and to initiate a fear reaction. With repeated exposure to stressful experiences, elements are added and connections between different nodes are established or strengthened by ways of Hebbian learning, so that the activation threshold of the fear structure is lowered [6], [7]. As a result, fear-related stimuli may readily excite the fear network, which, in turn, can trigger a fear response and interrupt on-going cognitive mechanisms [8].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Early Affective Processing in Patients with Acute Posttraumatic Stress Disorder: Magnetoencephalographic Correlates

et al. 2013

View full text Add to dashboard Cite

BackgroundIn chronic PTSD, a preattentive neural alarm system responds rapidly to emotional information, leading to increased prefrontal cortex (PFC) activation at early processing stages (<100 ms). Enhanced PFC responses are followed by a reduction in occipito-temporal activity during later processing stages. However, it remains unknown if this neuronal pattern is a result of a long lasting mental disorder or if it represents changes in brain function as direct consequences of severe trauma.MethodologyThe present study investigates early fear network activity in acutely traumatized patients with PTSD. It focuses on the question whether dysfunctions previously observed in chronic PTSD patients are already present shortly after trauma exposure. We recorded neuromagnetic activity towards emotional pictures in seven acutely traumatized PTSD patients between one and seven weeks after trauma exposure and compared brain responses to a balanced healthy control sample. Inverse modelling served for mapping sources of differential activation in the brain.Principal FindingsCompared to the control group, acutely traumatized PTSD patients showed an enhanced PFC response to high-arousing pictures between 60 to 80 ms. This rapid prefrontal hypervigilance towards arousing pictorial stimuli was sustained during 120–300 ms, where it was accompanied by a reduced affective modulation of occipito-temporal neural processing.ConclusionsOur findings indicate that the hypervigilance-avoidance pattern seen in chronic PTSD is not necessarily a product of an endured mental disorder, but arises as an almost immediate result of severe traumatisation. Thus, traumatic experiences can influence emotion processing strongly, leading to long-lasting changes in trauma network activation and expediting a chronic manifestation of maladaptive cognitive and behavioral symptoms.

show abstract

Section: Discussionsupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Early Affective Processing in Patients with Acute Posttraumatic Stress Disorder: Magnetoencephalographic Correlates

et al. 2013

View full text Add to dashboard Cite

show abstract

“…These results bear some similarity to reaction times shown to change as a function of PTSD with evidence reaction time to a neutral word is faster if it follows a threat in PTSD patients (Amir et al, 2009) and neural activity in PTSD patients is faster to threat stimuli with reactions becoming faster the more severe the trauma (Rockstroh & Elbert, 2010). This is not unequivocal however, because there is also evidence of longer reaction times and longer evoked-response potentials as a result of PTSD (Hennig-Fast et al, 2009).…”

Section: Discussionsupporting

confidence: 58%

Predictors of susceptibility and resilience in an animal model of posttraumatic stress disorder.

Smith-Bell

Burhans

Schreurs

2012

Behavioral Neuroscience

View full text Add to dashboard Cite

Animal models of post traumatic stress disorder (PTSD) are based on fear conditioning where innocuous cues elicit reactions that originally occur to traumatic events – a core feature of PTSD. Another core feature is hyperarousal – exaggerated reactions to stressful events. One limitation of animal models of PTSD is that group effects do not model the sporadic incidence of PTSD. We developed an animal model of PTSD in which rabbit nictitating membrane responses become exaggerated as a function of classical conditioning to a tone conditioned stimulus (CS) paired with a shock unconditioned stimulus (US). Exaggerated responses to the US are a form of hyperarousal termed conditioning-specific reflex modification (CRM) and occur in the absence of the CS. Inspecting data across several experiments, we determined 25% of our rabbits exhibit strong CRM despite all subjects having high levels of conditioning. To determine how prone rabbits were to CRM (susceptibility) or how resistant (resilience), we examined data from 135 rabbits analyzing for factors during CS-US pairings and during US prescreening that would predict CRM. We found the magnitude of CRM was correlated with the onset latency and area of conditioned responding during CS-US pairings and with the peak latency of a response during US pretesting. In an animal model of PTSD that more accurately reflects clinical prevalence, we can begin to predict susceptibility not only during responding to a stressful conditioning situation but also during a screening process before the stressful situation takes place. The results suggest relatively innocuous testing may help detect PTSD after trauma and screen for it before trauma occurs.

show abstract

“…Other studies used MEG recordings to explore the neurophysiological basis of the “trauma network” in PTSD. Elbert and colleagues found that in these patients, processing of arousing stimuli (e.g., IAPS pictures) relied more on a fast sensory processing pathway, which is uncoupled from prefrontal control, and less on elaborate processing along the ventral visual stream (Rockstroh and Elbert, 2010). This may be due to a reduced connectivity with neural assemblies representing context-related (“cold”) and trauma-related (“hot”) information; as a result, trauma victims are unable to locate their trauma memories in time and space and experience them as flashbacks (Elbert and Schauer, 2002).…”

Section: Introductionmentioning

confidence: 99%

Natural Memory Beyond the Storage Model: Repression, Trauma, and the Construction of a Personal Past

Axmacher¹,

Lam²,

Kessler³

et al. 2010

Front. Hum. Neurosci.

View full text Add to dashboard Cite

Naturally occurring memory processes show features which are difficult to investigate by conventional cognitive neuroscience paradigms. Distortions of memory for problematic contents are described both by psychoanalysis (internal conflicts) and research on post-traumatic stress disorder (PTSD; external traumata). Typically, declarative memory for these contents is impaired – possibly due to repression in the case of internal conflicts or due to dissociation in the case of external traumata – but they continue to exert an unconscious pathological influence: neurotic symptoms or psychosomatic disorders after repression or flashbacks and intrusions in PTSD after dissociation. Several experimental paradigms aim at investigating repression in healthy control subjects. We argue that these paradigms do not adequately operationalize the clinical process of repression, because they rely on an intentional inhibition of random stimuli (suppression). Furthermore, these paradigms ignore that memory distortions due to repression or dissociation are most accurately characterized by a lack of self-referential processing, resulting in an impaired integration of these contents into the self. This aspect of repression and dissociation cannot be captured by the concept of memory as a storage device which is usually employed in the cognitive neurosciences. It can only be assessed within the framework of a constructivist memory concept, according to which successful memory involves a reconstruction of experiences such that they fit into a representation of the self. We suggest several experimental paradigms that allow for the investigation of the neural correlates of repressed memories and trauma-induced memory distortions based on a constructivist memory concept.

show abstract

Traces of fear in the neural web — Magnetoencephalographic responding to arousing pictorial stimuli

Cited by 20 publications

References 49 publications

Early Affective Processing in Patients with Acute Posttraumatic Stress Disorder: Magnetoencephalographic Correlates

Early Affective Processing in Patients with Acute Posttraumatic Stress Disorder: Magnetoencephalographic Correlates

Predictors of susceptibility and resilience in an animal model of posttraumatic stress disorder.

Natural Memory Beyond the Storage Model: Repression, Trauma, and the Construction of a Personal Past

Contact Info

Product

Resources

About