The Tortured Brain
Imaging Neural Representations of Traumatic Stress Experiences Using RSVP With Affective Pictorial Stimuli
Abstract
Traumatic stressors such as water boarding, electric shock, or false execution all activate similar bodily, affective, and cognitive responses even when they are quite different from one another. As a result, the memory traces merge into a “trauma network” that includes sensory memories but becomes detached from the particular episodic memory; that is, the trauma network has no time or place. As, with increasing traumatic experiences, more and more cues become integrated in the network, the threshold for excitation is continually lowered and the individual is likely to show frequent alarm and other defense responses to reminders of the trauma. Neuroplastic mechanisms determine subsequent reorganization of brain circuitry in order to adapt to a presumed permanent need for defense.
We hypothesized that aversive pictorial material is differentially processed in visual as well as frontal and limbic areas of the traumatized brain. We used Rapid Serial Visual Presentation (three pictures per second) to present aversive, neutral, and appetitive pictorial stimuli. Event-related magnetic fields were recorded in 41 survivors of torture and organized violence who suffered from posttraumatic stress disorder (PTSD) as well as 43 controls with a comparable ethnic background. Traumatized individuals showed an early shift in the processing of aversive pictures from sensory visual areas to fronto-temporal areas and the amygdala compared to controls without trauma-related symptoms. For survivors, as opposed to controls, these stimuli automatically activate aspects of the defense cascade and thus lead to an excitation of action-related neural activity. We conclude that an enlarged fear network in survivors of organized violence has a low excitation threshold, thus leading to prominent PTSD symptoms. A disintegration of the fear network by reconnecting its elements to the respective episodic memory or by some form of inhibition of the network may bring relief.
References
(2011). Narrative Exposure Therapy for PTSD increases activity in cortical regions associated with top-down processing of aversive stimuli – evidence from a randomized controlled treatment trial. Manuscript submitted for publication.
(2010). Early processing of threat cues in posttraumatic stress disorder – evidence for a cortical vigilance-avoidance reaction. Biological Psychiatry, 68, 451–458.
(1994). Measuring emotion: The Self-Assessment Manikin and the semantic differential. Journal of Behavior Therapy & Experimental Psychiatry, 25, 49–59.
(2009). Pattern of cortical activation during processing of aversive stimuli in traumatized survivors of war and torture. European Archives of Psychiatry and Clinical Neuroscience, 259, 340–351.
(2004). Plasticity in single neuron and circuit computations. Nature, 431, 789–795.
(2011). Structural alterations in lateral prefrontal, parietal and posterior midline regions of men with chronic posttraumatic stress disorder. Journal of Psychiatry and Neuroscience, 36, 176–187.
(2004). Reorganization of human cerebral cortex: The range of changes following use and injury. The Neuroscientist, 10, 129–141.
(2006). The influence of organized violence and terror on brain and mind – a co-constructive perspective. In , Lifespan development and the brain. The perspective of biocultural co-constructivism (pp. 326–349). New York: Cambridge University Press.
(2010). Fascination violence – on mind and brain of man hunters. European Archives of Psychiatry and Clinical Neuroscience, 260, S100–S105.
(1997). The validation of a self-report measure of posttraumatic stress disorder: The Posttraumatic Diagnostic Scale. Psychological Assessment, 9, 445–451.
(1994). Interpreting magnetic fields of the brain: Minimum norm estimates. Medical & Biological Engineering & Computing, 32, 35–42.
(2011). The trauma of torture and the rehabilitation of torture survivors. Zeitschrift für Psychologie / Journal of Psychology, 219, 133–142.
(2011). Dehumanized perception: A psychological means to facilitate atrocities, torture, and genocide?. Zeitschrift für Psychologie / Journal of Psychology, 219, 175–181.
(2002). Comparison of data transformation procedures to enhance topographical accuracy in time-series analysis of the human EEG. Journal of Neuroscience Methods, 113, 111–122.
(2011). Treatment of victims of war and torture: A randomized controlled comparison of Narrative Exposure Therapy and Stress Inoculation Training. Psychotherapy and Psychosomatics, 80, 345–352.
(2001). Fleeting images: A new look at early emotion discrimination. Psychophysiology, 38, 175–178.
(2000). Statistical control of artifacts in dense array EEG/MEG studies. Psychophysiology, 7, 523–532.
(2006). Fleeting images: Rapid affect discrimination in visual cortex. Neuroreport, 17, 225–229.
(2007). Structural and functional neuroplasticity in relation to traumatic stress. Current Directions in Psychological Science, 16, 326–329.
(2010). Spontaneous remission from PTSD depends on the number of traumatic event types experienced. Psychological Trauma: Theory, Research, Practice, and Policy, 2, 169–174.
(1999). International affective picture system (IAPS): Instruction manual and affective ratings. Technical Report A-4. Gainesville, FL: The Center for Research in Psychophysiology, University of Florida.
(1980). Behavioral treatment and bio-behavioral assessment: Computer applications. In , Technology in mental health care delivery systems (pp. 119–137). Norwood, NJ: Ablex Publishing.
(2010). Adverse experiences in childhood influence brain responses to emotional stimuli in adult psychiatric patients. International Journal of Psychophysiology, 75, 277–286.
(2010). Can asylum seekers with posttraumatic stress disorder be successfully treated? A randomized controlled pilot study. Cognitive Behaviour Therapy, 39, 81–91.
(2004). Psychological trauma and evidence for enhanced vulnerability for PTSD through previous trauma in West Nile refugees. BMC Psychiatry, 4, 34.
(2011). On the imposition of torture, an extreme stressor state, to extract information from memory: A baleful consequence of folk cognitive neurobiology. Zeitschrift für Psychologie / Journal of Psychology, 219, 159–166.
(2010). Emotion processing and the amygdala: From a ‘low road’ to ‘many roads’ of evaluating biological significance. Nature Reviews Neuroscience, 11, 773–782.
(2008). Emotion processing in the visual brain: A MEG analysis. Brain Topography, 20, 205–215.
(2009). Parallel processing of affective visual stimuli. Psychophysiology, 46, 200–208.
(2011). Are the APA’s detainee interrogation policies ethical and effective? Key claims, documents, and results. Zeitschrift für Psychologie / Journal of Psychology, 219, 150–158.
(2011). Screening for torture: A narrative checklist comparing legal definitions in a torture treatment clinic. Zeitschrift für Psychologie / Journal of Psychology, 219, 143–149.
(2007). The ghosts of past and future. Nature, 445, 27.
(2010). Dissociation following traumatic stress: Etiology and treatment. Zeitschrift für Psychologie / Journal of Psychology, 218, 109–127.
(2006). Wiedererfahrung durch Psychotherapie modifiziert Geist und Gehirn
[Imaginary reliving in psychotherapy modifies mind and brain] . Verhaltenstherapie, 16, 96–103.(2009). Narrative Exposure Therapy versus Interpersonal Psychotherapy: A pilot randomized controlled trial with Rwandan genocide orphans. Psychotherapy and Psychosomatics, 78, 298–306.
(2011). Narrative Exposure Therapy (2nd ed.). Göttingen, Germany: Hogrefe.
(1998). The Mini-International Neuropsychiatric Interview (M.I.N.I.): The development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. Journal of Clinical Psychiatry, 59 (Suppl. 20), 22–33; quiz 34–57.
(2011). Rapid and highly resolving: Affective evaluation of olfactory conditioned faces. Journal of Cognitive Neuroscience. Advance online publication. doi: 10.1162/jocn_a_00067.
