Reduced neural activation during an inhibition task is associated with impaired fear inhibition in a traumatized civilian sample.
Cortex
; 49(7): 1884-91, 2013.
Article
em En
| MEDLINE
| ID: mdl-23020899
ABSTRACT
INTRODUCTION:
Impaired inhibition of fear in the presence of safety cues and a deficiency in the extinction of fear cues are increasingly thought to be important biological markers of Posttraumatic stress disorder (PTSD). Other studies have suggested that there may be altered neural activation during behavioral inhibition tasks in subjects with PTSD. The current study aimed to see whether neural activation during inhibition was reduced in a highly traumatized civilian population, and whether atypical activation was associated with impaired fear inhibition.METHODS:
The participants were 41 traumatized women (20 PTSD+, 21 PTSD-) recruited from Grady Memorial Hospital in Atlanta, GA. We used a Go/NoGo procedure with functional magnetic resonance imaging (fMRI) in a high-resolution 3T scanner. Participants were instructed to press a button whenever an "X" or "O" appeared on the screen, but not if a red square appeared behind the letter. Participants were assessed for trauma history and PTSD diagnosis, and completed a fear-potentiated startle and extinction paradigm.RESULTS:
We found stronger activation in the ventromedial prefrontal cortex (vmPFC) in traumatized subjects without PTSD compared to those with PTSD in the NoGo greater than Go contrast condition. Activation in the vmPFC was negatively correlated with fear-potentiated startle responses during safety signal learning (p = .02) and fear extinction (p = .0002).CONCLUSIONS:
These results contribute to understanding of how the neural circuitry involved in inhibitory processes may be deficient in PTSD. Furthermore, the same circuits involved in behavioral inhibition appear to be involved in fear inhibition processes during differential fear conditioning and extinction.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Desempenho Psicomotor
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Transtornos de Estresse Pós-Traumáticos
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Medo
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Inibição Psicológica
Tipo de estudo:
Risk_factors_studies
Limite:
Adult
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Female
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Humans
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Middle aged
Idioma:
En
Revista:
Cortex
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Estados Unidos