Salience and central executive networks track overgeneralization of conditioned-fear in post-traumatic stress disorder.
Psychol Med
; 51(15): 2610-2619, 2021 11.
Article
em En
| MEDLINE
| ID: mdl-32366335
ABSTRACT
BACKGROUND:
Generalization of conditioned-fear, a core feature of post-traumatic stress disorder (PTSD), has been the focus of several recent neuroimaging studies. A striking outcome of these studies is the frequency with which neural correlates of generalization fall within hubs of well-established functional networks including salience (SN), central executive (CEN), and default networks (DN). Neural substrates of generalization found to date may thus reflect traces of large-scale brain networks that form more expansive neural representations of generalization. The present study includes the first network-based analysis of generalization and PTSD-related abnormalities therein.METHODS:
fMRI responses in established intrinsic connectivity networks (ICNs) representing SN, CEN, and DN were assessed during a generalized conditioned-fear task in male combat veterans (N = 58) with wide-ranging PTSD symptom severity. The task included five rings of graded size. Extreme sizes served as conditioned danger-cues (CS+ paired with shock) and safety-cues (CS-), and the three intermediate sizes served as generalization stimuli (GSs) forming a continuum-of-size between CS+ and CS-. Generalization-gradients were assessed as behavioral and ICN response slopes from CS+, through GSs, to CS-. Increasing PTSD symptomatology was predicted to relate to less-steep slopes indicative of stronger generalization.RESULTS:
SN, CEN, and DN responses fell along generalization-gradients with levels of generalization within and between SN and CEN scaling with PTSD symptom severity.CONCLUSIONS:
Neural substrates of generalized conditioned-fear include large-scale networks that adhere to the functional organization of the brain. Current findings implicate levels of generalization in SN and CEN as promising neural markers of PTSD.Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Transtornos de Estresse Pós-Traumáticos
/
Medo
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Rede Nervosa
Tipo de estudo:
Prognostic_studies
Limite:
Humans
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Male
País como assunto:
America do norte
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article