Dissociable neural systems for unconditioned acute and sustained fear

Loading...
Thumbnail Image

Access rights

openAccess
publishedVersion

URL

Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2020-08-01

Major/Subject

Mcode

Degree programme

Language

en

Pages

11

Series

NeuroImage, Volume 216

Abstract

Fear protects organisms by increasing vigilance and preparedness, and by coordinating survival responses during life-threatening encounters. The fear circuit must thus operate on multiple timescales ranging from preparatory sustained alertness to acute fight-or-flight responses. Here we studied the brain basis of sustained and acute fear using naturalistic functional magnetic resonance imaging (fMRI) enabling analysis of different time-scales of fear responses. Subjects (N ​= ​37) watched feature-length horror movies while their hemodynamic brain activity was measured with fMRI. Time-variable intersubject correlation (ISC) was used to quantify the reliability of brain activity across participants, and seed-based phase synchronization was used for characterizing dynamic connectivity. Subjective ratings of fear were used to assess how synchronization and functional connectivity varied with emotional intensity. These data suggest that acute and sustained fear are supported by distinct neural pathways, with sustained fear amplifying mainly sensory responses, and acute fear increasing activity in brainstem, thalamus, amygdala and cingulate cortices. Sustained fear increased ISC in regions associated with acute fear, and also amplified functional connectivity within this network. The results were replicated in an independent experiment with a different subject sample and stimulus movie. The functional interplay between cortical networks involved in sustained anticipation of, and acute response to, threat involves a complex and dynamic interaction that depends on the proximity of threat, and the need to employ threat appraisals and vigilance for decision making and response selection.

Description

Keywords

Fear, Horror movies, Naturalistic fMRI, Neural synchronization, Threat

Other note

Citation

Hudson, M, Seppälä, K, Putkinen, V, Sun, L, Glerean, E, Karjalainen, T, Karlsson, H K, Hirvonen, J & Nummenmaa, L 2020, ' Dissociable neural systems for unconditioned acute and sustained fear ', NeuroImage, vol. 216, 116522 . https://doi.org/10.1016/j.neuroimage.2020.116522