uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Genetic influence on brain function supporting imminent and social threat
Show others and affiliations
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Evolution has selected for brain circuits regulating appropriate defensive responses to different types of threats. Two kinds of threats of interest to human evolution are social threat and imminent, or proximal threat. We estimated the heritability of activation of neural circuits supporting these two types of threat using functional magnetic resonance imaging (fMRI) in 294 identical and fraternal twins. Imminent threat activated brain areas associated with early visual processing, including the lateral geniculate nucleus, as well as the amygdala and a fronto-parietal network. We observed medium to strong heritability in the occipital lobe (with strongest heritability in area V1) (h2 = 42-63%), fusiform cortex (h2 = 51%) and the lingual gyri (h2 = 49%). Social threat activated the lateral occipital lobe, fusiform gyri and amygdala with strong heritability in the occipital (h2 = 51-58%) and fusiform gyri (h2 = 54%). Activations to imminent social threat was greater than activation to non-social imminent threat in the middle occipital gyrus and superior occipital gyrus with heritability estimates ranging between 27-42% in this region. We conclude that activity in the human brain associated with imminent and social threat is heritable, supporting the view that the brain function expressed by these defensive systems have been subject to substantial evolutionary selection.

Keywords [en]
Emotion, SCR, innate fear, twins, evolution, face, personal space
National Category
Psychology
Identifiers
URN: urn:nbn:se:uu:diva-395763OAI: oai:DiVA.org:uu-395763DiVA, id: diva2:1365197
Available from: 2019-10-23 Created: 2019-10-23 Last updated: 2019-10-24
In thesis
1. Innate and Conditioned Fear: Investigating Responses to Threat using Psychophysiology, Functional Magnetic Resonance Imaging, and Twin Methodology
Open this publication in new window or tab >>Innate and Conditioned Fear: Investigating Responses to Threat using Psychophysiology, Functional Magnetic Resonance Imaging, and Twin Methodology
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Evolution has shaped systems in the human brain to respond to danger. Some of these systems are innate or hard-wired, while others are learned throughout the entire life span. One commonly studied type of learned threat, conditioned fear, is acquired from experiencing aversive consequences. When considering innate threat, processing imminent and social threat may be especially relevant for understanding the neural circuitry of human fear. Imminent fear refers to experiencing proximal encounters whereas social fear refers to exposure to an unknown conspecific. Investigating whether different brain systems process innate and conditioned threat could provide us with knowledge on how defensive systems interact and inform on development and treatment of fear-related disorders. The first aim of this thesis was to investigate whether different brain systems process innate and conditioned threat. The second aim was to investigate if neural functions supporting imminent and social threat are heritable. In Study I, skin conductance responses (SCR) to social, imminent and conditioned threat displayed in immersive virtual-reality were compared. The results showed that social threat modulated imminent threat, but neither imminent nor social threat modulated conditioned threat, indicating that distinct processes regulate imminent and social threat on one end and conditioned threat on the other. Study II compared SCR to imminent and conditioned threat displayed either in an immersive virtual-reality head-mounted display or a regular computer monitor. The findings indicated that displaying stimuli in an immersive virtual-reality head-mounted display enhanced imminent threat responses as compared to displaying them on a regular computer monitor, suggesting a modulation of SCR by display type. Conditioned SCR was similar across displays. The conclusion of the study was that imminent threat and conditioned threat are different processes as it was possible to modulate one without affecting the other. Study III was a twin study comparing the genetic influence on neural responses to imminent and social threat using functional magnetic resonance imaging (fMRI) and SCR. The results demonstrated strong genetic influence on responses in the lateral occipital cortex and the fusiform cortex to social threat whereas genetic influence on imminent threat was strong in early visual areas and occipito-parietal areas. In summary, innate and conditioned fear may depend on separate processes in the brain. Innate threat activates early visual areas, indicating a role for these areas in threat processing. Genetic influences on fMRI responses to social and imminent threat suggests that separate pathways may have evolved to process these threats.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2019. p. 67
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Social Sciences, ISSN 1652-9030 ; 174
Keywords
Emotion, Imminent threat, Social threat, Twins, Face, Personal space, fMRI, Virtual reality, Amygdala.
National Category
Psychology
Research subject
Psychology
Identifiers
urn:nbn:se:uu:diva-395864 (URN)978-91-513-0804-3 (ISBN)
Public defence
2019-12-12, Betty Pettersson, Blåsenhus, von Kraemers Allé 1A, Uppsala, 10:15 (English)
Opponent
Supervisors
Available from: 2019-11-20 Created: 2019-10-24 Last updated: 2019-11-20

Open Access in DiVA

No full text in DiVA

Psychology

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 18 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf