Genetic influence on brain function supporting imminent and social threat

• 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.

Subject headings

SAMHÄLLSVETENSKAP  -- Psykologi (hsv//swe)

SOCIAL SCIENCES  -- Psychology (hsv//eng)

Keyword

Emotion

SCR

innate fear

twins

evolution

face

personal space

Publication and Content Type

vet (subject category)

ovr (subject category)