In a nutshell: An alternative pathway carries detailed visual information about threats.

View Paper Abstract

Responding promptly to imminent danger is crucial to our survival. An almond-shaped bundle of brain cells called the amygdala coordinates these fear and emotional responses.

However, it’s not completely clear how quickly the amygdala receives information about the threats that we see, and whether or not it initially receives a coarse picture that’s only refined later.

Brain Function CoE PhD scholar Jessica McFadyen and colleagues at the Queensland Brain Instituteand Grenoble Alps University in France found evidence of a shortcut that allows detailed visual information to reach the amygdala quickly and efficiently.

The team used a mathematical method called dynamic causal modelling, which provides information about the direction in which information travels between different parts of the brain. Their findings add to existing anatomical evidence of this alternative pathway.

The experiments also show that the shortcut can send information about the threat in much more detail than previously thought. Detail is important, because knowing if the person who just jumped out in front of you is your best friend or the world’s most wanted serial killer is essential for determining how to respond.

Next steps:
The team is currently analysing brain images of over 600 people to investigate how the thickness of this pathway, which is determined by the number of brain cell connections within it, relates to fear and anxiety responses. In addition, the team plans to find out whether subliminal signals of threat – especially unexpected threat – also take this shortcut to the amygdala.

McFadyen, J., Mermillod, M., Mattingley, J. B., Halasz, V., & Garrido, M. I. (2017). A rapid subcortical amygdala route for faces irrespective of spatial frequency and emotion. Journal of Neuroscience, 37(14), 3864-3874.

Republish this article:

We believe in sharing knowledge. We use a Creative Commons Attribution 4.0 International License, which allows unrestricted use of this content, subject only to appropriate attribution. So please use this article as is, or edit it to fit your purposes. Referrals, mentions and links are appreciated.