New research looks at the timing of ‘gut feelings’ and how humans assess ‘face value’. 

Past research has shown that the amygdala - a small almond-shaped structure in the brain - responds to emotions and threats, but it has been unclear how fast this response arises.

A new study from the University of Queensland has investigated how quickly people can process and become aware of emotions.

“We know the amygdala responds to emotions but what we weren’t sure how rapidly its action kicks in,” lead author Dr Alan Pegna says.

“To determine the speed of processing we examined the electrical brain response for fearful expressions in people who had had parts of their amygdala removed to alleviate epileptic seizures, as well as healthy individuals with their amygdala intact.”

The study found that the amygdala was receiving information about facial expressions within two tenths of a second, producing an early brain response to images of emotive faces.

But while the amygdala receives and processes that information within two tenths of a second, awareness takes longer.

“We are processing emotions without any awareness and really rapidly, but awareness is taking place slightly later on – it takes around three tenths of a second for us to become aware of what we see,” Dr Pegna said.

“These findings, along with other observations in the literature, show that parts of the brain process emotionally important stimuli very rapidly, and without any awareness by higher-tier brain areas.”

The research team plans to expand its investigation into other responses. 

“We would like to explore whether this effect is observed for other types of threatening stimuli, such as body postures, looming stimuli, etc, and whether it has any repercussions on day-to-day behaviour,” Dr Pegna said.

The study is accessible here.