Page 16 - Annonce Dergi | İzmir Özel Saint-Joseph Fransız Lisesi

The Smell of Fear

While the importance of chemosensory cues or “alarm anxiety. So it was concluded that by taking in the sweat
substances” in communicating neurobiological of a stressed person triggered a feeling of stress in the
and behavioral changes consistent with increased person smelling it, even without conscious awareness.
arousal and threat-assessment is well-established in

other mammals, the ongoing researches are yet to The other primary finding of the study was the behavioral
discover a solid proof of olfactory processing and and changes of the participants and mostly the changes in
its role in sensing emotions in humans. But a research their visual perception. The researchers wanted to see
conducted by Kirsten J. P. de Groot, M. E. de Vries, how sensitive the participants were to emotional facial
A. F. T. A. de Kluiver came pretty close to explaining expressions after smelling the sweat samples so they
how humans perceive and react in neurological and showed them different pictures of faces, alternating
behavioral ways to chemical signals associated with between positive and negative emotions. They found

the emotional stress of conspecifics. that when exposed to the stress-related chemical
cues the individuals became hyper-fixated to notice
The experiment they ran was designated to test this the negative emotions while being less sensitive to
hypothesis by exposing participants to the sweat of the positive facial expressions. This indicated that the
individuals who had been placed under emotional chemosensory cues influenced not only emotional
stress and studying their brain activity. The first step in processing in the brain but also how individuals
the experiment involved obtaining human sweat stimuli perceive and react to social cues.
and inducing stress. So, to achieve this they divided
the participants into two groups and they The research underlines the importance of

collected axillary samples from participants in a chemosensory communication in human interactions.
stressful environment who had taken skydiving for Even in the absence of conscious awareness,
the first time, and a control group who had run on a chemical signals related to stress can shape emotional
treadmill for the same amount of time. After collecting experiences and social behaviors. This finding suggests
the sweat of a total number of 144 participants which that the olfactory system—traditionally considered
they confirmed that half of the participants’ sweats less prominent in human sensory processing—plays a
showed an increase in cortisol levels to make sure that crucial role in emotional and social exchanges.

the skydiving was successful in inducing stress, they
exposed the samples to a new group of individuals- Damla Töre
referred to as “receivers” in the study- and have them
sniff the two different sweat samples while looking at
their brain activity in a fMRI.

The results of the fMRI scans revealed that exposure
to the chemosensory cues from the sweat of stressed
individuals led to significant activation of the amygdala

in the participants. The amygdala is a key structure in
the brain, involved in processing emotions like fear and

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