New research suggests that our response to stress may at times be overexaggerated because of the evolutionary development of the brain linking emotional responses to perceptions of stress.
As a result, mildly stressful situations can affect our perceptions in the same way as life-threatening ones.
In the study, researchers studied the effects of money loss — a stressful event for most everyone. Money loss, real or perceived, can cause significant outcomes as financial loss can lead to irrational behavior.
Researchers determined that the stress inflicted by a financial loss can alter our sense of reality, interfering with a true grasp of the situation.
The findings, found in the Journal of Neuroscience, may also have implications for our understanding of the neurological mechanisms underlying post-traumatic stress disorder.
In the study, researchers trained subjects using a classical conditioning method on situations involving money.
Subjects were asked to listen to a series of tones composed of three different notes. After hearing one note, they were told they had earned a certain sum; after a second note, they were informed that they had lost some of their money; and a third note was followed by the message that their bankroll would remain the same.
Researchers discovered subjects improved their ability to distinguish the musical notes when a note was tied to a gain, or at least to no loss. But when they heard the “lose money” note, they actually got worse at telling one note from the other.
As part of the study, researchers used functional MRI (fMRI) scans to observe brain areas involved in the learning task. Investigators discovered the amygdala, an area of the brain known to be associated with emotions, was strongly involved during the learning process.
Researchers also noted activity in another area in the front of the brain, which functions to moderate or lessen the emotional response. Subjects who exhibited stronger activity in this area showed less of a drop in their abilities to distinguish between tones.
Neuroscientist and chief investigator Rony Paz, Ph.D., said the research demonstrates the evolutionary aspects of the brain in response to stress.
Our brain has been trained to blur certain inputs – if the best response to the growl of a lion is to run quickly, it would be counterproductive to distinguish between different pitches of growl. Any similar sound should make us flee without thinking, Paz said.
“Unfortunately, that same blurring mechanism can be activated today in stress-inducing situations that are not life-threatening – like losing money – and this can harm us.”
An overreaction to stress may be quite serious. For instance, it may be involved in post-traumatic stress disorder. If sufferers are unable to distinguish between a stimulus that should cause a panic response and similar, but non-threatening, stimuli, they may experience strong emotional reactions in inappropriate situations.
This perceptional blurring may even expand over time to encompass a larger range of stimuli detrimentally expanding the stress response.
According to Paz, future research in planned to investigate this possibility in future research.
Source: Weizmann Institute