When you work based on fear, you create adrenaline from the fight or flight response.

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"It's highly tied to the fight or flight response, " says George Preti, a faculty member at Monell Center.

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The so-called fight or flight response.

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Humans have a lot of reflexes that help keep us alive, part of the "fight or flight" response that arises when we're confronted with danger.

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Lee and Yun theorize that anti-inflammatory drugs counteract the body's self-destructive response to heart failure by decreasing the body's fight-or-flight response.

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As the oldest part of the brain, the amygdala prioritizes survival and regulates the fight-or-flight response.

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That same fight-or-flight response that prevented us from being eaten by tigers also warns us when our mental selves are in danger.

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They activate the fight-or-flight response.

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When we hold our breath, the brain is momentarily oxygen deprived and hits the flight or fight response, fueling a more emotional reaction to the words shooting out of our fingers.

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But the AbioCor lacks a response to "fight or flight, " a hormonal mechanism triggered by the brain.

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