Receiving a reward at an unpredictable time interval creates a stronger stress response than when it is received predictably
The fact that a lack of predictability as to when a stressor will occur has been shown to increase chronic stress is shown in an elegant, subtle study. A rat is going about its business in its cage, and at measured intervals the experimenter delivers a piece of food down a chute into the cage; rat eats happily. This is called an intermittent reinforcement schedule. Now, change the pattern of food delivery so that the rat gets exactly the same total amount of food over the course of an hour, but at a random rate. The rat receives just as much reward, but less predictably, and up go glucocorticoid levels. There is not a single physically stressful thing going on in the rat’s world. It’s not hungry, pained, running for its life—nothing is out of allostatic balance. In the absence of any stressor, loss of predictability triggers a stress-response.
References
- Sapolsky, Robert. (2004). Why Zebras Don’t Get Ulcers 13. Why Is Psychological Stress Stressful? (p. 364). New York, NY: Henry Holt and Company.
Metadata
Type:🔴 Tags: Biology / Neuroscience / Psychology / Neuropsychology Status:☀️