Stress can increase mental alertness

Psychoneuroendocrinology 33 , — Elzinga, B. Stress-induced cortisol elevations are associated with impaired delayed, but not immediate recall. Psychiatry Res. Andreano, J. Glucocorticoid release and memory consolidation in men and women. Rasch, B. A genetic variation of the noradrenergic system is related to differential amygdala activation during encoding of emotional memories.

Vukojevic, V. Epigenetic modification of the glucocorticoid receptor gene is linked to traumatic memory and post-traumatic stress disorder risk in genocide survivors.

Prenatal stress changes learning strategies in adulthood. Hippocampus 22 , — McIntyre, C. Amygdala norepinephrine levels after training predict inhibitory avoidance retention performance in rats. Buchanan, T. Enhanced memory for emotional material following stress-level cortisol treatment in humans. Psychoneuroendocrinology 26 , — Cahill, L.

Nature , — Hermans, E. Dynamic adaptation of large-scale brain networks in response to acute stressors. Trends Neurosci. Stress-related noradrenergic activity prompts large-scale neural network reconfiguration. Science , — Strelzyk, F. Tune it down to live it up? Rapid, nongenomic effects of cortisol on the human brain. Henckens, M. Stressed memories: how acute stress affects memory formation in humans.

Weymar, M. Stress sensitizes the brain: increased processing of unpleasant pictures after exposure to acute stress. Strange, B. Interacting noradrenergic and corticosteroid systems shift human brain activation patterns during encoding. Acute cortisone administration impairs retrieval of long-term declarative memory in humans.

Wiegert, O. Timing is essential for rapid effects of corticosterone on synaptic potentiation in the mouse hippocampus. Dynamically changing effects of corticosteroids on human hippocampal and prefrontal processing. Brain Mapp. Time-dependent effects of corticosteroids on human amygdala processing. Enhanced resting-state connectivity of amygdala in the immediate aftermath of acute psychological stress.

Neuroimage 53 , — Epinephrine enhancement of human memory consolidation: Interaction with arousal at encoding. Enhanced human memory consolidation with post-learning stress: Interaction with the degree of arousal at encoding. Beckner, V. Stress facilitates consolidation of verbal memory for a film but does not affect retrieval.

Roozendaal, B. Amygdaloid nuclei lesions differentially affect glucocorticoid-induced memory enhancement in an inhibitory avoidance task.

Glucocorticoids interact with emotion-induced noradrenergic activation in influencing different memory functions. Neuroscience , — Glucocorticoid enhancement of memory requires arousal-induced noradrenergic activation in the basolateral amygdala. Barsegyan, A. Glucocorticoids in the prefrontal cortex enhance memory consolidation and impair working memory by a common neural mechanism.

McGaugh, J. Involvement of the amygdala in memory storage: Interaction with other brain systems. USA 93 , — Stress and glucocorticoids impair retrieval of long-term spatial memory. Quaedflieg, C. Psychoneuroendocrinology 38 , — Impaired memory retrieval correlates with individual differences in cortisol response but not autonomic response. Quesada, A. Psychosocial stress exposure impairs memory retrieval in children. Psychoneuroendocrinology 37 , — Hupbach, A.

Moderate stress enhances immediate and delayed retrieval of educationally relevant material in healthy young men. Psychoneuroendocrinology 34 , — Kuhlmann, S. Impaired memory retrieval after psychosocial stress in healthy young men. The context counts: congruent learning and testing environments prevent memory retrieval impairment following stress. Tollenaar, M. Immediate and prolonged effects of cortisol, but not propranolol, on memory retrieval in healthy young men.

The hippocampus mediates glucocorticoid-induced impairment of spatial memory retrieval: dependence on the basolateral amygdala. De Quervain, D. Glucocorticoid-induced impairment of declarative memory retrieval is associated with reduced blood flow in the medial temporal lobe.

Preventive effect of beta-adrenoceptor blockade on glucocorticoid-induced memory retrieval deficits. Psychiatry , — Dudai, Y. The restless engram: consolidations never end. Nader, K. Fear memories require protein synthesis in the amygdala for reconsolidation after retrieval. A single standard for memory: the case for reconsolidation. Reconsolidation of human memory: brain mechanisms and clinical relevance. Psychiatry 76 , — Schacter, D. Memory and law: what can cognitive neuroscience contribute?

Sandrini, M. Causal role of prefrontal cortex in strengthening of episodic memories through reconsolidation. Cai, W. Postreactivation glucocorticoids impair recall of established fear memory. Wang, X. Stress impairs reconsolidation of drug memory via glucocorticoid receptors in the basolateral amygdala. Bos, M. Stress enhances reconsolidation of declarative memory. Psychoneuroendocrinology 46 , — Coccoz, V. The enhancement of reconsolidation with a naturalistic mild stressor improves the expression of a declarative memory in humans.

Neuroscience , 61—72 Stress impairs the reconsolidation of autobiographical memories. Loftus, E. Reconstruction of automobile destruction: an example of the interaction between language and memory. Verbal Learning Verbal Behav. Manageable stress increases alertness and performance. And by encouraging the growth of stem cells that become brain cells, stress improves memory.

The increase in stem cells and neuron generation makes sense from an adaptive point of view. The brain is constantly responding to stress. Extreme or chronic stress can have a negative effect.

But moderate and short-lived stress—like an upcoming exam or preparing to deliver a speech in public—improves cognitive performance and memory. DK: Individuals vary widely in how they respond to stress.

The same stressor may be manageable for one person and overwhelming for another, depending in part on perception. People who feel resilient and confident that they can manage stress are much less likely to be overwhelmed by it—and more likely to have a healthy response—than people who think of stress as bad. Another factor is control. Stress is much less likely to be harmful if people have some control over the situation.

A tight deadline is stressful but manageable if you have the ability to meet it. If not, if you feel helpless, the stress is more likely to be harmful. Early life experiences also shape how people respond to stress.

If you have a lot of stress in your early life, you may be more vulnerable to the harmful effects of stress. This is in addition to the effect that chronically elevated levels of stress hormones have on the entire body, such as increasing the risk of chronic obesity, heart disease and depression. To clear up the confusion, Kirby subjected rats to what, to them, is acute but short-lived stress — immobilization in their cages for a few hours.

This led to stress hormone corticosterone levels as high as those from chronic stress, though for only a few hours. The stress doubled the proliferation of new brain cells in the hippocampus, specifically in the dorsal dentate gyrus. Kirby discovered that the stressed rats performed better on a memory test two weeks after the stressful event, but not two days after the event. Using special cell labeling techniques, the researchers established that the new nerve cells triggered by the acute stress were the same ones involved in learning new tasks two weeks later.

They also found that nerve cell proliferation after acute stress was triggered by the release of a protein, fibroblast growth factor 2 FGF2 , by astrocytes — brain cells formerly thought of as support cells, but that now appear to play a more critical role in regulating neurons. So, rather than striving for no stress, strive for healthier responses to stress. There is evidence that chronic persistent stress may actually rewire your brain, says Dr.

Scientists have learned that animals that experience prolonged stress have less activity in the parts of their brain that handle higher-order tasks — for example, the prefrontal cortex — and more activity in the primitive parts of their brain that are focused on survival, such as the amygdala.

It's much like what would happen if you exercised one part of your body and not another. The part that was activated more often would become stronger, and the part that got less attention would get weaker, he says. This is what appears to happen in the brain when it is under continuous stress: it essentially builds up the part of the brain designed to handle threats, and the part of the brain tasked with more complex thought takes a back seat.

These brain changes may be reversible in some instances, says Dr. Ressler, but may be more difficult to reverse in others, depending on the type and the duration of the stress.

While stressful childhood experiences seem to take more of a toll on the developing brain, some research has found that people who demonstrate resilience in the face of past childhood trauma actually appear to have generated new brain mechanisms to compensate. It's thought that these new pathways help to overcome stress-related brain changes that formed earlier in life, he says.

While the effect of stress on the brain is well documented, it's less clear exactly what type of stress will prove damaging and raise the risk of memory problems later in life.

Do brain problems occur when you are under a small amount of stress or only when you experience long-term stress? The stress you might experience before you take a test is likely very different from the stress of being involved in a car accident or from a prolonged illness.

The stress is unpredictable. Animal research shows that animals that could anticipate a stressor — for example, they received a shock after a light turned on — were less stressed than animals that received the same number of shocks randomly. The same is true in humans, says Dr. If a person can anticipate stress, it is less damaging than stress that appears to be more random. There is no time limit on the stress. If you are stressed about a presentation at work or an upcoming exam, the stress you are experiencing has an end point when you know you will get relief.

If the stress has no end point — for example, you are chronically stressed about finances — it may be more challenging to cope with. You lack support.