How stress affects your learning

October, 2012

A small study shows that stress makes it more likely for learning to use more complicated and subconscious processes that involve brain regions involved in habit and procedural learning.

We know that stress has a complicated relationship with learning, but in general its effect is negative, and part of that is due to stress producing anxious thoughts that clog up working memory. A new study adds another perspective to that.

The brain scanning study involved 60 young adults, of whom half were put under stress by having a hand immersed in ice-cold water for three minutes under the supervision of a somewhat unfriendly examiner, while the other group immersed their hand in warm water without such supervision (cortisol and blood pressure tests confirmed the stress difference).

About 25 minutes after this (cortisol reaches peak levels around 25 minutes after stress), participants’ brains were scanned while participants alternated between a classification task and a visual-motor control task. The classification task required them to look at cards with different symbols and learn to predict which combinations of cards announced rain and which sunshine. Afterward, they were given a short questionnaire to determine their knowledge of the task. The control task was similar but there were no learning demands (they looked at cards on the screen and made a simple perceptual decision).

In order to determine the strategy individuals used to do the classification task, ‘ideal’ performance was modeled for four possible strategies, of which two were ‘simple’ (based on single cues) and two ‘complex’ (based on multiple cues).

Here’s the interesting thing: while both groups were successful in learning the task, the two groups learned to do it in different ways. Far more of the non-stressed group activated the hippocampus to pursue a simple and deliberate strategy, focusing on individual symbols rather than combinations of symbols. The stressed group, on the other hand, were far more likely to use the striatum only, in a more complex and subconscious processing of symbol combinations.

The stressed group also remembered significantly fewer details of the classification task.

There was no difference between the groups on the (simple, perceptual) control task.

In other words, it seems that stress interferes with conscious, purposeful learning, causing the brain to fall back on more ‘primitive’ mechanisms that involve procedural learning. Striatum-based procedural learning is less flexible than hippocampus-based declarative learning.

Why should this happen? Well, the non-conscious procedural learning going on in the striatum is much less demanding of cognitive resources, freeing up your working memory to do something important — like worrying about the source of the stress.

Unfortunately, such learning will not become part of your more flexible declarative knowledge base.

The finding may have implications for stress disorders such as depression, addiction, and PTSD. It may also have relevance for a memory phenomenon known as “forgotten baby syndrome”, in which parents forget their babies in the car. This may be related to the use of non-declarative memory, because of the stress they are experiencing.

Reference: 

[3071] Schwabe, L., & Wolf O. T. (2012).  Stress Modulates the Engagement of Multiple Memory Systems in Classification Learning. The Journal of Neuroscience. 32(32), 11042 - 11049.

Recent posts at Mynd

A study involving 97 healthy older adults (65-89) has found that those with the “Alzheimer’s gene” (APOe4) who didn’t...

An Indian study involving 648 dementia patients, of whom 391 were bilingual, has found that, overall, bilingual patients developed dementia 4.5...

A study, involving 371 patients with mild cognitive impairment...

A study involving 206 spousal and adult children caregivers of dementia sufferers (mostly Alzheimer’s) has found that about 84% of...

A study involving 254 people with dementia living at home has found that 99% of people with dementia and 97% of their caregivers had one or more...

A new U.S. study suggests that Alzheimer's disease and other dementias are markedly under-reported on death certificates and medical records....

It’s often argued that telling people that they carry genes increasing their risk of Alzheimer’s will simply upset them to no purpose...

11 new genetic susceptibility factors for Alzheimer’s identified

The largest international study ever conducted on Alzheimer's...

Understanding a protein's role in familial Alzheimer's...

A brain imaging study of 162 healthy babies (2-25 months) has found that those who carried the ApoE4...

A gene linked to Alzheimer's has been linked to brain changes in childhood. This gene, SORL1, has two connections to Alzheimer’s: it...

Analysis of data from 237 patients with mild cognitive impairment...

Two studies indicate that young people carrying the “Alzheimer’s gene” (ApoE4...

Analysis of data from more than 8,000 people, most of them older than 60, has revealed that, among the 5,000 people initially tested cognitively...

Analysis of 700 subjects from the Alzheimer's Disease Neuroimaging Initiative has revealed a genetic mutation (rs4728029) that’s associated...

Analysis of brain scans and cognitive scores of 64 older adults from the NIA's Baltimore Longitudinal Study of Aging (average age 76) has found...