Why acute stress makes it hard to think properly

October, 2012

A rat study indicates that acute stress disrupts feedback loops in the prefrontal cortex that may be keeping information alive in working memory.

Stress is a major cause of workplace accidents, and most of us are only too familiar with the effects of acute stress on our thinking. However, although the cognitive effects are only too clear, research has had little understanding of how stress has this effect. A new rat study sheds some light.

In the study, brain activity was monitored while five rats performed a working memory task during acute noise stress. Under these stressful conditions, the rats performed dramatically worse on their working memory task, with performance dropping from an average of 93% success to 65%.

The stress also significantly increased the discharge rate of a subset of neurons in the medial prefrontal cortex during two phases of the task: planning and assessment.

This brain region is vital for working memory and executive functions such as goal maintenance and emotion regulation. The results suggest that the firing and re-firing of these neurons keeps recent information ‘fresh’. When the re-firing is delayed, the information can be lost.

What seems to be happening is that the stress is causing these neurons to work even more furiously, but instead of performing their normal task — concentrating on keeping important information ‘alive’ during brief delays — they are reacting to all the other, distracting and less relevant, stimuli.

The findings contradict the view that stress simply suppresses prefrontal cortex activity, and suggests a different approach to treatment, one that emphasizes shutting out distractions.

The findings are also exciting from a theoretical viewpoint, suggesting as they do that this excitatory recursive activity of neurons within the prefrontal cortex provide the neural substrate for working memory. That is, that we ‘hold’ information in the front of our mind through reverberating feedback loops within this network of neurons, that keep information alive during the approximately 1.5 seconds of our working memory ‘span’.

Reference: 

Related News

When stroke or brain injury damages a part of the brain controlling movement or sensation or language, other parts of the brain can learn to compensate for this damage. It’s been thought that this is a case of one region taking over the lost function.

Because people with damage to their

Following on from earlier research suggesting that simply talking helps keep your mind sharp at all ages, a new study involving 192 undergraduates indicates that the type of talking makes a difference.

Previous research has indicated that obesity in middle-age is linked to higher risk of cognitive decline and dementia in old age.

Inflammation in the brain appears to be a key contributor to age-related memory problems, and it may be that this has to do with the dysregulation of

Confirming earlier research, a study involving 257 older adults (average age 75) has found that a two-minute questionnaire filled out by a close friend or family member is more accurate that standard cognitive tests in detecting early signs of Alzheimer’s.

A couple of years ago I reported on a finding that walking in the park, and (most surprisingly) simply looking at photos of natural scenes, could improve memory and concentration (see below). Now a new study helps explain why.

Reports on cognitive decline with age have, over the years, come out with two general findings: older adults do significantly worse than younger adults; older adults are just as good as younger adults.

A study involving 65 older adults (59-80), who were very sedentary before the study (reporting less than two episodes of physical activity lasting 30 minutes or more in the previous six months), has found that those who joined a walking group improved their cognitive performance and the connecti

Neurofibromatosis type 1 (NF1) is the most common cause of learning disabilities, caused by a mutation in a gene that makes a protein called neurofibromin.

Pages

Subscribe to Latest newsSubscribe to Latest newsSubscribe to Latest health newsSubscribe to Latest news
Error | About memory

Error

The website encountered an unexpected error. Please try again later.