How Stress can have a big impact on your brain and memory
Hi I’m Liz, a second year BBSRC funded cognitive neuroscience PhD student. Since A-level I have always wanted to be able to combine my interests in psychology with my interests in physics but was always told they were too different and I would never be able to study both…. LIES! Cognitive neuroscience lets me explore psychology, in my case the effects of stress on memory, while also using neuroimaging techniques (YAY Physics!) to examine the under-lying brain mechanisms involved. Before coming to Manchester to start my PhD, I completed my undergraduate degree in Psychology with Neuropsychology and my Master’s degree in Neuroimaging at Bangor University in North Wales.
How does stress affect memory?
Do you ever notice that some people can just handle stress really well while other people really struggle to cope and forget everything they were doing? This is known as a person’s stress reactivity. Highly stress reactive people experience much greater hormone responses when stressed than low stress reactive people, meaning that in comparison, they suffer more ‘mental blocks’ when trying to compete tasks. More seriously, however, continual high levels of stress have been linked to serious social and health problems such as job loss, divorce, heart disease and stroke.
Similarly, have you ever sat down in an exam that you thought you were prepared for and suddenly had a complete mind blank? During stressful situations memory can sometimes become impaired leading to these sudden ‘mind blank’ moments where we are unable to remember information we previously knew. These can happen to anyone but do more commonly happen to highly stress reactive individuals who struggle to cope under pressure.
In contrast however, it has been shown that sometimes, learning under stress or intense pressure can increase memory ability. This is because stress hormones help slow the rate of forgetting which can be shown using neuroimaging the highlights brain activity in certain regions.
What is Neuroimaging?
Neuroimaging covers a range of techniques that allow us to examine the brain and measure specific activation associated with certain tasks. The imaging techniques I use require magnetic resonance imaging (MRI) scanners. With these scanners we are able to explore different features of the brain including the size and structure of certain regions, the connectivity between these regions and the levels of neurotransmitters (chemicals) within different areas of the brain. MRI scans can also be used to explore the function (known as fMRI) of brain regions by examining levels of activation within these specific regions while completing a range of tasks. fMRI is one of the most common methods of imaging shown on medical TV shows- often they show areas of the brain ‘light up’ in response to sounds or images when people in the scanner- this isn’t exactly how fMRI works but the gist of it is about right.
(Image 2: This is an MRI scan of my brain)
Using Neuroimaging to Explore Stress & Memory
So, using MRI we are able to compare the brain differences between high and low stress reactive people. This allows us to attempt to understand why some people can and some people cannot cope during stressful situations. We are also able to examine the activation in the brain during memory to attempt to compare brain activity to behavioural memory task outcomes. Finding any differences in brain structure or activity between stress reactive groups will help us to better understand what causes this detrimental response to stress that may then allow us to control negative outcomes as bets as possible
To read more about neuroimaging work, check out this website (https://www.humanbrainmapping.org/i4a/pages/index.cfm?pageid=1) that explores current work using neuroimaging to discover more about the human brain.
There are lots of cool blog posts and YouTube videos that go into more detail about stress. Here are just a few to get you started:
· TedBlog- Stress as a positive (https://blog.ted.com/could-stress-be-good-for-you-recent-research-that-suggests-it-has-benefits/)
· TedEd- Stress in the Brain
· TedEd- How memories form (https://www.youtube.com/watch?v=yOgAbKJGrTA)
· Science Central- Stress & Memory (https://www.youtube.com/watch?v=OHl7BewJ0yU)
Finally, The Signal (https://thesignalmag.wordpress.com) is a student magazine founded by students at The University of Manchester and has some brilliant articles for young scientists interested neuroscience, behaviour, psychology and mental health. Issue 1 (https://issuu.com/thesignalmagazine/docs/issue_1_-_stress_oct17) was all about stress and is well worth a read for anyone interested.