January marks the start of a new type of post here at Neurofrontiers: the “Week in review”. In these posts, we discuss briefly neuroscience topics which have caught our attention during the week. We hope you’ll enjoy it.
1. Neurophysiological markers could help us better diagnose mental and neurological disorders.
Neurophysiological markers include both functional brain changes, measured via EEG (i.e., fast activity) or fMRI (i.e., slower activity), as well as structural ones, such as changes in brain volume or in the connections between regions. Currently, mental disorders are diagnosed only based on symptoms reported by patients and/or relatives. Identifying reliable markers would thus give us a more objective way of diagnosing them and could also help in designing better treatments. In terms of neurological disorders, they could be useful in the early identification (and thus treatment) of disease.
2. Brain activation images boost public confidence in the presented data.
A study by McCabe and Castel (2008) has shown that simply displaying some bogus cognitive data on a brain image increased people’s confidence in the accompanying article. The authors included three other conditions in the experiment:
- one where no image accompanied the data presented in text
- one where the information was also shown on a bar graph
- one with a complex topographical map
In all experiments, the article with the brain image was rated as “making more sense” compared to the other three. Scientists think this could happen because seeing the brain image gives us a more tangible explanation for an abstract process. Unfortunately, what techniques like fMRI measure in humans are not direct measurements of cognitive substrates, but correlates of the underlying activity, i.e. indirect measurements. The take-home message in this case is to pay extra attention to news articles including brain images.
3. Mouse neuronal activity correlates with cryptocurrency prices.
“What kind of bull is that?”, you’re probably wondering. It’s the “nonsense correlations” kind. Simply put, if one correlates two signals which evolve slowly over time (such as neuronal activity and crypto prices), there is a high chance to obtain a significant result, even though it doesn’t mean anything. Of course, it’s easy to recognize that correlating neuronal activity with crypto prices is meaningless. But what happens when we correlate brain activity to various slowly-evolving behavioural measures? We risk getting similar spurious correlations. That doesn’t mean that all brain-behaviour correlations are nonsense. However, scientists should properly control for false positives in their analyses and we should all be extra careful about how we interpret such results.
4. Vitamin D does not help against psychotic symptoms.
“Was it supposed to?…” Well, it appears that people who suffers from psychosis have lower levels of vitamin D compared to healthy controls. And animal studies have shown a correlation between vitamin D deficiency and certain brain changes. So researchers wondered whether bringing vitamin D levels back to normal for these patients would have some sort of effect against psychotic symptoms. It turns out that it doesn’t (typical example of correlation does not imply causation). On the other hand, vitamin D deficiency does lead to loss of bone density, as well as fatigue, muscle weakness, and pain. So the fact that these patients suffer disproportionately from vitamin D deficiencies should be addressed throughout their care.
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You might also like:
Gaughran, F., Stringer, D., Wojewodka, G., Landau, S., Smith, S., Gardner-Sood, P., … & McGrath, J. (2021). Effect of Vitamin D Supplementation on Outcomes in People With Early Psychosis: The DFEND Randomized Clinical Trial. JAMA Network Open, 4(12), e2140858-e2140858.
McCabe, D. P., & Castel, A. D. (2008). Seeing is believing: The effect of brain images on judgments of scientific reasoning. Cognition, 107(1), 343-352.
Meijer, G. (2021). Neurons in the mouse brain correlate with cryptocurrency price: a cautionary tale.