What Neuroscience Can and Can’t Tell Us

Images of the brain tend to impress above and beyond fancy graphs or actual math.

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When we tell people that we study neuroscience it usually leads to some interest and excitement – ‘it must be complicated!’ – but sometimes also questions about what it actually is that we study. We tend to answer simply with “we study the brain.” This is technically true, and it seems to answer their question. Still, there are a few underlying misconceptions about what exactly it is that neuroscientists do, and what they are able to do. Hence, we thought it would be good to give the reader a view beyond the wall of common misunderstandings in neuroscience, and an idea of what modern neuroscience is, where it comes from, and its relevance.

Everybody loves the brain!

Pictures of the cortex look impressive – whether in a research article or a presentation. In the 30 years since the invention of functional magnetic resonance imaging (fMRI) there has been an immense boom of published neuroimaging studies. Feeling closer to a better understanding of the brain is both fascinating and rewarding. However, all too often images of brains, both in the media and in scientific contexts, tend to fail in adding value to the presented research. Moreover, neuroimages are often difficult to interpret. Not only is there a strong variability in results when testing a single person but also when averaging results in groups. Additionally, the test-retest reliability of fMRI findings is low (1)Noble, S., Scheinost, D., & Constable, R. T. (2019). A decade of test-retest reliability of functional connectivity: A systematic review and meta-analysis. Neuroimage, 203, 116157. and researchers’ degrees of freedom in making decisions during the research process are higher than in other psychological disciplines. There are numerous ways of processing and analyzing neuroimaging data, with no single “gold standard” between labs. Different choices will inevitably lead to different results (2)Botvinik-Nezer, R., Holzmeister, F., Camerer, C. F., Dreber, A., Huber, J., Johannesson, M., … & Avesani, P. (2020). Variability in the analysis of a single neuroimaging dataset by many teams. Nature, 1-7. .

These are, of course, major issues within neuroscience. Another problem is how neuroimaging, and especially fMRI, perhaps through being “flashy”, has become what most people associate with neuroscience in general. Thinking of neuroscience exclusively as neuroimaging disregards equally important methods such as electroencephalography (EEG) or “brainwave reading”, surgical procedures (e.g., single-cell electrodes), biochemical measures, pharmaceuticals, behavioural tests, and transcranial stimulation using direct or indirect electric stimulation.

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Sometimes, neuroimaging techniques could be replaced by cheaper and less complex methods. Furthermore, the idea that a brain image equals truth can give a false sense of reliability. There is a glowing spot on a picture of a brain? It must be science! Both in academia and in popular media, people fall for this fallacy. After all, “Seeing is Believing” (3)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. !

What is neuroscience?

Before diving into the specifics of the neuroscientific world, perhaps we should start by defining what neuroscience is:

Neuroscience is a multidisciplinary science looking at how nervous systems work. Neuroscientists come from a range of disciplines reaching from biology to medicine, computer sciences to psychology.

Neuroscientists use different methods to look at how the brain works, both on a micro and a macro level. Exploring the brain on the micro level means looking at chemical substances such as hormones and neurotransmitters which in turn influence the functioning of glial cells and neurons (the brain’s building blocks). On the macro level we have whole networks of neurons firing throughout the entire cortex, the way this affects the body and vice versa. For example, did you know that there’s a chance that a prolonged suppression of the immune system might influence your chance of developing depression (4)Dantzer, R., O’Connor, J. C., Freund, G. G., Johnson, R. W., & Kelley, K. W. (2008). From inflammation to sickness and depression: when the immune system subjugates the brain. Nature reviews neuroscience, 9(1), 46-56. ?

Other neuroscientists try to answer big questions like: “what is the biological basis of consciousness?”, “what happens to our brain when we sleep?”, “what characterizes mental disorders? Can we help those affected by them?” Neuroscience is a broad field and the research within it has many forms and shapes – not just the research questions. Approaches and methods used to answer them are also very diverse.

Origins of modern neuroscience

Writings dating back to 1700 BC show that there was knowledge in ancient Egypt about symptoms of brain damage. Up to the 20th century, research contributions were mainly based on pathologies such as lesions and tumours, reasons being the lack of technology to research the brain without invasive methods like surgery. Technological advances in the second half of the 20th century, especially in neuroimaging, gave neuroscience an extreme popularity-boost. Soon, the first neuroscience departments were established at different US universities.

With the improvement of computational power and the accumulation of huge amounts of data, new opportunities opened up for neuroscientific modelling. After attributing functions to brain areas, neuroscientists now work on understanding neural networks, brain-body interactions and the neurological basis of behaviour.

Should we care?

The main purpose within psychology, some would argue, is to better understand human behaviour. Some neuroscientists use animal models to improve upon this understanding, others do research on humans, usually with less fatal outcomes. Whether scientists can accurately infer behaviour from neurobiology at this point in time is a different matter, which is something we will get back to in later articles. What we have learned so far, however, is that neuroscientific research provides us with unique ways to derive information about biological and psychological processes. Through these measures, the field has informed both clinical and non-clinical practice.

This is the first in a series of articles discussing neuroscience myths, methods and misconceptions. The following articles will (1) debunk general myths about neuroscience, (2) specifically look at fMRI as a method and issues regarding “fancy” neuroimages. Another article (3) will look at brain stimulation and what we know about it. Finally, two more articles will give insight into (4) EEG and (5) biological measures in sleep research.

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