Research methods in the news: brain scans and dead fish

Brain scanning method

Areas of the specification where supporting evidence comes from brain scan studies often allows students somewhat rare opportunities to use positive evaluative points to demonstrate their skills of analysis.  Scanning techniques such as fMRI, for example, are innovative, cutting edge, scientific methods and certainly appear objective. Research into memory and its functions (such as studies that attempt to identify areas of the brain active during different types of memory tasks; AQA spec A Unit 1, Memory) and Mirror Neurons (AQA Spec A, Unit 3, Cognition and Development) have used such methods to give us a glimpse into what was previously the unknown of the mind and brain.  Often a brain scan study seems to confirm speculation and findings that has come from more indirect evidence.

Criticising research methods

An article in Sunday’s Guardian (“Vaughan Bell: the trouble with brain scans”; published online 27th May 2012), however, suggested that this confidence we tend to place in the credibility of brain scan studies, and the weight we lend to these over other sources of evidence, might be misplaced. The article makes the claim that “Many of the methods on which brain scan studies are based have been flawed – as one image of a dead salmon proved”. The criticisms of relying on brain scans, raised by Bell, focus on both the analysis and interpretation of what the coloured imagery on the scans actually means. The article warns of the dangers of false positives, as the sheer number of scans taken during a session increases the likelihood the intended outcome occurs.

Quote: False positive

“To illustrate the problem, Craig Bennett and his colleagues at the University of California did a spoof experiment on a dead salmon. The standard techniques showed “brain activity” in the deceased fish”.

Resource: validity and the scientific method

Not only does this article make an interesting way to discuss the role of brain scans and their validity anywhere these methods crop up in the material in any A Level specification, but it also allows discussion at a higher level (addressing stretch and challenge requirements and meeting the needs of your gifted and talented students) of the concept of paradigms in science. The article points out that the output of scans (coloured blobs in certain areas of the brain) are interpreted in terms of beliefs that brain areas have particular functions. However, modern neuroscience views the brain and its functions as the product of complex interactions and therefore, interpreting scans in terms of which brain centre is active for a task is limited.

As a simple activity, students could be asked to rank pieces of evidence in terms of those which they feel have greater weight, where they have access to evidence using a range of methods. They are likely to rank brain scans high in their list (possible justifications being “they are more scientific”) which would create an excellent opportunity to discuss the article and Vaughan Bell’s views. Students could be asked to justify their position whether they agree or disagree with the articles author. Students could be asked to write a comment in response to the article (not necessarily to post but to create a discussion between students). If nothing else the article demonstrates that being reflective and evaluative is an essential skill in science, not just in the science classroom.


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