Tuesday, October 21, 2014

Burden of proof: does neuroscience have the upper hand?

As an undergraduate, I took several introductory level philosophy classes while majoring in neuroscience. Some of it I could appreciate and most of it went over my head, but a thought that kept nagging me was, “haven’t neuroscientists solved all of these issues by now?” It was only after I had worked in neuroscience laboratories for a few years that I began to realize just how qualified all of our statements had to be due to the plethora of limitations that go along with any result. I began to wince anytime I heard someone use the word “proof” (only salesmen use the term “clinically proven”, but don’t get me started on that…). It seems clear to me now that, for the most part, natural scientists, social scientists and humanities scholars are really all working toward the same goal just in different, albeit complimentary ways. At the first “Neuroscience, ethics and the news” journal club of the semester, Lindsey Grubbs, a PhD student in Emory University’s English Department, facilitated our discussion about a topic that she has previously written about for this site. The main focus was on what role neuroscience can and should play in answering questions that have long been in the realm of the humanities and how these results should be communicated to the general public.

From the Daily Mail Online


At the center of our discussion were two papers about the effects of reading that each created quite a stir in the popular press. First, Gregory Berns’ laboratory at Emory reported on a study that they had conducted which was aimed at determining how a good book can leave such a lasting impression (1).  They reasoned, “It seems plausible that if something as simple as a book can leave the impression that one’s life has been changed, then perhaps it is powerful enough to cause changes in brain function and structure.” Berns and colleagues asked undergraduates to read a novel over the course of nine days and had them come into the lab for a short resting-state functional Magnetic Resonance Imaging (fMRI) scan each morning during that time. They utilized an internal control model where each participant was also scanned prior to reading and after finishing the novel.

Dr. Berns and his colleagues found significant short-term changes in activity levels in areas that had previously been associated with “story comprehension” and “perspective taking” – the “left angular/supramarginal gyri and right posterior temporal gyri” – and somewhat persistent changes in somatosensory cortical connectivity. They interpreted the latter results as a possible substrate for the phenomenon of “embodied semantics,” where the brain’s somatosensory processing machinery can be recruited by just the thought of performing an action or experiencing a sensation (2). Importantly, nowhere in the paper do the authors put a valuation on these changes as “good” or “bad” yet headlines such as “Brain function improves for DAYS after reading a novel” appeared. Increased connectivity between discrete brain regions does not necessarily mean that brain function is improved. Is this simply a result of a positive bias in favor of reading? If the same neurological changes were found in chronic drug abusers, I doubt they would be interpreted as improvements.

From ScienceDaily

The second study (3), published in Science by Kidd and Castano (2013), took a very different approach and also received a great deal of attention (positive, negative, and borderline ridiculous). Here, the researchers from The New School set out to determine if literary fiction – defined as award-winning and/or canonical rather than best-selling – alters measures of Theory of Mind, the ability to infer and understand the mental states of others. To do this, they put subjects through a battery of tests aimed at measuring affective and cognitive Theory of Mind after reading either literary or popular fiction or nothing at all. Kidd and Castano conclude their article by arguing that their results highlight the importance of reading literature in contrast to the controversial US Common Core standards which de-emphasize reading fiction in secondary education. Slate’s Mark Liberman has written at length about the shortcomings of this study’s design and its perhaps over-reaching interpretations. His piece was titled “That study on literary fiction and empathy proves exactly nothing” – I couldn’t agree more (but I could say that about any paper). Liberman’s somewhat aggressive title may have been in response to Zach Schonfeld’s “Now we have proof that reading literary fiction makes you a better person” (shudder).

Hyperbole aside, there are two issues here that deserve attention. First, do we really need neuroscientific evidence in order to promote reading, and in particular, reading great, canonical works? Even hardcore, card-carrying reductionists would likely agree that a lack of biological evidence for the benefit of reading does not necessarily mean it isn’t good for you. The risk is that the public comes away from these articles thinking that now that neuroscientists have weighed in, the debate is over. Also of note, Kidd and Castano never use the word “brain” (or “neuron”, “neural”, etc.) because this is a psychology study, aimed at understanding the effects of reading on how the mind works. Neuroscientists could certainly look for neural correlates for the psychological changes exerted specifically by literary fiction on the brain but even if they were not able to find anything that would not mean that the changes aren’t real. An underlying issue here, outlined by Lindsey and discussed by the group, is that natural science results – and in particular those from neuroscience – are highly persuasive to the public (4, 5). Here, the media largely reported that these studies proved the benefits of reading, which hardly seems like a controversial topic. However, Common Core standards are quite controversial and the amount and type of reading (i.e. fiction vs. non-fiction) are hotly contested topics. While neuroscientists and psychologists certainly could weigh in here, there is a concern that their results may be more influential than perhaps they should be.

From alanrinzler.com

Second, a problem that arose with several of these popular press articles is the attachment of a value judgment to the changes that scientists reported. As mentioned above, it is likely that the reason that words like “improvement” were added to describe these neural changes is because reading is already seen as a positive influence. Internet pornography addicts probably would have had a similar change – if it existed – labeled as a “pathological rewiring.” Perhaps this is a remnant of the brain being thought of as a muscle that needs to be exercised. In that analogy, any increase does seem like an improvement but that obviously is not always the case (for example, uncontrolled excitatory activity can lead to seizures).

In reality, most of the things we do and see and feel can probably change our brains in some way, for better or worse – but whether or not neuroscientists alone are able to find these changes doesn’t actually prove anything.


References

1.         Berns GS, Blaine K, Prietula MJ, & Pye BE (2013) Short- and long-term effects of a novel on connectivity in the brain. Brain connectivity 3(6):590-600.
2.         Aziz-Zadeh L & Damasio A (2008) Embodied semantics for actions: findings from functional brain imaging. Journal of physiology, Paris 102(1-3):35-39.
3.         Kidd DC & Castano E (2013) Reading literary fiction improves theory of mind. Science 342(6156):377-380.
4.         Caulfield TR, C. Zarzeczny, A (2010) “Neurohype” and the Name Game: Who's to Blame? AJOB Neuroscience 1(2):13-15.
5.         Weisberg DS, Keil FC, Goodstein J, Rawson E, & Gray JR (2008) The seductive allure of neuroscience explanations. Journal of cognitive neuroscience 20(3):470-477.


Want to cite this post?

Purcell, R. (2014). Burden of proof: does neuroscience have the upper hand? The Neuroethics Blog. Retrieved on , from http://www.theneuroethicsblog.com/2014/10/burden-of-proof-does-neuroscience-have.html

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