Tuesday, 31 January 2012

Damasio's Error - Faith in Science and the Real Story of Phineas Gage

The story of Phineas Gage has become the iconic classic case study in Cognitive Neuroscience. It is the treasured parable, relentlessly churned out in the introductory chapters of cognitive neuroscience and neuropsychology textbooks as an example of how brain changes can lead to behavioural or even personality changes. It's a facinating story: But is it true?



If you haven't heard of this unlucky chap, let me briefly fill you in. 


Phineas Gage was an American railroad construction foreman in the mid 19th century. No biggy. One day an explosion caused a large iron tamping rod to pass through his skull destroying his left frontal lobe. Incredibly, Phineas not only survived but remained conscious throughout the ordeal, sitting up right and able to talk throughout the 3/4 mile cart ride to town, where he was subsequently treated by Dr John Harlow.


Post accident, the story goes, Gage was a completely different person, despite returning to seemingly full physical health. He changed from a quiet and popular man to being fitfull, impatient, agressive and at times 'indulging in the greatest profanity'. 


Dr Harlow himself states:

'In this regard his mind was radically changed, so decidedly that his friends and acquaintances said he was “no longer Gage" '

In Damasio's book 'Descartes Error', he describes Gage's decline in social functioning, his inability to hold down jobs or maintain social relationships and that...

'We would probably find him drinking and brawling in a questionable district, not conversing with the captains of commerce, as astonished as anybody when the fault would slip and the earth would shake threateningly'

But a detailed look at the sources by Macmillan paints a rather different story. He emphasizes that the accounts describing Gage's dramatic change in behaviour refer largely to the first two months post his accident. Beyond those first two months, Gage holds down a variety of jobs successfully, is reported to recite fanciful stories to his nieces and nephews and in  no way was an 'impatient, foul-mouthed, work-shy drunken wastrel'. Macmillan concludes that Gage made a good psychosocial recovery and despite not being the 'same Gage' as he was once before, he was much closer to his original self then is often depicted. 


I think there are two important issues here. For Kotowicz, it shows how neuroscience often tries to deny the importance of introspection, subjective feeling and our relationship with the environment and psychological factors. He uses this example, to argue against the kind of eliminitivist materialism put forward by the likes of Paul Churchland. Instead he proposes that much of Gage's behaviour can be explained as a normal Psychological reaction to the trauma of the accident and the subsequent deformity that Gage had to live with. 


I think he makes an important point, that to ignore the psychosocial factors affecting Gage after the accident is a gross error on the part of scholars such as Damasio and does provide a good example of the problems of studying the brain in isolation in order to explain behaviour. This is not of course, to deny that changes in brain can lead to changes behaviour, just go to the pub for a few hours, nor that neuroscience does not have in important part to play. The point here, is that the brain isn't the whole story and throughout Kotowicz's paper there is the undertone of a rejection of the biological direction Psychiatry seems to be heading in. By taking the brain out of context, not only do we miss other important e.g. psychological factors but the results we do achieve with regards to the brain risk being confounded.


Secondly, I think it raises an important issue within philosophy of science in general. Unless we are rigorous, critical and skeptical toward the paper or theory put in front of us, science becomes a  matter of faith. Take, for example, the problem of secondary citing, whereby a theory, model or idea becomes generally accepted on the basis of continuous secondary reporting and citing without reference and analysis of the original source. And it gets worse, unless you are an expert in that particular field (and even then), it is completely impractical to endlessly check the citations in a paper and then the citations in that paper and so on.


I imagine if you're reading this blog you are probably the kind of person who would argue passionately for the theory of evolution against a creationist - and so would I. But I wonder how many of us have actually looked and studied the evidence, sources and papers in support of evolution in the kind of rigorous depth that the scientific method would warrant to support our arguments? I have not.


I suppose the important factor that distinguishes science is that there is (arguably) certainty in the methodology. As scientists we are confident that the falsifiability of empirical evidence provides us with the best means of gaining knowledge. The faith then, comes in the form of our trust in its correct implementation by those who specialise in that particular profession - on these grounds Damasio has failed his fellow scientists.

References


Macmillan, M., & Lena, M. (2010). Rehabilitating Phineas Gage Neuropsychological Rehabilitation, 20 (5), 641-658 DOI: 10.1080/09602011003760527


Kotowicz, Z. (2007). The strange case of Phineas Gage History of the Human Sciences, 20 (1), 115-131 DOI: 10.1177/0952695106075178

A. Damasio 2008 Descartes' error: Emotion, reason and the human brain

3 comments:

  1. I share the same view regarding Gage, and have always been puzzled as to how this story is constantly plugged and sold to readers. I also find myself worrying that any discipline that continues to refer to a case study which long predates our present technologies and knowledge has to have a long look at itself.

    In all the literature it is rare to see a mention that many of his behavioural "changes" could also be attributed to the psychological impact of the event (e.g. PTSD). The one truth we will have over the misfortunes of Phineas Gage is that we will never have a full and objective account of his life pre or post injury. Although brain injury does seem the likeliest of causes this should not be seen as the only cause, nor the sole basis of any theory. Saying this, Damasio's theory of Somatic Markers and their role in decision making is by no means based on this one account of Gage's misfortunes, but drawn from evidence from other peer reviewed studies conducted in controlled conditions.

    I find your post unfair to highlight, as you call it Damasio's error, given that it is likely that he conducted any original work with the Gage accounts. Damasio, like all other scientists or researchers must base their work on the work of those who have gone before them.

    I will in my own research take care to accurately report the existing research I cite, but ultimately I must believe and as you have said, have faith in the work gone before me.

    If Damasio's error was to have faith in previous research (which may in retrospect not be as accurate as previously thought) then it is one that every researcher makes on a daily basis.

    There is a huge responsibility for researchers to report work accurately and for the peer review processes to be properly conducted so that we may have faith and confidence in this research.

    Research can not move forward without this faith, as I for one don't have the time to conduct every study or test every theory that influences my own research to check its reliability and validity.

    My faith therefore lies with the peer review process and the integrity of the researcher conducting the study. A faith that is not without tests given the recent accounts within academia of falsifying data by prominent and well respected authors.

    I have faith that researchers both in my own and other disciplines treat their work with the necessary responsibility, rigour and ethical considerations. That being said, it is crucial that peer review is up to the task to prevent research that is not fit for publication for whatever reason is identified as not fit for purpose.

    Whilst Damasio maybe guilty of peddling a questionable truth regarding Gage as result of relying on secondary sources. Damasio has been involved in peer reviewed primary research which has furthered knowledge and understanding in his field. To fail to mention these achievements but to focus on his retelling of the Gage story is unfair and misleading. To undertake novel research, for which the Gage story is nothing more than a back story, is not a failing but an asset to his fellow scientists.

    Dare I say, that in accusing Damasio of presenting an inaccurate and narrow picture of existing knowledge, you have yourself fallen into the very trap you were trying to highlight as a danger to scientific understanding.

    Whilst I take issue with the way in which you have singled out Damasio, your article does highlight how science must rely on the good faith of others. This leads to the further discussion as to how we maintain or improve the reliability of science and understanding in a world where research is being placed under increasing pressures to deliver novel and significant findings.

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  2. Thanks for your comments. I agree with much of what you have written actually. I think using Damasio to illustrate the point I was making without at least a caveat acknowledging his contributions to cognitive neuroscience and the method of science itself is unfair. As you rightly point out, his work does not rely on this one case alone and he has certainly made a huge contribution to the field.

    The only point I am unsure of is to what extent Damasio was relying on the research of others when he wrote about Gage - or rather to what extent his interpretations of events are justified. In his book he references Harlow and Bigelow directly, with regards to Gage's story. But (and the irony is I am putting my faith in Macmillan's and Kotowicz's work here!) according to the two papers I refereced there were no accounts by Bigelow or Harlow in these papers that would justify Damasio's description of Gage as the kind of agressive brawling drunkard that he paints him as. What annoyed me was that it seemed Damsaio cherry picked his quotes to portray Gage in a way that suited his narrative.

    That said, when you consider this 'error' in the wider context of Damasio's work there's not much of a problem. I actually read Descarte's error in first year of uni and loved it!

    It frustrates me that in science there's all kinds of reasons that people can get things wrong, through interpreting complex stats or working within an incorrect paradigm, for example, but describing a set of events shouldn't be a problem even from the limited sources that were available. Of course the interpretation of what the events mean is open to scientific debate but to describe the events themselves in a biased way is just bad science.

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  3. Your frustrations match my own with the Gage affair. I have read Descartes's error a number of times and I will be honest, the subsequent readings involved skipping the Gage chapter due to the way in which the account is presented. I am on my phone and not able to get in past the pay wall for the articles you referenced, although I think I have read Kotowicz before.

    I am researching emotion and decision making and as you can imagine Gage's name crops up all over the place with little critical discussion. Gage's account should be moved to the psychology back story and should be nothing more than a paragraph to discuss how this and other cases changed our understanding about human behaviour and its linkages to the brain, it should not be used as evidence as such.


    To address your wider and more important point.. its probably the most important lesson to teach students after dont plagurise or dont falsify data, which is to check your sources and never second cite, always read the original paper / research. Whilst Damasio may have cherry picked his quotes to set his scene as it were, any subsequent researcher should check the original sources. In doing so they would avoid perpetuating any poorly described or misleading descriptions of existing research.

    Oh, and I have a running competition to see how many days I can go without hearing Gage's name mentioned or see it written in print. I guess I have failed the last two days, although, reading your critical post I think it should go in the plus column.

    Scientriffic

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