Saturday, November 8, 2014

Hadyn Ellis' Article ‘Delusions: A suitable case for imaging?’

The article ‘Delusions: A suitable case for imaging?’ by Hadyn Ellis discusses the possibility and opportunities for using imaging technology for furthering research and understanding into the nature of delusions associated with recognition and identification.  The belief is that with using the imaging technologies that are available to hospitals and researchers, that there could be a link detected between the theoretical processes of identification and emotional arousal when viewing a familiar face.  The type of technology that would be used would be both spatial and temporal imaging.  The paper is mainly concerned with how these technologies and techniques can be applied to helping clarify different types of Delusional Misidentification and the related phenomena, such as covert face recognition.  It is hope also that, in the process of learning about Delusional Misidentification, it would shed further light on the process that goes into face, voice, and object recognition. 

The main problem that the article is addressing, however, is that while there is research backing up the idea that there should be neuroimaging of people suffering from delusions done, and that the technology is available, the imaging community has yet to embrace the ideas and the imaging is not being done.  Ellis is arguing for the imaging community to begin taking the scans of the delusional people not just for the sake of treating the delusions, but also in helping to come up with a way to treat and prevent it in others, and also as a means of learning more about how the mind develops the ability to recognize and identify voices, objects, and faces.  Further, Ellis states that even if the imaging doesn’t prove to be consistent with the models that have been designed around the delusional states, the imaging would provide new ways of understanding face processing which is valuable in and of itself. 

The crux of the main argument that Ellis is making is that whilst the models of the Delusional Misidentification patients seem sound and to work, there are a few holes in the models that cannot be explained or solved without the help and use of imaging studies.  Ellis goes on to outline the only published case of an imaging study performed by Lebert and their associates in 1994 which revealed that there were gross hemispheric changes in blood flow and reductions in right parietal activity.  This was held constant with a later study by Ellis that showed that there were slower responses in patients that were shown two faces tachistoscopically in the left field of vision, but that there was no difference in the right.  Ellis then goes on to argue that while these results are good, they are not enough to go on, and that there needs to be a more sophisticated and systematic method and means of investigation.  Ellis states that there are many fMRI studies that have revealed the role that the lateral fusiform gyrus and the temporal cortex plays in facial processing, and that even with this information, there are no systematic imaging processes or studies being done to further this model or the line of work in neuropsychiatry in relation to the delusional states, even though the equipment is readily available and there has been marked signs that such a procedure and study would be pertinent. 

In conclusion, Ellis makes a very good point about the lack of imaging research and studies that are being done on those who have delusional misidentification problems.  There is no reason why the imaging studies could not be performed in the manner that Ellis is recommending, especially since the equipment is already available and there is data to show that such studies would be good to have.  The weak spot in the argument, however, is not lack of data on Ellis’ part, but rather too much in a technical form.  Ellis is very thorough in researching statistics and methods and past models, however, the amount of raw data that is used in this article makes it difficult, or at least tedious, to read and get to the point that Ellis is trying to make.  


Ellis, H. (2007).  ‘Delusions: A suitable case for imaging?’ in International Journal of Psychophysiology, No.63, pp. 146-151.

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