Response to Dennis

Dennis,

Thanks so much for your interesting comments. I very much appreciate our shared interest and look forward to learning from, and with, you.

Your comment that ‘imposing our preconceptions’ on sensory data should not imply intentionality to do so certainly makes sense to me. Experientially, I seem to be totally unaware of this process. I wouldn’t have a clue as to how to ‘impose my preconceptions’ even if I wanted to. It just seems to happen naturally. I can talk about it intellectually, but experientially it just seems to roll along on its own; which means that I rarely question the validity of my sensory experiences. In the same way, I suppose, most people who have hallucinations, like hearing voices, assume that their experiences are ‘real’.

Your other comment, about Jill Taylor’s experience during a severe stroke, raises the question (among others) of the process by which a sense of separate ‘self’ is generated. Again, this seems to be something that happens without intention, and on a moment to moment basis I, for one, take the result to be ‘real’ without even thinking about it.

Recently there have been a couple of papers from Dr. Patrick McGorry and his Early Psychosis group in Melbourne, suggesting that a disturbance in this sense of self is an early and core aspect of the development of psychosis. Here is their latest abstract:

A disturbed sense of self in the psychosis prodrome: linking phenomenology and neurobiology. Neurosci Biobehav Rev. 2009 Jun;33(6):807-17. Epub 2009 Jan 20.
Nelson B, Fornito A, Harrison BJ, Yücel M, Sass LA, Yung AR, Thompson A, Wood SJ, Pantelis C, McGorry PD .ORYGEN Youth Health Research Centre, Department of Psychiatry, The University of Melbourne, Victoria, Australia. nelsonb@unimelb.edu.au

Interest in the early phase of psychotic disorders has risen dramatically in recent years. Neurobiological investigations have focused specifically on identifying brain changes associated with the onset of psychosis. The link between these neurobiological findings and the complex phenomenology of the early psychosis period is not well understood. In this article, we re-cast some of these observations, primarily from neuroimaging studies, in the context of phenomenological models of "the self" and disturbance thereof in psychotic illness. Specifically, we argue that disturbance of the basic or minimal self ("ipseity"), as articulated in phenomenological literature, may be associated with abnormalities in midline cortical structures as observed in neuroimaging studies of pre-onset and early psychotic patients. These findings are discussed with regards to current ideas on the neural basis of self-referential mental activity, including the notion of a putative "default-mode" of brain function, and its relation to distinguishing between self- and other-generated stimuli. Further empirical work examining the relationship between neurobiological and phenomenological variables may be of value in identifying risk markers for psychosis onset.