Neuroscientific psychiatry and the problem of consciousness
Psychiatric diagnosis and psychiatry is in crisis. Evidence of this is to be found in the National Institute of Mental Health’s (NIMH) decision not to use the American Psychiatric Association’s DSM-5 published in May.
Despite this, scientific evidence for the importance of contexts in understanding the experiences of people who suffer from psychosis is overwhelming, but persistently disregarded by funding bodies. These include personal histories of trauma and adversity, especially in childhood (Read et al, 2001; Read et al, 2005; Read et al, 2009, as well as other forms of oppression and abuse, such as racism and wider socio-economic contexts of inequality (Karlssen & Nazroo, 2002; Janssen et al, 2003; Karlssen et al, 2005). The nature of these contexts raises moral and ethical questions about our work. They flag up important issues about values in psychiatry. What do we really believe to be important about the way we try to help people who experience psychosis?
The assumption is that because we can now observe brain activity directly in real time this must tell us something of fundamental importance about the neural basis of consciousness. It is very easy to be seduced into believing this. The origins of these images are shrouded in mystery for most, so they must represent a truth about the nature of consciousness. But is this really the case?
A recent review of brain imaging studies of people with a diagnosis of schizophrenia who were hearing voices found ‘… insufficient neuroimaging evidence to fully understand the neurobiological substrate of [auditory hallucinations].’ (Allen et al, 2012).
The neuroscientist and philosopher Alva Noë (2009) points out that we have no idea of knowing whether, beyond current levels of discrimination, there are groups of neurons that are active or inactive in a given task or situation. The resolution of the technology is simply too blunt for us to be able to assume that that there is a one to one equivalence between experience and brain activity in a specific area.
The interpretation of these images is further clouded by the technique of normalisation widely used in such studies to generate a statistical average of brain activity. This irons out differences between individual subjects to make it possible to pool the data mathematically so that the average activity across subjects can be projected onto an idealised brain template. The Fauvist images that fMRI presents us with are not those of a real person, but an idealised average. They don’t even have the same relationship to the activity in a real person’s brain as an identikit picture of a crime suspect has to a real person’s face.
A future neuroscientific psychiatry, a ‘medicine of the brain’ with or without diagnosis, would strip all richness, pain and complexity out of the experience of psychosis, because it has nothing to say about these aspects of experience.