Where does the mind reside? It's a question that's occupied the
best brains for thousands of years. Now, a patient who is self-
aware – despite lacking three regions of the brain thought to be
essential for self-awareness – demonstrates that the mind
remains as elusive as ever. The finding suggests that mental
functions might not be tied to fixed brain regions. Instead, the
mind might be more like a virtual machine running on distributed
computers, with brain resources allocated in a flexible manner,
says David Rudrauf at the University of Iowa in Iowa City, who
led the study of the patient. Recent advances in functional
neuroimaging – a technique that measures brain activity in the
hope of finding correlations between mental functions and
specific regions of the brain – have led to a wealth of studies
that map particular functions onto regions. Previous
neuroimaging studies had suggested that three regions – the
insular cortex, anterior cingulate cortex and medial prefrontal
cortex – are critical for self-awa