A surprising amount of what we think we know about the brain
comes from neuropsychology; famous case studies such as HM have
informed theories of memory so that they include short and long
term storage, which are separable, and so on. These case studies
can have a profound effect on research; my favourite story,
though, was about a memory researcher who had a skiing accident
and temporarily developed retrograde amnesia - he couldn't
remember anything except that there was this guy in Connecticut
(HM) who couldn't remember things either! I always enjoyed
classes in neuropsychology; the case studies are always
fascinating. But they are deeply limited in what they can
actually tell us about the brain. First, they are typically
single patient case studies, which restricts how general the
conclusions are. Second, they are data from damaged brains; the
fairly linear assumption that some localised function has been
subtracted out is simply not true, and the damage will have had
complex effects on distributed functio