ABSTRACT

This proposal begs the obvious question of whether individual differences provide an explanation for category-specific deficits in semantic dementia alone or for other patients as well. It is possible that at least some of the other reported single cases could have arisen from premorbid differences in knowledge. Future case-series or group studies are required to rule out individual differences as a general explanation for category specificity. If a certain category-specific pattern is consistently associated with a certain disease type, underlying distribution of neurological damage, or pattern of cognitive deficits, then an account on the basis of individual differences would not be plausi ble. In any event, an explanation in terms of individual differences will continue to feel under constrained and unsatisfying unless and until there is some independent basis on which to predict who should fall where in the distribution. At present, however, it remains a leading contender for explaining an otherwise puzzling set of patterns in the domain of category specificity.