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The theoretical distinction between arithmetic facts and procedures was first made by Groen and Parkman (1972). This was confirmed with a neuropsychological single case described by Warrington (1982) who had impaired arithmetical facts but well preserved arithmetical procedures. Since this time there have been several patients described who showed a selective impairment of arithmetic facts. There have also been reports of cases with impaired arithmetical procedures. However, there has not yet been a case reported with the selective impairment of procedures in the context of intact arithmetic facts. This paper describes a patient, SR, with probable Alzheimer's dementia who had well preserved addition, multiplication and subtraction facts but who nevertheless had severe difficulties with a range of arithmetical procedures such as multidigit sums, decimals and fractions. The implications of this case for current theoretical models are discussed.

This report describes a person who confabulated following an anterior communicating artery aneurysm. His confabulation was limited to one very circumscribed area of his life and remained stable for twelve weeks, eventually improving with rehabilitation. It is argued that a content-specific confabulation of this nature challenges current theories of confabulation, and an integrative explanation is given based on previous findings by Burgess and Shallice (1996b) of the mechanisms of autobiographical recollection in healthy people.