Anomia for people's names.

The case of an anomia for people's names is reported. The study of this dissociation helps to clarify the difference in processing between proper and common names. Associated deficits in this and previously described cases provide support for the idea that an inability to retrieve arbitrary relations is the basis of the naming difficulty. This would confirm the role of proper names as purely referring expressions.

Impaired arithmetic facts but intact conceptual knowledge--a single-case study of dyscalculia.

We present the case of a young, highly educated patient who showed severe problems in basic arithmetic after a bone marrow transplant followed by extensive irradiation and chemotherapy. Despite his inability to resolve arithmetical fact problems (as 2 + 3), he showed intact processing of algebraic expressions and excellent understanding of complex arithmetic text problems. He perfectly knew arithmetic principles and applied them in various tasks. The performance of the patient suggests that conceptual knowledge (in addition to arithmetical fact knowledge and arithmetic procedures) is a functionally independent component of the calculation system.

Lyme encephalopathy: long-term neuropsychological deficits years after acute neuroborreliosis.

We studied long-term cognitive deficits in 20 patients with previously diagnosed Lyme borreliosis several years (average 51.6 months) after their acute phase of illness. Compared with an age- and education matched control group Lyme patients revealed deficits of verbal memory, mental flexibility, verbal associative functions and articulation, but performed adequately on tests of intellectual and problem solving skills, sustained attention, visuoconstructive abilities and mental speed. The late cognitive outcome was unrelated to disease variables from the acute stage of illness, but also to the interval elapsed since infection with B. burgdorferi. These and similar observations (Krupp et al. 1991) suggest that the so-called Lyme encephalopathy may be associated with a long-lasting neuropsychological deficit predominantly affecting mnestic functions.

Concepts and facts in calculation.

A patient is described who is affected by an inability to recall and use 'arithmetical facts' of one-digit multiplications and divisions. This loss contrasts with the preservation of a wide set of complex notions that the patient exploits in order to overcome his deficit and get the right result. This observation helps in isolating and describing an important component of arithmetical long-term memory that is not overlearnt and the functioning of which is not automatic or mechanistic. An account of such a component is lacking in models of arithmetic currently referred to in cognitive neuropsychology. In a remediation study, performed over several weeks, the effect of training was selective for each single arithmetical fact: not even skills with multiplication complements (e.g. 6 x 3, 3 x 6) fully benefited from the rehabilitation of a specific fact. This suggests that the storage format of each fact is independent from that of other facts.