Semantic errors of naming, reading, writing, and drawing following left-hemisphere infarction

A case is reported of a patient who made semantic errors in reading aloud, writing to dictation, oral and written naming, and drawing. On a number of occasions she showed discrepancies between her drawing on the one hand and a reading or writing response to the same stimulus word on the other. This patient also sometimes gave virtually simultaneous but different oral and written responses in naming a picture. These discrepancies are interpreted as providing support for the view that semantic errors can arise at the level of selection of items from the phonological and orthographic output lexicons (as well as at the level of semantics). An alternative explanation is that they reflect moment-to-moment random fluctuation in levels of activation of representations within the semantic system.