From 2 to two: an analysis of a transcoding process by means of neuropsychological evidence.

This study investigates the abilities of aphasic subjects to transcode numbers from the digital code into the alphabetic code. The subjects' performances are considered first as dependent on general structural parameters such as item length or due to general behavioral impairments such as serial ordering disturbances. The second analysis focuses on typical aphasic errors in the processing of lexical primitives that are not specific to the linguistic material used in this transcoding task, such as literal or morphemic paragraphias . The third analysis considers the erroneous transcriptions as resulting from partial or inappropriate use of a subset of normal transcoding strategies. The latter approach proves to be particularly powerful in accounting for the systematicity of the errors produced by aphasic subjects. The result thus appear to be relevant to the study of the psycholinguistic mechanisms responsible for performing such transcoding tasks by normals.