Are Number Words Fundamentally Different? A Qualitative Analysis of Aphasic Errors in Word and Number Word Production

Abstract

A number of previous studies reported dissociations between the processing of number words and other words and reasoned that there are fundamentally different mental representations and/or processing strategies related to these types of words. Messina et al. reported the performance of Italian aphasic patients with words and number words in different tasks [1]. In line with previous studies, they found that lexical errors formed the dominant error type in number words, whereas phonological errors were the most frequent error type in other words. Messina et al. [1] concluded that speech production processes differ categorically between number words and other words, leading to qualitatively different error patterns in language breakdown. The present study examined error types in number words and other words in a sample of 15 German patients with aphasia using the same tasks as Messina et al. [1]. Performance in reading and repeating number words and other words was analysed. In general, we replicated the dissociation of error types between number words and other words reported by Messina et al. [1] and others. However, in contrast to previous assumptions this dissociation was not categorical but rather gradual. We suggest that psycholinguistic stimulus properties (such as number of repetitions per morpheme) and type of task influenced error types in a gradual fashion.