Introduction

Aphasia is the loss of language ability following damage to the brain. In this chapter I first offer a brief description of the traditional aphasia syndromes, followed by an account of how these syndromes are manifest in aphasic speakers of Chinese. Although aphasic Chinese speakers often experience problems in reading Chinese characters (alexia or acquired dyslexia), this topic will not be discussed here; for a fuller discussion the reader is referred to Yin and Butterworth (1998) and Weekes (1998).

The aphasia syndromes

Broca's aphasia

Broca's aphasia (also known as nonfluent, anterior, or motor aphasia) results from injury to the portion of the brain just anterior to the Sylvian fissure known as Broca's area, damage to which results in the following abnormal speech characteristics: (1) slow, effortful speech – it is very difficult for these patients to talk, often because the aphasia is associated with dysarthria (impaired ability to move the muscles of the oral tract); (2) reduced phrase length – the length of phrases produced by these patients is shorter than that produced by normal speakers; (3) simplified syntactic structure – if we characterize the syntax of Broca's aphasic speech in terms of hierarchical syntactic phrase structure trees, Broca's aphasic speakers produce trees that are reduced in size and complexity; (4) omission and underuse of function words – the speech of these patients is therefore often referred to as “telegraphic”; (5) omission and substitution of grammatical word components (inflection, prefixes, suffixes) – these latter two characteristics ((4) and (5)) have been commonly referred to as agrammatism; see discussion on p. 344 below; (6) phoneme distortion and substitution – this is usually due either to a low-level motor output production difficulty, or to a degrading of the systematic relations among speech sounds that constitute a speaker's phonological system.