Paths of mental access in aphasic narratives

Background: Aphasia is generally taken to be a language-specific impairment and cognitive difficulties are not predicted from traditional models of aphasia. Furthermore, it has been shown that people with aphasia have relative strengths at the macro level of discourse, which is arguably more cognitive than linguistic. Many contemporary semantic approaches however, demonstrate the cognitive underpinnings of language and discourse structure. Within Cognitive Linguistics, all linguistic form is conceptually meaningful. Information structure follows temporal, spatial and causal paths of mental access, and builds upon what has already been established in the discourse space. Such an approach transcends lexicogrammatical analysis of discourse cohesion, and schematically unites macro and micro levels of discourse as instances of more generalised cognitive processes. Aims: This study uses a Cognitive Linguistics approach to investigate whether people with fluent and non-fluent aphasia have difficulty at macro and micro levels, and whether there is any correlation of difficulty at each level. Methods & Procedures: 32 Cinderella story samples were cleaned and segmented into attentional frames (10 normal controls, 16 with non-fluent aphasia and 6 with fluent aphasia). The samples were analysed for problems with macro and micro discourse levels as follows: 1. Macro level: temporal order, retrospective elements and prospective elements 2. Micro level: pronouns, definite / indefinite article omission or errors, subject +/or object omission and proportion of nominal attentional frames. Non-parametric testing was performed to determine evidence of significant differences between and within groups, and correlation across levels. Outcomes & Results: There is evidence of significant differences across groups for both macro-level variables and micro-level variables, apart from article errors. Problems with prospective and retrospective elements are correlated with the omission of subject +/or object; and high proportions of nominals are also correlated with retrospective element errors. There is no correlation between temporal order and micro-level difficulties. Furthermore inspection of the results suggest a double dissociation between temporal order difficulties and both omission of subject +/or object and proportion of nominals. 3 Conclusions: The results indicate that people with aphasia have difficulty at both macro and micro discourse levels. Furthermore, there is evidence for dissociation as well as correlation between macro and micro level errors. The results create possibilities for schematic description of aphasia across discourse levels within a cognitive linguistic paradigm. Further research is indicated regarding the pattern of correlation between levels, as well as more finely-grained analysis of the factors responsible for breakdown at the macro level.