Text comprehension in residual aphasia after basic-level linguistic recovery: a multiple case study

Abstract

Background: Text comprehension entails a complex interaction between cognitive and linguistic factors. In ageing, text comprehension depends on text characteristics, particularly semantic load. Persons with residual aphasia may complain of discourse comprehension difficulties without linguistic problems. Three levels of representation are involved in text comprehension (surface level, semantic level constituted by macrostructure and microstructure and situational level). Attention, verbal working memory, long-term memory and executive functions combine to allow processing of all levels of representation.Aims: The primary objectives of this multiple case study were (1) to examine microstructure, macrostructure and situational model updating in text comprehension in five participants with left-brain damage (PWLBD), who continued to complain about problems with discourse comprehension without linguistic problems, and (2) to examine executive function and memory in these participants.Methods & Procedures: Five PWLBD were selected for the study. We asked the participants to read and understand three narrative texts. The texts varied according to semantic load (the amount of information). In each text, we assessed macrostructure, microstructure and situational model updating. To evaluate memory and executive functions, we administered specific complementary tasks. Results were compared to normative data obtained from a previous study with a total of 60 neurologically intact control participants, divided into younger (N = 30) and older (N = 30) groups.Outcomes & Results: The results of the five PWLBD indicated that text comprehension is influenced by text characteristics, particularly semantic load; the findings demonstrated short-term memory and cognitive flexibility deficits.Conclusions: These findings have two major implications. Analysing text comprehension using several texts with varying semantic loads is a promising tool for diagnosing residual aphasia and for designing specific cognitive interventions that target reading comprehension abilities in persons with residual aphasia.