The Impact Of Neurological Fatigue On Linguistic Choices After TBI

Traumatic brain injury (TBI) is one of the leading causes of death or long-term disability in the United States. Individuals with these injuries must adapt to significant changes in neurological functioning, and oftentimes attention, memory, and processing difficulties mean that these individuals feel overwhelmed by the onslaught of information provided by the outside world, leading to mental fatigue. Mental fatigue, a common consequence of a TBI, may influence an individual’s ability to participate effectively in previous everyday work and social activities. Thus, it is not surprising that many individuals with TBI report significant fatigue. Research in the area of fatigue post injury has indicated that there is a relationship between fatigue and physical, cognitive, emotional, and social factors. Individuals with linguistic difficulties due to TBI related fatigue may experience difficulty with functional language, and understanding these deficits is critical for speech-language pathologists, who must understand the implications of fatigue on a client’s ability to communicate effectively. Systemic functional linguistics (SFL) is a theory of language use that focuses heavily on linguistic choices as influenced by social context. This research used principles from SFL to investigate the language use of one individual after a moderate-severe TBI. The individual’s interactions were analyzed to examine changes in her ability to successfully negotiate interactions that are secondary to the effects of fatigue. Overall findings indicated significant differences in the participant’s use of modality and appraisal between non-fatigued and fatigued samples. Differences include increases in the participant’s use of inclination and potential in modal auxiliaries, which demonstrate the participant’s aspirational tone during non-fatigued language samples, as well as increases in negative appraisal during fatigued samples, demonstrating negative emotional involvement in these exchanges. These differences are discussed in light of assessment and self-reported survey results and implications for treatment are outlined.