Discourse Communication in Individuals with and without Traumatic Brain Injury

Traumatic brain injury (TBI) is a global health epidemic that has detrimental consequences for individuals who sustain the brain injury, their families, and society. As a result of TBI, many individuals experience significant cognitive-communicative impairments, including difficulties with structuring and eliciting discourse. The purpose of this study was to gain a better understanding of these language difficulties and their possible clinical implications by comparing discourse communication samples from adults with TBI to those from adults without TBI. Audio recordings of 18 adults, consisting of narratives on different genres of discourse communication (e.g., conversational, procedural, personal narrative, and fictional narrative), were used for the purposes of this project. The discourse samples of 4 individuals with TBI were compared with the discourse samples of 14 individuals without TBI on the basis of several discourse communication measures including: (1) story length, (2) frequency of discourse errors, (3) elements, (4) story organization, (5) information content, and (6) information relevance. Overall, the differences observed between the TBI and non-TBI individuals on the discourse communication tasks reflect the typical communication impairments experienced by those living with TBI. Compared to the discourse samples of participants without TBI, the individuals with TBI produced more linguistic dysfluencies and discourse errors which indicated impairments related to pragmatic skill, information transfer and relevance, linking the events in a story, and effectively structuring discourse communication. The participants without TBI showed strengths in the quality and completeness of their spoken narratives. Ultimately, the differences observed among participants from each group provide important insight into what types of speechlanguage therapy might be appropriate and effective for these individuals. DISCOURSE COMMUNICATION IN TBI & NON-TBI 3 Discourse Communication in Individuals with and without Traumatic Brain Injury Chapter 1 Traumatic brain injury (TBI) is a major cause of death and disability in the United States, contributing to approximately 30% of all injury deaths (Faul et al., 2010). According to the Centers for Disease Control and Prevention (CDC), each day 138 people in the United States die from injuries that include TBI (Faul et al., 2010). The estimated 5.3 million Americans living with TBI-related disability typically face a number of challenges in their efforts to return to a full and productive life post-injury (Langlois et al., 2006). In addition, the CDC estimated that the total cost of acute care and rehabilitation for individuals with TBI in the United States to be around $10 billion per year, not including the indirect costs to families and society (e.g., lost earnings, work time, and productivity for family members, caregivers, and employers, or the costs associated with providing social services) (CDC, 2010). Over the course of an individual’s lifetime, it can cost between $600,000 and $1,875,000 to care for a survivor of severe TBI (CDC, 2010). Nevertheless, TBI is commonly referred to as the silent epidemic because the complications that result from TBI, such as changes affecting thinking, sensation, language, or emotions, may not be readily apparent to the observer (Faul et al., 2010). TBI is “the result of a bump, blow, or jolt to the head or a penetrating head injury causing trauma to the brain and consequently disrupting normal brain function” (Faul et al., 2010, p. 140). However, not all blows or jolts to the head will result in a TBI. “The severity of a TBI may range from “mild,” i.e., a brief change in mental status or consciousness to “severe,” i.e., an extended period of unconsciousness or amnesia after the injury” (CDC, 2010, para. 3). According to Rice et al. (2003), a common cause of TBI is the impact “of a mechanical insult, through means of an external force, to the brain that causes brain tissue damage, cerebral DISCOURSE COMMUNICATION IN TBI & NON-TBI 4 inflammation, and neurodegeneration in the central nervous system” (p. 407). The resulting trauma of a TBI frequently affects the brain’s frontal, parietal, and temporal lobes (Hellawell et al., 1999), resulting in a reduction in attention, memory, sequencing, and planning (Cicerone & Kalmar, 1995). Accordingly, TBI affects executive functions and cognitive processes, which foster communication, resulting in a number of cognitive-communication deficits (Vy Tu et al., 2010). The greatest communication challenge following TBI involves the individual’s ability to engage in discourse level tasks (Alexander et al., 1989). Deficits involving longer units of language (known as the discourse level) are known to remain long after the injury (Ehrlich, 1988). These discourse tasks demand highly integrated within the individual’s cognitive, linguistic, and social skills (Alexander et al., 1989) and involve long units of language that convey a message (Galski et al., 1998). Coelho (2007) has suggested that discourse proficiency, in terms of comprehension and production, involves a complex integration of linguistic and cognitive organizational processes. Furthermore, communication impairments following TBI are often difficult to delineate objectively (Coelho, 2007). However, the communication deficits resulting from TBI are often apparent during complex communication, which include the various forms of discourse, such as procedural, narrative, and conversational discourse, as opposed to disruptions at the word or sentence levels (Cannizzaro & Coelho, 2012). Some of the comorbid characteristic features of discourse communication following TBI include: increased dysfluency, reduced length of output, extended silent pauses, rapid topic shifts, and poor cohesion, along with limited efficiency, content accuracy, and semantic connectivity (Hartley & Jensen, 1991). Moreover, discourse following TBI has been characterized as off-target, disorganized, tangential, and constantly distracted from the point by DISCOURSE COMMUNICATION IN TBI & NON-TBI 5 trivial associations with environmental stimuli (Alexander et al., 1989). Additionally, individuals with TBI often display a number of behavioral deficits including apathy and socially inappropriate activities along with a lack of self-monitoring in conversation (Alexander et al., 1989). As a result of the numerous cognitive-communication difficulties, conversations with individuals with TBI have been rated as less interesting, less appropriate, less rewarding, and more effortful than conversations involving individuals without brain injury (Bond & Godfrey, 1997). Disruptions at the discourse level have also been linked with a number of negative social outcomes (Sim et al., 2013). These disruptions may continue for several years after the initial onset of a TBI and appear to have a negative impact on quality of life (Coelho, 2007). Overall, this loss of social communicative competence poses a major obstacle for the individual’s reintegration into the community (Dahlberg et al., 2007), and these difficulties have been linked to social isolation, increased reliance on family for social support, and significant problems returning to work, school, and premorbid avocations (Coelho et al., 2002). Coelho (2007) has suggested that discourse analysis is sensitive to the subtle communication deficits that are commonly demonstrated by individuals with TBI and are an integral aspect of the assessment process with this population. Furthermore, it has been suggested that discourse is an important point of intersection between language and cognition, requiring an intervention centered on cognition (Cannizzaro & Coelho, 2012). The analyses from samples of discourse language provide integral information regarding linguistic, cognitive, and social functioning, which can be very useful in designing customized interventions and treatment plans for individuals with TBI (Coelho, 2007). Ultimately, discourse studies involving the TBI DISCOURSE COMMUNICATION IN TBI & NON-TBI 6 population have varied relative to the type of discourse task. This study focused on procedural, narrative (fictional and personal), and conversational discourse analysis measures. Significance Examining the discourse tasks of individuals with TBI compared to non-TBI individuals provides important insight into which aspects of communication and language these individuals have difficulty with as a result of their injury, along with which aspects of communication and language these individuals excel in. Further research may help identify which areas of communication could be improved upon through means of speech-language therapy and other interventions. Disrupted discourse in this population has frequently been regarded as a serious handicap and a major obstacle to community reintegration (Galski et al., 1998). Unsurprisingly, this significant difficulty with discourse language is related to decreased quality of life, and can also result in a reduction in employment and academic opportunities (Togher, 2013). Understanding the challenges regarding certain difficulties with discourse and communication experienced by individuals with TBI could also lead to better clinical interventions. For instance, the utilization of communication partners who use story organizers, or support conversation through means of collaboration/elaboration may benefit individuals with disrupted discourse (Togher, 2013). Furthermore, adding to the body of literature regarding the difficulties with different discourse genres that individuals with TBI experience has important clinical implications that could eventually lead to improved effectiveness of speech-language therapy for the individuals affected by TBI. Due to the high incidence and prevalence of TBI, large monetary costs, and its detrimental impact on aspects of quality of life, it is imperative that TBI be