Preamble
This chapter was published as an article in Neuropsychology Review (VanSolkema et al., 2020). This journal article marked the beginning of my journey in exploring the topic. I knew that both constructs of attention and communication following TBI were vast. I wanted to capture the story of how previous researchers explored these areas, as well as determine if my question was new or novel. When identifying and selecting a methodology to use for my literature review, I spent time reviewing and exploring epistemology and how my worldviews as a clinician shaped my entire project. I was drawn to the familiarity of postpositivism, which seeks to measure objective reality that exists “out there” in the world. This allowed me to start with what I knew, which were the theories of attention and communication.
Positioning myself within the project and acknowledging that I do not see attention and communication as a single discipline-specific area of study but instead understand that multiple perspectives and research paradigms are involved. This perspective and approach aligned with a meta-narrative systematic review using the RAMESES methodology fit (Greenhalgh et al., 2005; Wong et al., 2013). Meta-narrative review is rooted in a
constructivist philosophy of science and was inspired by the work of Thomas Kuhn, who observed that science progresses in paradigms (Kuhn, 1970). Using this methodology, I could be comprehensive in my search and descriptions, alongside positioning these constructs in a historical manner to understand their evolution over the decades. I also wanted to capture the entire research landscape involved with attention and communication following TBI to understand how these terms were defined and conceptualised. My literature review did not seek to review a type of treatment nor a meta-analysis in the quantitative realm. Instead, it acknowledged the project as encompassing a mixed methods design that touched on
storytelling. I was able to begin this journey of finding evidence that would shape the rest of my doctoral project.
Introduction
A TBI is defined as an alteration in brain function or other evidence of brain pathology caused by an external force (Menon et al., 2010). The effects of a TBI on an individual’s functioning can be vast and devastating, ranging from physical changes (Ponsford, Downing, et al., 2014), sensory changes (Ponsford, Downing, et al., 2014), cognitive and social changes (McDonald et al., 2014a; Ponsford, Bayley, et al., 2014;
Ponsford, Downing, et al., 2014; Tate et al., 2014; Velikonja et al., 2014) to changes with communication and language (Colantonio et al., 2009; Elbourn et al., 2019; MacDonald, 2017; Togher, Wiseman-Hakes, et al., 2014). Two areas of functioning impacted by moderate-severe TBI and are the focus of this review are communication and cognition, particularly attention.
Communication After TBI
Communication difficulties are one of the hallmark characteristics of adults who present with TBI and can be either subtle or overt depending on a multitude of factors such as the environment and communication partners (Halper et al., 1991; MacDonald, 2017;
MacDonald & Wiseman-Hakes, 2010; Togher, McDonald, et al., 2014; Togher, Wiseman- Hakes, et al., 2014). Communication difficulties following TBI are specific to each person, depending on injury factors such as locus of the lesion, severity of injury, and type of injury.
The resulting cognitive, linguistic, emotional, physical, and behavioural changes contribute to communicative competence following TBI (MacDonald, 2017; McDonald et al., 2014b). In addition, communication difficulties can present not as a language disorder of form, such as aphasia, but a disorder in the use of language or ability to adhere to social rules that govern
an interactive exchange between people as seen within discourse and pragmatic language use (McDonald, 1998; McDonald et al., 2014b).
Cognitive Communication Disorder
This interactive exchange and complex interplay can also be referred to as cognitive communication and is frequently disordered following TBI. Cognitive communication disorder (CCD) is used to differentiate language difficulties post-TBI from the disorder of aphasia. CCD affects 80%–100% of adults with moderate-severe TBI (MacDonald &
Wiseman-Hakes, 2010). The American Speech-Language Hearing Association (ASHA, 2007a) defines CCD as difficulty with any communication aspect resulting from deficits or disruption of cognitive functioning. Communication includes listening, speaking, gesturing, reading, and writing in all language domains (e.g., phonologic, morphologic, syntactic, semantic, and pragmatic). Cognition includes cognitive processes and systems (e.g.,
processing speed, attention, memory, organisation, and executive functions) (ASHA, 2007a).
Areas of function affected by cognitive impairments include behavioural self-regulation, social interaction, activities of daily living, learning, and academic and vocational
performance (ASHA, 2007a). Further communication deficits associated with TBI relate to discourse, language, interpersonal communication, and affect recognition. These include tangentiality, topic maintenance, and social communication skills associated with interpreting emotions and social cues. Language difficulties following TBI relate to listening or auditory comprehension, verbal expression or word finding, subvocal rehearsal or self-talk, verbal response speed, verbal reasoning, and reading comprehension (McDonald et al., 2014b).
Attention After TBI
Attention or concentration difficulty is an area of cognition that affects 50% of people following TBI long-term (Ponsford, Downing, et al., 2014; van Zomeren & Van den Burg, 1985). This core cognitive process is considered a foundation for all other cognitive skills
(Cohen et al., 1993) and is the focus of the current review. William James’s (1890) definition of attention started the discussion about this cognitive concept,
Everyone knows what attention is. It is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought. Focalization, concentration, of consciousness are of its essence. It implies withdrawal from some things in order to deal effectively with others. (pp. 403–404) This process can be interpreted to be central to the function of communication. Over time, the exploration and definitions of attention have evolved, with periods of great discovery in the mid-20th century (Baddeley, 1986; Norman & Shallice, 1986; Posner & Petersen, 1990;
Schneider & Shiffrin, 1977; Shiffrin & Schneider, 1977) with further refinement and a shift to a more functional or natural observation of attention in everyday life, especially when viewing TBI within the context of social and communicative functioning (Beauchamp &
Anderson, 2010; McDonald et al., 2014b; Stierwalt & Murray, 2002; Youse & Coelho, 2009).
Multiple definitions and terminology for attention have been used within the literature. For this review, the fundamental concepts of attention will include Posner and Petersen’s (1990) three systems of functions of attention. Namely, 1) involves orienting to sensory events or arousal; 2) involves target detection and selecting sources of information from external stimuli and internal stimuli or memory to be processed; and 3) involves maintaining an alert or vigilant state over time for further processing of information paired with action (Posner & Petersen, 1990). Attention can be defined clinically as separate entities involving different aspects of concentration. The clinical model of attention from Mateer and Sohlberg (2001) separates attention into subtypes and provides a model of attention that relates to the behaviours of function. It is separated into five distinct attention processes:
Focused attention: The ability to respond discretely to specific visual, auditory, or tactile
stimuli; Sustained attention: The ability to maintain a consistent behaviour response during continuous and repetitive activity, where vigilance is maintained over time during continuous activity. This also implies working memory in which the mind actively holds and manipulates information; Selective attention: The ability to maintain a behavioural or cognitive set in the face of distracting or competing stimuli. Freedom from distractibility; Alternating attention:
Capacity for mental flexibility that allows individuals to shift their focus of attention and move between tasks with different cognitive requirements, thus controlling what information will be selectively processed; Divided attention: Ability to respond simultaneously to
multiple tasks or multiple task demands and where multiple simultaneous task demands are being managed (Mateer & Sohlberg, 2001). Another critical definition of attentional
functioning is the Supervisory Attentional System (SAS), where attention operates as a control function of multiple schemas to either activate or inhibit behaviour depending on motivation and goal-related behaviour (Norman & Shallice, 1986). SAS is seen to be related to other attentional terms of executive functioning, or where attention is a control function for further cognitive abilities. Finally, aspects of memory can also be included in the definition of attention, such as attention span and working memory, where visual or auditory information is held momentarily and has limited capacity but is still processed (Baddeley, 1986). The processing of multiple stimuli can also be viewed as a system that modulates language
through the cognitive process of executive functioning and attention. “All executive functions require the continuous modulation of attention across brief time spans” (Alexander, 2006a).
Executive function is a cognitive ability that has long been part of the attention debate and multiple models view attention to be part of executive function or controlling function (Alexander, 2006; Baddeley, 1986; Lezak, 1983; Luria, 1969; Norman & Shallice, 1986;
Posner & Petersen, 1990; Pribram & McGuinness, 1975; Ylvisaker & DeBonis, 2000).
Executive function can be viewed as a system that controls and modulates behaviours based
on goals both internal and external. Executive function is best represented as a core set of abilities, including regulating or inhibiting behaviours and emotions; self-monitoring and changing behaviours in response to “online” information from the immediate environment and from past experiences; allocation of attention to support the constant changing or modulation of new information; problem-solving and decision making; metacognition;
adapting mental flexibility; organisation and planning; and working memory (Baddeley, 1986; Goldstein & Naglier, 2014; Lezak, 1983; Luria, 1969).
The complex acts of communication following TBI and attention following TBI have been researched extensively separately, but the joining of the two empirically has been attempted by only a few authors (Alexander, 2006a; Hinchliffe, Murdoch, Chenery, Baglioni, et al., 1998; Isaki & Turkstra, 2000; Kurland, 2011; Peach, 2013a; Stierwalt & Murray, 2002;
Youse & Coelho, 2009). There remains a lack of empirical research that successfully links these two complex behaviours and processes. One possibility for why this has not occurred is the sheer number of disciplines and methodologies that conduct research into attention and communication following TBI. The current review aims to tell the story of how attention and communication have evolved over the past century and how they have been researched within the scope of TBI. A second aim is to link these two complex concepts into a manageable construct that can be further refined through future research. (Figure 2.1).
Methods
A meta-narrative systematic review (Greenhalgh et al., 2005) was undertaken to explore a heterogeneous body of research exploring the areas of attention and communication abilities following TBI in adults. This methodology was specifically chosen because it helps to address the complexity and diversity of the two topics being studied. Multiple disciplines and various research traditions have reviewed these topics, all of which contribute to the overall meaning, with a limited number of studies looking specifically at how attention
abilities contribute to or interact with communication skills following TBI in adults.
Acknowledgment and inquisitive exploration of these research traditions are required to build a more comprehensive theory and understanding of how communication and attention
abilities interact with one another following TBI. Separating the two in the literature has offered essential insights into the difficulties experienced by adults following TBI. Placing these two concepts side by side can offer more specific guidance into the complicated but important relationship between them.
Figure 2.1
Aim of the current review
The systematic approach of meta-narrative methodology has previously been outlined within a structured framework, and quality reporting standards have been described in the RAMESES project (Wong et al., 2013). The application of this approach is provided in Table 2.1, and each phase is outlined below.
Table 2.1
Meta-Narrative Review Phases (Adapted from Greenhalgh et al., 2005) Meta-Narrative Phases
Meta-narrative review - Historical perspective - Disciplines / Research
traditions - Theories
Communication Diffculties
Traumatic Brain Injury Attention /
Concentration
Difficulties
1. Planning Phase
a. Multidisciplinary team (MDT) that incorporates the relevant research traditions:
neuropsychology, speech language pathology, health researcher, and subject librarian.
b. Outline the initial research question in a broad, open-ended format:
i. What is the relationship between attention and communication in adults following TBI?
ii. What aspects of attention interact with communicative abilities in adults?
2. Search Phase
a. Scoping the literature – Initial search led by intuition, informal networking and “browsing” with the goal of mapping the diversity of perspectives and approaches.
i. Communication: theories, cognitive communication, social communication, discourse, social cognition, emotional regulation, communication difficulties following TBI, sociolinguistic.
ii. Attention: theories, executive function, working memory, information processing, types of clinical attention.
iii. Perspectives from speech language pathology, psychology, neuropsychology, and cognitive neuroscience.
b. Search for seminal conceptual papers in each research tradition by tracking references of references. Evaluate these by the generic criteria of scholarship, comprehensiveness, and contribution to subsequent work within the tradition.
c. Search for empirical papers by electronic searching key databases and reference lists of key papers (1st–3rd phases).
3. Mapping Phase
Identify (separately for each research tradition):
i. The key elements of the research paradigm (conceptual, theoretical, methodological and instrumental).
ii. The key actors and events in the unfolding of the tradition (including main findings and how they came to be discovered).
iii. The prevailing language and imagery used by scientists to “tell the story” of their work.
iv. identification of key groups/ of topics reviewed and relating to the review question.
v. Allow multiple phases (4th–6th phases) of mapping for refinement of the articles chosen to be included in the final group.
4. Appraisal Phase
Using appropriate critical appraisal techniques/quality assessments:
i. Evaluate each primary study for its validity and relevance to the review question.
ii. Extract and collate the key results, grouping comparable studies together.
5. Synthesis Phase
a. Identify all the key dimensions of attention and communication following TBI that have been researched.
b. Taking each dimension in turn, a narrative account of the contribution made to it by each separate research tradition.
c. Treat conflicting findings as higher order data and explain in terms of contestation between the different paradigms from which the data were generated.
6. Recommendation Phase
Through reflection, multidisciplinary dialogue, and consultation with the intended users of the review.
i. Summarise the overall messages from the research literature along with other relevant evidence.
ii. Distil and discuss recommendations for practice, policy, and further research.
Search Phase
The initial phases of scoping the literature began with reviewing literature led by intuition, informal networking, and “browsing” within TBI and CCDs (MacDonald &
Wiseman-Hakes, 2010; Ponsford, Janzen, et al., 2014). This was the starting point to begin
exploring other disciplines within the field of TBI that have researched the topic of attention and communication. Within the initial scoping phase, the research paradigms of
neuroscience, cognitive psychology, neuropsychology, SLP, and medicine were present and were the leading disciplines to study the topic of attention extensively. These research traditions emerged looking at attention with varying definitions, instruments of assessment, specificity, and functionality.
A comprehensive initial search was carried out exploring multiple databases and key journals that would incorporate the pluralism of disciplines that research the core concepts, including Pub Med, Library of Congress, PsychArticles, PsychBITE, PsychINFO,
SpeechBITE, PsychEXTRA, Linguistics and Behaviour, Medline, Psychology and
Behavioural Sciences Collection, Scopus, Embase, CINAHL, Journal of Head Trauma and Rehabilitation, ASHA wire, University of Auckland library catalogue, and further informal searches through previous literature scoping and examination of references contained within key papers. The time frame for the search was January 1900 to January 2019. Search terms included: attention, and/or communication, and/or TBI. Further refinement of the searches was completed by including the more specific and alternative keywords: adults, English, attention, cognition, language processing, traumatic brain injuries, head injury, cognitive communication, and executive functioning.
The total number of articles that emerged from the initial search phase was 38,063.
Selection of Documents
The inclusion criteria for document selection, based on each paper’s title, abstract, or keywords, required the following: human population/sample with TBI or head injury. The inclusion criteria for selecting full scientific articles required the following: an aspect of attention (e.g., sustained, divided, alternating, selective, focused); adult population 18 years or older; written in English. Alternative acceptable words or terms included listening,
working memory, social cognition, discourse, social communication, language processing, and executive functioning. The multiple and closely associated definitions and theories of attention (e.g., working memory, executive functioning, and listening) within the different research paradigms were included to ensure a fully comprehensive understanding of attention as it relates to communication.
The exclusion criteria were used to exclude papers that focused on different clinical populations, aetiologies, and disorders of acquired brain injury. Acquired brain injuries that include stroke and hypoxic/anoxic brain injuries were excluded, as these represent different aetiologies that could potentially impact the findings. TBI is a heterogeneous group that, at best, should be compared alongside each other rather than against all types of acquired brain injury. Papers were excluded if it was clear that attention was not assessed (e.g., abstract reasoning). The final inclusion term CCD, joins cognitive abilities with communication abilities. This term can be broad but needs to be included because articles about CCD typically discuss attention within their definition.
The remaining exclusions were pragmatically determined during the final sixth phase of review. All assessment and treatment literature were removed from the search as it was not within the scope of this review. While reviewing the literature on topics of communication, multiple avenues could have been explored. The decision was made to exclude skills associated with reading, writing, and literacy and literature that did not indicate a clear reference or description to the topic of attention being evaluated because this is separate from the functional act of communication.
After applying the exclusion criteria, there were 1,499 articles; after removing duplicates, there were 576.
Mapping / Appraisal / Synthesis Phases
Data extraction included key elements that were anticipated to provide important historical, theoretical, and overall area of study that could begin to bridge the concepts of attention abilities and communication skills. The data extracted from the literature during the fourth phase of mapping included author(s), date, discipline, research tradition, key concept or question, theory, level of evidence, methods, tools or assessments used, types of attention, types of communication, key findings from each paper, and source of literature. The articles were organised within eight groups: one main group with seven subgroups. The main group comprised those papers which covered attention and communication. Subgroups included those papers which separately represented each of the following: attention, executive function, working memory, cognition, cognitive communication, discourse, and emotional recognition/affect recognition. These eight groups were created following the fifth phase of mapping.
Theories
The cognitive communication concepts that emerged during the fifth phase from the set of 74 articles were recorded to track the theories or themes most commonly used to indicate the key theoretical ideas that potentially hold the most empirical weight. The process of capturing theories occurred during the initial scoping phase but also during the fifth phase of mapping. Theories were placed in a matrix that charted the progression over time as well as the discipline responsible (see Table 2.2). The analysis of theories recorded the frequency of most reported or referenced theories within the set of literature reviewed. Historicity was captured through the development of key attentional theories over time. These theories were also set against other cognitive communication or discourse-based theories to extend the larger picture of how these concepts evolved and overlapped over time. General cognitive theories were reviewed and were reflected in the context of the TBI population.