Rehabilitation of Children and Adults With Cognitive-Communication Disorders After Brain Injury
Mark Ylvisaker, Robin Hanks, and Doug Johnson-Greene
About this Document
This technical report was prepared by Mark Ylvisaker, Robin Hanks, and Doug Johnson-Greene, on behalf of the Ad Hoc Joint Committee on Interprofessional Relationships of the American Speech-Language Hearing Association (ASHA) and Division 40 (Clinical Neuropsychology) of the American Psychological Association (APA). ASHA representatives included Pelagie Beeson, Susan Ellis Weismer, Audrey Holland, Susan Langmore, Lynn Maher, Diane Paul-Brown (ex officio), and Mark Ylvisaker. Alex F. Johnson, ASHA vice president for professional practices in speech-language pathology (2000–2002), was monitoring vice president. APA representatives included Kenneth Adams, Sharon Brown, Jill Fischer (chair, 1997–1999), Robin Hanks, Doug Johnson-Greene, Sanford Pederson, Steven Putnam, and Joseph H. Ricker (chair, 2000–2002). The ASHA- Special Interest Division 2 (Neurophysiology and Neurogenic Communication Disorders) Working Group on Cognitive-Communication also assisted with the development of this report. Working group members are Lynn Maher (chair), Ron Gillam, Leora Cherney, Dava Waltzman, Mary Kennedy, Mark Ylvisaker, Diane Paul-Brown (ex officio), and Alex Johnson (monitoring vice president). The technical report was approved by ASHA's Executive Board (EB 35-2002).
Professionals from diverse disciplines, including clinical neuropsychology and speech-language pathology, provide cognitive rehabilitation services. The functional domains affected by cognitive disability—such as activities of daily living, communication, learning and academic performance, vocational performance, behavioral self-regulation, and social interaction—extend into the scope of practice of many rehabilitation professions. Therefore, cognitive rehabilitation has been aptly described as a collaborative service (American Speech-Language-Hearing Association, 1995).
This report was developed to examine two theoretical paradigms, based on relevant theory, available empirical studies, clinical experience, and trends in service delivery and reimbursement. The specific purposes of this report are threefold: (a) to explore the historical and conceptual foundations of cognitive rehabilitation for individuals with brain injury; (b) describe alternative paradigms for service delivery; and (c) promote studies examining efficacy of cognitive rehabilitation, particularly studies that employ novel and theoretically sound paradigms. It is beyond the scope of this report to systematically review the efficacy literature. Readers are directed to Carney and colleagues (1999) and Cicerone and colleagues (2000) for evidence reviews.
Although this report was developed to address service issues related to individuals with cognitive impairments associated with acquired brain injury, the theoretical and practical considerations apply equally to children and adults whose impairments are congenital. Indeed, theory construction and clinical research have a longer history in work with the latter population. Mann (1979) and Kavale and Forness (1999) discuss the distinction between process-oriented and context -sensitive approaches applied to developmental disabilities and special education, and summarize relevant literature.
Specific definitions of cognitive rehabilitation typically include assumptions about cognition or rehabilitation that can be disputed. Nevertheless, discussion of a topic should begin with a general characterization of the topic. The following definition of cognitive rehabilitation is taken from the widely distributed 1998 NIH Consensus Statement on Rehabilitation of Persons With Traumatic Brain Injury:
The goals of cognitive and behavioral rehabilitation are to enhance the person's capacity to process and interpret information and to improve the person's ability to function in all aspects of family and community life. Restorative training focuses on improving a specific cognitive function, whereas compensatory training focuses on adapting to the presence of a cognitive deficit. Compensatory approaches may have restorative effects at certain times. Some cognitive rehabilitation programs rely on a single strategy (such as computer-assisted cognitive training); others use an integrated or interdisciplinary approach. A single program can target either an isolated cognitive function or multiple functions concurrently (NIH, 1998).
Later in this report we discuss the possible value of adding context-oriented interventions to the scope of cognitive rehabilitation, including improving the support behaviors of significant people in the person's environment and modifying task and environmental demands in a way that enables a person with chronic cognitive impairment to participate successfully in family and community life. Using the most recent 2001 modification of the World Health Organization (WHO) International Classification of Functioning, Disability and Health (ICF) framework, these interventions would fall under the heading, Contextual Factors/Environmental Factors (WHO, 2001). We also return later to a theme introduced in the NIH statement, that the distinction between restoration and compensation may not be as clear as past discussions have suggested.
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The modern history of cognitive rehabilitation for individuals with brain injury extends as far back as World War I, when large numbers of soldiers and civilians needed comprehensive rehabilitation after war-related traumatic brain injury (TBI). Cognitive rehabilitation in the United States gained momentum during the 1970s, with the organization of emergency medical services and consequent increases in survival rates following severe TBI. As a discrete service, cognitive rehabilitation came to be associated with rehabilitation programs developed jointly by the Israeli Ministry of Defense and the New York University Institute of Rehabilitation Medicine after the 1973 Yom Kippur war (Boake, 1989). Cognitive rehabilitation has become a common rehabilitative service for survivors of TBI in both acute and postacute rehabilitation settings, following proliferation of rehabilitation programs in the 1980s.
Cognitive rehabilitation, as currently conceptualized, is a service that has been both widely praised and criticized. There may be several reasons for the controversial nature of this service. First, because it has no clear professional home, individuals with varied educational backgrounds who may use many different conceptual frameworks deliver cognitive rehabilitation services. In such circumstances, controversies about the nature of the service and its method of delivery are almost inevitable. Second, there currently exist no generally agreed-on standards of clinical practice in this area of service delivery, despite an initial attempt by the Interdisciplinary Special Interest Group of the American Academy of Rehabilitation Medicine to establish basic guidelines for cognitive rehabilitation (Harley et al., 1992). Third, studies of treatment efficacy tend to be methodologically weak and frequently report ambiguous results (Carney et al., 1999; Park & Ingles, 2001). Finally, in some settings the service has been trivialized by indefensible practices implemented by inadequately trained practitioners (e.g., unsystematic exposure of clients to video games or other games; haphazard use of workbooks and cognitive retraining software on the often unsupportable assumption that engagement of a cognitive process in cognitive exercises will improve that process and thereby improve performance on real-world tasks that involve the process).
These controversies have led many critical observers, including many referring physicians, health insurance and health maintenance companies, state and federal oversight bodies, and consumers of rehabilitation, to question the service as lacking an accepted theoretical structure and insufficiently supported by well-designed studies of effectiveness, including evidence of meaningful impact on functional outcome. Furthermore, the rise of managed care and other cost-containing efforts in rehabilitation has created an atmosphere that does not tolerate services lacking official standards of practice and firm empirical support, with emphasis on functional outcome.
The Oregon Health Sciences University, under a contract with the Agency for Health Care Policy and Research, recently conducted a systematic review of the scientific literature dealing with the effectiveness of cognitive rehabilitation. This review identified very few reasonably controlled studies that yielded evidence supporting the effectiveness of cognitive rehabilitation in relation to functional outcome (e.g., employment, social reintegration; Carney et al., 1999). Furthermore, studies restricted to intermediate measures of outcome (e.g., performance on neuropsychological tests or customized laboratory measures) produced mixed results. A more recent review (Cicerone et al., 2000) yielded more positive results. However, it is likely that the inclusion of interventions targeting specific domains of content (e.g., language intervention for individuals with aphasia and social communication limitations) is partially responsible for the relatively optimistic conclusions of this systematic literature review.
Methodological weaknesses and inconsistencies abound in this growing body of efficacy literature. However, they can be charitably interpreted as the natural consequence of the relative youth of the field, extraordinary diversity within the population of people with cognitive disability, and varying conceptual frameworks within which interventions have been designed and implemented. Lack of support for an intervention does not constitute sufficient evidence to invalidate the approach. It was within this context that our interdisciplinary committee chose to examine possible alternatives to the conceptual framework that has dominated the service of many, but not all, providers of cognitive rehabilitation.
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We have chosen to describe two distinct conceptual frameworks for cognitive rehabilitation by outlining their positions in five domains needed to define a comprehensive theory of intervention. These domains are outlined in Table 1. Within each domain, what has come to be understood as the “traditional approach” to cognitive rehabilitation, that which dominated clinical activity during the early years of active program development in the 1970s and early 1980s, is compared to a “contextualized” paradigm, defined as a context-sensitive framework. The latter approach has evolved in recent years as a consequence of (a) research and clinical experience with individuals with TBI, (b) findings and theoretical developments in cognitive science, and (c) reflection on related intervention research and trends in fields with a longer history of service and outcome research than cognitive rehabilitation for individuals with brain injury. In offering two alternative frameworks, we recognize that all attempts to dichotomize complex domains are fraught with peril and that clinicians often choose to serve individuals using intervention strategies from alternative frameworks.
Table 1. Traditional and Contextualized Approaches to Cognitive Rehabilitation
Throughout this discussion, the WHO definitions of body structure/function (i.e., impairment), activity/participation (previously two categories—activity reduction [disability] and participation reduction [handicap]), and contextual factors were chosen to describe the applications of the traditional versus the contextualized paradigms (WHO, 1980; augmented in WHO, 1998, 2001). Within this classification system, body structure/function limitations refer to the underlying damage to psychological, physiological, or anatomic structures or functions (e.g., aphasia associated with perisylvian left hemisphere stroke). Activity/participation limitation refers to an associated reduction in the ability of an individual to execute tasks in a standardized environment (i.e., capacity) or to perform functional activities of everyday life (e.g., finding words during a conversation) in a natural environment (i.e., performance), and contextual factors refer to a social, familial, educational, vocational, or other role disadvantage associated with the disability (e.g., failure in school or loss of a job due to the communication disability). Contextual factors include both environmental factors (including attitudes of individuals in the environment) and personal factors (including attitudes of the person with disability). Context-oriented assessment and intervention would explore the supports available in the environment and attempt to improve those supports, including the support behaviors of significant people in the environment.
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Within traditional cognitive rehabilitation, the primary treatment goal is to improve an individual's performance by eliminating or reducing underlying cognitive impairments (Ben Yishay, Piasetsky, & Rattok, 1987; Meier, Benton, & Diller, 1987; Sohlberg & Mateer, 1989). That is, the focus of intervention is the underlying impairment and the goal is largely curative or restorative. With cure or restoration of cognitive function as the goal, intervention is largely restricted to hierarchically organized retraining exercises that target specific cognitive processes impaired by the injury. Exercises may be augmented by pharmacologic intervention. In the event of inadequate restoration of cognitive function with restorative exercises, clinicians often attempt to help the individual acquire compensatory behaviors (e.g., internal mnemonics or organizational strategies, self-cueing) or assistive devices (e.g., memory books, pager reminder systems). These methods are designed to reduce real-world disability despite enduring cognitive impairment. Whether restorative or compensatory, the goal is to improve outcome by directly changing the patient's impaired cognitive functions.
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Within a flexible and contextualized approach to rehabilitation, the broad goal is to help individuals with cognitive disabilities achieve functional objectives and participate in chosen activities that are at least temporarily blocked by the impairment. Depending on a variety of factors, the approach might include any combination of the following interventions:
Body structure/function-oriented interventions designed to improve real-world functioning by restoring cognitive functions with decontextualized retraining exercises, if there is good reason to believe that retraining exercises hold restorative potential.
Activity/participation interventions designed to improve real-world functioning by helping the individual to compensate for chronic cognitive impairment, if there is good reason to believe that strategic compensation is possible, and to improve performance of specific, functional tasks, thereby reducing disability without necessarily reducing the underlying impairment.
Context-oriented interventions designed to lessen the impact of cognitive disability on real-world status and functioning by engineering the individual's environment to reduce the impact of cognitive disability and by modifying the expectations and supportive behavior of people in the individual's everyday life (i.e., providing education, training, problem solving, and other forms of support).
With respect to breadth of focus, cognitive rehabilitation within the contextualized paradigm is analogous to physical rehabilitation. That is, clinicians are accustomed to making responsible decisions about combinations of body structure/function-oriented interventions (e.g., surgery, pharmacology, physical exercises and manipulations), activity/participation-oriented interventions (e.g., use of compensatory motor patterns and prosthetic equipment) and context-oriented interventions (e.g., environmental modifications, specialized supports provided by others). Efforts of the physical rehabilitation team may have a profoundly positive effect on an individual's success with everyday tasks without necessarily changing the profile of physical abilities. Similarly, cognitive rehabilitation may be effective in individual cases despite minimal change in cognitive impairments or even in specific performance abilities.
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Cognitive, neuropsychological, language, and related assessments can serve many distinct and important purposes. Comments in this section are restricted to assessment designed exclusively for purposes of developing, monitoring, and modifying intervention plans for children and adults with cognitive impairment after brain injury.
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Within the traditional approach, assessment is generally centered around a battery of tests of neuropsychological/cognitive functioning, resulting in judgments about areas of cognitive weakness that need to be strengthened and areas of strength that can be used to compensate for ongoing weaknesses. Often the same standardized tests and laboratory tasks that are used to create a profile of abilities and disabilities are also used to measure responses to treatment. This approach to assessment is consistent with a view of cognition in which discrete processes can be measured separately and strengthened with exercises, and when strengthened, support improved performance of tasks of everyday life. It is therefore natural to use the same assessment procedures for both diagnostic and treatment planning/monitoring purposes and to assume that functional, real-world improvements would be associated with improvement on standardized, laboratory measures. Recent reviews of efficacy studies in this field have been critical of the capacity of these measures to assess functional, real-world outcomes and long-term maintenance of treatment gains. Similarly, the validity of contextualized measures has been found to be superior to standardized neuropsychological tests in the context of vocational planning after TBI (LeBlanc, Hayden, & Paulman, 2000). Also criticized has been the circular reasoning involved with using the same measures as predictor and criterion (Carney et al., 1999).
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Within the contextualized approach, standardized tests are used to help delineate areas of cognitive strength and weakness, and to generate hypotheses about potentially fruitful approaches to rehabilitation. However, standardized tests are supplemented by situational observation (to confirm and enrich or to disconfirm test findings) and by ongoing, contextualized hypothesis testing, designed to systematically explore strategies, task modifications, supports, intervention procedures, and other variables that might positively influence task performance and learning. Test performance, if used as a measure of the effectiveness of intervention, is supplemented by carefully planned and reliably documented observation of the individual's in-vivo task performance (including documentation of the supports provided). Testing is supplemented by global markers of functional improvement, such as maintained employment, maintained independent living, success in school, reduction of caregiver burden, and reduction of cost for medical care. Finally, assessment for planning context-oriented intervention must include measures of the knowledge and support skills of the people in the everyday life of the person with a disability.
Contextualized observation is mandated by the frequent finding that people with TBI, particularly those with frontal lobe injury, often perform surprisingly better or worse in everyday contexts than can be predicted from standardized test performance (Crépeau, Scherzer, Belleville, & Desmarais, 1997; Dennis, 1991; Dywan & Segalowitz, 1996; Eslinger & Damasio, 1985; Grattan & Eslinger, 1991; LeBlanc et al., 2000; Lezak, 1982; Norris & Tate, 2000; Stuss & Buckle, 1992; Varney & Menefee, 1993; Wilson, 1993). Ongoing assessment for planning intervention is necessitated by neurologic improvement that may occur for months or longer after some types of severe brain injury, or by the individuals' unpredictable responses to rehabilitation and to life after the injury.
A major aspect of assessment for cognitive rehabilitation within a contextualized paradigm is collaboration. Collaboration in assessment has several bases: (a) Failure to collaborate with other professionals can result in over-testing and general inefficiency in assessment. (b) Assessment can be more accurately targeted if relevant collaborators jointly identify the questions that need to be answered and the best procedures to answer those questions. (c) Collaborative assessments lay the foundation for integrated, consistent, and coherent intervention. (d) Collaboration in assessment is often an efficient training procedure for staff and other communication partners. (e) Collaboration in assessment with the individual with a disability is an effective procedure in relation to improving the person's self-awareness of strengths and limitations and strategic thinking in general.
Assessment with the goal of creating and refining intervention plans also involves thoughtful and organized testing of hypotheses. Because all behavior is multiply determined and successful performance of real-world tasks involves complex relationships among the individual's profile of abilities, the individual's motivational structure, characteristics of the task and setting, and available supports, there exists no formula for deriving the wisest intervention plan from the results of tests alone. Decisions about specific interventions and supports are best made on the basis of careful experimentation, based on thoughtfully formulated hypotheses regarding specific intervention procedures and supports. It should be noted that this approach has its drawbacks and has been the object of some criticism by those who have expressed concern over problems with standardization and psychometric properties inherent in this type of approach.
Executive function deficits, including weakness in the areas of self-awareness, goal setting, and strategic thinking, are often among the most debilitating problems following brain injury. This makes collaboration with the patient in setting goals, testing intervention hypotheses, exploring strategic compensations, and monitoring outcome a critical component of assessment and treatment. Finally, if a goal of the cognitive rehabilitation program is to increase the abilities of support people in the individual's life and improve the supports available in the individual's environment, then objective documentation of these improvements in the knowledge and skills of people in everyday situations is necessary. Further, reduction of supports needed by the individual with a disability is a critical measure of the effectiveness of intervention.
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Within the traditional approach, initial emphasis is placed on decontextualized exercises designed to restore cognitive processes and skills. The goal is to eliminate or at least reduce cognitive impairment. Computers are often used as a vehicle for delivering cognitive exercises. The exercises themselves are typically designed to isolate, as clearly as possible, specific components of cognition (e.g., selective attention, organized visual perception, prospective memory, and associational abilities) and to rebuild cognitive skills in a hierarchical manner. In the event that compensatory behaviors or assistive equipment prove necessary, training is again typically delivered by means of discrete and massed learning trials in clinical settings.
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Within the contextualized paradigm, decontextualized cognitive exercises designed to reduce impairment may be used if there is evidence for a positive and generalizable outcome of such exercises. However, in many cases it may be more effective to encourage individuals to practice functional tasks important in their lives or to practice strategic thinking and compensatory behavior in functional contexts (Park & Ingles, 2001). In addition, cognitive specialists employ task and environmental modifications to facilitate the individual's success on otherwise difficult tasks and, if possible, promote gradual restoration of function through repeated successful performance of functional tasks with external mediation or support (i.e., a scaffolding approach). Environmental modifications may include training and coaching of work supervisors and other communication partners so that they know how to provide appropriate types and amount of support and are effective in reducing those supports as the individual regains function (i.e., fading).
Strategic thinking and behavior, that is, the effortful use of special procedures to succeed at tasks that are cognitively challenging, are critical components of normal cognitive functioning. Indeed, developmental cognitive psychologists highlight the gradual evolution of strategic thinking and behavior as among the most critical strands in normal cognitive development in childhood, and much is known about how this aspect of development can be facilitated (Bjorklund, 1990; Bronson, 2000; Flavell, Miller, & Miller, 1993). Therefore, focusing on strategic behavior in cognitive rehabilitation programs can and should be considered restorative. That is, it is incorrect to assume that a strategic, compensatory focus in cognitive rehabilitation is second best and should be considered only if restorative retraining exercises are disappointing in their results (as is suggested by theories that sharply distinguish between restoration and compensation).
Environmental compensations and supports provided systematically by others can also be considered restorative interventions. Among the most effective ways to facilitate development and restoration of cognitive functions is through modification of functional tasks and mediated interaction with others (Vygotsky, 1978). This philosophy supports environmental and task modifications and mediated practice of compensatory behavior as a critical approach to cognitive development and restoration. Vygotsky's theory has led to development of validated programs of intervention in many fields, including educational psychology (Brown, Campione, Weber, & McGilly, 1992; Campione & Brown, 1990), reading instruction (Palinscar & Brown, 1989), early childhood education (Berk & Winsler, 1995; Bodrova & Leong, 1996), special education (Ashman & Conway, 1989; Evans, 1993), and speech-language pathology (Schneider & Watkins, 1996; Westby, 1994).
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Within the traditional paradigm, many attempts have been made to identify concrete treatment hierarchies within cognitive processes and systems. For example, intervention programs often include systematic progression from attentional processes (and subprocesses within this category such as maintaining, shifting, and dividing attention) to perceptual processes, memory, organization, reasoning, and other “higher” cognitive processes (Sohlberg & Mateer, 1989). Similarly, treatment typically progresses from training exercises conducted in a training context to systematically expanding generalization contexts. Early focus on body structure/function-oriented exercises progresses to include activity/participation- oriented compensatory exercises (if necessary), and finally to context-oriented task modifications and environmental modifications (if necessary). Treatment sequences and hierarchies of this sort are said to be useful in organizing treatment, ensuring the individual's success with training tasks, and building skills incrementally.
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Within the contextualized paradigm, these three forms of treatment hierarchy (i.e., intra-cognitive hierarchies, generalization hierarchies, and the body structure/function-to-activity/participation-to context hierarchy) may be modified or even reversed. With respect to body structure/function, activity/participation, and context, it may be efficient in the case of people with chronic cognitive disabilties to first modify the routines of everyday life, enabling the individual to be successful with task modifications and possibly the support of others (context-oriented intervention). With extensive contextualized practice of supported compensatory behavior, the intervention may gradually shift to an activity/participation orientation (as the individual takes increasing responsibility for strategic compensations). Finally, with automatization of cognitive strategies, the body structure/function limitation itself may be reduced. Thus the traditional sequence in rehabilitation may reasonably be reversed in the case of chronic cognitive impairment after TBI. In this respect, cognitive rehabilitation may differ from intervention for sensory and motor impairments, in which it is often necessary to block compensatory behaviors in order to facilitate recovery of function.
With respect to generalization, investigations of cognitive growth in children and adults with developmental disabilities have led increasingly to the recommendation that teaching and other forms of intervention be contextualized from inception, with expansion outward of functional tasks and settings as mastery is achieved (Detterman & Sternberg, 1993). This is in contrast to the common practice of pursuing mastery in decontextualized training tasks prior to beginning gradual transfer to functional tasks. This fundamental change in perspective was motivated, in part, by failure to achieve generalization in treatment of persons with developmental disabilities. The change was also motivated by increased recognition of the possibility that acquisition of a skill or behavior in a training context may actually interfere with transfer to a functional context, particularly among stimulus-bound individuals.
Finally, hierarchies within the domain of cognition itself may shift profitably from an abstract serial ordering of cognitive processes characteristic of traditional cognitive rehabilitation programs (e.g., from attention to perception to organization), to hierarchies of tasks and task demands based on task difficulty relative to the individual's specific profile of abilities and on progressions observed in normal cognitive development. Cognitive development is characterized by systematic growth along the following dimensions: (a) concrete to abstract thinking; (b) context-dependent to context-independent skills; (c) real-event routines and scripts to more abstract organizing schemes; (d) involuntary, nonstrategic processing to controlled, strategic processing; and (e) surface to depth (Flavell, Miller, & Miller, 1993).
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Within the traditional approach, emphasis is placed on decontextualized exercises (e.g., content-free computer exercises), purportedly designed to facilitate broad transfer from training tasks to functional application tasks. This approach is taken, in part, because of the absence of specific functional content and because the generality of the exercises is not contaminated by specific setting cues. That is, if cognitive processes exist devoid of any specific content and can be strengthened with exercise, it makes sense to design exercises that are as content-free as possible. These exercises are typically offered in a clinical (inpatient or outpatient) setting. Cognitive rehabilitation services are largely delivered by licensed rehabilitation professionals who specialize in the service, possibly supported by trained and supervised technicians.
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Within the contextualized paradigm, decontextualized exercises may be used if there is good evidence for broad transfer of the cognitive skill to be exercised (which is often not the case). However, emphasis is typically placed on contextualized exercises (e.g., personally meaningful routines and activities of everyday life; relevant social, vocational, or educational tasks) designed to promote improved performance of personally meaningful tasks. The ultimate goal is to facilitate transfer of these skills to increasingly broad domains of functional tasks. Further, following acute rehabilitation, personally relevant settings (e.g., school, and vocational settings) and routines in those settings are often the ideal context for cognitive rehabilitation activities.
In addition, cognitive rehabilitation services are delivered by rehabilitation specialists, in most cases supported and augmented by people in the individual's everyday life. That is, if rehabilitation is delivered in part through modifications and supports in the everyday routines of life, the participants in those routines may need considerable training and coaching from specialists if they are to play their role effectively. Finally, because of the frequency of executive system impairment after brain injury and the consequent need to engage patients in meaningful executive function tasks, it may be critical to include the patient in collaborative decision making about self-determined and self-paced intervention activities (Malec, 1996).
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The prominence of the traditional paradigm for cognitive rehabilitation can be explained by reference to several attractive features. First, if restorative exercises can have the effect of substantially reducing the individual's cognitive impairment and thereby improving functional performance in a generalizable manner, then clinicians would be well advised to use this approach. Similarly, if training in compensatory strategies delivered outside the routines of everyday life could result in habituation of strategic behavior that is sufficiently flexible to apply to a wide domain of tasks of everyday life and sufficiently durable to be maintained over time, then again there would be no reason to challenge the traditional approach to intervention.
Unfortunately, these assumptions have grown increasingly tenuous. Currently, there exists at best weak support for a generalized, functional effect of process-specific, decontextualized cognitive retraining exercises. In some areas of cognition (e.g., declarative, explicit memory), there is general agreement that simply exercising the process has little functional restorative effect (Schacter, 1996; Schacter & Glisky, 1986). In other areas (e.g., attention, reasoning) controversies persist regarding the effectiveness of decontextualized, targeted exercises. Attention training has been subjected to the most intense experimental scrutiny. In a recent meta-analysis of attention rehabilitation, Park and Ingles (2001) found that across the available studies, there was no statistically significant effect of decontextualized attention training when appropriate controls were employed in the study. In contrast, they found a robust effect when the intervention was contextualized (e.g., driver training), although they identified only four studies of contextualized intervention for individuals with attention deficit after brain injury. It is worth noting that ineffective experimental designs in the field of brain injury rehabilitation may have encouraged an inefficient approach to rehabilitation, a point to which we return later.
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Second, the standard organization of services within the traditional approach offers many logistical advantages. Clinic-based intervention is certainly easier to deliver than intervention that requires entering the everyday routines of the people being served. Furthermore, cognitive rehabilitation packaged as a sequenced series of exercises, using computer programs or other commercially available materials, substantially reduces clinicians' planning time and effort. In addition, objective documentation of performance and progress is relatively simple when the intervention is largely delivered through well-defined exercises in clinical settings.
Not surprisingly, payers of cognitive rehabilitation services, particularly within the managed health care market of the past several years, are more willing to reimburse professionals for objective, measurable, time-limited activities that are part and parcel of the traditional approach (assuming its effectiveness). Logistical simplicities of this sort are equally attractive to researchers seeking reliable measures of outcome. Contextualized services, in addition to being logistically complex, often presuppose alliances between specialists and everyday people whose availability and competence in supporting contextualized intervention is variable. Such alliances are often difficult to create.
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The effectiveness of massed, hierarchically organized, and apparently decontextualized practice in domains of intervention apparently similar to cognitive rehabilitation may be understood by some observers as support for the traditional approach to cognitive rehabilitation. For example, “direct instruction” teaching methodology, based on thorough task analysis and organization of teaching around small progressions of task difficulty and massed learning trials in a training context, has been found to be useful in teaching many types of academic content (Englemann & Carnine, 1991). More recently, Merzenich and colleagues (1996) found that computer-delivered massed learning trials have been successful in improving phonological and more general language processing in children with neurogenic language disorders, with reported evidence of an impact on brain structure and function.
However, a critical difference exists between teaching content (e.g., phonological rules, word meaning, academic or vocational content) and training purported cognitive processes devoid of any specific content (e.g., selective attention, cognitive organization, episodic memory, and reasoning). Cognitive rehabilitation, as traditionally conceived, takes the latter as the targets of its training efforts. Therefore, evidence of the effectiveness of content instruction or training in any domain may not be relevant to the question of the validity of cognitive process retraining.
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As emphasized in the review by Carney and colleagues (1999), most published studies of the effectiveness of cognitive rehabilitation have been developed within the traditional intervention framework. Therefore, other than a meta-analysis of four studies (Park & Ingles, 2001), promising single-subject designs and case reports by a handful of authors (Feeney & Ylvisaker, 1995; Von Cramon & Matthes-von Cramon, 1994; Ylvisaker & Feeney, 1996, 1998), and one positive randomized clinical trial with children with TBI (Braga & Campos da Paz, 2000), little direct empirical evidence is available to support the contextualized approach to cognitive rehabilitation for children or adults with TBI. Therefore, support for this approach is largely derived from (a) evolving theories of cognition and cognitive development, (b) research with related disability populations, (c) the long-term needs of people with significant impairment, and (d) the current funding environment with its emphasis on functional improvement with decreasing resources for rehabilitation. The following sections address these four themes.
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The history of cognitive training in fields other than brain injury rehabilitation has frequently involved a shift from a narrow focus on training cognitive “faculties” in the abstract to a broader and more contextualized orientation to improve specific domains of performance that have a cognitive dimension (Mann, 1979). This shift is consistent with the current family of theories of human cognition that highlight context as critical to the analysis of cognitive functioning. These theories of cognition, including mediated action theory (Wertsch, 1981), situated learning theory (Lave, 1991), situated cognition theories of processing (Clancey, 1997), and apprenticeship theories of cognitive development (Rogoff, 1990), have their historical roots in the socio-historical approach of Vygotsky and Luria, and Dewey's pragmatic epistemology.
Context-focused theories have been supported by many studies on experts, which tend to conclude that their special expertise lies primarily in domain-specific knowledge, domain-specific strategies, and domain-specific motivation to be strategic, rather than superior cognitive processing abilities in the abstract. In their review of the literature on expertise, Meichenbaum and Biemiller (1998) suggest that, whatever their domain, experts have a well-developed knowledge base in that domain, are effective users of strategies in that domain (i.e., they possess more efficient and more flexible strategies, have automatized the strategies through practice, and tend to have environmental support for the use of strategies), and are highly motivated to succeed in their chosen domain. These features of expert information processors, together with the frequent finding that people with great expertise in one domain tend to process information no better than novices in other domains, call into question the practice of targeting general, nonspecific cognitive processes in people with cognitive impairment after brain injury. Therefore, current efforts to improve low-achieving students' thinking, reasoning, and strategic approaches to academic problems tend to be embedded in meaningful domains of content.
Furthermore, current models of cognitive processing predict the common phenomenon of training-induced improvements on laboratory tasks or neuropsychological tests followed by minimal transfer of cognitive skill to functional, real-world tasks (Detterman & Sternberg, 1993). The experimental literature in cognitive science emphasizes the relative domain specificity of cognitive processes and skills, even in the case of adults with normal cognitive functioning (Singley & Anderson, 1989). Minimal transfer of cognitive skill has been observed in normal learning, based on careful experimentation as well as experience in higher education (e.g., failure of transfer of improved writing and reasoning skills from composition and logic classes to other academic course work). For this reason, the contextualized training embodied in apprenticeship programs has a long and honored history in vocational training, clinical education, and increasingly in other domains of educational practice.
It is worth noting that the paradigm shift has largely occurred in vocational rehabilitation. That is, the traditional model, within which formal assessment was followed by decontextualized remediation and skill development, which in turn was followed by job placement, has been replaced by a contextualized assessment and supported work model that parallels the paradigm shift described in the current paper. It is noteworthy that Chesnut and colleagues (1999) found supported employment services to be one of the brain injury interventions most solidly upheld by scientific evidence.
One explanation for the relative domain specificity of cognitive skill is the frequent finding that efficiency and effectiveness of information processing are in large part contingent on domain-specific declarative and procedural knowledge and its organization. Indeed, cognitive neuroscientists have increasingly explicated varied cognitive processes in terms of organized knowledge structures within which information in a given domain is processed. At a high level of generality (e.g., scripts, plans, general schemas), knowledge structures (e.g., managerial knowledge units [MKUs]) are generally associated with frontal lobe function (e.g., Grafman, 1995). Damage to these knowledge structures slows information processing; creates disorganization in thinking, planning, and social behavior; interferes with directed and sustained attention; and causes ineffective encoding, storage, and retrieval of information.
The emphasis on the critical relationship between domain-specific knowledge (and its organization) and effective cognitive performance yields insight for cognitive intervention. For example, there would seem to be value in engaging individuals in tasks with personally relevant content with the goal of improving efficiency of cognitive processes by means of developing appropriate knowledge structures or MKUs. More generally, the distinction between process and content must be questioned, with acquisition and organization of content knowledge considered in many cases the most efficient approach to improving cognitive processing.
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Indirect experimental support for the contextualized approach has come from empirical studies of the effectiveness of teaching individuals with mental retardation content knowledge and functional skills in meaningful contexts (Horner, Dunlap, & Koegel, 1988; Kavale & Forness, 1999; Koegel, Koegel, & Dunlap, 1997). Further, in the learning disability research literature, Deshler and Schumaker (1993) emphasized the critical importance of integrating cognitive strategy instruction with content instruction, customizing intervention to meet a specific student's individual and classroom needs. These authors emphasize generalization from the earliest stages (by contextualizing the teaching), continuing instruction until mastery is achieved (possibly requiring many months of instruction), and engaging the student as much as possible in recognizing the importance of personal effort and the positive effects of those efforts.
One of the well-studied interventions for individuals with ADHD, cognitive behavior modification (CBM), is consistent with the approach we have referred to as the contextualized paradigm for cognitive rehabilitation, if CBM is delivered in the context of the routines of everyday life. A recent meta-analysis of contextualized CBM for adolescents with ADHD and associated aggressive behavior yielded a strong effect size (0.79) and solid maintenance over time (Robinson, Smith, Miller, & Brownell, 1999).
Cross-population inferences can be controversial. However, in some cases, nominally different clinical populations are functionally equivalent. For example, the students with ADHD included in Robinson and colleagues' meta-analysis had disability characterized by disinhibition and more general behavioral dyscontrol associated with frontal lobe dysfunction and executive function impairment (Barkley, 1997). A sizable and clinically significant subpopulation of young people with TBI similarly evidence impulsiveness and behavioral dyscontrol, associated with frontal lobe dysfunction and executive function impairment, as their salient clinical characteristic. Therefore, when the two groups are given a functional diagnosis, the cross-population inference vanishes and substantial evidence from ADHD studies becomes applicable to this TBI subpopulation.
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Following severe brain injury, even the most successful graduates of acute and post-acute rehabilitation programs typically experience some degree of ongoing cognitive disability. This results in the need for cognitive assessment and rehabilitation to address chronic obstacles to success in everyday life, with additional tools that address activity/participation limitations and environmental supports.
To this end, the contextualized framework proposes that long-term intervention may appropriately be directed to supportive modification of routines of everyday activity, including educational, vocational, social, and other everyday routines. Individuals who figure prominently in these everyday routines may become critical allies in delivering cognitive intervention and supports. The effectiveness of this indirect approach to intervention has been supported by investigations in other disability fields in which the impairment is chronic and the need for intervention long-term, including early intervention for young children with disabilities (e.g., Girolametto, Pearce & Weitzman, 1996; Girolametto, Weitzman, Wiigs & Pearce, 1999; Kaiser & Hemmeter, 1996), autism and developmental disabilities (e.g., Carr, Horner & Turnbull, et al., 1999), augmentative communication, and supported employment for individuals with brain injury (Curl, Fraser, Cook, & Clemmons, 1996; Wehman et al., 1993; Wehman & Kreutzer, 1990; Wehman, West, Kregel, Sherron, & Kreutzer, 1995).
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Private and public rehabilitation financiers have increasingly reduced resources available for rehabilitation while at the same time demanding improvements in functional outcome. In some cases, service providers have been urged to focus their efforts on lessening activity/participation limitations in contrast to the traditional emphasis on eliminating or reducing the underlying impairment. The legitimate demand of such financiers—as well as consumers—is that effectiveness of intervention be documented in terms of meaningful improvements in the tasks of everyday life. The cost effectiveness of a contextualized approach has been suggested in a recent analysis of a New York State TBI Medicaid Waiver Program, designed to support adults with cognitive and behavioral impairment in community settings (Feeney, Ylvisaker, Rosen, & Greene, 2001). At the same time, the demand for objective, quantitative documentation of improvement may be taken as support for the traditional paradigm.
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In this report, we have explored the recent history of cognitive rehabilitation, and the controversies associated with that service, with the goal of suggesting that an alternative to the traditional intervention framework may have merit based on several theoretical and practical considerations. Both approaches are limited by insufficient evidence, however, and much more work needs to be done to demonstrate their effectiveness. Specifically, what is needed is increased understanding of what constitutes effective procedures for particular patient groups, under specific conditions, and in relation to distinct goals.
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Treatment research characteristically begins with the examination of evidence in related disability domains, as well as clinical case reports and single-subject experiments. These research activities are precursors to randomized clinical trials with large numbers of subjects. Data from such methodologically rigorous studies is the most accepted way to establish treatment efficacy, especially in an atmosphere of evidence-based medicine (Sackett & Rosenberg, 1995). Random assignment may involve designation to cognitive rehabilitation or no cognitive rehabilitation groups, active cognitive rehabilitation versus sham cognitive rehabilitation groups, or experimental groups using alternative approaches to cognitive rehabilitation. Such studies should involve large numbers of patient and control participants who have been selected to reduce bias from clinical referral sources. They should be matched for demographic and pre-injury characteristics, and severity of brain injury and non-central-nervous-system injuries. To date, one randomized clinical trial comparing the two paradigms has been described in the TBI literature, suggesting the superiority of contextualized rehabilitation for children with TBI (Braga & Campos da Paz, 2000).
It may appear that such a scientifically rigorous protocol to measure the effectiveness of the contextualized approach to cognitive rehabilitation may not be feasible. One of the main tenets of this approach is that the treatment needs to be fluid and functional, rather than rigid, and that patients participate with clinicians in planning and monitoring the effectiveness of their treatment. It is the research methodology that needs to be rigid, however, rather than the treatment. Although treatment may be flexible and fluid, the science that measures such dynamics is not. If it is the flexibility, context sensitivity, functionality, and patient-engagement of the approach that makes the treatment successful, then a carefully constructed study should demonstrate that it is these characteristics of the intervention that make it successful. Good therapeutic process research can be conducted with dismantling, constructive, or parametric strategies to discern the individual therapeutic elements (Kazdin, 1994).
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The treatment protocol must have sufficient flexibility to allow for (or systematically include) participation of the patient in identifying needs, planning intervention activities, monitoring progress, selecting strategic compensations, and the like. This component would make the intervention truly an executive system intervention. Rigorous research methodology is compatible with appropriate flexibility in the intervention itself. Investigation of the relative impact of flexible treatment, which includes patient engagement in treatment decisions, with rigid treatment protocols in which there is no such participation is itself worth pursuing as an independent research question.
The treatment may need to be relatively long-term if the goal is to have a genuine impact on cognitive habits. Furthermore, the treatment must explore various aspects of context. For example, does it make a difference when the intervention is delivered within the context of tasks meaningful to the patient? Does it make a difference when people in the individual's everyday life are included on the intervention team?
There are also several issues related to selection of dependent variables. Outcome measurement must include measures that tap a variety of functional domains (e.g., employment, academic success, social integration, and reduction of caregiver burden) in addition to whatever intermediate measures (e.g., standardized tests) are selected. “Efficacy” must not be taken to mean simply that the experimental group is statistically superior to the control group or that post-treatment scores are statistically superior to pretreatment scores. Rather, investigators must identify clinically meaningful and important differences in real-world functioning. Further, maintenance of treatment gains must be measured over substantial periods of time, at least several months. Longitudinal investigation of treatment effects allows for evaluation of maintenance and generalization over time.
Because of the heterogeneity embodied in diagnostic categories like “brain injury” and “traumatic brain injury,” measures of variance are often as illuminating as measures of central tendency. Therefore, analysis and interpretation of results should include exploration of measures of variance and discussion of individuals and subgroups that fall outside the central tendencies of the study samples.
With this call for more treatment outcome research, we also highlight the need for greater funding of such research. As Malec (1996) has noted, rigorous and tightly controlled research is expensive. Traditionally, efficacy research in the field of cognitive rehabilitation has not been competitive with basic sciences for NIH funding. Such funding would allow for more rigorous experimental designs and therefore should be given high priority on research agendas.
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In an ideal world, responsible professionals make clinical decisions on the basis of sound judgment that is supported by empirically validated clinical protocols. In the absence of empirically validated protocols, responsible clinicians may make decisions about intervention (whether to intervene, and if so, how) for individual clients based on clinical necessity and informed answers to the following questions:
Is the proposed intervention supported by efficacy studies with populations possessing the same disability and needs as the client?
Is the proposed intervention supported by efficacy studies with closely related populations (e.g., learning disabilities, developmental disabilities)?
Is the proposed intervention supported by trial intervention with the client?
Is the proposed intervention supported by clinical experience with members of the client's clinical population?
Is the proposed intervention supported by theory, including neuropsychological, cognitive, behavioral, pedagogical, and other theories?
Is the proposed intervention supported by negotiation with the client and relevant stakeholders in the client's life?
Is the proposed intervention consistent with known constraints, including expertise of service providers, availability of support personnel, time to complete the intervention, and adequate resources?
Can the proposed intervention be judged to be preferable to known alternatives—in relation to predicted functional outcome for the client—based on the previous considerations?
Is the proposed intervention humane, morally justifiable, and consistent with the scope of practice and relevant licensing laws governing the provider of services?
In this report we have urged clinicians and researchers involved in the delivery and validation of cognitive rehabilitation for children and adults with brain injury to examine the historical, theoretical, and empirical support for this service. We outlined two conceptual frameworks within which the service has been understood. Available reviews of efficacy studies conducted within the traditional framework have failed to yield a solid empirical basis for the service. Furthermore, developments in cognitive theory and work with related disability groups invite exploration of an alternative to the traditional framework. We outlined one such alternative and called for systematic investigations of its usefulness in serving children and adults with cognitive impairment after brain injury. Until such investigations yield validated clinical protocols, clinicians are obligated to guide their practice by thoughtful answers to the questions listed above.
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