functional deficits lead to restrictions in home, work, and but overlapping disciplines, including neurorehabilitation, community activities, even if by clinical assessment the cognitive psychology, and cognitive neuroscience (Elliot, deficits are considered "mild" (Pohjasvaara et al., 2002; 2003). Rather than exhaustively review the decades of 15 EXECUTIVE FUNCTIONS Rochette et al., 2007). The cognitive deficits associated research pertinent to executive functions, including the with stroke vary in type and severity from individual to large bodies of research carried out on working memory individual, based on site and lesion(s) location, but Zinn, and attention, we decided to use this chapter as an oppor­ SUSAN M. FITZPATRICK and CAROLYN M. BAUM Bosworth, Hoenig, and Swartzwelder (2007) found that tunity to explore how the concept "executive function" is nearly 50% of individuals show deficits in executive func­ used by different disciplines, in what ways the uses of the tion. We suspect this number underestimates the true inci­ concept are similar or difrerent, and the opportunities dence of high-level cognitive difficulties. and challenges to be met when integrating findings from The Cognitive Rehabilitation Research Group (CRRG) across the disciplines to yield a coherent understanding at at Washington University in St. Louis maintains a large the neural, cognitive, and behavioral/performance levels, database of information regarding stroke patients admit­ so that research findings can be used to inform clinical ted to Barnes-Jewish Hospital. As of December 2009, the practice aimed at ameliorating executive dysfunction. It is CRRG research team had classified 9000 patients hospi­ our goal to identify the language and knowledge gaps that talized for stroke. Although stroke is often associated with could be hindering the successful translation of experimen­ elderly populations, nearly half of the patients (46%) were tal knowledge into practical applications for individuals younger than age 65. About 4500 patients (50%), were recovering from stroke. It is not possible to overemphasize classified as having mild stroke (National Institute of how difficult such integrative work can be. For the past H ealth Stroke Scale score = 0 to 5). In a subsample of 110 several years, the James S. McDonnell Foundation has 15 .1 STROKE REHABILITATION: THE a performance-based perspective, executive functions are patients, 65% were found to have executive dysfunction been encouraging working groups composed of basic cog­ ROLE OF EXECUTIVE FUNCTIONS called on when individuals make plans, initiate actions, as measured on behavior and performance tests (Baum, nitive neuroscientists and academic clinicians to develop and modify activities as problems are experienced or infor­ 2009; Wolf et al., 2009). The demographics of stroke evi­ consensus reviews for diagnosis and treatment based on a Rehabilitation for people recovering from stroke focuses mation from the environment changes. A performance­ denced in the Washington University database-younger cognitive neuroscience model called CAP (computation­ on restoring the ability to perform the activities required based approach to executive functions starts with an and with milder disease-presents an eye-opening chal­ anatomy-psychology; Corbetta & Fitzpatrick, 2011). The for living independently. For the most part, clinical neu­ examination of how well a person is able to run errands, lenge for rehabilitation professionals. Younger stroke sur­ first series of papers, on action rehabilitation, recently rorehabilitation concentrates on interventions designed to multitask at work, or quickly alter a route because of road vivors had higher expectations of returning to work and to appeared as a special supplement to Neurm·ehabilitation treat motor and language impairments. The difficulties an congestion, and then attempt to identify the underlying the myriad demands of ac tive family and social life. Unlike and Repair (Frey et al., 2011; Pomeroy et al., 2011 ; Sathian individual may experience from impairments of high-level cognitive and neural substrates. older stroke survivors, whose lives may be more structured et al., 2011) and serves as one model for developing mutu­ cognitive functions, typically labeled executive functions) are Chen et al. (2006) suggest that the brain networks and thus more readily routinized, younger individuals were ally agreed-upon language and concepts. not always apparent in clinical settings and are often not supporting executive functions are central to learning, and engaged in precisely the kind of activities most reliant on In this chapter, we review the measures used to iden­ the focus of therapy. Part of the reason executive functions thus executive functions are important to the relearning the flexibility provided by intact executive functioning tify executive dysfunction and the interventions targeted may be somewhat overlooked in clinical care is that execu­ and retraining necessary for successful rehabilitation as (Wolf et al., 2009; O'Brien & Wolf, 2010). To meet the to executive dysfunction at the neural, behavior, and per­ tive functions have been defined in a number of contexts measured by real-world performance. Clinicians are encour­ needs and expectations of younger stroke patients, neu­ formance levels. For the purposes of this chapter, only key ranging from experimental cognitive studies to neuropsy­ aged to exercise care during client evaluations. Individuals rorehabilitation must be prepared to address deficits in findings from the cited papers pertinent to the chapter's chological assessments. There is no commonly agreed set of with executive dysfunction can often perform adequately executive functions. goals are provided; readers are encouraged to consult the cognitive abilities or neural structures uniquely identified as on standard neuropsychological evaluations because they In this chapter, our performance-based definition of original papers for more complete details. The approach supporting executive functions. Rebecca Elliot (2003) pro­ are administered in a structured and supportive environ­ executive functions and executive dysfunction overlaps with we've selected begins with examining the current under­ vides a good summary of why the term executive functions ment (Lezak, 1982, 2000; Prigatano, 1999; Dosenbach but is not synonymous with fi'ontal lobe functions or .fi'on­ standing of executive function at the multiple levels of is not a unitary concept. In this chapter, we will attempt et al., 2008). Their difficulties may not become appar­ tal syndr·ome, respectively. These have been described most analysis we call Brain (including neural and cognitive sys­ to integrate across the behavioral, cognitive, and neural ent until they attempt to resume unstructured activities notably by Stuss and colleagues (for review see Levine, tems), Behavior, and Perfonnance. Figure 15.1 provides a descriptions of executive functions in an effort to identify at home, work, or in social situations. Chan et al. (2008) Turner, & Stuss, 2008). Individual performance on some gaps in our knowledge that, if filled, could be helpful in provide a comprehensive review of the various cognitive behavioral measures provides strong support that execu­ BRAIN BEHAVIOR PERFORMANCE translating research findings into clinical practice. neuroscience models proposed for executive functioning tive function shares characteristics with, but need not be Neural Brain Behavior Behavioral Daily Life Tasks In general, cognitive psychologists describe executive and discuss some of the difficulties with assessing cogni­ identical to, neuropsychological tasks primarily reliant on Constructs Relationship Consequences functions as (i) the ability to exhibit flexible adaptive tive contributions to complex behaviors in the laboratory, working memory (Frank, Loughy, & OReilly, 2001) or • Plasticity • Working • Risk taking • Initiate memory behavior, (ii) the use of appropriate problem-solving strat­ in clinical settings, and in everyday life. with "top-down" control mechanisms (Dosenbach, 2008). • Connectivity • Reaction time • Organize • Attention • Change sets egies as required for maintaining and updating goals, (iii) Brain injury as a result of stroke is a leading cause of Due to the complex nature of the tasks dependent upon • N eural • Sequence processing • Distractibility the capacity to monitor the consequences of actions, and individuals becoming unable to carry out the activities executive functions it is likely that executive functions are • Awareness • Judgment/ • Failure to • Multimodal safety • Automaticity (iv) the ability to use prior knowledge to correctly inter­ central to their daily life (Cardol et al., 2002). Considering supported by networks of brain region comprised of corti­ integration inhibit • Impulsivity • Completi on pret future events (Miyake & Shah, 1999). Cognitively, the impact of stroke on everyday functioning, it is sur­ cal, subcortical, and cerebellar regions (Chen et al., 2006; • Regional the term executive functions also derives in part from the prising that 85% of people who survive a stroke return Dosenbach, 2008; Pessoa, 2008). specializations • Fatigue idea of top-down control by a central executive, as pro­ home (Reutter-Bernays & Rentsch, 1993). Stroke can TI1e ability of individuals to carry out the behavioral posed in models of working memory (Baddeley, 2001) or result in a wide range of deficits, including executive func­ tasks associated with intact or disrupted executive func­ of attentional control (Posner & Petersen, 1990). From tion deficits. When not identified and managed, these tions is an active area of research in a number of distinct Figure 15.1 The Language of Executive Function At Multiple Levels

208 I STROKE REHABILITATION 15 . EX ECUTIVE FUNCTIONS I 209 ~ ~ -- -=-~-=~----

summary of some of the language commonly used at each BRAIN BEHAVIOR PERFORMANCE disruptions of executive functions suspected of support­ predictions in the real-world settings of neurorehabilita­ Neural Brain Behavior Behavioral of the levels. Daily Life Tasks Constructs Relationship Consequences I ing complex human behaviors onto discrete neural struc­ tion yields information needed to refine or correct neural What is readily observable is that there is very little • Neuromodulatory • Working memory • Self-regulation • Dynamic tures. In part, the difficulty derives from the observation and cognitive models. overlap in terminology across the levels. A major barrier, drugs training • Goal management interactional that executive functions are behaviorally context-depen­ in our view, of cross~disciplinary research and attempts • Electrical • Strategy training training approach sti mulation • In creasing dent, and are characterized as the dynamic deployment • Functional skills • Cognitive to translate research into practice is the lack of a shared, automaticity • Smart train ing o rientation to of cognitive resources. Although published more than 2 15.3 NEURAL SUBSTRATES OF prosthetics • Self-awareness mutually understood language. Recognizing that at pres­ • Real-life problem daily li ving decades ago, a review by Posner and Petersen pro­ EXECUTIVE FUNCTIONS solving/cueing (1990) ent there are few effective, theory-driven, experimentally vides a cogent discussion of the challenges inherent in the tested interventions for executive dysfunction, our pur­ attempts to map processes described at the cognitive level lviuch of what is known about the neural systems support­ pose is to review the groundwork and suggest the research Figure 15.3 Interventions for Executive Function at Multiple Levels. Note: This list is not exhaustive but is meant of analysis onto neural substrates. Posner and Petersen's ing executive functions has been derived from neuropsy­ agenda needed if the field of neurorehabilitation is to use to introduce interventions at different levels. concerns remain relevant today and should guide practical chological studies with patients with brain lesions, mostly cognitive neuroscience findings to inform the development interpretation of research findings. resulting from trauma (reviewed 111 Zoccolotti et a!., of therapeutic approaches. For cognitive neuroscientists, it Neurorehabilitation researchers and clinicians should 2011). Increasingly, the availability of noninvasive imag­ is also critically important that theories and explanations change, and there is often competing stimuli that must be cautious of overgeneralizing from brain models of ing methodologies has allowed cognitive neuroscientists concerning brain function be tested and refined as needed be ignored to accomplish the task (Burgess & Shallice, executive functions proposed by cognitive neuroscientists, to study the neural basis of cognitive functions in intact in the context of real world behaviors. Well-structured 1996; Kaplan & Berman, 2010). When considering per­ particularly if based primarily on functional imaging stud­ subjects, in neurological patients with well-characterized neurological and cognitive theories concerning informa­ formance, at least five cognitive constructs have empirical ies, because imaging results are dependent on the task per­ structural lesions, and in psychiatric populations. In gen­ tion processing and performance should have some infor­ support as major components of executive functioning: fotmed during data acquisition and on the experimental eral, however, experimental constraints make it impossible mative and predictive power for post-stroke rehabilitation. (i) inhibition, (ii) working memory, (iii) strategic process­ context. The current use of task-free resting state func­ for cognitive neuroscientists to study complex, real-world 1he practice of rehabilitation is often built on asking the ing, (iv) set shifting, and (v) emotional regulation (Norman tional connectivity imaging does not completely mitigate behaviors and, as a result, most functional imaging studies patient to participate in relearning or retraining. 1his may & Shallice, 1986; Shallice, Levin, Eisenberg, & Benton, the challenges of translating findings from research to focus on dissociable components of executive functions as create an ongoing tension between the natural need for 1991; Baddeley, 1996; Goldman-Rakic, 1996; Smith & practice, particularly in the context of the altered physi­ previously defined in this chapter (e.g., working memory, neural systems to be both resilient (stable following per­ Jonides, 1999; Jonides & Smith, 1997; Miyake et al., ological context of the human brain post-stroke. Cognitive inhibition, set-shifting). turbations) and plastic (able to alter with experience). It 2000; Braver, Cohen, & Barch, 2002; Diamond, 2002). In neuroscience studies of attention, working memory, or One component of executive functions extensively is imperative that we understand how injury and thera­ essence, executive functions make it possible for humans set-shifting with exper-imental tasks designed to probe studied is top-down control (or voluntary control) over peutic interventions interact with, and can be helped or to successfully encounter novelty. Executive functions specific cognitive processes (e.g., Stroop task, N-back test, automatic processes (see Cohen, Dunbar, & McClelland, hindered by, the resilient and plastic aspects of neural sys­ allow humans to synthesize information coming from the ' or Wisconsin card sorting task) should not be taken as 1990; and Robbins & Arnsten, 2009 for review). It is tems. Figures 15.2 and 15.3 will serve as a reference for external environment, as well as from memory stores in complete proxies for more complex behaviors (see discus­ commonly agreed that top-down control involves areas the measures and interventions that will be discussed in the brain, to generate, implement, and correctly implement sion in Chan et al., 2008). of the prefrontal cortex, specifically the dorsal lateral pre­ this paper. strategies necessary to accomplish tasks (Goldberg, 2001; Translating from cognitive neuroscience to neuroreha­ frontal cortex, and the dorsal anterior cingulate cortex/ Manchester, Priestley, &Jackson, 2004). These abilities are bilitation (and vice versa) also requires contending with a medial superior frontal cortex (Miller & Cohen, 2001). among the most complex functions of the human brain suite of challenges posed by the multi-scale nature of brain However, new experimental data from imaging studies 15.2 OVERVIEW OF A MULTI-LEVEL and are central to being able to perform activities at home, function. 1he neural elements implicated in performance­ indicate that top-down control is likely to involve a larger UNDERSTANDING OF EXECUTIVE work, and in community life. dependent executive functions span temporal scales rang­ number of interacting brain regions organized into two FUNCTIONS Both experimental and clinical findings indicate that ing from milliseconds to years, and spatial scales ranging distinct networks operating at different temporal scales frontal lobes of the human brain are a primary center of from the molecular to whole organisms interacting with (Seeley et al, 2007; Dosenbach et al., 2008). The evidence Executive functions are needed to perform complex tasks. executive functions. It is also clear that executive functions environments. TI1e scale an investigator chooses for moni­ supports one network, described by Dosenbach and col­ Complex tasks require goals to be formulated, and per­ rely on connections to other areas throughout the brain. toring function, for measuring the loss of function, and for leagues as "fronto-parietal" and a second as "cingula­ formance requires a particular sequence of actions. In For years the healthcare community attributed executive determining recovery has far-reaching implications for the opercular" (2008). 1he frontoparietal network responds carrying out complex tasks, the task rules or contexts can dysfunction only to frontal lobe injury; however, we now validity of the conclusions and generalizations that can be with fast dynamics to cues signifying task onset and, are aware that individuals can experience executive dys­ BRAIN BEHAVIOR PERFORMANCE made at other scales. in the experimental laboratory setting, plays a role in ..... Neural Brain Behavior Behavioral ....------function even in absence of frontal lobe injury (Tranel, It is not possible for this chapter to review the exten­ initiating and adjusting control of performance on a Daily Life Tasks Constructs Relationship Consequences Anderson, & Benton, 1994; Manchester et a!., 2004). In sive functional brain imaging literature relating to execu­ trial-by-trial basis. 1he frontoparietal network responds fact, there has been some evidence to support the theory tive functions that has been amassed in the past two differentially depending on whether participants per­ • Biomarkers • Wisconsin Card • Test of Everyday • Executive • Blood flow Sorting Task Attention Function that executive dysfunction is more likely attributed to dif­ decades. Rather, we describe a limited number of recently form correctly or incorrectly on individual trials, indi­ • Anatomical • Trail Making • Behavioral Performance fuse lesions in the brain (SnlSS & Levine, 2002; Pessoa, proposed working models derived from cognitive neurosci­ cating the network's activity is sensitive to feedback. The imaging Test • Wechsler Adult Assessment of • BOLDMR 2008). Almost any brain injury disrupting the networks ence research that have sufficient detail to make predictions cingula-opercular network, which includes the thalamus, Intellig ence Scale- Dysexecutive • The Kettle Test imaging Syndrome IV Letter-Number • The Multiple supporting executive function can be expected to lead about the neural underpinnings of executive functions and operates at a slower temporal scale and is involved with • Functional • Priagatano Errand Test connectivity to cognitive, behavioral, and performance problems to a the risk for dysfunction as a result of injury or disease that maintaining set (the ability to be prepared to respond Competency Rating Scale greater or lesser extent. Being able to identify patterns of can and should be tested in both clinical and real-world in a particular way) over many trials (Dosenbach et a!., ....______, .______, neural injury predictive of the nature and extent of execu­ environments. We do not mean to imply that informa­ 2006) during what might be considered the entire task ~------' tive dysfunction is central to creating a feasible post-stroke tion should flow in only one direction-from cognitive epoch. 1he cingula-opercular network also monitors Figure 15.2 Measures of Executive Function at Multiple Levels. Note: treatment plan. I£ as we discuss above, the concept of neuroscience toward rehabilitation. Rather, we believe it response choices in light of task goals. A set of interact­ This list is not exhaustive but is meant to introduce measures at differ­ "executive functions" does not neatly map onto identifiable is imperative that researchers and clinicians work together ing cerebellar regions, functionally connected to both ent levels. cognitive operations, it is even more difficult to map the to generate knowledge and to validate findings. Testing the frontoparietal and cingula-opercular networks and

210 I STROKE REHABILITATION 15. E XEC UTIVE FUNCTIONS I 211 ascribed with processing error-related activity contribut­ performance by tinkering with the complex, dynamic, and multiple neurotransmitter systems. Some of the questions BOX .1 TRANSLATIONAL CASE STUDY: DOPAMINE ing to improvement of task performance, were also found adaptive nature of chemical neurotransmission requires that will need to be answered include the following: AUGMENTATION AND POTENTIAL USE IN STROKE during the experiments summarized by Dosenbach et al. detailed understanding of mechanisms. REHABILITATION (2008) and are included in the rather comprehensive Wallace et al. (2011) evaluated the influence of dopamin­ • Could dopamine augmentation help individuals dem­ and updated model they provide for the neural systems Evidence is accumulating on how neuromodulatory neu­ ergic modulation on measures of prefrontal cortex-striatal onstrating post-stroke deficits dependent on working responsible for human top-down control. rotransmitters influence activity in cortical-striatal circuits functional connectivity by reanalyzing data from a study memory functions? In an interesting Nature Reviews Neuroscience opinion responsible for performance of complex cognitive tasks, with healthy human subjects (Gibbs & D'Esposito, 2005) • Are there diagnostic measurements that could reliably article, Luiz Pessoa (2008) proposes an expanded model such as those known to rely on working memory, a key that monitored the effects of the dopamine D2 receptor ascertain which patients are likely to benefit? of interacting brain regions contributing to executive component of executive functions (for reviews see Cools & agonist bromocriptine in conjunction with a functional neu­ functions. Pessoa's model describes integrated cognitive­ D'Esposito, 2009; Robbins & Arnsten, 2009). In particular, roimaging study during performance on verbal delayed • Knowing that undertreatment or overtreatment could emotional networks supporting complex, flexible behav­ converging evidence from cognitive neuroscience studies recognition tasks. The principle finding was that bromocrip­ result in negative effects, how will the optimal dose be iors, and adds the amygdala and nucleus accumbens to carried out with rodent, nonhuman primates, and human tine appeared to modulate the putative PFC-dependent determined for individual patients? the frontal executive network. A particularly intriguing subjects underscore the importance of dopamine neuro­ retrieval rate, but not the encoding or retention stages of • How could dopamine augmentation be optimally aspect of Pessoa's model is the conceptual proposal he puts modulation on performance of working memory depen­ the task. paired with behavioral interventions? forward: that particular brain areas could be characterized dent tasks. Following up the previous findings, Wallace et al. (2011) along a gradient of connectivity. Highly connected brain Although most of the functional imaging studies report­ reanalyzed the neuroimaging data obtained from subjects • Will pharmacological resistance develop over time as areas serve as hubs regulating the Row and integration of ing results on the role of neurotransmitters and neuromod­ in the Gibbs and D'Esposito 2005 study in an effort to part of an adaptive response? information (for details see Figure 4 in Pessoa, 2008). It ulators during performance of cognitive tasks are typically t E; ase out the effects of bromocriptine on the functional • What are the unwanted effects? is tempting to speculate that focal disruption of a highly carried out with healthy participants without neurological connectivity of the prefrontal cortex and the striatum during connected hub would result in global dysfunction, while a deficits, a few studies have also been carried out with working memory tasks. Before exploring the neuroimaging • Will dopamine augmentation yield behaviorally meaning­ lesion localized to sparsely connected regions would yield patient populations. People with Parkinson's disease are, results, it is critical to note the behavioral observation that ful improvement? a specific behavioral impairment. Considering that areas not surprisingly, important for studies looking at the effects dopamine augmentation yields an inverted U-shaped curve implicated as integrative hubs are also the brain regions of dopamine on cognitive function. The results of such with respect to task performance. Too little or too much Answering these questions, and the myriad others expected affected in the most common clinical strokes resulting studies taken together with theoretical models describing dopamine appears to negatively influence behavior (see dis­ to arise in the clinical setting, suggests some general trans­ from vascular accidents involving the middle cerebral how different brain regions interact to accomplish complex cussion in Gjedde et al., 2010). Behaviorally, individuals can lational research principles regarding what needs to be artery and anterior cerebral artery, it should be anticipated tasks are intriguing enough to encourage further experi­ be characterized as bel~nging to either a high-span work­ determined prior to adoption of neurochemical adjuvants that stroke patients will experience some degree of execu­ mental studies and are of potential interest to rehabilita­ ing memory group or a low-span working memory group. to behavioral rehabilitation interventions. This will be the tive dysfunction (Levine, Turner, & Stuss, 2008). Chen tion. Before pharmacological interventions can be used Interestingly, bromocriptine administration improved task­ case whether the neuromodulation is obtained via phar­ et al. (2006) have also put forward a conceptual rubric effectively, much remains to be learned from studies with related speed and accuracy only in low working memory macological treatments or by the application of electrical for considering structure/function relations in the human defined patient populations with an eye toward delineating span individuals. High working memory span individuals stimulation (for further discussion see Butefisch, 2004, and brain that suggest that there are regions in the brain that how pharmacological approaches may or may not be help­ trended toward a decrement in performance. Importantly, Chapter 10). Carrying out such research will require the carry out specific cognitive functions, while other cogni­ ful with individuals with compromised neurological func­ the effects are not explained by changes in either motor infrastructure and resources needed to support multidis­ tive processes require interactions among a network of tion and difficulties performing complex working-memory speed or vigilance. The findings raise important implica­ ciplinary teams with expertise in neuroscience, computa­ brain regions. Damage to brain areas as a result of stroke dependent tasks. tions for use of dopamine augmentation in rehabilitation, tional modeling, imaging, cognitive psychology, neurology, should be expected to yield both specific impairments and The current understanding is that neurons in the pre­ as discussed below. and rehabilitation. impairments of a more generalized nature, such as execu­ frontal cortex, an area known to be important in the per­ When Wallace et al. (2011) analyzed the imaging tive dysfunction. formance of working memory-dependent tasks, receive data to obtain a measure of frontal-striatal connectivity, It is important to keep in mind that the character­ modulatory input from ascending fibers from dopamine­ the principal finding was that bromocriptine administra­ 15 . 3 . 1 NEURAL MEASURES AND ization of these networks derive from data obtained in releasing midbrain (i.e., the striatum) neurons (for review tion increased the measured connectivity in low working INTERVENTIONS experimental contexts. The operations of task-dependent, see Cools & D'Esposito, 2009). Communication between memory span individuals and was positively correlated experimentally determined functional networks in real­ the prefrontal cortex (PFC) and the striatum is important with the improved behavioral performance on the experi­ It is important that stroke patients be assessed with strtlC­ world, everyday tasks (e.g., packing for a trip) remains to for optimal working memory performance. In theory, the mental task. Similarly, bromocriptine exerted a negative tural neural imaging methods to determine the full extent be determined. It is also important to keep in mind that role of these ascending fibers is to stabilize task-relevant effect on frontal-striatal connectivity in the high working of their injuries. Refer to Figure 15.2 and 15.3. It is useful functional models based on brain imaging tools must be working memory representations or, in other words, to memory span individuals, again correlating with the behav­ to have anatomical imaging (CT or MRI) to make a deter­ interpreted in light of the numerous assumptions built decrease an individual's susceptibility to distractions dur­ ioral data, although both the imaging and the performance mination of the structural integrity of the brain, and dif­ into the protocols for acquiring, processing, and interpret­ ing task performance. data failed to reach statistical significance, possibly due to fusion tensor or diffusion weight imaging to assess white ing functional imaging data (Fitzpatrick and Rothman, It can be tempting in light of the experimental evidence the small sample size. matter integrity. Ramirez, Gao, and Black (2008) provide 2002). The assumptions made regarding the requisite to consider the possibility that neurological patients suf­ The findings, albeit obtained from healthy young par­ a detailed overview of clinical brain imaging methods hemodynamics and brain tissue properties may or may not fering from working memory deficits could be helped by ticipants in a carefully controlled experimental setting, still and how these tools can contribute to a neuroanatomi­ generalize to patients after brain injury. A final caveat for the administration of dopamine agonists, either alone or in offer some intriguing implications for additional research, cal!neurophysiological context for neurorehabilitation consideration is that most basic science functional imaging conjunction with rehabilitation. However, a series of publi­ particularly with individuals recovering from mild or mod­ (see also Chapter 4). Increasingly, resting state functional studies report findings obtained from data averaged across cations from Mark D'Esposito's laboratory, reviewed below, erate stroke demonstrating deficits in working memory­ connectivity blood oxygenation level dependent (BOLD) subJects. To be useful in clinical rehabilitation research, it provide a case study underscoring the care that must be dependent function. Additional research is needed that can magnetic resonance imaging (fcMRI) is being called will be necessary to be able to extrapolate group findings taken when rehabilitation practitioners look to translate specifically address the needs of clinical populations with upon to identify functional neural networks in both intact or general principles to an individual. experimental results. Attempting to modulate cognitive neurological insults affecting large neural networks and and patient populations (for a historical review of this

212 I STROKE REHABILITATION 15. EXECUTIVE FUNCTIONS I 213 measurement see Lowe, 2010). Other approaches for assess­ for all researchers and clinicians interested in considering neuropsychology, a subspecialty of the field of psychology response to the cnt1c1sms, new neuropsychological tests ing functional connectivity have been proposed, most how neuropharmacology could influence the mechanism that focuses on the relationship between brain function­ were developed that do not rely on the performance of sin­ notably the use of perfusion MR imaging, which moni­ of post-stroke dysfunction or recovery. Narushima and col­ ing and behavior. Lezak's (1982) work describes the char­ gle tasks delivered in a controlled environment but rather tors changes in cerebral blood flow (CBF), rather than the leagues also suggest that antidepressant therapy may aid acteristics of the person with brain injury and challenges provide more complex tasks closer to the demands made in BOLD signal, which is dependent on changes in blood oxy­ recovery of executive functions by upregulating neurotro­ neuropsychologists to develop tools to better characterize "real life" situations (Wilson et al., 1996). However, it is an genation, CBF. and cerebral blood volume (CBV; Chuang et pins and thereby enhancing neuroplasticity (Narushima et these behaviors. Two levels of neuropsychological tests important caveat that these are still administered in test­ al., 2008). Despite more than a decade of research, it remains al., 2007). A similar mechanism of action has been sug­ describe both the brain function and the behavioral conse­ ing rooms under controlled conditions and therefore do to be seen how useful resting state functional connectivity gested, based on experimental studies with murine brain quences of executive function. Several instruments in each not fully mimic the rich complexity of real life situations. measurements will be when they are used in neurorehabili­ slices, as contributing to the action of cortical stimulation category will be described. Figure 15.2 lists the measures It is not always necessary that tests be carried out in fully tation, particularly in the context of the altered cerebrovas­ techniques (Fritsch et al., 2010). that will be discussed. naturalized settings to be valid for assessing performance. cular milieu characteristic of patients post-stroke. We admit that it is appealing to consider the use of However, to be useful in rehabilitative practice, we believe Urgently needed to advance the science of neuroreha­ pharmacological agents to alter plasticity and network reor­ it is necessary that an individual's performance on such 15 . 4 .1 MEASURES TO IDENT I FY BRAIN - bilitation is the development of methods amenable to the ganization to make the state of the system more respon­ tests (i) be highly correlated with performance in everyday RELATED BEHAVIORS clinical rehabilitation and outpatient settings that allow sive to rehabilitation. However, a reading of the cautionary life, (ii) reveal in a meaningful way the underlying neural temporally dynamic measurements of the neural changes "case study" provided in Box 1 exposes the knowledge gaps The Wisconsin Card Sorting Test (WCST; Grant & Berg, or cognitive deficits that are contributing to poor perfor­ accompanying behavioral change. We think it would also that must be bridged if the field of neurorehabilitation is to 1948; Heaton, Cheelune, Talley, Kay & Curtiss, 1993) is a mance, and (iii) guide therapy. be beneficial to have long-term studies of individuals post­ translate experimental findings into clinical applications. test of set-shifting. It measures the person's ability to dis­ The Test of Everyday Attention (TEA; Robertson, stroke. The ability to capture the neural changes occurring The challenge for any intervention directed at the neural play flexibility as he is presented with changing schedules Ward, Ridgeway & Nimmo-Smith, 1994) uses a range of at different grain sizes that continue to shape the brain level is demonstrating that the resulting changes are not of reinforcement. In a sample of 112 persons with stroke, attentional tasks that are necessary in everyday life (search­ years after injury will be especially useful with the younger confined to the neural level but can yield or enable changes the WCST-64 resulted in a three dimensional model: ing maps, using a telephone directory, listening to lottery populations of patients, many of whom can expect to live and meaningful improvements at higher levels of analysis. (i) inflexibility, (ii) ineB-ective hypothesis-testing strategy, number broadcasts). The factors of sustained attention, decades after a stroke. If an intervention is to be useful in rehabilitation, it is not and (iii) set maintenance (Su Lin, Kwan, & Guo, 2008). selective attention, attentional switching, and auditory­ Very few rehabilitative interventions for executive dys­ enough to demonstrate that a pharmacological agent may The Trail Making Test (Reitan ·& Wolfson, 1995) verbal working memory match the current evidence for function are directed at the neural level. It is most likely increase, for example, long-term potentiation (LTP) as a provides information regarding attention, visual scanning, functionally independent attentional circuits in the brain that interventions directed at the neural level will be phar­ proxy for synaptic plasticity unless there is also evidence and executive function. Part A requires the participant to (Posner & Petersen, 1990). The data from the TEA reveal macological or based on the use of electrical stimulation. that alterations in synaptic plasticity allows for meaning­ draw lines to connect 25 numbers scattered on a page. Part problems with attention that will require rehabilitation Not surprisingly, a recent review summarizing the useful­ ful, beneficial gains in behavior and performance. B requires the connection of numbers and letters (a trail) professionals to engage with the patient, caregivers, and ness of pharmacological interventions or cortical stimula­ Chen and colleagues (2006) have also proposed a theo­ in order, alternating between letters and numbers without prospective employers in devising a care plan. Strategies tion protocols to aid recovery in patients following stroke retical framework for executive dysfunction interventions lifting the pencil from the paper. The time it takes for the may include training on subtasks that are made routine, (Floel & Cohen, 2010) primarily focused on motor and based on cognitive neuroscience/functional neuroimaging person to connect the trail is reported. If the person makes thereby increasing automaticity and allowing working language impairment, areas of rehabilitative need where findings (Chen et al., 2006). The level of the interventions an error, the administrator points out the error so she can memory and attentional resources to be deployed to more the authors could identify experimental findings and they propose and the predictions they make for determin­ correct it. The two scores reflect the total time in seconds "on-line" task demands. small-scale trials data. We agree with the general conclu­ ing outcome, however, are at the cognitive-behavioral level required to complete each task. Behavioral Assessment of the Dysexecutive sions drawn by authors of this revie>v that there remain and not the neural level. It remains to be seen whether The Wechsler Adult Intelligence Scale-IV Syndrome (BADS; Wilson, Alderman, Burgess, Emslie, many open questions that require answers before the neu­ multi-level combinations of pharmacology, .targeted cogni­ (WAIS-IV) Working Memory Index. The WAIS was & Evans, 1996). The BADS is a battery of six tests and two rorehabilitation community can implement such adjuvant tive retraining, and behavioral interventions will not only created in 1955 (Wechsler, 1955) and revised in 2008 questionnaires that requires the person to plan, initiate, therapy to traditional practice. In particular, research is improve performance on targeted tasks but also improve (WAIS_IV) after being standardized on 2,200 persons monitor, and adjust behavior in response to the explicit needed on determining optimal dosing, timing, and dura­ patients' performance on everyday tasks. Restoring or aug­ in the United States and 688 in Canada (http://cps.nova. and implicit demands of a series of tasks. The tasks include tion of treatment. Considering the heterogeneity of stroke menting cognitive processes may very well turn out to be edu/~cpphelp/WAIS-R.html). The Working Memory a "rule shift" to demonstrate shifting between two rules in patients, determining the correct pairings of drugs and necessary but not sufficient to meet patient-centered reha­ Index has three tests: Digit Span, which measures work­ a card task; an "action program" requiring a solution to a behavioral interventions will require careful titration for bilitation goals (Swartz, 1997). ing memory/attention, concentration, and mental control; practical problem of getting a cork out of a narrow tube each patient in the context of the neural and cognitive Arithmetic, which measures concentration while the using rules; "key search," which identifies the ability to sequelae of stroke, and individual goals for rehabilitation. subject manipulates mental mathematical problems; and solve a problem; "temporal judgment," requiring estimat­ This was essentially the conclusion reached in a review 15 .4 BEHAVIORAL MEASURES AND Letter-Number Sequencing (a supplemental task), which ing times for everyday events; "zoo map," which requires on the use of amphetamines for improving recovery after INTERVENTIONS measures attention and working memory. The test can be the ability to follow a route through a map that does not stroke (Martinsson, Hardemark, & Eksborg, 2007). used with people with brain injury to identify the area break rules; and "modified six elements," which assess time There is some evidence that antidepressant therapy can Persons with executive dysfunction have difficulty plan­ of the brain that has been affected, and specific subtests management with the person dividing the available time have a positive effect on executive functioning post-stroke ning, lack insight, are distractible, make poor decisions, identify the extent of the damage. between a number of tasks while not breaking rules. The (Narushima et al., 2007). The authors propose that the and have little concern for social rules (Burgess & Simons, assessment also includes the Dysexecutive ~estionaire eB-ect could be mediated via a monoaminergic modula­ 2005). Executive functions are needed to fulfill roles (DEX), a behavioral questionnaire to identify the occur­ 15 . 4 . 2 MEASURES TO IDENTIFY THE tion of frontal-striatal networks. Robbins and Arnsten in family, work, and community life, and post-stroke rence of behaviors. It can be used as a measure of aware­ B E HAVIORAL CONSEQUENCES OF STROKE (2009) have published an authoritative and comprehen­ deficits should be identified and addressed as a part of ness, as one version is for the respondent and the second sive· review of experimental and clinical evidence for the rehabilitation services. In this section of the chapter we The tests discussed in this section were designed to respond for a family member to rate the respondent. role of monoaminergic modulation of executive functions focus less on what has been learned from cognitive neu­ to the concerns that neuropsychological tests were failing The Patient Competency Rating Scale (Prigatano, in the context of mental disorders that is recommended roscience research and more on what can be learned from to generalize to performance in naturalistic settings. In 1986) is a measure of self-awareness or the ability to

214 I STROKE REHABILITATION 15. EXECUTIVE FUNCTIONS I 215 appraise one's strengths and weaknesses in acnvmes of unsuccessful task completion; rather, it identifies what an (Elliot, 2003). It should not come as a surprise that, as a Poor Performance Good Performance daily living, behavioral and emotional function, and cog­ individual can do and how much assistance is needed for result of this complexity, individuals with executive func­ nitive and physical function following brain injury. TI1e Daily Life him or her to carry out a task. Via the cueing system, a tion are somewhat resistant to rehabilitative efforts. There Demands respondent's responses are compared to a relative's or ther­ wider range of abilities, previously thought to be untestable, are some promising strategies addressing the rehabilita­

apist's observations. Awareness is a serious problem when Executive are captured in persons. This cueing system is standardized tion of executive functions that deserve further study. Of a person experiences executive dysfunction, since the first Dysfunction and is associated with the degree of cognitive impairment. course, rehabilitation interventions for executive functions Unrecognized and step in learning new strategies to manage an executive Unmanaged Because the EFPT can be used in both the clinic and the share many of the problems encountered in rehabilitation function deficit is to know that you have a problem that home, it is a bridge linking the data obtained in controlled more generally, including lack of well-designed interven­ Executive needs new strategies. Dysfunction research studies with the rehabilitation goal of assessing an tion trials with outcome measures linked to the stated Recognized and Managed individual's ability to perform in everyday life. outcome goals. Four promising intervention strategies will The Kettle Test (Hartman-Maier et al., 2009) is be presented, two at the behavioral level and two at the 15.4.3 PERFORMANCE - BASED TESTS Social and designed to indicate one's ability to perform daily tasks. performance level. Refer to Figure 15.3. Environmental Neuropsychological tests are designed to document the rela­ Support The patient's task is to prepare two hot drinks, one for tionship between brain function and behavior. The intent the clinician and one for the patient. The clinician and 15.5.1 INTERVENTIONS AT THE of neuropsychological assessment is to provide an accurate patient make the decisions about the details of the task to Figure 15.4 Factors Contributing to Resuming Participation Post­ BEHAVIORAL LEVEL depiction of an individual's specific cognitive impairments Stroke. This figure depicts how rehabilitation directed at executive be completed from some options of coffee, tea, hot choco­ (e.g., working memory deficit), as well as assessing how well dysfunction, including environmental and social support systems can late; and the clinician observes while the patient completes Goal Management Training (GMT) is a neuropsycho­ component cognitive processes work together to accomplish result in vastly different outcomes for individuals with similar post rhe task. The performance is scored for each element of the logical intervention developed to teach patients with brain stroke clinical profiles. a task. However, these tasks tend to ignore the person­ task, including assembling the kettle, obtaining the water injury a strategy to improve their ability to plan activities environment interaction. The natural and built environ­ and ingredients, putting the ingredient into the cup, and and to structure their intentions. It is based on Duncan's ment can both support and hinder performance in ways that return to work (see Figure 15.4 for a summary). Support is serving the beverage (a 12-step task). Each of the steps is theory of goal neglect. 1he theory states that any activity might not be obvious in the absence of a complete under­ also the variable that is most dependent on social, cultural, scored based upon the speed, receipt of cues, incomplete requires the person to establish goals and/or task require­ standing of what cognitive resources are actually required. and political norms. performance, and necessity of assistance. Following com­ ments to create the structure to guide the actions that Clarity in the task demands and the available affordances In our view, it is unwise to base an intervention strat­ pletion of the task performance, the therapist engages the can lead to the goals being achieved. While performing are critical in planning interventions and working with egy solely on the results of functional imaging studies or client in a debriefing that focuses on the client's evaluation a task, the current state of affairs and the goal state are patients and their families to help them learn to manage the results from a neuropsychological battery. At this time of the performance. compared, and actions or mental operations are selected to the consequences of executive dysfunction. Performance there are still gaps in our ability to interpret brain and cog­ 1he Multiple Errand Test by Shallice and Burgess address the mismatch. This process continues until there is tests, primarily developed by occupational therapists, take nitive measures in terms of what is or is not sufficient for (1991), which was adapted and studied in clients with no mismatch between the current state and the goal state. a different approach from what we have described for neu­ determining an individual's overall ability to function. The traumatic brain injury (Knight et al., 2002; Alderman et Because there can be many actions associated with a task, ropsychological tests and seek to answer a different question results of neuropsychological assessments should be sup­ al., 2003) and following stroke (Dawson et al., 2009), is it is important to inhibit irrelevant actions that will not about brain function: "How does the brain and cognition plemented with performance-based assessments (Burgess a multiple sub-goal task performed in a shopping district contribute to a particular goal. The GMT contains several support the everyday performance of tasks necessary to live et al., 2006) in the hope that more insightful measure­ or a health facility. It was developed to elucidate cogni­ stages that are based on this notion: (i) Stop! Alerts and independently, be safe, to manage daily affairs?" Using a ments can be created with a combination of these two tive problems persons have in managing the challenges of orients the person to the task; (ii) the person defines the performance approach, executive function is examined as assessment strategies. everyday life. The person being tested must accomplish 6 main tasks, (iii) lists the main steps, (iv) learns the steps, a person performs an entire task, an actual task that is The Executive Function Performance Test (EFPT) tasks: buy 3 items (using only a specific amount of money), and (v) checks or monitors the process. In the final stage, necessary in everyday life. Clearly, linking performance to was developed by Baum et al. (2003) in an effort to address make a phone call, mail something, and meet the inves­ "checking," the outcome of the selected actions is com­ the underlying neural structures supporting performance some of the challenges raised above. The EFPT provides tigator 10 minutes afi:er starting the assessment. They pared with the goals to be achieved (Levine, Robertson, requires intermediate cognitive models. A discussion of this a record of executive functions serving in the perfor­ also must collect information about opening and closing Clare, Carter, Hong, Wilson, et al., 2000). It is likely that point in the context of education carries important lessons mance of a task. It has been validated in studies with the times, identify the cost of an item, and say when they are these operations map onto the frontoparietal and cingula­ for rehabilitation (Bruer, 1997). elderly, with individuals with stroke, and with clients with finished. They are scored in terms of errors (omissions, opercular networks discussed earlier in this chapter, and It should not be assumed that impairment in a cog­ schizophrenia (Katz, Tadmor, Felzen, & Hartman-Maeir, partially completed tasks, inefficiencies, and the strategies are likely to be disrupted by the damage caused by strokes nitive process will result in impairments in overall func­ 2007; Baum, Connor, Morrison, Hahn, Dromerick, & used). By observing the task failures, rehabilitation pro-. to anterior regions of the brain (Dosenbach et al., 2008). tional capacity, because activities can be accomplished Edwards, 2008; Wolf, Stith, Connor, & Baum, 2010). fessionals may find it helpful to identify strategies they The Neurofunctional Retraining Approach, an by employing different strategies and by different levels The EFPT includes 4 standardized instrumental activi­ can use to help individuals either learn new strategies or occupational therapy intervention, recognizes the impair­ of motivation, interest, and different environments. For ties of daily living (IADL) tasks (cooking, telephone use, learn compensation strategies to help them function afi:er ments faced by persons with brain injury and trains example, there are many ways individuals can navigate a medication management, and bill paying) that the client an injury that results in executive dysfunction (Alderman them to develop habits and routines for real-world skills grocery store even if the end goal, buying all the items on has to perform to live independently at home. The clini­ et al., 2003). with the goal of developing behavioral automaticity and a list as quickly as possible, is identical. By conceptualizing cian provides a series of graded cues: (1) a verbal prompt, a greater reliance on the environment, including cueing the task difrerently, different cognitive resources and brain (2) a gestural prompt, (3) direct verbal instruction, (Giles, 2005). Such an approach is used to train clients networks are brought to the goal. It is, however, impor­ (4) physical assistance, and (5) cessation of the task because the 15.5 BEHAVIORAL AND PERFORMANCE in behavioral routines when there is little expectation of tant to learn how it is that a person plans and executes a person is not capable of completing it. A total score is deter­ INTERVENTIONS generalized application of strategies to novel circumstances task, responds to errors, and how much external support mined based on the individual's ability to initiate the task, encountered in the real world. For example, to train in is rieeded in order to be successful. Assessing the level of execute the task (including organization, sequencing, judg­ Throughout this chapter we have made the point that exec­ a specific morning routine, therapy would involve repeat­ support required is key, because support is the variable ment, and safety), and complete the task. Importantly, utive junctions serves as an "umbrella term" for a constel­ ing the sequence and activities over many days until the most likely to determine if someone can remain at home or the EFPT does not simply determine successful or lation of cognitive processes supporting complex behaviors process becomes automatic. Another example of therapy

216 I STROKE REHABILITATION 15. EXECUTIVE FUNCTIONS I 217 for a circumstance encountered in everyday life would be em opportunities for the individual to experience different The following reflect the gaps we identified that can be of Rehabilitation Science, the University Hospital of Columbia and Cornell, \Veill Cornell Medical College, New York. training a person to walk to the same restaurant on the environments, difl-erent levels of demands of the activity, addressed: Baum, C., & Katz, N. (2009). Occupational therapy approach to same route with specific instructions of where to turn, how and bring to consciousness a new level of awareness (Baum assessing the relationship between cognition and function. In to look before crossing a street, how to obey street lights, & Katz, 2009). • Cognitive and rehabilitation scientists need to develop T. D. i'vlarcotte & I. Grant (Eds.), Neuropsycholog:;' ofevel)'daJ'.func­ etc. Training would also cover what the individual should Cognitive Orientation to Daily Occupational a shared language that will allow cross-level validation tioning (pp. 62-91). New York: Guilford Press. Baum, C., Morrison, T., Hahn, M., & Edwards, D. (2003). Executive do upon arrival to the restaurant, how to become familiar Performance (CO-OP), also developed by occupational of interventions and outcome measures. Specifically, Function Pe1jormance Test: Test protocol booklet. Sc. Louis, MO: with the staff and the menu, and how to use the menu therapists, is a client-centered, performance-based, prob­ there needs to be better definitions and assessment of Program in Occupational Therapy, \Vashington University School and order a dish. The aim is to maintain a schedule that lem-solving approach that enables the person to acquire executive functions at all levels. For example, to under­ of Medicine. can become routine, doing the same activities in the same skills through a process of strategy use and guided discov­ stand the effectiveness of behavioral interventions, a Baum, C. M ., Connor, L. T., Morrison, T., Hahn, lvl., Dromerick, A. W., & Edwards, D. F. (2008). Reliability, validity, and clini­ sequence each day (Baum & Katz, 2009). ery (Polatajko & Mandich, 2004, 2005; see also Chapter good starting point would be to use outcome measures cal utility of the Executive Function Performance Test: A measure N eurofunctional retraining considers the person's 2). CO-OP fosters skill acquisition, cognitive strategy at both the behavioral and performance levels. This of executive function in a sample of people with stroke. American learning capacity in the design and implementation of pro­ use, generalization, and transfer of learning. The founda­ approach could lead to a greater understanding of journal of Occupational ThempJ'• 62(4), 446-455. grams. The specific cognitive capacities are not the target tional theories are drawn from behavioral and cognitive the neural and cognitive contributions to behavioral Braver, T. S., Cohen, ]. D., & Barch, D. lvl. (2002). The role of the of the interventions; however, the person's capacities-par­ psychology, movement science, and occupational therapy. performance. prefrontal cortex in normal and disordered cognitive control: A cognitive neuroscience perspective. In D. T. Scuss & R. T. Knight ticularly memory, attention, and executive function-must Behavioral theories focus on the relationship between stim­ • ~estions that need to be addressed about the per­ (Eds.), Principles ofJi'ontal lobe jimction (pp. 428-448). Oxford: be considered in the design of functional skills training. ulus, response, and consequence. Learning is viewed as a Oxford University Press. formance of tasks include: What cognitive resources One problem associated with cognitive impairments is permanent change in the form, duration, or frequency of a Bruer, ]. B. (1997). Education and the brain: A bridge too far. are needed to accomplish everyday tasks? What is when the person fails to recognize limitations, a lack of behavior. Reinforcement is seen as an integral component Educational Researcher, 26(8), 4-16. · automated? What requires attentional resources? How Burgess, P. W., & Shallice, T. (1996). Response suppression, initiation awareness called anosognosia . Therapy enables the individ­ of learning. CO-OP uses reinforcement, modeling, shap­ is task set maintained over an entire task epoch? How and strategy use following frontal lobe lesions. NettropS)'Chologia, ual to integrate awareness of deficits of memory, attention, ing, prompting, fading, and chaining techniques to support 34(4), 263-273. many independent ways are there to complete a task? and executive control in order to allow the individual to skill acquisition (Polatajko & Mandich, 2004). CO-OP Burgess, P. WI., Alderman, N., Forbes, C ., Costello, A., Coates, L. At the cognitive and neural levels, are difl-erent strate­ have a new view of self after brain injury. There may be a requires the mental organization of knowledge (prob­ M-A., Dawson, D. R., et a1.(2006). The case for the development gies truly independent? and use of "ecologically valid" measures of executive function in distinction between a motivated lack of awareness (embar­ lem solving, reasoning, and thinking) in the acquisition experimental and clinical neuropsychology. journal ofInternational rassment) and an organic lack of awareness (McGlynn & and performance of skills (Schunk, 2000). The problem­ • We need to develop and maintain shared databases Nettropsychological Societ)'• 12(2), 194-209. Schacter, 1989). This lack of awareness hinders the indi­ solving strategy used in CO-OP is "GOAL, PLAN, DO, of patients that include comprehensive clinical evalu­ Burgess, P. \V., & Simons,]. S. (2005). Theories of frontal lobe execu­ vidual from engaging in everyday life; thus, integration of CHECK." It was adopted from Meichenbaum (1977, 1994) ations, results from neuropsychological tests, perfor­ tive function: Clinical applications. In P. W. Halligan & D. T. Wade (Eds.), E_{fectiveness of rehabilitation for cognitive deficits (pp. awareness into interventions is critical. as a framework for guiding the discovery of self-generated mance-based tests, and self and caregiver reports. These 211-231). Oxford: Oxford University Press. domain-specific strategies that support skill acquisition. databases must be maintained over time to begin to Biitefisch, C. lvl. (2004). Plasticity in the human cerebral cortex: The Fitts and Posner (1967) model of motor learning understand the consequences of aging with a brain Lessons from the normal brain and from stroke. Neuroscientist, 15.5 . 2 INTERVENTIONS AT THE provides theoretical support for CO-OP. Their three-stage injury. Such information is necessary to guide inter­ 10(2): 163-173. PERFORMANCE LEVEL Cardol, lvl., Beelen, A., v.an den Bos, G. A., den Jong, B. A., de Groot, model of motor learning guides the process. The cognitive ventions and anticipate outcomes. I. J., & de Haan, R. ]. (2002). Responsiveness of the impact on Toglia (1993, 2005), an occupational therapist, proposes a stage guides the individual as he or she seeks to under­ participation and autonomy questionnaire. Archives of PhJ'Sical • Patient-centered outcomes will always rely on the inter­ strategy learning and awareness approach that encour­ stand the task and how to perform it; the associative stage Medicine and Rehabilitation, 83(11), 1524-1529. actions among the nature of the injury, the recovery Chan, R. C. K., Shum, D., Toulopoulou, T., Chen, E. Y. H. (2008). ages the clinician to discover the cognitive capacities and is where the individual focuses attention and performs processes, patients' expectations, their life demands, Assessment of executive functions: Review of instruments and processing strategies that can influence the person's perfor­ with greater speed and precision; and the autonomous and their environments. Each will make contributions identification of critical issues. Archives ofClinical Nmropsychology, mance. Treatment focuses on helping the person develop stage is where the skill is performed consistently and in a 23(2), 201-216. to actual and perceived outcomes. 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