ABSTRACT AN INTENSIVE TREATMENT PROTOCOL FOR SEVERE CHRONIC AUDITORY COMPREHENSION DEFICITS IN APHASIA: A FEASIBILITY STUDY by Kelly Anne Lundeen Stroke is the leading cause of long-term disability in the United States. As medical technology improves, more people are surviving stroke and living longer with stroke-related disabilities, including aphasia. Auditory comprehension deficits resulting from aphasia are associated with lower functional outcomes and higher treatment dropout rates. Previous research has indicated the effectiveness of treatment intensity which targets verbal expression abilities; however, the results of these studies cannot be transferred to auditory comprehension. The present study explored the feasibility of an intensive treatment protocol on single-word auditory comprehension abilities, the ability to self-detect breakdowns in auditory comprehension, and tolerance of an intensive treatment among three people with severe chronic aphasia resulting from a single, left hemisphere stroke. Results of the study reveal that an intensive protocol leads to increased single-word auditory comprehension in some people with severe chronic aphasia; however, not all people are candidates for this type of treatment.
AN INTENSIVE TREATMENT PROTOCOL FOR SEVERE CHRONIC AUDITORY COMPREHENSION DEFICITS IN APHASIA: A FEASIBILITY STUDY A Thesis Submitted to the Faculty of Miami University in partial fulfillment of the requirements for the degree of Master of Arts Department of Speech Pathology and Audiology by Kelly Anne Lundeen Miami University Oxford, Ohio 2011 Advisor: Kathleen Hutchinson, Ph.D. Reader: Kelly Knollman-Porter, M.A. Reader: Donna Scarborough, Ph.D
Table of Contents Introduction...1 Methods...5 Results...9 Single-Word Comprehension...9 Requests for Repetition...12 Fatigue and Frustration...15 Discussion...15 References...21 Appendices...26 Appendix A...26 Appendix B...27 Appendix C...29 ii
List of Tables 1. Demographic and Aphasia-Related Data for the Three Participants in This Study...7 2. Single-Word Comprehension Effect Size Data...12 3. Repetition Data...14 4. Requests for Repetition Effect Size Data...15 5. Fatigue/Frustration Rating Data...15 iii
List of Figures 1. Average percent of correct responses of single high frequency words by Participant 1...10 2. Average percent of correct responses of single high frequency words by Participant 2...11 3. Average percent of correct responses of single high frequency words by Participant 3...12 4. Average number of independent requests for repetition during comprehension breakdowns by Participants 1 and 2...14 iv
An Intensive Treatment Protocol For Severe Chronic Auditory Comprehension Deficits In Aphasia: A Feasibility Study Stroke is the leading cause of long-term disability in the United States and can affect individuals of any age, nationality, race, or gender (Center for Disease Control and Prevention [CDC], 2010; National Aphasia Association [NAA], 2010). In the last 30 years, significant medical advances, improved acute medical care, and use of neuroimaging techniques have contributed to increased detection of stroke, improved accuracy of stroke diagnosis, and decreased mortality rates (Lakshminarayan, Anderson, Jacobs, Barber, & Luepker, 2009). Given these recent medical advances, stroke mortality has declined from 97.1 per 100,000 in 1979 to 43.6 per 100,000 in 2006 (United States Environmental Protection Agency [EPA], 2009). Currently, 6 million people in the United States are stroke survivors, with approximately 795,000 additional strokes occurring annually (United States Department of Health and Human Services [DHHS], 2010; Lloyd-Jones et al., 2010). Approximately 1 million of these stroke survivors have a diagnosis of aphasia, which can affect all areas of communication, including verbal and written expression, and auditory and reading comprehension (NAA, 2010). The incidence and severity of auditory comprehension deficits resulting from aphasia is unknown. As the number of people surviving stroke increases, it is safe to conclude that more people may live with auditory comprehension deficits associated with aphasia for a longer period of time. Auditory comprehension deficits can negatively impact performance in purposeful activities and quality of life. People with comprehension deficits following stroke have greater long-term functional disabilities in activities of daily living and mobility as compared to people who have aphasia without this impairment (Paolucci et al., 2005). The severity of the comprehension deficit has a direct correlation with overall rehabilitative outcomes. Physical, occupational, and speech therapy dropout rates are greater for individuals with comprehension deficits (Paolucci et al., 2005). People with aphasia often become frustrated because their comprehension impairments adversely impact the quantity and quality of social relationships, as well as vocational opportunities. Decreased and inefficient social interactions may lead to reduced independence, decreased quality of life, and social isolation (Davidson et al., 2008; Garcia, Laroche, & Barrette, 2002; LaPointe, 1997), which in turn may lead to depression (Hackett, Yapa, Parag, & Anderson, 2005). 1
Speech Perception and Auditory Comprehension Comprehension of a spoken word or message is a complex, multi-step process that relies on linguistic and nonlinguistic processing. A prerequisite of single-word comprehension is speech perception, which is necessary for access to higher level linguistic processing functions (Boatman, 2004). When a speech sound is detected, the acoustic information is encoded and analyzed by the peripheral auditory system based on psychophysical properties (Pisoni & Luce, 1987; Klatt, 1982). The acoustic features of the coded speech signal are further analyzed in the central auditory system, and speech signal interpretations are formed (Stevens, 1980; Pisoni & Luce, 1987). These representations are then mapped based on their distinctive phonetic features during acoustic-phonetic analysis (Pisoni & Luce, 1987). Acoustic-phonetic analysis leads to phonological processing. By decoding the acoustic-phonetic information to be translated to internal representations specific to the listener, access is given to higher level information about a word, i.e., lexical and semantic (Boatman, 2004). Previously analyzed speech characteristics are paired with similar word representations stored within the long-term memory. Lexical access occurs when word meanings are retrieved from the long-term semantic memory, which allows for single-word comprehension (Pisoni & Luce, 1987). Neurologic damage can notably impact the ability to understand speech input at any level on this continuum (Boatman, 2004; Morris, Franklin, Ellis, Turner, & Bailey, 1996). Neurologic correlates for lexical-phonetic analysis are more diffuse than the levels of speech perception. Auditory comprehension deficits have been found to be associated with impairments to sites identical to those where acoustic-phonetic and phonological processing deficits are induced. Areas responsible for lexical-semantic processing include multiple temporal, parietal, and frontal lobe sites (Boatman, 2004; Dronkers, Wilkins, Van Valin, Redfern, & Jaeger, 2004). Hence, word comprehension deficits can occur in isolation or in combination with phonological processing and/or acoustic-phonetic analysis deficits. Aphasia and Cognition The relationship between aphasia and cognition is not fully understood. Models of phonemic and semantic processing suggest that target representations of a sound or word must compete with similar non-target representations that are activated in the short-term working memory (Dell, 1986). These competing forms may be phonemically related (cat/hat) or semantically related (couch/bed). If the phonemic or semantic representation cannot be 2
maintained for sufficient processing, a non-target may be selected, causing a breakdown in comprehension. In order for the target to successfully compete with neighboring words and concepts, the semantic and phonological representations must be maintained for an adequate amount of time in working memory (Martin, Schwartz, & Kohen, 2006). Anosognosia is a cognitive deficit resulting from brain injury, including stroke, that impairs an individual s awareness or appreciation of cognitive, perceptual, behavioral, sensory, or motor deficits (Orfei, Caltagirone, & Spalletta, 2009; Hartman-Maeir, Soroker, Ring, & Katz, 2002). Similar to the hierarchy of comprehension, four levels of self-awareness of deficits in people with traumatic brain injury (TBI) have been identified: 1) accurate acknowledgment of the presence of a problem or deficit, 2) demonstration of an appropriate emotional response toward the deficit, 3) comprehension of the implications the deficit has on daily life, and 4) taking the deficit into account in future actions/behaviors (Flashman, Amador, & McAllister, 1998). While extensive research exists on self-awareness in TBI and right hemisphere stroke, there is limited data on self-awareness deficits in individuals with left hemisphere stroke. A review revealed that most studies that address self-awareness after stroke included patients with co-existing right and left hemisphere damage (60%) or right only (35%), with no study exclusively analyzing participants with injury to the left hemisphere (Orfei et al., 2009). It has been suggested that self-awareness among patients with left hemispheric involvement is more challenging to assess secondary to aphasia; therefore, the diagnosis of aphasia is often criteria for exclusion from research studies. Additionally, it was proposed that patients with global or severe comprehension deficits associated with aphasia cannot be tested on self-awareness of language disorders (Orfei et al., 2009). Treatment of Auditory Comprehension Deficits For decades, researchers and clinicians have explored and developed interventions to offset the debilitating effects aphasia has on speaking ability. A review of the literature reveals a plethora of interventions designed to improve the verbal expression skills of people with aphasia (Schuell, Jenkins, & Landis, 1964, Robey, 1998, Mortley, Wade, & Enderby, 2004; Choe, Azuma, Mathy, Liss, & Edgar, 2007). However, research protocols addressing the restoration of comprehension deficits are limited (Helm-Estabrooks & Albert, 2004; Crerar, Ellis, & Dean, 1996), with even fewer involving patients with severe chronic deficits associated with aphasia 3
(Morris et al., 1996). Research suggests that intensive treatment improves the verbal expression skills of people with chronic aphasia (Cherney, Patterson, Raymer, Frymark, & Schooling, 2008; Kleim & Jones, 2008). Specifically, a meta-analysis revealed that treatment sessions that lasted between 2-4 hours daily facilitated improved communicative ability (Basso, 2005). Historically, intervention protocols for chronic comprehension deficits have involved 1 hour sessions, 2 days per week (Crerar et al., 1996; Morris et al., 1996). Although there is research to support how an intense treatment protocol can positively impact verbal expression for people with chronic aphasia, limited data exists regarding how these interventions impact auditory comprehension abilities. Tolerance of an Intensive Protocol Research has determined that only some patients in the acute stages following stroke can tolerate an intense speech and language treatment (Bakheit et al., 2007); however, more recently it was found that individuals in the chronic stage of stroke were able to tolerate an intensive physical therapy treatment protocol (Combs, Kelly, Barton, Ivaska, & Nowak, 2010). Previous research examining the intensity of treatment has not addressed fatigue and frustration that might result from an intensive treatment, or how fatigue and frustration may impact performance. Given that emotional reactions, i.e., frustration, are influenced by cognition, tolerance for frustration may vary (Ekman, 1999; Hybl & Stagner, 1952). Frustration may serve as a source of motivation for one individual or it may adversely impact performance on a given task and/or subsequent task for another individual (Child & Waterhouse, 1953). Purpose The current investigation was designed to study the feasibility of an intense auditory treatment protocol on single-word auditory comprehension abilities in individuals with severe chronic aphasia. Evidence suggests that higher treatment intensity can lead to positive changes in verbal expression abilities in chronic aphasia; however, the results of the high intensity programs targeting expressive abilities cannot be generalized to auditory comprehension abilities (Cherney et al., 2008). The study also examined if a change in the ability to detect word-level auditory comprehension breakdowns would occur as a result of the intense auditory treatment protocol. Finally, research conducted on the intensity of treatment has not explored the relationship between treatment intensity and the presence or absence of fatigue or frustration. Given the target population of people with severe chronic aphasia, it was unknown if a daily, two 4
hour treatment session could be tolerated. Therefore, the study was designed to determine if people with severe chronic aphasia could tolerate a high intensity treatment protocol, and to explore if fatigue and frustration secondary to intensity impacted performance. The purpose of this investigation was to answer the following research questions: 1. Will an intensive 2 hour per day, 4 week auditory treatment protocol result in a change of single-word auditory comprehension abilities? 2. Will an intensive auditory treatment protocol result in a change in ability to selfdetect auditory comprehension breakdowns at the word-level? 3. Can participants with severe chronic aphasia tolerate a high intensity treatment protocol? Methods Participants Four participants with chronic aphasia were recruited from aphasia support groups and clinics in the greater Cincinnati area. The following inclusionary criteria were met prior to participation in the experimental phase of the study: (a) a single, left hemisphere stroke, (b) at least one year post-diagnosis of aphasia, (c) severe auditory comprehension deficits, (d) between 25 and 85 years of age, (e) pre-morbid history of right-hand dominance, (f) completion of at least a high school education, (g) monolingual speaker of English, (h) adequate vision and hearing, and (i) negative history of major psychotic episodes or intractable substance abuse. All participants were required to pass a hearing screening, visual acuity screening, and response screening. A bilateral pure-tone hearing screening was administered at 25 db HL at 1000, 2000, and 4000 Hertz (Hz). To pass the hearing screening, all tones presented had to be identified. The visual acuity screening consisted of three 4x6 pictured objects placed in front of the participant. Each participant was required to match a picture given by the examiner to the appropriate image. To pass the visual acuity screening, participants were required to obtain nine of ten correct responses. Finally, a response screening was administered to determine ability to differentiate between yes and no responses. Participants were required to respond to nine of ten simple yes/no questions; however, accuracy of the responses was not taken into consideration. The response screening also served to rule out perseveration of a yes or no response as a 5
factor. Gestural and verbal instructions were given to complete the screenings with consistent behaviors accepted as correct responses, i.e., turning head towards the source of sound during the hearing screening. One participant was excluded from participation secondary to failing the hearing screening. The appropriate referral was made to an audiologist for more extensive testing. All methods and procedures were reviewed and approved by the Miami University and University of Cincinnati Institutional Review Boards. Three participants were included for the purposes of this study. Aphasia diagnoses were confirmed using the Western Aphasia Battery (WAB) (Kertesz, 2007) Aphasia Quotient (AQ), and the Peabody Picture Vocabulary Test 4 th Edition (PPVT-4), Form A (Dunn & Dunn, 2007) (see Table 1). Results of the WAB classified Participant 1 as having Wernicke s aphasia, and Participants 2 and 3 as globally aphasic. Severe verbal apraxia was exhibited by Participant 2. Gestures were the primary form of communication with minimal vocalizations noted; the use of real words was not demonstrated. Participant 3 presented with severe neologistic verbal perseveration errors. Characteristics displayed by Participants 2 and 3 did not interfere with testing or completion of the treatment protocol. Auditory comprehension severity ratings were determined using the WAB Auditory Comprehension Subtest; scores between 0 and 5 were required to be classified as severe (Kertesz, 2007) (see Table 1). Informed consent or assent to participate following permission from a legal guardian was obtained from each individual prior to commencement of treatment. No monetary compensation was provided for participation in the study. 6
Table 1 Demographic and Aphasia-Related Data for the Three Participants in This Study Variable P1 P2 P3 Months Post-Onset 65 15 56 Age 72 67 73 Gender Female Female Female Race Caucasian Caucasian Caucasian Years Of Education 12 12 12 Type of Aphasia Wernicke's Global Global WAB Aphasia Quotient 53.2 11.8 7.6 WAB Auditory Comprehension Subtest Score 4.3 3.9 1.6 PPVT-4 Standard Score 47 55 20 Design A single subject, ABA design was utilized to examine single-word auditory comprehension of treated and untreated stimuli. A stable baseline was achieved during the pretreatment phase (A 1 ). The treatment phase (B) consisted of 20 high intensity treatment sessions over the course of one month. Baseline probes were completed using untreated stimuli each week of treatment. Stability of treated stimuli was measured one and four weeks following termination of treatment (A 2 ). Baseline Phase Twenty-five colored 4x6 pictures depicting high-frequency objects were viewed by each participant three times non-consecutively (see Appendix A). The examiner verbally presented a corresponding target word (i.e., light), phonemic foil (i.e., fight), or semantic foil (i.e., dark) at random. Participants were required to determine if the word spoken by the examiner corresponded with the pictured object. To receive credit for a correct response, correct identification of the target word and rejection of the corresponding phonemic and semantic foils was required through verbalization, gesture, or a written choice of yes or no. The assessment phase was terminated when accuracy dropped between 60 and 80 percent or lower; this determined the complexity level of stimuli utilized in the experimental phase. All participants obtained a stable baseline at the high frequency single-word level. 7
Experimental Phase Participants received two hours of treatment, five days a week, for four weeks, or until 95% accuracy was obtained for three consecutive treatment sessions. Participants viewed 40 colored 4x6 pictures depicting high frequency objects, three times non-consecutively (120 views of the picture stimuli) per experimental session (see Appendix B). Following the baseline phase procedure previously described, participants were required to determine if the word spoken by the examiner corresponded with the pictured object. Each response was recorded as correct or incorrect. Immediate verbal reinforcement was provided for correct or incorrect responses. The total number of correct responses was reported verbally and/or written at the end of each experimental session, if requested by the participant. Supplementary training, i.e., repeating the target word, writing the target word, or saying the target word, phonemic foil, or semantic foil and modeling the correct response, was provided on stimuli that were consistently in error for Participants 1 and 2. Experimental sessions were repeated following the same procedure until the two hour treatment session was completed. Breaks were provided approximately every 20 minutes and lasted between three and five minutes in duration, during which the participants were engaged in conversation or encouraged to take a walk. The number of independent requests for repetition made by each participant was measured. Participants were instructed at the beginning of each daily treatment session to request repetitions if a breakdown in comprehension occurred. No additional cueing was given during the experimental session. Repetitions were provided by the examiner only when requested through verbalization or gesture by the participant. There was no ceiling for the number of repetitions requested. The level of fatigue and frustration experienced by each participant was measured at the beginning and end of each daily treatment session. The rating scale was modeled off of the Wong-Baker FACES Pain Rating Scale, and consisted of visual representation with corresponding words and a number likert scale, which was adapted to reflect the level of fatigue and/or frustration that might be experienced (Wong, Hockenberry-Eaton, Wilson, Winkelstein, & Schwartz, 2001). Participants were encouraged to rate themselves throughout experimental sessions. If not used spontaneously, a cue was provided by the examiner and ratings were collected after completion of each experimental session. 8
Maintenance and Follow-Up Phase Maintenance of treated stimuli was measured by completion of one experimental session one-week and four weeks post-treatment. Follow-up baseline probes were conducted one and four weeks post-treatment utilizing untreated stimulus words. Requests for repetitions were monitored for both treated and untreated stimuli. Data Analysis The effect size (ES) was calculated by subtracting the mean of the three pre-treatment baseline values (A 1 ) from the mean of the two post-treatment baseline values (A 2 ) and dividing by the standard deviation of A 1 (Beeson & Robey, 2006). Small, medium, and large effect sizes are 0.2, 0.5, and 0.8 respectively (Cohen, 1988). Reliability The researchers completed inter-rater reliability measures on at least 20% of the treatment sessions to the level of treatment fidelity. The original examiners completed reliability measures at random throughout the experimental phase. The frequency ratio resulted in 100% agreement between independent observers. A Pearson product-moment correlation revealed a strong, positive correlation (r = +1.00). Results Single-Word Auditory Comprehension Participant 1. A stable baseline was demonstrated following completion of three initial probes. Participant 1 received four weeks of intensive treatment at the single, high frequency word level. Improvements in auditory comprehension of the treated stimuli increased from 27.5% to a high of 84.2% accuracy; the criterion level of 95% was not achieved (see Figure 1). Improvements in auditory comprehension were observed to generalize to the untreated stimuli with a high of 68% (see Figure 1). Follow-up probes of treated stimuli show a decline in maintenance one and four weeks post-treatment, 67.5% and 65% accuracy respectively. The one-week follow-up of treated stimuli falls below the untreated probe (68% accuracy). Probes of untreated stimuli display an increase in auditory comprehension abilities as compared to initial baseline testing (ES = 11.5) (see Table 2 for effect size and Figure 1 for average percentage correct). 9
A c c u r a c y 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Baseline Treatment Maintenance 1 2 3 4 5 6 7 8 9 101112131415161718192021222324252627 Session Number Treatment Stimuli Probe Stimuli Figure 1. Average percent of correct responses of single high frequency words by Participant 1. Participant 2. A stable baseline was obtained after completing three baseline probes. Participant 2 received four weeks of intensive treatment at the single, high frequency word level. Treated stimuli improved from 48.75% to a high of 90% accuracy (see Figure 2). Generalization to the untreated stimuli was observed with a high of 64% accuracy (see Figure 2). A one-week post-treatment follow-up probe of treated stimuli demonstrated maintenance of treatment effects (82.5% accuracy); however, a decline in performance was noted four weeks post-treatment (57.5% accuracy). Change in performance from initial baseline levels to follow-up baseline probes was observed (ES = 21.4) (see Table 2 for effect size and Figure 2 for average percentage correct). 10
A c c u r a c y 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Baseline Treatment Maintenance 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Session Number Treatment Stimuli Probe Stimuli Figure 2. Average percent of correct responses of single high frequency words by Participant 2. Participant 3. A stable baseline was obtained following three baseline probes. Participant 3 received four weeks of intensive treatment at the single, non-word level. Due to a lack of response to the treatment protocol, the following modifications were made during the first week of the experimental phase: (a) stimuli were decreased to 13, (b) choices were modified to include the target word, a non-word, and a phonemically related non-word, and (c) two to three repetitions were provided for each stimulus presented by the examiner (see Appendix C). Two written choices served as the primary response format of Participant 3. The limited change in comprehension of the treated (Mean = 9.9% accuracy) and untreated stimuli (Mean = 5.7% accuracy) during the experimental and maintenance phases suggest that correct responses were due to chance (Breese & Hillis, 2004). Effect size was unable to be calculated due to a lack of variance in the pre-treatment phase. 11
100% Baseline Treatment Maintenance A c c u r a c y 90% 80% 70% 60% 50% 40% 30% 20% 10% Treatment Stimuli Probe Stimuli 0% 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Session Number Figure 3. Average percent of correct responses of single high frequency words by Participant 3. Table 2 Single-Word Comprehension Effect Size Data Variable P1 P2 Mean of A 1 4.0 1.67 Mean of A 2 15.5 14.0 Standard Deviation of A 1 1.0 0.577 Cohen s d 11.5 21.4 Requests for Repetitions Participant 1. The total number of repetitions requested per daily treatment session increased as the experimental phase progressed (see Table 3 for repetition data and Figure 4 for average number of repetitions). At the initial treatment session, 72 verbal requests for repetition were made as compared to 268 requests at the conclusion of treatment. Requests for repetition for treated stimuli were observed to decline at the one-week follow-up (58 requests); however, 12
increased at the four-week follow-up (81 requests) (see Figure 4). Change from initial baseline levels to follow-up baseline probes was observed (ES = 0.96) (see Table 4 for effect size and Figure 4). The number of experimental sessions completed within a daily treatment session decreased from a high of five to three at the conclusion of the experimental phase (Mean = 3.5). The decrease in experimental sessions suggests that as the number of repetitions requested increased, the time allotted for each response also increased, therefore leading to a decrease in the number of experimental sessions completed at the end of treatment. Participant 2. The total number of repetitions requested per daily treatment session gradually increased then declined as comprehension improved (see Table 3 for repetition data and Figure 4 for average number of repetitions). At the initial treatment session, three gestural requests for repetition were made. The number of requests for repetition peaked at 183 midexperimental phase, and decreased to 103 requests at the end of treatment. Requests for repetition for treated stimuli were observed to decrease at both the one-week and four-week follow-ups, to 68 and 54 requests respectively (see Figure 4). Change from initial baseline levels to follow-up baseline probes was observed (ES = 17.1) (see Table 4 for effect size and Figure 4). The number of experimental sessions completed decreased from a high of four to two at the conclusion of treatment (Mean = 2.4). This decrease suggests an increase in response time secondary to the general increase in requests for repetition. 13
R e p e t i t i o n s 100 90 80 70 60 50 40 30 20 10 0 Baseline Treatment Maintenance 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 22 23 24 25 26 Session Number Participant 1 Participant 2 Probes: Participant 1 Probes: Participant 2 Figure 4. Average number of independent requests for repetition during comprehension breakdowns by Participants 1 and 2. Participant 3. Comprehension strategies were not employed independently by Participant 3. An interest in requesting repetition was not displayed even with verbal prompts given by the examiner. Participant 3 was noted to visually attend to the examiner s mouth upon presentation of a stimulus word. The number of experimental sessions completed per daily treatment session remained consistent throughout the experimental phase (Mean = 4.5); therefore, it can be concluded that no change in response time occurred. Table 3 Repetition Data Variable P1 P2 Daily Treatment Session Requests Maximum 296 183 Minimum 38 3 Mean 201.3 100.2 Standard Deviation 68.54 48.67 14
Table 4 Requests for Repetition Effect Size Data Variable P1 P2 Mean of A 1 17.67 1.67 Mean of A 2 30.5 51.0 Standard Deviation of A 1 13.32 2.89 Cohen s d 0.96 17.1 Fatigue and Frustration All participants displayed the ability to tolerate a high intensity treatment protocol. Fatigue and frustration were determined not to affect performance during the high intensity treatment sessions. No evidence of refusal to participate or inability to continue with the treatment protocol was observed (see Table 5). Table 5 Fatigue/Frustration Rating Data Variable P1 P2 P3 Total Ratings 93 95 100 Maximum Rating 4 3 3 Minimum Rating 0 1 0 Mean Rating 0.44 2.11 0.71 Standard Deviation 0.88 0.57 0.94 Discussion The current investigation was conducted to determine: (a) the effect of an intensive treatment protocol on auditory comprehension abilities in people with severe chronic aphasia, (b) the effect of an intensive treatment protocol on the ability to self-detect auditory comprehension breakdowns, and (c) the ability to tolerate an intensive treatment protocol. Previous research has indicated the effectiveness of an intensive treatment on verbal expression abilities in people with 15
aphasia; however, the application of intensity to treatment of auditory comprehension deficits has not been explored. Results of the current study reveal that single-word auditory comprehension can improve in some people with severe chronic aphasia following an intense treatment protocol. These findings further support data that has shown improvements in verbal expression skills subsequent to an intense protocol (Cherney et al., 2008; Poeck, Huber, & Willmes, 1989; Bhogal, Teasell, Foley, & Speechley, 2003). Additionally, positive treatment outcomes can be demonstrated in people with chronic deficits overall, as supported by the current findings and verbal expression research (Cherney et al., 2008; Meinzer, Elbert, Djundja, Taub, & Rockstroh, 2007; Robey, 1998). Participants 1 and 2 displayed an increase in single-word auditory comprehension of treated stimuli. Similarly, large effect sizes were obtained indicating that an intense single-word auditory comprehension protocol can lead to generalization of untreated stimuli. There are many factors that may have contributed to the positive change in comprehension ability for Participants 1 and 2, including the intensity of treatment, as well as the use of independently initiated compensatory strategies. During the experimental phase, Participants 1 and 2 demonstrated an increase in verbal and/or gestural requests for repetition when a breakdown in comprehension occurred. This suggests that an intensive treatment protocol may contribute to an increase in self-awareness of deficits in this population. Improved self-monitoring and detection of comprehension breakdowns allowed for utilization of selfinitiated compensatory strategies. In addition, participants were provided with feedback regarding correct or incorrect responses. Research conducted on patients with self-awareness deficits following TBI, indicates that providing feedback about performance on a task can influence awareness of strengths and weaknesses (Prigatano, 2005). Despite demographic similarities, Participants 1 and 2 displayed noticeably different patterns of improvement. One factor that could have impacted performance is information storage in the short-term working memory. It is suggested that there are two types of processing deficits based on memory load variations that can impact comprehension abilities (Martin, Kohen, & Kalinyak-Fliszar, 2010). Throughout the treatment phase, Participant 1 gradually increased and consistently requested multiple repetitions, which may indicate impaired working memory. The high number of repetitions requested is consistent with a too-fast decay processing deficit. Too-fast decay describes the inability to maintain activation of representation in the 16
working memory long enough for processing (Martin et al., 2010). In contrast, Participant 2 gradually increased requests, peaked mid-treatment, and then decreased. The ability to better monitor the rate of requests as comprehension improved was displayed. Participant 2 did not require the extensive number of repetitions Participant 1 needed, demonstrating a slowed activation processing deficit, where the listener requires more time to successfully process words (Martin et al., 2010). The role of working memory as it relates to repetition further illustrates the number of variables that may have influenced auditory comprehension abilities. Research is currently being conducted on the use of more sensitive diagnostic methods to determine how verbal short-term memory may influence speech perception and comprehension; however, this diagnostic tool is not commercially available for clinical use at this time (Martin et al., 2010). Findings of the study indicate that not all individuals with severe auditory comprehension deficits are candidates for this type of treatment. No change in single-word auditory comprehension ability was observed in Participant 3. Within the first week of the experimental phase, treatment materials were determined to be too difficult, prompting the change in treatment protocol. Despite the alterations in protocol, the materials were still too complex at the conclusion of treatment. Several possible explanations exist for Participant 3 s lack of change in auditory comprehension. Given the difficulty of the protocol, a deficit in comprehension at the speech perception level may have been present. Additionally, no observable change in self-detection of auditory comprehension breakdowns was noted as demonstrated by a lack of interest in requesting repetitions albeit prompting and verbal feedback provided by the examiner. This suggests impaired self-awareness. Research has shown that rehabilitation outcomes are related to self-awareness impairments in patients with TBI (Malec & Degiorgio, 2002). Another possible contributing factor includes short-term working memory storage. As previously mentioned, the short-term working memory is activated when target representations of phonemic or semantic information competes with similar non-targets (Dell, 1986); however, a non-target may be chosen when the target phonemic or semantic representation is unable to be stored adequately in working memory, leading to a breakdown in comprehension (Martin et al., 2006). It was previously found that 2 to 4 pre-response repetitions of material led to notable improvements in Token Test performance (LaPointe, Rothi, & Campanella, 1978). Given that 2 to 3 pre-response repetitions were immediately provided by the examiner following each 17
presentation of a stimulus word and no change in performance was observed, it may be suggested that deficits in short-term memory storage existed. Testing protocols often used in the assessment of aphasia, i.e., WAB (Kertesz, 2007), Boston Diagnostic Aphasia Examination (BDAE) (Goodglass, Kaplan, & Barresi, 2001), only measure auditory comprehension at the word level by including subtests that assess simple to complex yes/no questions and/or the identification of a named picture or object from a group. These subtests do not assess a patient s ability to distinguish differences between phonemes a precursor to word comprehension and/or activation of the working memory (Pisoni & Luce, 1987). Performance during the experimental phase suggests that the WAB Auditory Comprehension subtest, completed to determine inclusion in the study, may not have been sensitive enough to differentially diagnose the specific level of breakdown in auditory processing. Neurologic damage to the areas responsible for acoustic-phonemic analysis can cause breakdown in levels of comprehension beyond the single-word level (Boatman, 2004). Historically, attempts have been made to further classify comprehension deficits based on more discrete diagnostic methods. Use of tests of phoneme discrimination, lexical decision, synonym matching, and word and non-word repetition was utilized to analyze single-word comprehension performance in fluent aphasia. Results demonstrate that different types of comprehension impairment were seen and that the areas of deficit were extremely diverse across participants so diverse, that no two patients demonstrated exactly the same pattern of impairment across all tests administered (Franklin, 1989). The results of the current study support these findings. Despite differences between participants, results of the study revealed that persons with severe chronic aphasia are able to tolerate an intense auditory treatment protocol. Previous research found that a limited number of people in the acute stages of stroke could tolerate intensive speech and language therapy (4 hours per week) (Bakheit et al., 2007). More recently, it was shown that patients in the chronic stages of stroke were able to tolerate an intense physical therapy rehabilitation program (Combs et al., 2010). The results of the current study support these findings as it applies to language tasks in the chronic population. Based on verbal and nonverbal language communicated regarding overall performance at the completion of an experimental phase, both Participants 1 and 2 were observed to have high standards for performance. Reactions that resulted from not achieving a high performance standard 18
manifested more as disappointment, and acted as a motivating factor for the subsequent experimental session (Child & Waterhouse, 1953). Participant 3 did not exhibit an emotional reaction to feedback provided for incorrect responses or to the correct response totals obtained. Several limitations to the current study exist. The primary limitation is the number of variables that could have contributed to improvements in comprehension for both Participants 1 and 2, including the intensity of treatment, increased self-awareness, and the ability to independently utilize compensatory comprehension strategies. Given the presence of these factors, it is difficult to determine which variable ultimately led to the greatest changes in comprehension. Future studies must include more controls to determine which variable is most important to bring about positive change in single-word auditory comprehension. The current study exposed participants to non-personally relevant high frequency words that were selected based on the frequency of occurrence in the English language (Francis & Kučera, 1982). Previous research has shown that performance on auditory comprehension, reading comprehension, speech repetition, and naming tasks, as well as the ability to identify contextualized photographs increases when presented with personally relevant materials (Wallace & Canter, 1985; McKelvey, Hux, Dietz, & Beukelman, 2010). Further exploration is needed to determine if the use of personally relevant stimulus items increases functionality of outcomes and/or leads to improved auditory comprehension abilities. Similarly, it is necessary to explore an extended home program which would increase exposure to stimuli and the impact it may have on treatment outcomes. As previously discussed, the relationship between aphasia and cognition is not fully understood. Because of this, another consideration involves the presence and/or severity of cooccurring cognitive deficits with aphasia. Treatment outcomes could potentially be impacted by cognitive deficits; therefore, an in-depth assessment of cognition, specifically short-term working memory, should be completed in future studies. Currently, a diagnostic assessment that specifically examines how cognition impacts language function does not exist (Martin et al., 2010). Similarly, testing of auditory comprehension deficits should include examination of comprehension abilities down to the speech processing level, to determine where breakdown occurs. Extensive testing such as this would better indicate the point at which treatment should be initiated. Although testing subsequent to treatment was not completed, pre-treatment and post-treatment WAB Auditory Comprehension Subtest and PPVT-4 scores would be necessary 19
to compare. Analysis of the standardized assessments is important not only for comparison of auditory comprehension abilities, but for examination of the effect of an intensive treatment on other language modalities not specifically targeted in treatment. Conclusions The data presented indicates that an intense auditory comprehension treatment protocol results in improvements in auditory comprehension abilities at the single-word level and can generalize to untreated stimuli in some people with severe chronic aphasia. An intensive protocol can lead to increased self-detection of auditory comprehension breakdowns at the word level. The results also indicate that people with severe chronic aphasia are able to tolerate an intensive treatment protocol. Increased self-awareness and ability to self-detect breakdowns in comprehension are necessary, as the use of compensatory strategies allows for improved comprehension. Patients with both fluent and non-fluent aphasia are able to utilize verbal and gestural compensatory strategies; however, the presence of self-awareness, short-term working memory, or speech processing deficits may negatively impact treatment outcomes. The clinical relevance of the study is evident. Single-word auditory comprehension abilities in patients with chronic aphasia and severe auditory comprehension deficits can improve following an intense treatment program. Additional research and assessment batteries with increased sensitivity to auditory comprehension deficits, including speech processing impairments, are needed to identify those candidates most appropriate for this type of treatment. The findings of this study are preliminary; future research should address the specific treatment protocol that will result in the largest treatment gains in patients with varying degrees of severe chronic auditory comprehension deficits. 20
References Bakheit, A.M., Shaw, S., Barrett, L., Wood, J., Carrington, S., Griffiths, S., Koutsi, F. (2007). A prospective, randomized, parallel group, controlled study of the effect of intensity of speech and language therapy on early recovery from poststroke aphasia. Clinical Rehabilitation, 21, 885-894. doi: 10.1177/0269215507078486 Basso, A. (2005). How intensive/prolonged should an intensive/prolonged treatment be? Aphasiology, 19(10/11), 975-984. doi: 10.1080/02687030544000182 Beeson, P.M., & Robey, R.R. (2006). Evaluating single-subject treatment research: Lessons learned from the aphasia literature. Neuropsychology Review, 16, 161-169. doi: 10.1007/s11065-006-9013-7 Bhogal, S.K., Teasell, R., & Speechley, M. (2003). Intensity of aphasia therapy, impact on recovery. Stroke, 34, 987-993. doi: 10.1161/01.STR.0000062343.64383.D0 Boatman, D. (2004). Cortical bases of speech-perception: Evidence from functional lesion studies. Cognition, 92, 47-65. doi: 10.1016/j.cognition.2003.09.010 Breese, E.L., & Hillis, A.E. (2004). Auditory comprehension: Is multiple choice really good enough? Brain and Language, 89, 3-8. doi: 10.1016/S0093-934X(03)00412-7 Center for Disease Control and Prevention [CDC]. (2010). Stroke facts. Retrieved on February 15, 2010, from http://www.cdc.gov/stroke/facts.htm Cherney, L.R., Patterson, J.P., Raymer, A., Frymark, T., & Schooling, T. (2008). Evidence-based systematic review: Effects of intensity of treatment and constraint-induced language therapy for individuals with stroke-induced aphasia. Journal of Speech, Language, and Hearing Research, 51, 1282-1299. Child, I.L., & Waterhouse, I.K. (1953). Frustration and the quality of performance: A theoretical statement. Psychological Review, 60(2), 127-139. Choe, Y., Azuma, T., Mathy, P., Liss, J.M., & Edgar, J. (2007). The effect of home computer practice on naming in individuals with nonfluent aphasia and verbal apraxia. Journal of Medical Speech-Language Pathology, 15(4), 407-421. Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2 nd ed.). Hillsdale, NJ: Lawrence Erlbaum Associates. 21
Combs, S.A., Kelly, S.P., Barton, R., Ivaska, M., & Nowak, K. (2010). Effects of an intensive, task-specific rehabilitation program for individuals with chronic stroke: A case series. Disability and Rehabilitation, 32(8), 669-678. doi: 10.3109/09638280903242716 Crerar, M.A., Ellis, A.W., & Dean, E.C. (1996). Remediation of sentence processing deficits in aphasia using a computer-based microworld. Brain and Language, 52(1), 229-275. Davidson, B., Howe, T., Worrall, L., Hickson, L., & Togher, L. (2008). Social participation for older people with aphasia: The impact of communication disability on friendships. Topics in Stroke Rehabilitation, 15(4), 325-340. doi: 10.1310/tsr1504-325 Dell, G.S. (1986). A spreading activation theory of retrieval in language production. Psychological Review, 93, 283-321. Dronkers, N.F., Wilkins, D.P., Van Valin, R.D., Redfern, B.B., & Jaeger, J.J. (2004). Lesion analysis of the brain areas involved in language comprehension. Cognition, 92, 145-177. doi: 10.1016/j.cogntion.2003.11.002 Dunn, L.M., & Dunn, D.M. (2007). Peabody picture vocabulary test (4th ed.). Minneapolis, MN: Pearson Assessments. Ekman, P. (1999). Basic emotions. In T. Dalgleish and M. Power (Eds.), Handbook of cognition and emotion (45-60). Sussex, U.K.: John Wiley & Sons, Ltd. Flashman, L.A., Amador, X., & McAllister, T.W. (1998). Lack of awareness of deficits in traumatic brain injury. Seminars in Clinical Neuropsychiatry, 3(3), 201-210. Francis, W.N., & Kučera, H. (1982). Frequency analysis of English usage: Lexicon and grammar. Boston: Houghton Mifflin. Garcia, L.J., Laroche, C., & Barrette, J. (2002). Work integration issues go beyond the nature of the communication disorder. Journal of Communication Disorders, 35(2), 187-211. Goodglass, H., Kaplan, E., & Barresi B. (2001). The Boston diagnostic aphasia examination. (3rd ed.). Baltimore: Lippincott Williams & Wilkins. Hackett, M.L., Yapa, C., Parag, V., & Anderson, C.S. (2005). Frequency of depression after stroke. A systematic review of observational studies. Stroke, 36, 1330-1340. doi: 10.1161/01.STR.0000165928.19135.35 Hartman-Maeir, A., Soroker, N., Ring, H., & Katz, N. (2002). Awareness of deficits in stroke rehabilitation. Journal of Rehabilitation Medicine, 34, 158-164. 22
Helm-Estabrooks, N. & Albert, M.L. (2004). Manual of aphasia and aphasia therapy (2nd ed.). Austin, TX: Pro-Ed. Hybl, A.R., & Stagner, R. (1952). Frustration tolerance in relation to diagnosis and therapy. Journal of Consulting Psychology, 16(3), 163-170. Kertesz, A. (2007). Western aphasia battery revised. San Antonio, TX: Harcourt Assessment, Inc. Klatt, D.H. (1982). Speech processing strategies based on auditory models. In R. Carlson and B. Granstrom (Eds.), The representation of speech in the peripheral auditory system. New York: Elsevier Biomedical Press. Kleim, J.A., & Jones, T.A., (2008). Principles of experience-dependent neural plasticity: Implications for rehabilitation after brain damage. Journal of Speech, Language, and Hearing Research, 51, S225-S239. Lakshminarayan, K., Anderson, D.C., Jacobs, D.R., Barber, C.A., & Luepker, R.V. (2009). Stroke rates: 1980-2000: The Minnesota stroke survey. American Journal of Epidemiology, 169(9), 1070-1078. doi: 10.1093/aje/kwp029 LaPointe, L.L. (1997). Aphasia and related neurogenic language disorders (2 nd ed.). New York: Thieme. LaPointe, L.L., Rothi, L.J., & Campanella, D.J. (1978). The effects of repetition of token test commands on auditory comprehension. Clinical Aphasiology: Proceedings of the Conference 1978, 262-269. Lloyd-Jones, D., Adams, R.J., Brown, T.M., Carnethon, M., Dai, S., De Simone, G., Wylie- Rosett, J. (2010). Heart disease and stroke statistics 2010 update: A report from the American Heart Association. Circulation, 121, e46-e215. doi: 10.1161/CIRCULATIONAHA.109.192667 Malec, J.F., & Degiorgio, L. (2002). Characteristics of successful and unsuccessful completers of 3 postacute brain injury rehabilitation pathways. Archives of Physical Medicine and Rehabilitation, 83(12), 1759-1764. doi: 10.1053/apmr.2002.36072 Martin, N., Kohen, F., & Kalinyak-Fliszar, M. (2010). A processing approach to the assessment of language and verbal short-term memory abilities in aphasia. Unpublished Manuscript, Department of Communication Sciences and Disorders, Temple University, Philadelphia, PA. 23