Evaluation of Verbal Behavior in Older Adults

Transcription

1 Western Michigan University ScholarWorks at WMU Dissertations Graduate College Evaluation of Verbal Behavior in Older Adults Amy Gross Western Michigan University Follow this and additional works at: Part of the Communication Sciences and Disorders Commons, Geriatrics Commons, and the Gerontology Commons Recommended Citation Gross, Amy, "Evaluation of Verbal Behavior in Older Adults" (211). Dissertations This Dissertation-Open Access is brought to you for free and open access by the Graduate College at ScholarWorks at WMU. It has been accepted for inclusion in Dissertations by an authorized administrator of ScholarWorks at WMU. For more information, please contact

2 EVALUATION OF VERBAL BEHAVIOR IN OLDER ADULTS by Amy Gross A Dissertation Submitted to the Faculty of The Graduate College in partial fulfillment of the requirements for the Degree of Doctor of Philosophy Psychology, Behavior Analysis Advisor: R. Wayne Fuqua, Ph.D. Western Michigan University Kalamazoo, Michigan June 21

3 EVALUATION OF VERBAL BEHAVIOR IN OLDER ADULTS Amy Gross, Ph.D. Western Michigan University, 21 Older adults make up a large and increasing portion of the population (U.S. Census Bureau, 28). Approximately % of older adults have a dementia diagnosis, and language deterioration is a common symptom associated with this disorder (Kempler, 2). In order to assess and treat language deficits in older adults, accurate and sensitive measures of verbal skills are needed. Language has traditionally been considered an existing entity that resides inside individuals, but the entity of language is unobservable and difficult to study or manipulate. Skinner (197/1992) proposed that language was simply operant behavior. He classified a number of verbal operants based on their function, describing the antecedents and consequences that control various forms of verbal behavior. A conceptualization based on the function of verbal behavior allows for altering the occurrence of verbal responses by manipulating the controlling conditions. To the author's knowledge, there are no empirical studies evaluating verbal behavior in older adults using Skinner's analysis of functionally independent verbal operants. The purpose of this study was to develop assessments using Skinner's functional verbal operants and

4 apply those assessments to the evaluation of verbal behavior in older adults with and without dementia. The research addressed two questions. First, in what way do verbal behavior problems differ between older adults with and without dementia? Second, does language deteriorate in a pattern compatible with Skinner's analysis of functionally independent verbal operants? Thirty-one participants were categorized into Control (n=1) and Dementia (n=16) Groups based on their score on the Dementia Rating Scale-2. Verbal behavior assessments were administered to participants on two occasions, separated by one week. Results revealed individuals with dementia performed significantly more poorly on the Tact Assessment than those without dementia; however, no significant differences were found on the other assessments. These findings suggest tacts are sensitive to language decline associated with dementia. Results also indicated participants from both groups performed better on measures of tacts than on measures of intraverbals or mands, even though topographically identical verbal responses were required across these assessments. Differential performance across these assessments provides support for Skinner's conceptualization of functionally independent verbal operants.

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6 Copyright by Amy Gross 21

7 ACKNOWLEDGMENTS I would first like to thank my advisor, Dr. Wayne Fuqua, for his guidance and support through this and many other projects during my graduate career. I also want to express gratitude for the time and assistance provided by my committee members: Dr. Cynthia Pietras, Dr. Amy Naugle, and Dr. Raymond Miltenberger. Many thanks to my research assistants: Todd Merritt, Lauren Flannery, and Erica Kasemodel. Their dedication and hours of work made this project a success. Thank you to Dr. Alan Lewandowski for his generosity with both time and clinical resources. I would also like to thank my family and friends for making me who I am today. Thank you to my parents, Roger and Cathy Mackner, for always believing in me and for providing unending guidance and support. Finally, I would like to express my gratitude to my husband, Samuel Gross, for showing tremendous patience and continuously encouraging me to pursue my goals and dreams. Amy Gross u

8 TABLE OF CONTENTS ACKNOWLEDGMENTS LIST OF TABLES LIST OF FIGURES ii vi vii INTRODUCTION 1 Language in Older Adults 2 Conceptual Models of Language Decline 3 Neurological 3 Cognitive 4 Linguistic Behavior Analysis 6 Assessment of Language Deficits in Older Adults 11 Purpose 13 METHOD 14 Participants and Setting 14 Measures 14 Demographic Questionnaire 14 Dementia Rating Scale-2 (DRS-2) 1 Boston Naming Test (BNT) 1 Verbal Behavior Assessment Battery (VBAB) 16 Selection Assessment 16 Echoic Assessment 16 iii

9 Table of Contents continued Tact Assessment 17 Intraverbal Assessment 17 Mand Assessment 18 3D Mand Assessment 18 Procedure 21 Session One 21 Session Two 21 Target Behaviors, Data Collection, and Data Analysis 21 Interobserver Agreement 22 Procedural Integrity 23 RESULTS 26 Between Groups Differences Within Subject Differences and Non-Statistical Error Analysis Regression Analyses 3 Test-Retest Reliability 37 Correlations with Short-Form BNT 38 DISCUSSION 39 Group Differences 4 Functional Independence 4 Limitations 49 Future Research 1 Conclusion 3 IV

10 Table of Contents continued REFERENCES APPENDICES A. Demographic Questionnaire 9 B. Selection Assessment Form 61 C. Echoic Assessment Form 63 D. Tact Assessment Form 6 E. Intraverbal Assessment Form 67 F. Mand Assessment Form 7 G. 3D Mand Assessment Form 72 H. Verbal Behavior Assessment Raw Scores During Session One and Session Two 73 I. HSIRB Approval Letter 74 v

11 LIST OF TABLES 1. Summary of Test Instructions 2 2. Interobserver Agreement Data Procedural Integrity Data 2 4. Participants' Level of Impairment 26. Assessment Score Means, Standard Deviations, and Ranges Number of Participants with Consistent Errors Across Tact, Intraverbal, and Mand Assessments Number of Participants with Inconsistent Errors Across Tact, Intraverbal, and Mand Assessments Regression Analysis Summary for Total Score Regression Analysis Summary for Intraverbal Regression Analysis Summary for Mand 37 VI

12 LIST OF FIGURES 1. Verbal Behavior Assessment Mean Correct Between Groups Mean Rank Differences 3. Within-Subjects Mean Rank Differences 31 vn

13 1 INTRODUCTION Based on results from the 2 census, adults 6 years old and older made up 12.4% of the population (U.S. Census Bureau, 21). Projections indicate that this age group will grow in the coming years, reaching 17.8% of the population in 22 and 2.1% in 2. Baby Boomers will begin entering older adulthood in 211 and will continue to enter this age category until 2, contributing greatly to the increase (U.S. Census Bureau, 28). With growing numbers of older adults, the number of individuals with age-related disabilities also increases. In 2,43% of women and 4.4% of men who were 6 years of age and older indicated some type of disability, as compared to 17.6% and 19.6% of the year old women and men, respectively. Of the disability types, 1.8% of the older adults endorsed a mental disability, defined as difficulty with learning, remembering, or concentrating, whereas only 3.8% of working adults indicated a mental disability (U.S. Census Bureau, 23). Approximately % of adults over 6 years old suffer from some form of dementia (Kempler, 2). Dementia is a condition characterized by memory loss and at least one other area of cognitive dysfunction including aphasia, apraxia, agnosia, or disturbed executive functioning. (American Psychiatric Association [DSM-IV-TR], 2). There are several subtypes of dementia (e.g., Dementia of the Alzheimer's Type, Vascular Dementia), each defined by specific courses or neurological findings. Estimates indicate that the number of adults with dementia diagnoses worldwide will grow from 2 million in 2 to 63 million in 2 (Kempler, 2). With the increasing numbers of older adults diagnosed with dementia, developing appropriate assessment and treatment methods is of critical importance.

14 Language in Older Adults 2 Aphasia, one of the cognitive dysfunctions included in the dementia diagnosis, is a "deterioration of language function (DSM-IV-TR, 2, p. 148)." Aphasia often occurs after a specific, focal brain injury. However, the term aphasia also describes language difficulties that appear as part of another disorder or syndrome, for example, dementia (Kempler, 2). The most common language complaint associated with dementia is word finding difficulty (Kertesz, 1994). Word finding difficulty is a broad category that can refer to a number of problems. For example, complaining of word finding difficulties might mean that the individual cannot name viewed objects or items, is unable to provide names of known individuals, has difficulties with spontaneous speech, or has other problems that interfere with producing the appropriate word in a specific context (Rohrer et al., 28). Notably, word finding deficits may be inconsistent across different contexts. That is, a person may be able to name a photo of a spoon and read the printed word spoon, yet have difficulty finishing the phrase, "you eat with a knife, fork and." In general, describing a language deficit as a "word finding difficulty" lacks the specificity needed to adequately characterize the problem, to determine the cause of the problem, or to inform an intervention or remedial training method (Rohrer et al., 28). Other language complaints associated with dementia include word and sentence organization difficulties; problems comprehending the speech of others; repetitive vocalizations; reading or writing problems; or a lack of content in speech (Bourgeois & Hickey, ). Many of these language problems suffer from the same weakness associated with labeling a problem as a "word finding difficulty," that is, they lack specificity. Adults without dementia often experience language changes as they age, thus, changes in language abilities are not unique to those diagnosed with dementia (Benson &

15 3 Ardila, 1996; Kempler, 2). Researchers have found that confrontation naming (i.e., naming a presented item), verbal fluency, and sequential language comprehension decrease with age, even in those without a diagnosis of dementia (Benson & Ardila, 1996; Kempler, 2). However, older adults' ability on verbal tasks is highly variable, and some do not experience any deficits in language-related skills (Kempler, 2). Although many older adults do experience changes in language-related skills, researchers find that individuals with dementia diagnoses perform more poorly on verbal tasks than their unimpaired peers (Benson & Ardila, 1996). Because of the deterioration in speech and language of older adults with and without dementia, it is important to determine the degree to which speech and language deficits of individuals diagnosed with dementia are worse than those which are typical of normal aging. Moreover, language assessments that sample a range of behavior under several contexts need to be developed in order to: (a) evaluate functional language skills of older adults, (b) more accurately specify language problems, and (c) develop interventions that are specific to particular language deficits. Neurological Conceptual Models of Language Decline Neurological explanations attempt to describe language difficulties by finding brain lesions, or damaged brain tissue (Davis, 2). Brain lesions may be caused by specific incidents (e.g., stroke), or they can occur from general atrophy, or shrinking of brain tissue (Davis, 2). Aphasia and dementia diagnoses can be related to focal lesions (i.e., localized), multifocal lesion patterns (i.e., multiple lesions), or diffuse brain damage (i.e., damage throughout). Examples of diagnoses related to focal lesions include Broca's and Wernicke's aphasias. Broca's aphasia is a syndrome in which there is damage to the frontal region of the left cerebral cortex, whereas Wernicke's aphasia is

16 4 related to lesions in the left temporal cortex (Davis, 2). An example of a diagnosis related to multifocal lesions or diffuse damage is multiple infarct dementia, which is associated with damage in any location in the brain (Davis, 2). The primary criticism of the neurological approach is that many syndromes or symptom patterns are not consistently correlated with independently verified brain damage (Rohrer et al., 28). Notably, there are syndromes that have high clinicoanatomical correlation; however, in many cases, brain scans reveal ambiguous or negative findings (Rohrer et al., 28). Moreover, many clinicians (e.g., psychologists, speech and language therapists) do not have access to brain scan technology. Thus, basing a diagnosis or treatment plan on neurological damage may prove to be difficult. Furthermore, identifying the locus of brain damage associated with clinical symptoms does not necessarily yield well-validated treatments to remedy the language-related difficulties. Cognitive According to Davis (2), "Cognitive theories of language deficits are based on two primary features: knowledge and process. Knowledge is a relatively stable storage of information (p. 13)," and process is the "mind's activity (p. 13)." According to this model, a stimulus in the environment is transformed by one's brain and a mental representation of the stimulus is made. The mental representation is either stored temporarily or permanently in memory. There are several types of memory: long-termmemory, episodic memory, semantic memory, procedural memory, lexical memory, and working memory. Each type of memory is responsible for different processes or for storage of different mental representations. For example, long-term memory is the area in which knowledge is stored, whereas working memory is largely responsible for the

17 processing of information. Cognitive explanations state that language difficulties give evidence for the different types of memory, because individuals with language deficits experience language-related strengths and weaknesses, often associated with differing memory systems (Davis, 2). For example, an individual may be able to tell about events that happened many years prior using long-term memory, but unable to process and react to new information appropriately using working memory. In terms of aphasia, cognitive theorists would assert that the language problems are a processing issue, not a loss of stored knowledge (Davis, 2). Cognitive theorists attribute all language functions to memory, including language acquisition and decline. Davis (26) noted that memory is difficult to explain functionally; therefore, metaphors of mental images as photographs are used to describe the process. Not being able to provide a functional description is a weakness of the cognitive theory because these theorists must depend on hypothetical constructs as explanations for behavior. Basing a theory on hypothetical constructs is problematic because these constructs cannot be manipulated in meaningful ways to evaluate their existence or nonexistence (Skinner, 193/196). Without a functional explanation of language, it is difficult to adequately assess language skills and deficits or develop intervention strategies to address language-related difficulties. Linguistic According to a linguistic analysis, aphasia can affect any aspect of language, including features, phonemes, morphemes, syntagms, or semantics (Benson & Ardila, 1996). These aspects range in complexity from simple muscular movement, to the meanings of words. Linguists note that aphasia can affect any level of language, and some of these deficits are characteristic of particular types of aphasia. However, it is

18 6 often the case that the relationship between linguistic impairments and specific diagnostic categories is complex. That is, individuals with a specific diagnosis may experience multiple linguistic deficits. Furthermore, the same linguistic deficit may be present in several diagnostic categories (Benson & Ardila, 1996). Another curious aspect of the linguistic account is that linguistic deficits are not always consistent across contexts. That is, an individual may be able to give an appropriate response when requesting an item, but then fail to produce the very same response (i.e., the particular word) when asked to name a picture of the same item. Therefore, this response is at strength under certain conditions, but not others, possibly indicating the deficit is not related to specific linguistic abilities (Baker, LeBlanc, & Raetz, 28). Because of overlapping symptoms and indistinguishable diagnostic categories, assessment and diagnosis based on linguistic deficits may have significant limitations, and therefore, may not inform specific treatment approaches. Behavior Analysis Behavior analysis offers a different conceptual approach to language acquisition and decline. Rather than focusing on underlying neurological causes of language problems or hypothetical entities that are claimed to account for language acquisition and decline, behavior analysis views "language" as simply operant behavior. Skinner noted the difference between language and verbal behavior by describing language, as it is traditionally characterized, as an entity that individuals acquire, but verbal behavior as vocal and non-vocal behavior that is controlled by its effect on listeners (Skinner, 1974). He asserted that analyzing verbal behavior the same way as any other behavior was more beneficial than attempting to study the entity of language (Skinner, 1974), much of which is attributed to inaccessible mechanisms that are impossible to study via direct

19 7 observation (e.g., various memory systems). Skinner (197/1992) provided a classification system of verbal operants, each of which is controlled by a unique set of antecedents and consequences. A verbal operant is a type of verbal behavior, as opposed to a specific instance of verbal behavior (Skinner, 197/1992, p. 2). There are certain controlling variables for each verbal operant (Skinner, 197/1992). The following is a review of a subset of Skinner's verbal operants: echoics, tacts, intraverbals and mands. An echoic is a verbal operant in which the response produced is similar to a preceding vocal verbal stimulus. The consequence for an echoic is generalized reinforcement by listeners (Skinner, 197/1992). Generalized reinforcers are those that have been paired with several primary reinforcers. Therefore, they are effective reinforcers across various conditions because at least one state of deprivation is likely to be present at any given time (Skinner, 193/196). An example of an echoic is as follows: the caretaker says, "say ball," and the child says, "ball," after which the caretaker provides praise. Tacts are responses that are "evoked (or at least strengthened) by a particular object or event or property of an object or event (Skinner, 197/1992, p. 82)." The consequence for a tact is generalized reinforcement from the listeners. For example, a caretaker says, "name this" while holding up a ball. The child says, "ball" and then the caretaker provides praise. An intraverbal is a verbal operant that is occasioned by a verbal stimulus that has no point-to-point correspondence or formal similarity with the response (Skinner, 197/1992). That is, the preceding verbal stimulus does not match the response in any way. Intraverbals are reinforced by generalized reinforcement produced by the listener (e.g., the reinforcing effects associated with correct responding). Examples of intraverbal

20 8 responses include answering questions, engaging in word association tasks, or filling in the blank. Finally, mands are controlled by an antecedent condition of an establishing operation, and the reinforcer is a "characteristic consequence (Skinner, 197/1992, p. 3)" related to the establishing operation (Michael, 1988). For example, when one is in a state of water deprivation and asks for a glass of water, the consequence is receiving a glass of water. Unlike other forms of verbal behavior, the listener does not typically provide generalized reinforcement (e.g., social praise) as the reinforcing consequence. Rather, the listener provides a characteristic consequence (Michael, 1988; Skinner, 197/1992). Skinner (197/1992) proposed that each verbal operant is functionally independent, meaning that a response may occur under certain controlling conditions, but the topographically identical response may not occur under other controlling conditions. That is, an individual may be able to tact "ball" but not mand for a ball. Studies evaluating Skinner's analysis of verbal behavior have been able to demonstrate the functional independence of verbal operants in young children (see review by Sautter & LeBlanc, 26). Sautter and LeBlanc (26) reviewed empirical articles that evaluated verbal behavior and found that from 1989 to 24 nine articles specifically addressed functional independence of verbal operants. These research studies evaluated if direct training of one verbal operant resulted in the emergence of another verbal operant without explicit training of that topographically similar but functionally different verbal operant. Results from these studies largely indicated functional independence of verbal operants in young children with and without disabilities (Sautter & LeBlanc, 26). That is, training one verbal operant did not result in the emergence of topographically similar but untrained verbal operants. However, two studies from this review showed at least

21 9 some emergence of untrained verbal operants in children (Sautter & LeBlanc, 26). Others have conducted research that shows speaker and listener repertoires are functionally independent (Guess & Baer, 1973). Speaker repertoires are evaluated through productive language tasks (e.g., vocal verbal behavior) and listener repertoires are evaluated through receptive language tasks (e.g., pointing to items). Guess and Baer (1973) showed that training specific listener responses did not necessarily result in emergence of similar speaker behavior, nor did training speaker behavior result in related listener behavior. However, the results of this study were variable, with some transfer of skills across speaker and listener repertoires despite direct training of only one repertoire (Guess & Baer, 1973). Further research is needed in the area of functional independence of verbal operants. Such research can be conducted during acquisition or deterioration of verbal repertoires to determine the extent to which topographically similar but functionally different verbal responses covary. According to Skinner's analysis, verbal operants may remain functionally independent upon their deterioration. He noted that a response that was previously in an aphasic individual's repertoire might continue to occur under certain controlling conditions, but that same response might no longer occur under other conditions. He described aphasia by stating, "What has been damaged in aphasia is clearly the functional control of the behavior, and the damage respects the lines of control (Skinner, 197/1992, p. 19)." Skinner indicated that individuals can have deficits specific to speaking or listening, and he added specificity by predicting that speaker behavior might degrade in a manner that is compatible with his classification of verbal operants. Skinner expected that verbal behavior receiving generalized reinforcers would be most likely to degrade. Thus, mands may be resilient against change because they are not reinforced with generalized reinforcers; rather, controlling conditions for mands involve establishing operations and

22 1 characteristic consequences (Michael, 1988; Skinner, 197/1992). Intraverbals, tacts, and echoics all receive generalized reinforcers. In terms of these verbal operants, Skinner predicted that intraverbals and tacts would be damaged more easily than echoics because of the differences in the minimal repertoire involved with each type of verbal behavior. Because of the point-to-point correspondence and functional similarity between very small units of behavior (e.g., speech sounds) and echoed responses, the minimal repertoire of echoics is much smaller than that of other verbal operant categories. Therefore, echoics may remain intact longer than tacts or intraverbals (Skinner, 197/1992). Skinner's analysis of verbal behavior has resulted in relatively little empirical work (Dymond, O'Hora, Whelan, & O'Donovan, 26). Dymond and colleagues (26) found that 8% of articles citing Verbal Behavior from were non-empirical articles. Only 4% and 1.4% of these articles were applied and basic studies, respectively. Therefore, Verbal Behavior has generated a great deal of theoretical writing and debate, but it has resulted in much less empirical work (Dymond et al., 26). Much of the empirical work based on Skinner's analysis has focused on language acquisition, often with children with developmental disabilities (Sautter & LeBlanc, 26). To the author's knowledge, no empirical research has been conducted to assess verbal behavior in older adults using a verbal operant conceptualization. Because of the lack of empirical evidence, it is unclear if assessments of verbal behavior in older adults will provide clear evidence regarding specific verbal behavior deficits. Furthermore, if assessments are developed and provide clear data on verbal behavior deficits, it is not known if these data will provide clinically relevant information to inform intervention methods. In order to evaluate Skinner's predictions regarding the degradation of language, researchers must develop appropriate assessment methods. Assessment batteries must

23 11 include tests that assess each category of verbal behavior. Assessing the verbal operants independently allows for the comparison of performance across various types of verbal behavior. If meaningful differences in the deterioration of language are documented with the assessment measures, then the next phase of research can be undertaken, the development and evaluation of interventions linked to the function-based assessment. A similar research sequence has proven very effective in a related area, the development of functional assessment and functional analysis strategies for problem behavior and the validation of function-based interventions (e.g., Didden, 27). The research described in this experiment is a first step in this process, the development and preliminary evaluation of a function-based assessment for language deficits in older adults. Assessment of Language Deficits in Older Adults Evaluation of verbal skills in older adults typically occurs when there are concerns regarding a decline in language functioning or problems with general memory. When assessing for language deterioration, evaluators examine individuals' ability to repeat spoken words or phrases, engage in spontaneous speech, comprehend language, name items, read text, and write words or sentences (Lezak, Howieson, & Loring, 24). Several aphasia batteries have been developed that include opportunities to evaluate these skills within one assessment measure. Furthermore, independent verbal assessment measures are used to assess verbal expression (e.g., naming, vocabulary, discourse, fluency) and verbal academic skills (e.g., reading, writing, spelling, acquired knowledge) (Lezak et al., 24). In the context of general memory concerns, evaluators administer specific verbal memory tests that include tasks such as recalling digit sequences, word lists, word pairs, and/or stories. These memory tests assess for short-term and long-term recall, as well as recognition (Lezak et al., 24). Memory assessment batteries contain a

24 12 verbal memory score, which is a summation of individuals' performance on the verbal memory scales. Results from traditional language evaluations contribute to diagnosing aphasia, dementia, or other disorders. However, when a diagnosis is made, it is often assumed that deficiencies are due to brain damage or problems with underlying hypothetical constructs that contribute to the construct of language. These assessment findings and resulting diagnoses may yield little information that can guide efficacious treatment strategies. Behavioral conceptualizations may provide a framework to develop assessment measures with greater sensitivity and treatment utility. Skinner (197/1992) suggested that researchers consider the controlling conditions of verbal behavior, rather than the topography verbal responses. Likewise, Sidman (1971) recommended analyzing the specific stimulus-response relations that contribute to verbal behavior skills, noting the influence of stimulus control on responding. Using a behavioral approach focuses the assessment on the function of verbal behavior. Traditional approaches, which focus on the topography of responses, rely on hypothetical constructs of language and assume responses are consistent across contexts (Baker et al., 28; Davis, 26). However, it is often observed that individuals are able to produce a word in some contexts but cannot produce the same word in other situations. This context specific performance may be due to the same topographic response being controlled by different stimuli (e.g., a word endures as an echoic but not as an intraverbal) or because of the interference of other controlling variables (e.g., stimuli strengthening competing verbal behavior). Similarly, one stimulus might influence a number of responses (Sidman, Stoddard, Mohr, & Leicester, 1971). Therefore, in order to evaluate the variables controlling verbal behavior, Sidman and colleagues (1971) recommended researchers hold either the stimulus or the response constant across testing conditions. After reviewing various behavioral

25 13 conceptualizations of language, Baker et al. (28) provided a behavioral taxonomy of aphasia depicting Skinner's verbal operants and various stimulus-response relationships. The behavioral taxonomy was highly specific and revealed 4 different verbal behavior deficits that could be evaluated (Baker et al., 28). Because of its specificity, this taxonomy might benefit those developing assessments and interventions for older adults with verbal skills deficits. Purpose Dementia is a condition affecting both memory and other cognitive functions, one of which is language. Although many have written about language deficits, there are weaknesses in the literature. Primarily, language deficits are assessed and categorized in ways that do not necessarily lead to effective intervention methods. Skinner's (197/1992) analysis of verbal behavior may lend itself to assessment methods that will identify specific skill deficits, which, in turn, may inform more effective treatment recommendations, in a manner analogous to functional assessment methodology and function-based treatments. However, before determining whether intervention methods can be developed from this analysis, researchers must develop an assessment methodology based on Skinner's model of functional verbal operants and evaluate the manner in which verbal behavior deteriorates in older adults. The purpose of this study was to evaluate verbal behavior in older adults with and without dementia. There were two primary research questions. First, in what ways do verbal behavior problems differ between older adults with and without dementia? Second, does language deteriorate in a pattern compatible with Skinner's analysis of functionally independent verbal operants?

26 METHOD 14 Participants and Setting Thirty-one individuals, aged 6 years and older, participated in the study. Fifteen participants met criteria for the Control Group, and 16 participants met criteria for the Dementia Group. Three additional individuals participated in the first session, but did not return to the second session. Of these three individuals, one would have been in the Control Group and two in the Dementia Group, but because they did not complete the study, they were not included in the total sample. All participants were Caucasian and participants were native English speakers. One participant from the Control Group reported Latvian as his first language, but he was a fluent English speaker and had been speaking English for years. The entire sample was made up of seven males and 24 females, with four males in the Control Group and three in the Dementia Group. Selfreported participant ages ranged from 6-86, with mean reported ages of 72.9 and 73.9 for the Control and Dementia Groups, respectively. Researchers recruited participants from a neuropsychology clinic and a local senior living facility by posting flyers, hosting an informational meeting, and/or calling potential participants. Sessions were conducted in the location from which the participants were recruited. Demographic Questionnaire Measures During the first session, investigators collected information on a number of demographic variables including sex, age, educational history, race, living situation, and diagnosed cognitive impairments (see Appendix A).

27 Dementia Rating Scale-2 fdrs-21 The DRS-2 measures attention, initiation/perseveration, construction, conceptualization, and memory (Jurica, Leitten, & Mattis, 21) and is used to screen and track cognitive status in older adults (Schmidt, Mattis, Adams & Nestor, 2). Specific tasks on the DRS-2 include repeating digits forward and backward, following administrator commands, naming items in a category, copying line drawings, identifying similarities and differences, answering factual questions, reading, creating a sentence, remembering words or sentences after a brief delay, and remembering line drawings after a brief delay. Investigators administered the DRS-2 to participants during the first session in order to determine if they met criteria for the Control Group or the Dementia Group. For the purposes of this study, individuals who scored in the mildly, moderately, or severely impaired range were categorized into the Dementia Group. Participants scoring in the below average, average, and above average were classified as "intact" by the DRS- 2 manual (Jurica et al., 21), and were placed in the Control Group for this study. Boston Naming Test (BNT) This instrument contains 6 line-drawn pictures and it measures individuals' ability to name the items depicted in the drawings, often called "confrontation naming" (Mitrushina, Boone, Razani, & D'Elia, 2). For this study, investigators used a validated short-form of the test by administering only the even-numbered items (Fisher, Tierney, Snow & Szalai, 1999). Because this is a standard assessment often used to assess cognitive and/or language impairment, it was administered to all participants and the results were compared to the results from the other assessment measures. The shortform BNT was administered during the second session.

28 Verbal Behavior Assessment Battery (VBAB") 16 The investigators developed materials and procedures to assess echoics, tacts, intraverbals, and mands, as detailed in Skinner's conceptual model of verbal behavior. Materials and procedures were also developed to assess selection-based responses. Each of the primary assessments (i.e., Selection, Echoic, Tact, Intraverbal, and Mand) contained items, which were developed from the odd numbered items on the full version of the BNT. The order of the items was randomized across assessment measures. The 3D Mand Assessment contained five items, all of which were different from the stimuli used for the other assessment conditions. Selection Assessment The investigator placed a series of three line drawings on the table and asked the participant to point to a certain item, an example of a selection-based response. The selection assessment is compatible with traditional receptive language tasks and evaluates the listener repertoire (Guess & Baer, 1973). Investigators assessed selection for all odd-numbered BNT items. The participant had s to respond. Investigators recorded the item selected by the participant and the latency to the response (see Appendix B). Participants completed the Selection Assessment during both sessions (see Table 1 for specific instructions for all verbal operant assessments). Echoic Assessment Investigators asked participants to repeat words, one at a time. The participant had s to respond. Investigators recorded whether the response was correct or incorrect and the latency to the response (see Appendix C). Correct responses occurred when the participant vocally repeated the word provided by the investigator within five seconds. If

29 17 participants responded incorrectly, the investigators recorded the incorrect response. The words were the names of the odd-numbered items on the BNT. Participants completed this assessment during sessions one and two. Tact Assessment Investigators presented the odd-numbered items from the BNT and asked the participant to name each item. Participants had s to initiate responding and 1s to complete their response. Investigators recorded the response as correct or incorrect and noted the response given if it was incorrect (see Appendix D). Investigators also recorded the latency to the response. Correct responding included providing the appropriate name of the presented item within 1s. Participants completed this assessment during both sessions. Intraverbal Assessment Investigators described items, without showing a picture of the item, and asked the participant to name the item described. The items were the odd-numbered items from the BNT (see Appendix E). The primary investigator developed the original descriptions by using definitions from the Longman Advanced American Dictionary (2). Descriptions were revised in order to take out words that were the same or highly similar to the item name (e.g., removing "hang" from the description of a "hanger") and to add detail to the descriptions. Participants had s to initiate a response and 1s to complete the response. Investigators recorded responses as correct or incorrect, noting the answer given if incorrect, and recorded the latency to the response. Participant responses were considered correct if they said the name of the item described by the investigator within 1s. Participants completed this assessment during each session.

30 Mand Assessment 18 Investigators showed participants pairs of scenes. The first scene of each pair was complete; the second scene was the same but with an item missing (see Appendix F). The investigator instructed the participant to request the missing item in order to complete the scene (i.e., the instructor said, "what do you need to complete this picture"). Upon requesting the appropriate item, the investigator gave the participant the item, and the participant placed it in the appropriate location. An error at this point in the Mand Assessment could be the result of two factors: a memory problem or a deficit in a mand repertoire. Therefore, when errors occurred, the investigator administered a remedial, selection-based assessment under the assumption that accurate performance on the selection-based assessment would rule out the memory deficit explanation, leaving the mand deficit as the most likely explanation for the poor performance. That is, if participants did not name the correct item given the original Mand Assessment procedures, the investigator showed the participant pictures of three items. Then, the investigator instructed the participant to point to the item that belonged in the missing space. If participants pointed to the correct picture, the investigator gave the participant the item to place in the scene. If they did not point to the correct picture, the next item was presented. Participants had s to initiate each response. Each response (i.e., vocal and selection) was scored separately as correct or incorrect, noting the response given if incorrect. If the vocal mand was correct, the selection aspect was not administered and the response was recorded as correct. Investigators also recorded the latency to the responses. Participants completed the Mand Assessment during each session. 3D Mand Assessment Investigators gave participants a task to complete with three-dimensional objects,

31 19 but one object needed to complete the task was missing (see Appendix G). The investigator instructed the participant to complete the task and to ask for any additional items needed to complete the task. If the participant asked for the missing item, the investigator presented it. If the participant did not request the missing item, the investigator took the other items away and presented the next task. Investigators presented five tasks for this assessment. Participants had s to initiate a response and 1s to complete the response. Investigators recorded the responses as correct or incorrect and the latency to the response. If incorrect, the response given was recorded. Participants completed the 3D Mand Assessment during each session. The 3D Mand Assessment was used to probe mands for three-dimensional objects, because it was thought that these procedures might allow for more powerful establishing operations than the procedures used for the Mand Assessment.

32 2 Table 1 Summary of Test Instructions Test Introduction Instructions Item-bv-Item Instructions Selection Echoic Tact Intraverbal Mand Mand Selection 3D Mand In this part, I am going to show you groups of pictures. Then, I will ask you to point to a picture from the group. In this part, I am going to say words. I want you to repeat each one after me. In this part, I am going to show you pictures of items. I want you to name each item. In this part, I am going to describe a word or item. I want you to tell me what I am describing. In this part, I am going to show you sets of two pictures. The first picture will be a complete picture. The second picture will be the exact same picture, but one piece will be missing. I want you to tell me what you need to complete the picture. Once you do, I will give you the item to place on the picture to complete it. (no general instructions - this is only given immediately after each item missed on mand assessment items) In this part, I am going to give you jobs to do and I want you to complete each job. If you are missing any items that you need to complete the job, tell me what you need and I will give you the item. Note. Bold print indicates the exact instructions given by evaluator. Point to the (present array) Say Name this. (present picture) This is (e.g., This is a piece of furniture that you sleep on.) Look at the first picture of this set. Look at the second. What do you need to complete this picture? (present picture 1, cover it and present picture 2) (if correct, give missing item; if incorrect, move to mand selection) Point to what you need to complete this picture. (present array) (if correct, give missing item; if incorrect move to next item on mand assessment) For this job I want you to. Tell me if vou need anything else to complete the job. (present task) (if correct, give item; if incorrect, move to next task)

33 21 Procedure Session One Investigators obtained consent and then administered the Demographic Questionnaire and the DRS-2. Then, investigators administered the VBAB, which included the Selection Assessment, Echoic Assessment, Tact Assessment, Intraverbal Assessment, Mand Assessment, and 3D Mand Assessment. The order of administration of the verbal operant assessments was randomized across participants, but it was held constant across sessions for each individual participant. Investigators offered participants a break between each assessment. Session Two During session two, investigators administered the short-form BNT and the VBAB. The purpose of session two was to examine test-retest reliability of the verbal operant assessments. As in session one, investigators offered breaks between each assessment. At the end of session two, investigators thanked the participant for their participation and offered to send a brief report of the final research findings upon completion of the study. Target Behaviors, Data Collection, and Data Analysis For verbal operant assessments, investigators recorded responses as correct or incorrect. Correct responses included pointing to the correct line drawing or saying the name of the item. Other verbal behavior in which the participant engaged was not considered part of the answer for scoring purposes. If a participant offered several answers or ambiguous answers, investigators asked the participant to choose one answer

34 22 or to be more specific in responding. Investigators also collected data using standardized tests (i.e., DRS-2 and BNT) and did so by following the assessment protocols published in the administration manuals. Investigators did not provide verbal feedback on the accuracy of responding on the assessment measures. Between group differences were analyzed using Mann-Whitney tests, and withinsubjects differences were evaluated using Friedman's ANOVAs. In addition, data were analyzed using regression analyses with age and DRS-2 scores as predictor variables and total and individual verbal operant assessment scores as outcome variables. Kendall's tau correlations were used to determine test-retest reliability of the verbal operant assessments and the degree to which the short-form BNT was correlated with the DRS-2 and the verbal operant assessments. Moreover, a Wilcoxon Signed Rank Test was used to compare performance at session one and session two. Finally, a non-statistical error analysis was completed to determine whether participants made errors on the same stimuli across all assessments (e.g., responded incorrectly on "protractor" across assessments) or if errors were inconsistent across assessments (e.g., responded incorrectly on "protractor" on the intraverbal assessment but gave the correct response on the other assessments). Data from the error analysis helped determine if verbal operants were functionally independent. Interobserver Agreement Interobserver agreement (1A) data were collected on the accuracy with which the participants' responses to the DRS-2, short-form BNT, and verbal operant assessments were scored. Before evaluating IOA, the independent observer was trained by viewing videotaped sessions, scoring participant responses, and discussing results with the primary investigator. Training continued until the independent observer and the

35 23 primary investigator reached over 9% agreement for the DRS-2 and BNT and 1% agreement for the verbal operant assessments. The independent observer viewed videotaped sessions for 1 of the 31 participants, or about 32% of the sessions. Agreement was defined as the in-session evaluator and the independent observer scoring a participant's response in the same manner on a particular trial, for example, agreeing that a response was correct or incorrect, or giving the same numerical value to a response on a specific item. The primary investigator calculated percentage of agreement by dividing the number of agreements by agreements plus disagreements and multiplying by 1. Agreement for the DRS-2 and BNT were 98.9% and 99%, respectively. The total agreement for verbal operant assessments was 99.8% (see Table 2 for individual assessment agreement and agreement ranges). Procedural Integrity The independent observer was trained to evaluate procedural integrity in the same manner, and met the same criterion, as previously described for IOA. The independent observer viewed videotaped sessions for the same 1 participants as were viewed for IOA (i.e., 32% of participants) and evaluated the degree to which the in-session evaluator followed the assessment protocols. Following the protocols included appropriately delivering introduction instructions and item-by-item instructions. Procedural integrity was calculated by dividing the correctly administered instructions for each assessment by the total number of instructions and multiplying by 1. The percent of correctly implemented instructions was 99.1 and 96. for the DRS-2 and BNT, respectively. The percent of correctly implemented steps for all of the verbal operant assessments was 99.9 (see Table 3 for individual assessment data and ranges).

36 Table 2 24 Interobserver Agreement Data Assessment DRS-2 BNT % Agreement" Range" Selection Session 1 Echoic Session 1 Tact Session 1 Intraverbal Session 1 Mand Session 1 3D Mand Session 1 Verbal Operant Assessment Session 1 Total Selection Session 2 Echoic Session 2 Tact Session 2 Intraverbal Session 2 Mand Session 2 3D Mand Session 2 Verbal Operant Assessment Session 2 Total Verbal Operant Assessment Total Overall Total "Calculated by dividing the agreements by agreements plus disagreements and converting to a percentage.