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Augmentative and alternative communication in autism: A comparison of the Picture Exchange Communication System and speech-output technology

ProQuest Dissertations and Theses, 2011
Dissertation
Author: Miriam Chacon Boesch
Abstract:
The purpose of this comparative efficacy study was to investigate the Picture Exchange Communication System (PECS) and a speech-generating device (SGD) in developing requesting skills, social-communicative behavior, and speech for three elementary-age children with severe autism and little to no functional speech. Requesting was selected as the primary measure while social-communicative behavior (eye contact, smiling, and physical proximity) and speech were selected as ancillary measures. A multiple baseline design (Baer, Wolf, & Risley, 1968) was combined with an alternating treatment design (Barlow & Hayes, 1979) to evaluate the treatment effects across participants and between modalities for each condition. A 3-stage preference assessment was conducted to systematically identify food reinforcers prior to treatment. Training conditions for both treatment modalities included the implementation of PECS phase 1 ( how to communicate ), phase 2 (distance and persistence ), and phase 3 (picture discrimination ). PECS followed the traditional protocol as outlined by Bondy and Frost (1994) and the ProxTalker, a device developed to closely follow the principles of PECS, used a modified PECS protocol. Results demonstrated increases in requesting behavior for all participants across conditions and treatment modalities, however, difficulties were evident with picture discrimination. Statistical analysis did not reveal significant differences between PECS and the SGD for any participant. Results for social-communicative behavior were mixed although an increasing trend was present in phase 2 for all participants and treatment modalities. However, no significant differences between modalities were found. Data for speech outcomes did not reveal any increases across participants and no statistical differences between treatment modalities were found. Findings suggest PECS and the ProxTalker device are equally appropriate for developing initial requesting skills. Results on social-communicative behavior are inconclusive however; data patterns suggest phase 2 is conducive to encouraging social-communicative behavior. The lack of speech emergence supports previous research. Based on the current findings, successful implementation of either modality is achievable when appropriate teaching strategies are used. Further research is needed to address difficulties in picture discrimination, mixed results in social-communicative behavior, and the non-emergence of speech. Non-significant differences between modalities suggest the behavioral principles inherit in the PECS protocol are responsible for the findings in this study; therefore, future research directions are provided.

TABLE OF CONTENTS

Page

LIST OF TABLES

.............................................................................................................. x

LIST OF FIGURES

........................................................................................................... xi

LIST OF ABBREVIATIONS

........................................................................................... xii

GLOSSARY

.................................................................................................................... xiii

ABSTRACT

..................................................................................................................... xvi

CHAPTER 1: INTRODUCTION

....................................................................................... 1

Augmentative and Alternative Communication

......................................................... 2

Picture Exchange Communication System (PECS). ........................................... 3

Speech - generating Devices (SGD).

.................................................................... 6

Picture - based versus auditory - based interventions

.................................................... 8

Infusing PECS with Voice Output Technology

....................................................... 10

Purpose Statement

.................................................................................................... 11

Research Questions

.................................................................................................. 11

Research Hypotheses

............................................................................................... 11

CHAPTER 2: LITERATURE REVIEW

.......................................................................... 13

Picture Exchange Communication System (PECS)

................................................. 13

Theoretical Background.

................................................................................... 13

Influence on PECS

.................................................................................... 15

Defining PECS

.......................................................................................... 16

Organization of Literature Review

........................................................................... 18

Evidence - Based Practice (EBP) in AAC

................................................................. 19

Hierarchy of Evidence

.............................................................................................. 21

Meta - analyses and systematic reviews

..................................................................... 23

Group research designs

............................................................................................ 26

vi

Page

Requesting ......................................................................................................... 26

Speech production outcomes

............................................................................ 26

Single - subject research designs

................................................................................ 27

Requesting.

........................................................................................................ 27

Speech production outcomes

............................................................................ 29

Problem behaviors

............................................................................................ 31

Comparative Studies. ........................................................................................ 32

Narrative reviews

..................................................................................................... 34

PECS with other populations

................................................................................... 35

Conclusion................................................................................................................ 36

CHAPTER 3: METHOD

.................................................................................................. 38

Participants

............................................................................................................... 38

Inclusion criteria

............................................................................................... 38

Setting

...................................................................................................................... 41

Materials

................................................................................................................... 42

Design

...................................................................................................................... 42

Independent variables

....................................................................................... 43

Dependent variables

.......................................................................................... 44

Preference Assessment

............................................................................................. 45

Parent interview

................................................................................................ 46

Trial - based assessment

...................................................................................... 46

Forced - choice assessment

................................................................................. 46

Baseline

.................................................................................................................... 49

Intervention

.............................................................................................................. 50

Mastery Criterion and Criterion to Stop Treatment

.......................................... 51

Phase 1

.............................................................................................................. 52

Phase 2

.............................................................................................................. 53

Phase 3A

.......................................................................................................... 55

Phase 3B

........................................................................................................... 56

vii

Page

Follow - up

................................................................................................................. 58

Interobserver Agreement

.......................................................................................... 58

Treatment Integrity

................................................................................................... 58

Social Validity

.......................................................................................................... 59

Data Analyses

........................................................................................................... 59

CHAPTER 4: RESULTS

.................................................................................................. 61

Pre - and Post - communicative Profile ....................................................................... 61

Christian

............................................................................................................ 61

Nadia

................................................................................................................. 62

Zeth

................................................................................................................... 62

Reliability Analyses

................................................................................................. 63

Interobserver Agreement

.................................................................................. 63

Treatment Integrity

........................................................................................... 64

Experimental Condition

........................................................................................... 65

Requesting ......................................................................................................... 65

Christian

.................................................................................................... 65

Nadia

......................................................................................................... 68

Zeth.

.......................................................................................................... 70

Social - Communicative Behavior

...................................................................... 72

Christian

................................................................................................... 72

Nadia

......................................................................................................... 75

Zeth

.......................................................................................................... 77

Speech

............................................................................................................... 79

Christian

.................................................................................................... 79

Nad ia

......................................................................................................... 82

Zeth

.......................................................................................................... 83

Rate of Acquisition

........................................................................................... 84

Social Validity

.................................................................................................. 85

CHAPTER 5: DISCUSSION

............................................................................................ 88

viii

Page

Overview

.................................................................................................................. 89

Requesting ......................................................................................................... 89

Social - Communicative Behavior

...................................................................... 90

Speech

............................................................................................................... 92

Competing Problem Behaviors with Intervention Success

............................... 93

Advantages and Disadvantages of the AAC M odalities

................................... 94

Practical Implications

............................................................................................... 97

Contributions

............................................................................................................ 99

Limitations

............................................................................................................. 101

Future Research Directions

.................................................................................... 104

R EFERENCES

............................................................................................................... 109

APPENDICES

Appendix A: Single - Stimulus Preference Assessment

......................................... 127

Appendix B: Forced- Choi ce Preference Assessment

............................................ 128

Appendix C: Event Recording Form

..................................................................... 129

Appendix D: Treatment Protocol Manual

............................................................. 130

Appendix E: PECS Phase 1 (Trainer 1) Treatment Integrity Checklist

................ 138

Appendix F: PECS Phase 1 (Trainer 2) Treatment Integrity Checklist

................. 139

Appendix G: SGD Phase 1 (Trainer 1) Treatment Integrity Checklist

................. 140

Appendix H: SGD Phase 1 (Trainer 2) Treatment Integrity Checklist

................. 141

Appendix I: PECS Phase 2 (Trainer 1) Treatment Integrity Checklist

................. 142

Appendix J: PECS Phase 2 (Trainer 2) Treatment Integrity Checklist

................. 143

Appendix K: SGD Phase 2 (Trainer 1) Treatment Integrity Checklist

................. 144

Appendi x L: SGD Phase 2 (Trainer 2) Treatment Integrity Checklist

.................. 145

Appendix M: PECS Phase 3 (Trainer 1) Treatment Integrity Checklist

............... 146

Appendix N: SGD Phase 3 (Trainer 1) Treatment Integrity Checklist

................. 147

Appendix O: Treatment Acceptability Rating Form

............................................. 148

Appendix P: Interobserver Agreement for Requesting ......................................... 151

Appendix Q: Interobserver Agreement for Social - Communicative Behavior

...... 152

ix

Page

Append ix R: Interobserver Agreement for Speech

............................................... 153

Appendix S: Treatment Integrity for Trainer 1 ...................................................... 154

Appendix T: Treatment Integrity for Trainer 2 ..................................................... 155

V ITA

................................................................................................................................ 156

x

LIST OF TABLES

Table

............................................................................................................................. Page

Table 1 . PECS Phases

......................................................................................................... 4

Table 2 . Hierarchy of Evidence in Augmentative and Alternative Communication

........ 21

Table 3 . Participant Characteristics

.................................................................................. 41

Table 4 . Operational Definitions of the Dependent Variables

.......................................... 45

Table 5 . Food Reinforcers ................................................................................................. 48

Table 6 . Phase 1 Protocol .................................................................................................. 52

Table 7 . Phase 2 Protocol .................................................................................................. 53

Table 8. Phase 3A Protocol

............................................................................................... 55

Table 9 . Phase 3B Protocol

............................................................................................... 57

Table 10 . The MacArthur CDI: Christian

......................................................................... 61

Table 11 . The MacArthur CDI: Nadia

.............................................................................. 62

Table 12 . The MacArthur - Bates CDI: Zeth

...................................................................... 63

Table 13 . PND/NAP Scores for Requesting: Christian

.................................................... 68

Table 14 . PND/NAP Scores for Requesting: Nadia

......................................................... 69

Table 15 . PND/NAP Scores for Requesting: Zeth ............................................................ 71

Table 16 . PND/NAP Scores for Social - Communicative Behaviors: Christian

................ 75

Table 17 . PND/NAP Scores for Social - Communicative Behaviors: Nadia

..................... 76

Table 18 . PND/NAP Scores for Social - Communicative Behaviors: Zeth

....................... 78

Table 19 . PND/NAP Scores for Speec h: Christian

........................................................... 81

Table 20 . PND/NAP Scores for Speech: Nadia

................................................................ 82

Table 21 . PND/NAP Scores for Speech: Zeth

.................................................................. 83

Table 22 . Number of Sessions to Reach Mastery

............................................................. 85

Table 23 . Summary of Social Validity Questionnaire (TARF - R)

.................................... 87

xi

LIST OF FIGURES

Figure

Page

Figure 1 . Total Number of Requests

................................................................................. 66

Figure 2 . Total Number of Social - Communicative Behaviors

......................................... 73

Figure 3 . Total Number of Speech Use

............................................................................ 80

xii

LIST OF ABBREVIATIONS

Applied Behavior Analysis

ABA

Alternating Treatment Design

ATD

Autism Spectrum Disorders

ASD

Augmentative and Alternative Co mmunication

AAC

Evidence Based Practice

EBP

Interobserver Agreement

IOA

Multiple Baseline Design

MBD

Mean Baseline Reduction

MBR

Non - overlap of All Pairs

NAP

Picture Exchange Communication System

PECS

Picture Communication Symbols

PCS

Percentage of Data Points Exceeding the Median

PEM

Percentage of Non - overlapping Data

PND

Percentage of Zero Data

PZD

Responsive Education and Prelinguistic Mileau Training

RPMT

Self - injurious Behavior

SIB

Speech Generating Device

SGD

Single Subject Experimental Design

SSED

Treatment Acceptability Rating Form – Revised

TARF

Treatment Integrity

TI

xiii

GLOSSARY

AAC user: A person with deficits in verbal comm unication who require AAC interventions.

Applied Behavior Analysis: The scientific study of behavior and its relationship to the environment.

Aided communication : Communication that r equires an external aid to convey its meaning (e.g., pictures, speech - g enerating devices, etc.).

Aided symbol: A symbol produced using an external aid to convey its meaning such as a picture or a written word.

Augmentative and alternative communication:

“(1) The supplementation or replacement of natural speech and/or writing using aided and/or unaided symbols.” “(2) The field or area of clinical/educational practice to improve the communication skills of individuals with little or no functional speech” (Lloyd, Fuller, & Arvidson, pp. 524).

Autism: A pervasive developmental disorder in which symptoms are typically evident by three years of age

and

is “characterized by severe and pervasive impairment in several areas of development: reciprocal social interaction skills, communication skills, or the presence of stereotyped behavior, interests, and activities” (APA, 2000, pp. 69).

Autism spectrum dis order s : A term used to classify a group of developmental disorders exhibiting deficits in verbal and nonverbal communication, social behavior, and/or

unusual

repetitive/stere otypic interests and behaviors. The three types of ASDs include autistic disorder , Asperger Syndrome, and Pervasive Developmental Disorder - Not Otherwise Specified (CDC, 2011).

Backward chaining:

Sequential steps taught in a reverse order, from the last required step to the first required step to complete the task.

Communication:

“The transmission or exchange of thoughts and information from one individual to another” (Lloyd, Fuller, & Arvidson, pp. 526).

Communication board: A board used to display symbols.

Developmental Disability: A disorder that manifests before the age of 18 and affects several areas of functioning, including cognition, communication, self - help skills, and social behavior.

xiv

Digitized speech:

Electronically recorded speech.

Evidence - based practice:

The decision - making of treatment implementation based on relevant research, clinical/educational expertise, and stakeholder input.

Generalization: The transfer of learned behavior to other settings, activities, trainers, or items.

Ges ture :

A visual message without linguistic rules and displayed using the body or body parts (e.g., nodding, saluting, pointing, etc.).

Graphic symbol : A symbol represented visually.

Language: A communication system governed by a set of rules

that can be spoken, written, and/or manually signed.

Mand: A term developed by Skinner (1957) to describe a request.

Manual sign :

A v isual representation produced using the fingers and/ or hands and with linguistic rules.

Nonverbal: Without language or without spoken language.

Physical prompter: A person who physically guides and shapes the target behavior of the AAC user during training.

Picture Communication Symbols: A set of line drawings (e.g., Boardmaker symbols).

Picture Exchange Communication Symbols:

A six - phase, picture - based system de veloped by Andy Bondy and Lori Frost. P icture symbols are exchanged with a communicative partner to requests or to comment . In phases one through five, t he user make s

requests and in phase six the user comment s .

Preference Assessment:

A set of procedures used to systematically identify preferred (or sometimes non - preferred) items or activities.

Prelinguistic skills: Skills developed prior to language.

Prompt: “An added stimulus that increases the probability that a desired response w ill occur” (Simpson, 2005, pp. 87).

Reinforcer:

An item or activity that maintains a particular behavior .

Self - injurious behavior:

Aggressive behavior directed towards oneself such as hitting, biting, slapping, etc.

xv

Speech generating device:

A device th at produces synthesized or digitized speech upon activation.

Sym bol: A representation of something

and can be aided or unaided .

Synthesized speech:

Artificial speech produced electronically.

Tact: A term developed by Skinner (1957) referring to commenti ng/labeling.

Unaided communication : C ommunicati on conveyed through one’s own body without the use of external devices (e.g., natural speech, gestures, manual signs, etc.) .

Unaided symbol: A symbol produced using on ly the body such as natur a l

sp eech

or manual sign ing .

Verbal: With speech or language.

Vocalizations: S ounds produced that may / may not convey a communicative message

such as crying or moaning.

Word approximation: A

spoken attempt to “pronounce a standard word” (McCurry & Irwin, 1953, pp. 133).

xvi

ABSTRACT

Boesch, Miriam Chacon. Ph.D., Purdue University, August 2011. Augmentative and Alternative Communication in Autism: A Comparison of the Picture Exchange Communication System and Speech- Output Technology. Major Professor: Oliver Wendt.

The purpose of this comparative efficacy study was to

investigate the P icture Exchange C ommunication S ystem

(PECS) and a speech - generating device

(SGD)

in

developing requesting skills , social - communicative behavior , and speech for three elementary - age ch ildren with

severe

autism and little to no functional speech. Requesting was selected as the primary measure while social - communicative behavi or ( eye contact, smiling, and physical proximity) and speech were selected as ancillary measures. A multiple base line design (Baer, Wolf, & Risley, 1968) was combined with an alternating treatment design (Barlow & Hayes, 1979) to evaluate the treatment effects across participants and between modalities for each condition. A 3 - stage preference assessment was conducte d to systematically identify f ood reinforcers prior to treatment . Training conditions

for both treatment modalities included the implementation of PECS phase 1 ( how to communicate ), phase 2 ( distance and persistence ), and phase 3 ( picture discrimination ). PECS followed the traditional protocol as outlined by Bondy and Frost (1994) and the ProxTalker , a device developed to

closely follow the principles of PECS, used a modified PECS protocol.

xvii

Results demonstrated increases in requesting behavior for all participants across conditions and treatment modalities , however, difficulties were evident with picture discrimination . Statistical analysis did not reveal significant differences between PECS and the SGD for any participant. Results for social - communic ative behavior

were mixed

although a n increasing trend was present in phase 2 for all participants and treatment modalities . H owever, no significant differences between modalities were found. Data for s p eech outcomes did not reveal any increases across p articipants and no statistical differences between treatment modalities

were found . Findings suggest PECS and the ProxTalker device are equally appropriate for developing initial requesting skills. Results on social - communicative behavior are inconclusi ve however; data patterns suggest phase 2 is conducive to encouraging social - communicative behavior. The lack of speech emergence supports previous research. Based on the current finding s, successful implementation of either

modality is achievable when appropriate teaching strategies are used. Further research is needed to address difficulties in picture discrimination, mixed results in social - communicative behavior, and the non- emergence of

speech . Non - significant differences

between modalities suggest the behavioral principles inherit in the PECS protocol are responsible for the findings in this stud y ;

therefore,

future research directions are provided.

1

CHAPTER 1: INTRODUCTION

One of the most prevalent developmental disabilities gaining attention in today’s society is autism. Autism is a disorder typically diagnosed in children by age 3 under the broader category of Autism Spectrum Disorders (ASD). According to the Diagnostic and Statistical Manual of Mental Disorders (DSM - IV - TR; American Psychiatric Association, 2000), a hallmark characteristic of autism is the “delay in, or total lack of, the development of spoken language” (pp. 75). Rather than using spoken words in a meani ngful way, many with speech abilities engage in echolalia. Individuals with autism also have “restricted repetitive and stereotyped patterns of behavior, interests, and activities,” and impairment in social interactions (pp. 75). The foll owing vignette pr ovides an example of a person with severe autism

with limited functional communication skills :

Destiny

is a 6 - year old girl with severe autism.

She is primarily nonverbal and communicates through gestures (i.e., pointing). At times, Destiny

requests by leading an adult to the desired item or by bringing the item to the adult. However, Destiny

typically attempts to retrieve the item herself.

Although she does not use spoken communication, Destiny

can verbally approximate the words “bye” and “yeah ” when prompted. S he engages in problem behavior such as screaming, crying, and throwing herself on the floor . This behavior is seen

several times per day usually

when

communicative breakdowns occur . During play time , Destiny

prefers to play alone rather than with others. When another child attempts to interact with her, Destiny

does not make eye contact or demonstrates other

appropriate social skills for her age. Instead, she remains focused on her object of interest.

2

The prevalence of ASDs i s steadily increasing in the United States. In 2002, the Centers for Disease Control and Prevention (CDC) reported the average prevalence of ASDs at 1 in 166 (CDC, 2010). In later reports, the number increased to 1 in 150 with the most recent reports indicating an average of 1 in 110 children being diagnosed with an ASD in the U.S. (CDC, 2010). For those with the diagnosis of autism prototype, about 50% have limited or no functional speech (Charlop & Haymes, 1994; Light , Roberts, DiMarco, & Greiner , 1998; Peeters & Gillberg, 1999; Wing & Attwood, 1987). These numbers are alarming especially when we spend our daily lives communicating with others. To address these communication deficits, augmentative and alternative communication (AAC) interventions are often used (Mirenda & Schuler, 1988 ).

Augmentative and Alternative Communication

AAC is the supplementation or replacement of natural speech and/or writing through alternate means of communication such as electronic communication aids, gestures, graphic sy mbol sets/systems, or manual signs (Lloyd, Fuller, & Arvidson, 1997). AAC is often divided into two broad categories, aided and unaided communication. Natural speech, manual signs, and gestures are all forms of unaided communication. Unaided communicati on does not depend on external sources to convey a message and be understood (Lloyd, Fuller, & Arvidson, 1997). On the contrary, aided communication requires an external apparatus to facilitate the message (Lloyd, Fuller, & Arvidson, 1997). For example, conventional writing is considered aided communication because it requires a writing utensil to create the intended message.

3

The Picture Exchange Communication System (PECS; Bondy & Frost, 1994) and speech - generating devices (SGDs) are also aided AAC s trategies which have recently increased in popularity for targeting communication disorders in autism and other developmental disabilities (Lancioni , Cuvo, Singh, Sigafoos, & Didden, 2007) . Picture Exchange Communication System (PECS) . PECS is a prominent intervention for increasing prelinguistic skills and teaching functional communication. Additionally, PECS involves the systematic instruction of self - initiated communication skills using six phases (Bondy & Frost, 1994, 1998). The tr aining protocol was designed to systematically build on each learned behavior to achieve more communicative independence. In other words, as proficiency is gained, the u ser advances to other stages. Initially, the user is taught to request by selecting p icture cards and exchanging them with a communicative partner to make requests of preferred items. In the latter stages, the user is taught to respond to “what do you want?” and to comment. It is expected that by the end of the training program, PECS use rs are able to make more detailed requests using descriptors (e.g., “I want a yellow gummy bear”) and make comments (e.g., “I see a blue sky”). Although PECS is a six phase intervention, not all PECS learners are able to advance through all six phases (Sc hlosser & Wendt, 2008). T able 1 descri bes the six phases according to the PECS manual (Frost & Bondy, 2002) .

4

Table 1

PECS P hases

Phase

Title

Description of Terminal Objective

1

“How” to Communicate

Upon seeing a “highly preferred” item, the student will pick up a picture of the item, reach toward the communicative partner, and release the picture into the trainer’s hand.

2

Distance and Persistence

The student goes to his/her communication board, pulls the picture off, goes to the trainer, gets the trainer’s attention, and releases the picture into the trainer’s hand.

3

Picture Discrimination

The student requests desired items by going to a communication book, selecting the appropriate picture from an array, going to a communication partne r, and giving the picture.

4

Sentence Structure

The student requests present and non - present items using a multi - word phrase by going to the book, picking up a picture/symbol of “I want,” putting it on a sentence strip, picking out the picture of what is wanted, putting it on the sentence strip, removin g the strip from the communication board, approaching the communicative partner, and giving the sentence strip to him.

5

Responding to Questions

The student spontaneously requests a variety of items and answers the question, “What do you want?”

6

Comme nting

The student answers “What do you want?”

“What do you see?” “What do you have?” “What do you hear?” and “What is it?” and spontaneously requests and comments.

N umerous studies exist on PECS (e.g., Charlop- Christy, Carpenter, Le, LeBlanc, & Kellet, 2002; Kravits, Kamps, Kemmerer, & Potucek, 2002; Magiati & Howlin, 2003; Schwartz, Garfinkle, & Bauer, 1998; Stoner , Beck, Bock, Hickey, Kosuwan, & Thompson, 2006; Yokoyama, Naoi, & Yamamoto, 2006) .

5

Research shows PECS is successful in promoting functional communication skills such as requesting, choice - making, and commenting. However, the most common skill successfully taught using a picture exchange system

such as PECS is requesting (Lancioni, O’Reilly, Oliva, & Coppa, 2001; Schepis, Reid, Behr man, & Sutton, 1998; Sigafoos, O’Reilly, Seely - York, & Edrisinha, 2004; Son, Sigafoos, O’Reilly, & Lancioni , 2006). Increases in social - communicative behaviors and speech are also reported in several PECS studies (Charlop- Christy et al., 2002; Yoder & Stone, 2006 ).

A dditional a d vantages

associated with PECS

are noted . First, PECS

is inexpensive and can be created using basic materials

such as a 3 - ring binder, Velcro strips, and sturdy plastic inserts for storing the picture cards . Second, for individuals who prefer visual stimuli, PECS is a suitable intervention.

It is widely reported that individuals with autism have a preference of visual stimuli over auditory stimuli (Hodgdon, 1995, 1996; Mirenda & Schuler, 1988; Schuler & Baldwin, 1981). A speculati on for

visual preference is that individuals with autism may be hypersensitive to

auditory stimuli ( Wing, 1997 ).

Therefore, they tend to make attempts to mentally remove themselves from the overwhelming auditory input. However, individuals with autism ar e heterogeneous and may not be avers e

to auditory stimuli. Thus , care should be taken when selecti ng an appropriate intervention. In a review by Lancioni et

al ., (2007) it was concluded that when

comparing pictured - based interventions with other interventions most participants demonstrated preferences for one intervention over the other. Although reasons for preference are unclear, it is speculated that ease of use and accessibility may play

a r ole. Furthermore, i n a self - operated auditory prompting intervention, Taber, Seltzer, Heflin, and Alberto (1999 ) reported decreases in problem behavior for an

6

adolescent with autism upon treatment implementation providing

further evidence that auditory - ba sed interventions are just as suitable for individuals with autism.

Speech - generating Devices (SGD) .

SGDs are electronic communication aides that produce digitized or synthesized speech upon activation and are used by individuals with little to no functio nal speech (Lloyd, Fuller, & Arvidson, 1997) . Users have the option of activating the device through direct selection ( e.g., finger/hand, head pointer, etc.) or through indirect selection (e.g., eye gaze scanning). SGDs vary greatly in terms of features,

cost, and appearance. Due to advances in technology, SGDs are viable alternatives to exchange - based approaches.

Most research investigating SGDs focused on requesting ( Durand, 1993; Schlosser et al., 2007; Sigafoos, Didden, & O’Reilly, 2003; Sigafoos et al., 2004 ).

In a review by Lancioni and colleagues (2007), 16 studies us ing SGDs were examined (n=39 participants). From those, only three participants were unsuccessful in making requests via SGDs. Other SGD studies investigated communicative interacti ons ( e.g., Schepis et al., 1998), and speech production ( e.g., Dyches, 1998; Olive et al., 2007; Parsons & La Sorte, 1993; Schlosser et al., 2007). A systematic review by Schlosser and Wendt (2008) revealed that SGDs were reasonably effective in increasin g speech production for participants in the studies; however, only a limited number of studies were located. Although SGDs are found to be effective in increasing some speech, only a single study exists that addresses the effectiveness of SGDs on social i nteraction skills (Sigafoos,

Green, Payne, Son, O’Reilly, & Lancioni , 2009).

There are further benefits to using SGDs. One of the most notable benefits is the added speech feedback for the learner providing

extra speech modeling that may help

7

increase skil l acquisition and promote faster skill acquisition (Romski & Sevcik, 1993, 1988). Another potential benefit of SGDs is their

ability to help the user become more communicatively independent (Mirenda, 2001; Schepis, Reid, & Behrman, 1996). Once

an

SGD is activated, the speech signal is immediately made available to anyone within hearing distance. Thus, there is no reliance on the communication partner to engage in a communicative exchange unlike picture exchange systems.

This creates greater communicativ e independence and permits unfamiliar or untrained communicative partners in comprehend ing

the message.

Additionally, Schlosser and Blischak (2001) theorize d SGDs with synthesized speech output offer an advantage over other AAC interventions that incorpor ate traditional/natural speech because

Full document contains 187 pages
Abstract: The purpose of this comparative efficacy study was to investigate the Picture Exchange Communication System (PECS) and a speech-generating device (SGD) in developing requesting skills, social-communicative behavior, and speech for three elementary-age children with severe autism and little to no functional speech. Requesting was selected as the primary measure while social-communicative behavior (eye contact, smiling, and physical proximity) and speech were selected as ancillary measures. A multiple baseline design (Baer, Wolf, & Risley, 1968) was combined with an alternating treatment design (Barlow & Hayes, 1979) to evaluate the treatment effects across participants and between modalities for each condition. A 3-stage preference assessment was conducted to systematically identify food reinforcers prior to treatment. Training conditions for both treatment modalities included the implementation of PECS phase 1 ( how to communicate ), phase 2 (distance and persistence ), and phase 3 (picture discrimination ). PECS followed the traditional protocol as outlined by Bondy and Frost (1994) and the ProxTalker, a device developed to closely follow the principles of PECS, used a modified PECS protocol. Results demonstrated increases in requesting behavior for all participants across conditions and treatment modalities, however, difficulties were evident with picture discrimination. Statistical analysis did not reveal significant differences between PECS and the SGD for any participant. Results for social-communicative behavior were mixed although an increasing trend was present in phase 2 for all participants and treatment modalities. However, no significant differences between modalities were found. Data for speech outcomes did not reveal any increases across participants and no statistical differences between treatment modalities were found. Findings suggest PECS and the ProxTalker device are equally appropriate for developing initial requesting skills. Results on social-communicative behavior are inconclusive however; data patterns suggest phase 2 is conducive to encouraging social-communicative behavior. The lack of speech emergence supports previous research. Based on the current findings, successful implementation of either modality is achievable when appropriate teaching strategies are used. Further research is needed to address difficulties in picture discrimination, mixed results in social-communicative behavior, and the non-emergence of speech. Non-significant differences between modalities suggest the behavioral principles inherit in the PECS protocol are responsible for the findings in this study; therefore, future research directions are provided.