Use of microswitches and speech output systems with people with severe/profound intellectual or multiple disabilities: a literature review

Augmentative and Alternative Communication for Children with Intellectual and Developmental Disability: A Mega-Review of the Literature

Establishing evidence- and research-based practices relies upon research synthesis of individual studies in reviews and meta analyses. Further summarizing scientific evidence about a specific topic by synthesizing reviews is an area of need to determine practices that have a strong evidence base and to identify areas of methodological weakness and gaps in the literature. A mega-review of literature reviews, systematic reviews, and meta-analyses on interventions using aided augmentative and alternative communication (AAC) interventions for children with intellectual and developmental disabilities from 2000 to mid-2020 was conducted. Participant and interventionist demographics, interventions, settings, outcomes, and recommendations of each review were reported and summarized. A MeaSurement Tool to Assess systematic Reviews Revised (AMSTAR 2; Shea et al., 2017) was used to examine the methodological rigor of 84 included reviews. Over the past 20 years, published reviews have increased slightly in methodological rigor but demonstrate a number of methodological weaknesses that detract from the strength of evidence for AAC interventions with this population. Suggestions for improving the methodological rigor of literature reviews and areas for future research specific to AAC interventions are discussed.

Eye- and Mouth-Opening Movements Replacing Head and Hand Responses in a Microswitch Program for an Adolescent with Deteriorating Motor Condition

This study assessed the possibility of replacing head and hand responses (no longer feasible) with minimal movements within the microswitch-based program of an adolescent with deteriorating motor condition and multiple disabilities. The new movements, i.e., eye- and mouth-opening, were introduced individually and then combined through the simultaneous availability of the related microswitches. Data showed the participant acquired the new movements (responses) successfully and retained them at a 2-mo. postintervention check. Mood improvements, i.e., increases in indices of happiness, also occurred through the program. The conclusion was that a person with deteriorating motor conditions may be able to revitalize a microswitch-based occupational program and retain a constructive engagement if new, feasible responses are identified.

Enabling a Man with Multiple Disabilities and Limited Motor Behavior to Perform a Functional Task with Help of Microswitch Technology

This study evaluated the extent to which two microswitches used as interfaces would enable a man with multiple disabilities and limited motor behavior to operate an electric door opener at the entrance of the day center that he attended. Analysis showed the man (a) learned to use the two microswitches, (b) preferred the microswitch placed at his wheelchair's footrest (which also allowed more effective responding) over the microswitch placed at his wheelchair's armrest, and (c) maintained his positive performance at the 1- and 2-mo. postintervention checks. The results were discussed from a technical and practical standpoint and in terms of implications for the quality of life of persons with disabilities.

Further Evaluation of Microswitch Clusters to Enhance Hand Response and Head Control in Persons with Multiple Disabilities

This study was a further evaluation of microswitch clusters (combinations of two microswitches) to improve adaptive responding together with correct head position in two persons with multiple disabilities. The two participants were 19.7 and 6.6 yr. old and had profound intellectual disabilities, spastic tetraparesis, and visual impairment. They were initially taught an adaptive hand response that activated a pressure microswitch and produced favorite stimulation. Thereafter, their performance of the hand response produced favorite stimulation only when it was combined with a correct head position (detected through a mercury microswitch). Analysis showed that both participants increased the frequency of the hand response and, subsequently, the percentage of times they emitted this response in combination with correct (upright) head position. In essence, they were able to coordinate constructive occupation with exercise of appropriate posture. Performance was maintained at a 2-mo. postintervention check.

Adapting a Grid into a Microswitch to Suit Simple Hand Movements of a Child with Profound Multiple Disabilities

We adapted a grid into a microswitch for the hand movements of a girl with profound multiple disabilities who lay on her back. The grid, suspended above the girl's face, was equipped with two mercury devices, i.e., small sealed ampoules containing a mercury drop and ending with conductive leads. A lateral or forward movement of the grid would make the mercury drop of at least one device slide to the conductive leads and activate the device. During the intervention, activations of the devices, i.e., microswitch activations, produced the occurrence of favorite stimuli. Analysis showed that the girl increased the frequency of hand movements and microswitch activations during the intervention phases compared to the baseline phases (when the favorite stimuli were not available). The increase was retained at a 1-mo. postintervention check.

Challenges of developing communicative interaction in individuals with congenital profound intellectual and multiple disabilities

BACKGROUND

Physiological responses have been used in individuals with acquired disability to enable communicative interaction without motor movement. This study explored four autonomic nervous system (ANS) signals-electrodermal activity, skin temperature, cardiac patterns and respiratory patterns-to enable interaction with individuals born with profound intellectual and multiple disabilities (PIMD).

METHOD

A series of case studies were conducted to teach a 15-year-old individual with PIMD to voluntarily control his ANS signals for the purposes of communicative interaction. Training was carried out according to an alternating treatment single-subject research design.

RESULTS

Training was unsuccessful; however, ANS signal patterns revealed issues unique to people with PIMD: profound intrasubject variability, discrepancy between physiological responses and caregiver perspectives, and the participant's lack of contingency awareness.

CONCLUSIONS

These three priority areas unique to people with congenital PIMD must be addressed before ANS signals can be used to enable communicative interaction with this population.

Barriers and facilitators to the use of high-technology augmentative and alternative communication devices: a systematic review and qualitative synthesis

BACKGROUND

There has been a rapid growth in recent years of available technologies for individuals with communication difficulties. Research in the area is currently underdeveloped with practitioners having a limited body of work on which to draw to guide the process of intervention. Concerns have been raised that this newly developed technology may have limited functional usage.

AIMS

This review aims to investigate the potential barriers and facilitators to high-technology AAC provision and its ongoing use. The aim of the analysis is to explore factors underpinning use rather than effectiveness, thus it synthesized data from predominantly qualitative and survey studies reporting the views and perceptions of AAC users or staff providing the devices.

MAIN CONTRIBUTION

The review highlights the range of factors that can impact on provision and use of high-technology AAC, which practitioners should consider and address as appropriate in the intervention process. These include: ease of use of the device; reliability; availability of technical support; voice/language of the device; decision-making process; time taken to generate a message; family perceptions and support; communication partner responses; service provision; and knowledge and skills of staff. The work outlines how qualitative synthesis review methods may be applied to the consideration of published material that is not reporting outcomes data, and how this may provide valuable information to inform future studies.

CONCLUSIONS

Practitioners should be aware of barriers and facilitators to successful use when making recommendations, and consider how barriers where present might be overcome. Aspects of service delivery such as ongoing technical support and staff training may require further consideration. The synthesis of evidence describing views of users and providers, and the implementation of high-technology AAC systems, can provide valuable data to inform intervention studies and functional outcome measures.

Teaching individuals with profound multiple disabilities to access preferred stimuli with multiple microswitches

We replicated and extended previous research on microswitch facilitated choice making by individuals with profound multiple disabilities. Following an assessment of stimulus preferences, we taught 6 adults with profound multiple disabilities to emit 2 different responses to activate highly preferred stimuli. All participants learnt to activate both microswitches. Five participants showed a higher overall level of responding when both switches activating preferred stimuli were available concurrently. After completion of microswitch training, a choice assessment was conducted in which participants had access to 2 microswitches concurrently, with 1 connected to the most highly preferred stimulus and the other to a least preferred stimulus. Choice making behavior was shown in 3 participants and provided support for the preference assessment results. The results of the 3 remaining participants showed that both the most highly preferred and the least preferred stimuli may serve as reinforcers for microswitch activation responses.

The use of speech generating devices in communication interventions for individuals with developmental disabilities: a review of the literature

OBJECTIVE

This review synthesizes communication interventions that involved the use of speech generating devices (SGD) for individuals with developmental disabilities.

METHODS

Systematic searches of electronic databases, journals and reference lists identified 35 studies meeting the inclusion criteria. These studies were evaluated in terms of (a) participants, (b) SGD function, (c) SGD characteristics, (d) intervention procedures, (e) intervention results and (f) certainty of evidence.

RESULTS

Across these studies, intervention was provided to a total of 86 participants aged 1-42 years. Communication skills targeted included requesting, social or conversational skills, labelling items and receptive language. Intervention approaches were categorized as using Discrete Trial Training, Milieu teaching or a combined instructional approach. Positive outcomes were reported in 86% of the studies with 54% of studies categorized as providing conclusive evidence.

CONCLUSION

This literature base is considered promising due to the large number of conclusive studies and the replication of intervention approaches.

Assisting Two Children with Multiple Disabilities and Minimal Motor Skills Control Environmental Stimuli with Thumb Poke Through a Trackball

Background: Microswitches are the most commonly used input device for people with multiple disabilities to control environmental stimulation. However, little is known about adopting the commercial trackball with a revised trackball driver as a more feasible input device. Aims: To assess whether two children with profound multiple disabilities and minimal motor skills would be able to control environmental stimulation using thumb poke ability through cordless trackballs installed with a newly developed mouse driver (i.e. a new mouse driver replacing a standard mouse driver, turning a trackball mouse into a precise thumb poke detector). Method: An ABAB design and a 2-month post-intervention check were adopted to perform the study. Results: Data showed that the two children improved significantly in their target response (thumb poke) to activate the control system to produce environmental stimuli during the B (intervention) phases. This performance was maintained at the post-intervention check. Conclusions: The use of thumb poke in connection with a trackball allowed the children with multiple disabilities and minimal motor skills to increase their level of response and stimulation control.

A new movement detector to enable people with multiple disabilities to control environmental stimulation with hand swing through a commercial mouse

This study assessed whether two persons with profound multiple disabilities would be able to control environmental stimulation using hand swing and a standard mouse with a newly developed mouse driver (i.e. a new mouse driver replaces standard mouse driver, and turns a mouse into a precise two-dimensional motion detector). The study was performed according to an ABAB design and included a 2-month post-intervention check. Data showed that both participants significantly increased their target response (hand swing) to activate the control system to produce environmental stimulation during the B (intervention) phases. This performance was maintained at the post-intervention check. Practical and developmental implications of the findings were discussed.

Assisting people with multiple disabilities and minimal motor behavior to control environmental stimulation through a mouse wheel

This study assessed whether two people with profound multiple disabilities and minimal motor behavior would be able to control environmental stimulation using thumb poke ability with a mouse wheel and a newly developed mouse driver (i.e., a new mouse driver replacing standard mouse driver, and turning a mouse into a precise thumb poke detector). The study was carried out according to an ABAB design and included a 2-month post-intervention check. The two people increased significantly in the target response (thumb poke) to activate the control system to produce environmental stimulation during the B (intervention) phases. This performance was maintained at the post-intervention check. Practical and developmental implications of the findings were discussed.

Enabling a person with multiple disabilities and minimal motor behaviour to control environmental stimulation with chin movements

PURPOSE

To assess whether a young man with multiple disabilities and minimal motor behaviour would learn to control environmental stimulation using chin movements and a mechanical microswitch.

METHOD

The study was carried out according to an ABAB design in which A represented baseline and B intervention phases. The chin movements controlled the stimulation only during the intervention phases. A 2-month post-intervention check was conducted.

RESULTS

The man increased the frequency of his chin movements, thus increasing the level of environmental stimulation, during the intervention phases. This performance was maintained at the post-intervention check.

CONCLUSION

The use of chin movements is a practical strategy for enabling individuals with minimal motor movements to control environmental stimulation. Future research should examine whether similar types of movements may enable some individuals to control voice-output communication devices.

Social and Communicative Interventions and Transition Outcomes for Youth with Disabilities

The relationship between social and communicative interventions and transition-related outcomes for secondary-aged youth with disabilities is explored in this systematic review. In all, 30 studies intervening with 316 youth with a broad range of disability labels (both high- and low-incidence disabilities) were reviewed. Subgroup analyses were conducted on original research in these areas: augmentative and alternative communication (AAC), conversation skills, decreasing aberrant behavior, and social skills training (SST). Little support was found for AAC and modest support for interventions designed to increase conversation skill acquisition and for SST, and the research in decreasing aberrant behavior was unable to be synthesized because of effect size calculation formula problems. Results are discussed in terms of alignment with extant literature reviews, methodological issues in meta-analysis, recommendations for further research, and practical implications.

Microswitch-Based Programs for Persons with Multiple Disabilities: An Overview of Some Recent Developments

Persons with multiple disabilities are often unable to interact with their environment due to their limited response repertoire. Microswitch programs are designed to help them control environmental events, generally preferred stimulation, through simple (feasible) responses. To make microswitch programs a more widely usable and relevant resource for intervention with these persons, a number of new developments were pursued in recent years. This paper examines three of those developments as specifically addressed in our research activity, namely, (a) assessment of new, nontypical responses and matching microswitches, (b) fostering of multiple responses and exercise of choice, and (c) targeting of habilitative and clinical (therapeutic) objectives. The encouraging outcomes of these developments are reviewed in relation to their potentially wide implications for daily practice and the need of additional developments in the area.

Three persons with multiple disabilities accessing environmental stimuli and asking for social contact through microswitch and VOCA technology

BACKGROUND

Direct access to environmental stimuli and opportunity to ask for social contact/attention may be considered highly relevant objectives for persons with multiple disabilities. We assessed the possibility of enabling three of these persons (two children and one adolescent) to combine two microswitches (for accessing environmental stimuli) and a Voice Output Communication Aid (VOCA), which allowed them to ask for caregiver's attention.

METHODS

Initially, the participants were required to use each of the two microswitches individually and then together. Thereafter, they were taught to use the VOCA. Eventually, the VOCA was available together with the microswitches, and the participants could use any of the three.

RESULTS

The results, which support preliminary data on this topic, showed that all participants (1) were able to operate the two microswitches as well as the VOCA; and (2) used all three of them consistently when they were simultaneously available.

CONCLUSIONS

Teaching persons with multiple disabilities to combine a VOCA with conventional microswitches may enrich their general input, emphasize their active social role and eventually enhance their social image.

PECS and VOCAs to enable students with developmental disabilities to make requests: an overview of the literature

This paper provides an overview of the literature dealing with the use of the Picture Exchange Communication System (PECS) and voice output communication aids (VOCAs) for promoting the performance of requests by students with developmental disabilities. Computerized and manual searches were carried out to identify the studies published during the last 15 years (i.e., the period between 1992 and 2006 during which PECS and VOCA approaches became popular). Thirty-seven studies were identified and then divided into three groups concerning the use of the PECS or equivalents, the use of VOCAs or equivalents, and the comparison of both these approaches, respectively. Of the 173 students involved in studies using the PECS or equivalents only three could be considered failures, while a fourth one did not progress in the program due to illness. Similarly, of the 39 students who used VOCAs or equivalents only three could be considered failures, while one was partly successful. Finally, of the 11 students involved in the comparisons between PECS and VOCAs none could be classified as a failure. The results are very encouraging but methodological concerns and the relatively limited use of the systems in terms of request items and request opportunities suggest caution. Caution may also be needed in interpreting the reported similarities between the two systems in usability and effectiveness.

Persons with multiple disabilities and minimal motor behavior using small forehead movements and new microswitch technology to control environmental stimuli

Persons with multiple disabilities and minimal motor behavior may be unable to use available microswitch technology to control environmental stimuli. For these persons, one may need to rely on small motor expressions (as responses) and new, matching microswitch technology to ensure a successful outcome. In the present study, a small movement of the forehead skin was selected as the response for two participants (ages 6.5 and 14.2 years) with profound multiple disabilities. The microswitch technology included (a) an optic sensor, i.e., barcode reader, (b) a small tag with horizontal bars attached to the participants' forehead, and (c) an electronic control system which activated stimuli in relation to response occurrence. Movement of the forehead skin shifted up or down the tag with bars and this shifting, if greater than a preset limit and therefore recorded as a response, led to the activation of the control system. Each participant received an ABAB sequence, in which A represented baseline and B intervention phases, and a 6-wk. postintervention check. Analysis showed both participants increased their responding during the intervention phases and maintained that responding at the postintervention check. Implications of the findings were discussed.

Extending the Evaluation of Novel Microswitch Technology for Small Responses in Children With Profound Multiple Disabilities

This study extended the evaluation of microswitch technology (i.e., a position sensor and an optic device), recently introduced for chin and eyelid responses, with two new participants with profound multiple disabilities. The participants were girls of 12.5 and 4.0 years of age who did not possess any specific response that they could profitably use in their environment. The study was conducted according to an ABAB design with a 3-week postintervention check. The results showed that both participants increased their level of responding during the intervention phases and postintervention check compared to the baseline phases. This positive outcome was discussed in terms of (a) the apparent suitability of the technology and responses used in the study, (b) the beneficial implications for the participants, and (c) new developments in the area.

Enabling students with multiple disabilities to request and choose among environmental stimuli through microswitch and computer technology

This study assessed the possibility of enabling two students with multiple disabilities to request and choose among environmental stimuli through microswitch and computer technology. Each student was provided with two basic microswitches the activation of which made a computer system present a sample of a preferred or non-preferred stimulus. The student could select or reject such a stimulus by vocal utterances discriminated by the computer system as 'yes' or 'no'. If the student selected the stimulus, the computer system presented it for a preset time. If the student rejected the stimulus, the computer system waited for the next input of one of the basic microswitches. Data showed that both students learned to activate the basic microswitches consistently, selected the preferred stimuli about 90% of the times, and largely rejected the non-preferred stimuli. The students also showed some preferences between the two basic microswitches/responses. The performance was maintained at the post-intervention checks carried out 3 and 6 weeks after the end of the intervention. Implications of the findings are discussed technically, practically, and in terms of quality of life.

Assessing the effects of stimulation versus microswitch-based programmes on indices of happiness of students with multiple disabilities

BACKGROUND

Stimulation and microswitch-based programmes are considered main strategies to promote indices of happiness in students with multiple disabilities. However, only limited attempts have been made to assess the relative effects of the two programmes. This study conducted such an assessment with seven students with multiple disabilities.

METHODS

The first four phases of the study served to: (1) provide the students with a systematic exposure to each of the programmes; and (2) measure the programmes' effects on indices of happiness by comparing them with baseline levels. The fifth phase served to compare the programmes with each other.

RESULTS

The first four phases of the study showed that the microswitch-based programme produced a significant increase in indices of happiness for all seven students, and the stimulation programme produced a significant increase for six students. During the fifth phase of the study (i.e. when the two programmes were alternated), the microswitch-based programme promoted significantly higher indices of happiness than the stimulation programme for four of the seven students.

CONCLUSIONS

Microswitch-based programmes might be deemed preferable to stimulation programmes because they can promote higher or comparable indices of happiness while promoting the acquisition of adaptive responses and self-determination.

Micro-switch programmes for students with multiple disabilities and minimal motor behaviour: assessing response acquisition and choice

This study assessed (a) whether three girls with multiple disabilities and minimal motor behaviour could acquire pairs of responses taught through micro-switch-based programmes and (b) how the girls would eventually choose between those responses. In relation to the choice issue, a response-choice analysis was conducted to find out whether possible differences in performance rates for the two responses were due to the stimuli linked to them and/or to potential response preferences. Results indicated that all three girls succeeded in the acquisition of the two responses programmed for them and showed clear response choices. The choices seemed to be largely motivated by the stimuli linked to the responses. Implications of these findings were discussed, including the need to assess their generality and extend the scope of the work in this area.

Children with multiple disabilities and minimal motor behavior using chin movements to operate microswitches to obtain environmental stimulation

In these two studies, two children with multiple disabilities and minimal motor behavior were assessed to see if they could use chin movements to operate microswitches to obtain environmental stimulation. In Study I, we applied an adapted version of a recently introduced electronic microswitch [Lancioni, G. E., O'Reilly, M. F., Singh, N. N., Sigafoos, J., Oliva, D., & Baccani, S., et al. (2004). Technological aids to promote basic developmental achievements by children with multiple disabilities: evaluating two cases. Cognitive Processing 5, 232-238]. In Study II, we set up a new microswitch detecting the chin-movement response through an optic sensor. Each study was carried out according to an ABAB sequence in which A represented baseline and B intervention phases. A 2-month post-intervention check also occurred. The data showed that both children increased the frequency of the chin response, thus increasing the level of environmental stimulation, during the intervention phases. This performance was retained at the post-intervention check. The overall suitability of this response and related microswitches as well as the need to explore other potential responses and microswitches for children with minimal motor behavior is discussed.

A microswitch cluster to enhance arm-lifting responses without dystonic head tilting by a child with multiple disabilities

This study assessed whether a microswitch duster with favorite stimulation could help a 9.1-yr.-old child with multiple disabilities increase arm-lifting responses without dystonic, sideways head tilting. The microswitch cluster involved two microswitches, one at the child's arm to monitor the lifting response, and the other at the child's head to monitor whether it was tilted during arm lifting. Analysis showed that the percentage of arm-lifting responses occurring without head tilting increased most visibly when favorite stimulation focused on those (appropriate) responses.

Microswitch programs for persons with multiple disabilities: an overview of the responses adopted for microswitch activation

BACKGROUND

To introduce a person with multiple disabilities to a microswitch-aided program, one has to select a plausible response(s), that is, a response(s) that can be performed reliably and without excessive effort by the person and can successfully activate the microswitch(es) available (producing preferred stimuli). This paper provides an overview of the responses adopted for microswitch activation in research studies during the last 20 years.

METHOD

Computerized and manual searches were carried out to identify the studies published between 1986 and 2005. Forty-eight research studies were identified. They concerned the use of (1) a single (typical) response, (2) a single (non-typical) response, (3) multiple (typical and non-typical) responses, and (4) multiple (vocal) responses.

RESULTS AND DISCUSSION

The results showed that 151 of the 190 participants involved in the studies had a positive outcome (i.e., clear increases in their responding, which suggested that they had learned the association between responding and consequent preferred stimuli). Failures were largely concentrated in the first group of studies. The discussion focused on (a) the importance of selecting plausible responses for increasing the chances of success, (b) the need of non-typical responses for persons with minimal motor behavior, (c) implications of programs with multiple responses on engagement and choice, and (d) relevance of using vocal utterances. Some suggestions for future research concerning these points were also examined.

A novel method for testing learning and preferences in people with minimal motor movement

Ten individuals with profound multiple impairments were given novel tests for learning and preference with adaptive switches and leisure-oriented devices, such as audio tape players. Typically, tests for learning include a baseline or extinction component in which the adaptive switch and device are not connected as a control for incidental or involuntary switch use. As an alternative, conditions were compared in sets of six sessions each in which switch closure caused (a) Activation of a device, (b) Deactivation of an already operating device, and (c) Deactivation of one of two devices and Activation of the other (Two-Choice). Changes in behavior indicative of learning were observed in eight participants in Activation-Deactivation conditions. The Two-Choice Condition produced indices of learning that also showed a preference for one device over the other with five participants. The preferences observed in the Two-Choice Condition had not been seen in the Activation or Deactivation Condition data. People with profound multiple impairments evinced leisure-device preferences, but such preferences may not lead to differential responding across opportunities with only one device at a time.

Effects of ambient stimuli on measures of behavioral state and microswitch use in adults with profound multiple impairments

The effects of different types and amounts of environmental stimuli (visual and auditory) on microswitch use and behavioral states of three individuals with profound multiple impairments were examined. The individual's switch use and behavioral states were measured under three setting conditions: natural stimuli (typical visual and auditory stimuli in a recreational situation), reduced visual stimuli, and reduced visual and auditory stimuli. Results demonstrated differential switch use in all participants with the varying environmental setting conditions. No consistent effects were observed in behavioral state related to environmental condition. Predominant behavioral state scores and switch use did not systematically covary with any participant. Results suggest the importance of considering environmental stimuli in relationship to switch use when working with individuals with profound multiple impairments.

Using computer systems as microswitches for vocal utterances of persons with multiple disabilities

We assessed the effects of two computer systems used as microswitches for the vocal utterances of an adolescent and a young adult with multiple disabilities. The systems were to respond to three one-syllable utterances of the first participant and nine word-like utterances of the second participant by presenting favorite stimuli linked to those utterances. The computer system used for the first participant relied on a software program developed specifically for this study. The computer system used for the second participant combined a new software program with a commercially available speech recognition program. Results showed that both participants increased the frequencies of their target utterances and obtained high levels of stimulation. Positive performance was maintained at post-intervention checks. Technical and practical implications of the data are discussed.

Using microswitches with persons who have profound multiple disabilities: evaluation of three cases

This study evaluated the effectiveness of microswitch programs in promoting and maintaining responding of persons with profound multiple disabilities. Three participants were provided one or two microswitches. Their responding (microswitch activation) produced favorite stimuli. Analysis showed that all participants increased responding significantly, albeit with clear differences among them, during the intervention period of a few weeks. Two participants continued with the microswitch program in the daily context and had 3-mo. follow-up data similar to the intervention data. One participant did not continue with the program (reportedly because of inconsistent/low responding) and so did not receive a follow-up assessment. Links between responding and vigilance conditions and stereotypy are discussed.

Evidence of contingency awareness in people with profound multiple impairments: response duration versus response rate indicators

Evidence of contingency awareness in people with profound multiple impairments is often elusive due to numerous variables that impede learning and contribute to performance variability. Recent research has shown that measuring duration of responding rather than rate has promise for more accurate inferences. Duration measures of adaptive-switch use were obtained with 50 participants during empirical tests for contingency awareness. Nearly 80% had test performance patterns indicative of cause-and-effect learning or contingency awareness. Rate data were obtained concurrent with duration measures for 33/50 participants. Although statistical analysis indicated an interaction of test condition and rate of responding, the performance pattern indicative of contingency awareness was observed in only about 50% of the sets of rate data. Further, rate-based indications of contingency awareness were not consistently confirmed by the duration data. The results strongly support inclusion of response duration measures in evaluation of adaptive-switch use and contingency awareness.

Microswitch responding and awareness of contingency in persons with profound multiple disabilities

This study was aimed at evaluating acquisition of responding on microswitches and awareness of contingency with 3 adolescents who had profound multiple disabilities. Their favorite stimulation was used contingently and noncontingently on their responding on microswitches. Analysis showed that they acquired and maintained high responding frequencies only with contingent stimulation, indicating that such responding reflected an awareness of contingency rather than stimulation-related arousal and activity. Implications of the findings are discussed.

Extending microswitch-based programs for people with multiple disabilities: use of words and choice opportunities

This study assessed a microswitch-based program in which three request and one choice microswitches were used for two participants with multiple disabilities. The program was then transferred into the participants' daily contexts. Each request microswitch was linked to different stimulation opportunities. Every activation of the microswitch triggered the verbal announcement of one such opportunity that the participant could choose or bypass. The request microswitches were introduced individually and then combined. During the last part of the intervention and the post-intervention checks, all three request microswitches plus the choice microswitch were simultaneously available. Both participants learned to use the microswitches very rapidly. Responding levels were high during intervention and the post-intervention checks carried out in the participants' daily contexts. Implications of the findings for advanced microswitch-based programs and vocal recognition technology are discussed.

A social validation assessment of the use of microswitches with persons with multiple disabilities

The purpose of this two-part study was to conduct a social validation assessment of microswitches versus interaction/stimulation conditions used with persons with multiple disabilities. In Part I, 32 teacher-assistant trainees were shown video-tapes reporting the use of microswitches versus interaction conditions for six children. In Part II, 40 teacher-assistant trainees or classroom aides and 44 rehabilitation staff were presented with video-tapes showing the use of microswitches versus systematic stimulation strategies for four adults. Raters scored the microswitch and the interaction or stimulation conditions on a 7-item questionnaire covering social/emotional and practical aspects. The microswitch condition was viewed as generally more positive than or comparable to the interaction or stimulation conditions. Main features of the findings and their implications are discussed.

Evaluating the use of multiple microswitches and responses for children with multiple disabilities

BACKGROUND

The present study assessed the feasibility of (1) establishing multiple microswitches and responses (some of which had not been used before) with two children with multiple disabilities, and (2) maintaining such microswitches and responses in the children's daily contexts.

METHODS

The microswitches were introduced individually and then combined. During the last part of treatment and the follow-up, each child had three microswitches.

RESULTS

The data show that both children learned to use all three available microswitches. Moreover, they retained fairly high levels of responding with the microswitches in their daily contexts during follow-up periods of 4 and 6 months.

CONCLUSIONS

The personal and practical implications of these findings are discussed.

Impact of stimulation versus microswitch-based programs on indices of happiness of people with profound multiple disabilities

This study was designed to assess whether the impact of a microswitch-based program on indices of happiness would be comparable with that of a stimulation program. Three persons with profound multiple disabilities participated. The microswitch-based program produced increases in indices of happiness which were fairly clear for the first two participants and quite modest for the third participant. These data were largely comparable with those obtained with the stimulation program. Implications of the findings in terms of program practicality, participants' independence and environmental control are discussed.