Promoting Choice Using Switches in People With Severe Disabilities: A Case Report

Abstract

People with severe intellectual disabilities have a remarkably high risk of spending most of their lifetime without the possibility of engaging their surroundings. This study aimed to verify if it is possible to teach operant and choice behaviours for autonomus managment of leisure activity throught switches to people with severe intellectual disabilities. A two-switches training program was implemented following three subsequent steps: (1) switch pressure learning; (2) choice behavior learning (Level 1: choices between preferred and non-preferred stimuli; Level 2: choices between preferred and neutral stimuli); (3) subjective satisfaction. A single subject (N=1) multiple probe design, using intermittent probe sessions across behaviors, demonstrated experimental control. Results confirm the effectiveness of training in promoting both repertoires of switch pressure and choice behavior. The response rate and accuracy were statistically significant (r range: .83–.99). The study shed light on the possibility of autonomous activity management through switches for persons with severe intellectual disabilities.

Keywords

switch training people with severe intellectual and multiple disabilities choices autonomous activity management

The literature clearly shows that people with severe and multiple intellectual disabilities (SMD), who have higher levels of impairment, have greater barriers in participating in daily life activities, in choice availability, and in experiencing relevant activities (Wehmeyer & Abery, 2013). Often, a low pattern of request behavior exposes these people to the risk of spending most of their daily lives in “empty time” or in the presence of inaccessible stimulations and opportunities (Realon et al., 2002). If the communication skills are compromised, the risk increases. These risks are at the same time attributable to levels of impairment and to poor opportunities for appropriate stimulation, enablement, and interaction that are typically provided to these people. Low levels of stimulation and enablement, in fact, reduce the chances of exercising direct control over one’s living environment and of expressing needs, preferences, and choices by inexorably lowering levels of self-determination (Lancioni et al., 2020). Neely-Barnes et al. (2008) empirically demonstrated that exercising more choice opportunities is positively correlated with improvements in different quality of life (QoL) domains such as rights, social inclusion, and interpersonal relationships. Summing up, the condition of severe disability negatively affects the ability to act actively in the environment, to perform tasks or actions independently, reducing the opportunities for commitment and choice, ultimately hindering the prospects for personal development, as well as the social perception of these people and their quality of life (De Pace & Stasolla, 2014).

At the same time, the literature in the field of intellectual disabilities highlights the possibility of effectively assessing the preferences of people with high levels of impairments, (Tullis et al., 2011) and using outcomes to promote and support choice behavior and positive outcomes in terms of autonomy and QoL (Cannella-Malone & Sabielny, 2020).

However, in order to ensure appropriate choice opportunities for people with higher levels of impairment, it is essential to provide the appropriate support and opportunities for daily experience, carefully assessing presentation methods and selection modality (Cannella-Malone & Sabielny, 2020). Granting these fundamental rights (United Nations, 2006) requires direct and structured interventions in the case of multiple and profound disabilities (Cannella-Malone & Sabielny, 2020). This implies the ability to address two main obstacles typically found by caregivers: being able to (a) identify the stimuli and subjective preferences of people with high communicative and expressive impairments; and (b) identify the appropriate support to promote the acquisition of functional behavioral repertories for positive interaction and environmental control.

In recent years, several studies have highlighted that “assistive technologies” may provide a variety of stimuli and sensory inputs to encourage multiple response methods as well as improve the ability to select stimuli, also ensuring the maintenance of learning over time (Stasolla et al., 2019a). These aids allow opportunities to actively explore, interact, and control some specific aspects of the environmental context (Lancioni et al., 2007; Lancioni et al., 2017), leading to a significant decrease in the liability as well as the promotion of positive outcomes in different QoL domains. The development of skills for autonomous control of significant activities is a prerequisite for the achievement of important objectives: independent exercise, engagement, and recreational activities (without help and in the absence of assistants), in addition to improving the social vision of these people (Lancioni, 2018; Lancioni et al., 2005a). These programs can be shaped according to the individual characteristics of the participants, and they can be used in different contexts of daily life (Lancioni et al., 2011, 2018).

Most studies have focused on single-switch training. However, in order to make a choice, at least two switches must be provided. Some studies have shown that people with SMD can learn to emit multiple behaviors through multiple switches with momentary activation (Lancioni et al., 2001; Simacek et al., 2018).

Research has shown that teaching the use of a sensor (microswitch) to people with SMD increases their level of involvement with the surrounding environment and the frequency of behaviors index of happiness. The most important clinical outcome of the intervention in this work area is attributable to the improvement of the quality of life and happiness. The latter is a construct that includes multiple components such as personal well-being, pleasure and contentment (Felce & Perry, 1995; Ivancic & Bailey, 1996; Stasolla & Caffò, 2013). When it refers to people with non-verbal behavior and low levels of functioning is complex to be able to measure it, observe it and make it evident. To overcome this methodological problem, researchers in the field have taken into consideration the range of behaviors that are socially recognized as related to possible conditions of pleasure and well-being, grouping them under the label of happiness indices (Lancioni et al., 2005a).

Switches are devices that transform a physical quantity (pressure, displacement, sound, breath) into an electrical one, in order to control various typologies of devices such as appliances, toys, and computers. In other words, a switch is an electrical sensor which is capable of communicating with an electronic instrument and which sends a signal using customized means of transmission. Using switches in the field of intellectual disabilities offers the opportunity to access different modalities of stimulation in order to facilitate communication. The results of multiple studies support the use of microswitch technology in educational programs in people with deep and multiple disabilities as an effective support to allow the person to act on their environment and with the people who live in that environment (Roche et al., 2015).

In accordance with the Lancioni et al. (2018) analysis, the studies that use microswitches to promote simple adaptive responses can be divided into subgroups based on the type of target behaviors used to activate these devices: studies that used typical, atypical single behaviors and a combination of the two and depending on the response; studies using commercial/conventional microswitches (e.g., a pressure device) and experimental microswitches (e.g., an optical sensor). This study is part of those contributions that used commercial/conventional microswitches, a pressure device activated by a behavioral response of hand movement that is one of the most commonly used response in conjunction to head movement (Leatherby et al., 1992; Saunders et al., 2003). In line with the evidence reported by Wacker et al. (1988) and Lancioni et al. (2002) pressing the switch with the hand or arm allowed participants to increase the duration of their response and also showed a preference for one of the toys over the other. The stimulation provided by pressure devices that can be activated with hand or head movements, can be of various kinds, for example in the study by Holburn et al. (2004) stimulation participants received based on their responses consisted of viewing images presented on a computer screen integrated by sound, sound and light stimulations as in the exemplary case of Lancioni and collaborators (2002), or games such as the case of Mechling (2006).

Furthermore, it is essential to verify whether the introduction of switches and the implementation of choice training is effectively practicable by operators in the residential facilities where people live. The more the sensor is set on an individualized response assessment, the more it can be functionally used as an effective support. In terms of learning procedures for the use of microswitches, there is consistent evidence in the combined use of prompting, prompt fading and contingent reinforcement procedures (Roche et al., 2015). The behaviors that activate the switches must necessarily be motor behaviors that do not require efforts to be issued. The element (item) connected to the switch is generally identified through preference assessment (Schaefer & Andzik, 2016). According to positive reinforcement principles, moreover, access to the preferred stimulus as a contingent consequence is necessary.

Consequence manipulation allows for an increase in the occurrence probability of the target behavior of the switch pressing on the electronic support. That operant behavior is in general the desirable target behavior of a switch-training program (Lancioni et al., 2004). Single switches have been used to enable the expression of preferences in people with SMD entailing eyelid and lip movements (Lancioni, 2018). These types of interventions are designed to allow participants with even extensive impairments of movement to acquire an active role (Lancioni et al., 2014, 2017). Allowing the possibility to relate the behavior, albeit subtle, of the person such as movements of hands, fingers, lips or eyelids to events in the environment so that they can be invested with communicative intentionality. For example, in the subsequent contributions of Lancioni and collaborators, finger or lip movements were used to activate optical sensors connected to certain environmental stimulation categories, thus allowing the participant to operate in the environment firsthand (Lancioni et al., 2015, 2017, 2018). If programs using motor responses and commercial microswitches would appear to be effective solutions for a variety of people with multiple disabilities, a different consideration must be made for those with very limited behavioral repertoires. For these people, only specific and idiosyncratic responses to microswitches can be considered (Lancioni et al., 2013), therefore the choice of the target response to be selected in the learning programs for the use of microswitches must be the subject of specific analysis. Furthermore research has documented the benefits of using momentary activation switches to teach to people with SMD the behaviors necessary for the activation of a range of stimuli (Lancioni et al., 2006; Saunders et al., 2007). Microswitch interventions aimed at increasing processes of choice, communication and leisure opportunities have also been used with populations in developmental age and with different types of diagnostic labels Rett syndrome, traumatic brain injuries (TBI), highlighting the effectiveness of these tools to operate autonomous requests for preferred stimuli (Stasolla et al., 2015, 2018, 2019b).

Switch training programs differ both in the number of switches and in their mode of operation: switches with fixed activation intervals that provide a temporary activation of the stimulus, or switches with momentary activation that by pressing or releasing the switch directly activates or deactivates the stimulus.

The objective of the present study was to verify whether it was possible to carry out switch training, aimed at teaching to persons with SMD operant and choice behaviors for autonomous management of leisure activity through switch.

Our aim was to extend the use of AT-based programs to build repertoires of choice in absence of functional communication modalities and in particular to provide opportunities in which to apply this repertoire to a range of free time stimuli. The purpose is therefore expanding the literature on the use of AT-based interventions for promote the choice process in line with the studies of Stasolla et al. (2015, 2019a) and Lancioni et al. (2017), Lancioni et al. (2018), highlighting the possibility of application in contexts of the person’s daily life. In particular, the objectives of this study are: (a) Verify the adequacy and effectiveness of technological support identified in order to teach a person with SMD to emit voluntary pressure behaviors to activate a stimulus; (b) investigate the adequacy of the selected teaching procedure in accordance with the evidence provided by the review by Roche et al. (2015); (c) Analyze if the intervention had outcomes on happiness indices, such as a subjective well-being measure in terms of quality of life.

Methods

Participant

The work was carried out within a residential context for people with high support needs of Health Agency of Udine (Italy) - Azienda Sanitaria Universitaria Friuli Centrale. The study was implemented with one participant as a pilot trial. The participant was selected as a person with severe impairments (as specified below) with residual limb movement skills as a condition common to the residents of the facility. The subject, A., is a 51-year-old man who presents a diagnosis of severe intellectual disability in perinatal cerebropathy, spastic tetra paresis and epilepsy and has always been living in residential services. The levels of intellectual and adaptive functioning are markedly deficient and imply high support needs in all areas of daily life activity. The evaluation was carried out with the Vineland Adaptive Behavior Scale II (Sparrow et al., 2005) and produced low scores in all scales (communication, daily living, community, motors) and an extremely poor composite scale index (percentile score of 0.4). In terms of support needs, the analysis conducted with the Support Intensity Scale (SIS) (Thompson et al., 2004) confirmed high support needs in all areas of daily life (percentile composite index equal to 97), while the assessment of non-ordinary support needs showed the presence of moderate vulnerability in physical health conditions and the absence of behavioral problems.

The evaluation of the QoL, conducted through the San Martin Scale (Verdugo et al., 2014) clearly showed the presence of low percentile scores in the domains of self-determination (25) and personal development (16).

Specific assessment for the use of a switch

Considering the levels of impairment of the subject and the consequent inapplicability or insensitivity of the most widely used standardized scales, the evaluation of the functioning was deepened through the use of the Gravity Scale (Pilone et al., 2002), a specific Italian rating scale for the evaluation of basic cognitive functions such as attention, memory, and space–time orientation. This scale made it possible to detect with greater precision the residual abilities and strengths of the subject, as well as all the support necessary to design the intervention (Figure 1).

Figure 1.

Summary synoptic table of residual skills—Gravity Scale (Pilone et al., 2002).

Prior assessment is necessary for implementing the learning program design of technological aids and includes: (a) assessment of communication skills and skills in making requests (attention, stimuli, objects); (b) evaluation of fine and gross-motor skills in order to identify suitable technological aids; and (c) analysis of the indicators of interest and satisfaction, aimed at evaluating the preferred stimuli able to promote communication initiative, motivation, and compliance with the subject to the intervention program (reported in the preliminary phase).

- Communication skills and ability to make requests: the repertory of communicative behavior of the subject includes non-verbal and also vocal expression with request function. For example, the subject is prone to vocalizing out loud, as we could also observe during training, when his favorite stimulus is taken away. He does not seem to present other forms of request and normally does not attempt to interact either with his surroundings or with caregivers.

- Fine and large motor skills: the subject’s motor skills are very limited: he cannot move independently and during the day is placed in a wheelchair that maintains a seated posture; although the arm and contralateral hand suffer from very limited mobility, some fine motor movement is detectable, although limited, in the right arm and hand.

The specific assessment highlighted the requirement of a range of support aids in order to structure switch-training intervention due to the severity of the subject’s impairment. The objective of the support is to provide access to the training site, allow the accessibility of communication aids, and configure the aids as behavioral strategies to increase motivation and the implementation of skills.

Setting and Material

The intervention is part of the “Fine Time” project (inspired by “Fun Time” program (Green & Reid, 1996)) available to all users of the residence, with the aim of giving an opportunity to freely access their preferred stimuli. In the specific case it was dedicated to listening to sound stimuli through a “Free Music Corner” equipped with devices such as a PC, radio, MP3 player, and iPod connected to the relative switches.

An operator, who directly managed the procedure, and who was assisted by a second operator, who independently observed 40% of each phase, conducted each session. The sessions were filmed in their entirety to facilitate the processes of observation and recording. All aspects related to the planning of the intervention were coordinated within a team comprising the authors of the present paper.

Intervention Planning and Definition of Objectives

The intervention had a twofold general purpose—learning the functional use of technological supports to communication, and teaching behavioral repertoires of choice—and it was structured as follows:

- Pre-intervention: preference assessment;

- Phase 1: switch pressure learning;

- Phase 2: choice behavior learning (Level 1: choices between preferred stimuli and non-preferred stimuli; Level 2: choices between preferred stimuli and neutral stimuli);

- Phase 3: subjective satisfaction.

Target behavior was defined as contingent switch pressure to the preferred stimulus with the right hand. The intervention in each phase was structured through antecedent manipulation (discriminatory stimuli, motivational operations, type of support, and latency time in providing support) and consequence manipulation (penalizing or reinforcing) of the target’s behavior. The result in terms of reaching the target repertoires of each phase was defined as a prerequisite for transition to the next phase.

Response Measurement and Experimental Design

Number of target behavior occurrences and type of support per instance were counted. Response’s value was assigned according to how closest to target response was it:

- Total Physical Support: the prompter moves from above subject’s hand and makes him all the movement. Value −2.

- Partial Physical Support: the prompter moves the arm from behind subject’s elbow and pushes it toward the switch. Value −2 (Phase 1), Value −1 (Phase 2)

- No response: unshed button; Value 0.

- Approximation of target behavior 1: subject crushes the switch however does not remove the hand in 7 seconds. Value 1.

- Approximation of target behavior 2: subject crushes the switch even if the music has not been stopped. Value 1.

- Target behavior: subject crushes the switch and lifts his arm from the switch within about 7 seconds. Value 2.

A second experimenter independently coded 40% of the videotape sessions in order to establish inter-observer agreement across phases. Agreement was calculated by the number of agreements on session-by-session comparison divided by the number of agreements plus disagreements and multiplied by 100.

A multiple-probe-across-behaviors design was employed in order to determine the effect of switch training as a choice support intervention package.

In multiple baseline design, baseline data are collected intermittently. This experimental design does not require that all behaviors included in the evaluation begin the baseline phase at the same time and does not require extended periods of time in an assessment condition prior to instruction of the independent variable (Zhan & Ottenbacher, 2001).

The behavioral conditions were three: switch pression contingent to preferred stimuli with one switch, switch pression contingent to preferred stimuli with two switches (stimuli are arranged in order to facilitate choice), and switch pression contingent to preferred stimuli with two switches (stimuli are not arranged in order to facilitate choice). Replication of effect across a minimum of three conditions is recommended in the determination of a functional relation between the independent and dependent variable (Hammond et al., 2010). Level of support and number of switch pression behavior per session and per phases were analyzed through R Pearson as measure of linear correlation between two sets of data.

Following the guidelines of Gast et al. (2014), three behaviors should be functionally independent, yet similar, in multiple probe design. If target behaviors are functionally independent for one another, they should be unlikely to be acquired without direct instructions so that baseline data remain stable until the intervention is introduced to each. Second, target behaviors have to be sufficiently similar in order to respond to the same intervention. The probe session differed from baseline conditions in two ways: in the probe session the three conditions were tested in a randomized manner immediately prior to baseline; and the following baseline session measured only the target response for the current condition. Maintenance probe sessions were planned at 1 week after reaching the criterion on each phase. We identified a criterion-level performance for introducing the intervention to the next behavior, as previously stated, and we introduced the intervention when the data path of all behaviors showed acceptable stability in level and trend while maintaining other behaviors in the pre-intervention condition. In summary the dependent variable was keep constant through all three phases and it was operationalized as: approaching and pressing the switch by the hand in order to activate the appreciated sound stimulus. Independent variable regards type of support provided. In Phase 1 one switch linked to a highly preferred stimulus was provided; in Phase 2, Level 1, two different colors and positions switches alternatively linked to a highly preferred stimulus and to an aversive stimulus, were provided; in Phase 2, Level 2, two different colors and positions switches alternatively linked to a highly preferred stimulus and to a neutral stimulus, were provided; finally in Phase 3 no support was provided, two different colors and positions switches both linked to a highly preferred stimulus, were arranged.

Switch Training Program

Pre-intervention: preference assessment

A preliminary preferences assessment was conducted. Numerous studies on the assessment of preferences have underlined the need to operate through direct systematic procedures in order to be able to accurately detect individually preferred stimuli and activities (Reid et al., 1999). Although providing choice opportunities does not necessarily constitute a reinforcing condition in itself when highly preferred stimuli are provided (e.g., Romaniuk & Miltenberger, 2001), it is necessary to consider the possibility of incurring a major risk at this level of intervention alone. The risk is inherent in the fundamental distinction between choice and preference: “choice is the mechanism through which an individual can express preferences” (Cannella-Malone & Sabielny, 2020, p. 200). In the absence of repertoires of choice, in fact, preferences may not be detected, and research has shown that the choice can take on preference value regardless of the items presented (Schmidt et al., 2009; Tiger et al., 2006) and can be an effective intervention in reducing certain classes of problem behavior (Cooper & Browder, 2001), providing further evidence to support the need to ensure its exercise.

In this study, preferences were analyzed through two modalities: initially it was carried out through an indirect assessment interviewing family members and operators. The result highlighted the category of sound stimuli (musical pieces) as the most preferred option, and consequently sound stimuli were considered as the category of selection of possible reinforcing stimuli (Fisher et al., 1992). Within the sound stimulus category, a more in-depth evaluation was carried out using the Stimulus Preference Coding System (SPCS) procedure (Smith et al., 2005). The procedure involves the presentation of one stimulus at a time and the systematic observation, at intervals of 3 minutes, of the occurrence of approaching behaviors (e.g., maintaining proximity to the stimulus, laughing, smiling, behaviors like shaking and crossing hands, specific vocalizations) and behavioral indicators of rejection (e.g., vocal expressions, particular vocalizations, body withdrawal, drumming on the table, looking around bored) according to a “partial interval” recording system with intervals of 10 seconds. The quantification of such behaviors allows the researcher to classify stimuli according to a hierarchy of preference.

Intervention: switch training

The objective is to make the person learn the behavior of “pressing the switch” for contingent access to a preferred stimulus. Before starting each session, the subject was engaged by the operator through a verbal anticipation (“Now let’s listen to music!”) along with the presentation of a discriminatory stimulus: a concrete object linked with the activity, such as headphones or a CD. The subject was then placed in front of the table, where a switch connected to a PC or an MP3 capable of delivering the preferred stimulus was placed. Each session lasted 12 minutes, during which the opportunity of listening to four tracks was provided (for 3 minutes per session).

All phases of the intervention involved the use of evidence-based learning procedures derived from the applied behavior analysis field (Fisher et al., 2019) and listed below:

- In Errorless Learning (Markham et al., 2020) the learning task is systematically manipulated in order to reduce the possibility of error occurrence and to facilitate higher levels of reinforcement and personal self-efficacy.

- Stimulus Fading commonly (Markham et al., 2020) used in the field of errorless learning, provides initial supports and structures their subsequent systematic reduction, aimed at making the correct response evident and thus supporting learning.

- Time delay (Steinbrenner et al., 2020) is defined as the introduction of increasing time intervals between the request and the provision of support, in order to facilitate the emission of correct answers in a variety of situations (Boutot & Hume, 2012);

- With Prompting and Prompt Fading (Cividini-Motta & Ahearn, 2013), in order to help subjects to provide the correct answer, verbal, gestural, and physical aids are given, and subsequently, as the appropriate responses increase, these aids are progressively reduced;

- Positive reinforcement provides contingent reinforcement to the behavior, in order to make it more likely that the desired behavior will be issued when the same stimulus conditions occur.

- In Establishing Operation (Cooper & Browder, 2001; Michael, 1982), modification of motivational operations is performed to alter the reinforcement effectiveness of certain stimuli, objects, or events.

Phase 1: Switch Pressure Learning

The procedure followed these successive steps: (a) start of the preferred track, (b) interruption of the track by the operator, (c) physical guidance to the user’s hand to press the switch, and (d) reactivation of the track and social reinforcement (“Good! You have restarted the music”). The procedure was repeated 10 times for each song. Prompting, fading, and time delay techniques were applied according to the method of errorless learning, and then, contingently to the appearance and the progressive increase of an autonomous approach and pressure behavior of the switch, they were faded. Levels of support provided were gradually decreased: the type of support ranged from the totally physical to partially physical until an absence of support, and, at the same time, the interval of time between the request and the provision of support was increased from 0 to 10 seconds. The subject’s motivation and training compliance were supported by Establishing Operation (EO) manipulations, in terms of momentarily suspending the preferred stimulus due to altering its reinforcing value and increasing the possibility of the heightened occurrence of switch pressure behavior. In addition, target behavior was reinforced with social praise and contingent access of the preferred sound stimulus. The reaching criterion was defined as at least 80% of the autonomous switch pressure responses for three consecutive sessions.

Phase 2: Choice Behavior Learning

In this second phase, an additional switch (one red and one blue) was introduced, allowing the possibility to promote learning of the choice behavior. Choice behavior is operationalized as switch pressure linked with preferred stimulus (selected from two switches). Number of target behavior occurrences and type of support per instance were counted, however in Phase 2 Level 1 and 2, operationalization changes.

The intervention was divided into two sub-phases characterized by the following levels of choice:

- Level 1 provided the choice between preferred and non-preferred stimulus in order to underline the difference in association between each consequence and corresponding switch. Accurate choice behavior allows immediate access to reinforcement, compared to an immediate penalization that follows inaccurate choice behavior (Shevin & Klein, 2004).

- Level 2 provided a choice between preferred and neutral stimulus in order to train the acquired skill (Stafford et al., 2002).

The selection of the option associated with the most preferred stimulus was considered to be an accurate choice behavior. According to the literature in the field of preference assessment, consistent choice behaviors are defined as those that tend to comport with the respective hierarchies detected through direct assessment (Conyers et al., 2002).

In order to control the possibility that response rate was influenced by position bias or intrinsic characteristics of the technological device, the associations between color and stimulus and relative spatial position of each switch were randomized. Consequently, conditions in which the choice was made were the result of the possible combinations of the variable positions (right or left) and colors (red or blue) of the switch linked with the preferred stimulus, resulting in four conditions: (a) the red switch in the right position linked with the preferred stimulus and the blue switch in the left position linked with the non-preferred stimulus; (b) the red switch in the left position linked with the preferred stimulus and the blue switch in the right position linked with the non-preferred stimulus; (c) the red switch in the right position linked with the non-preferred stimulus and the blue switch in the left position linked with the preferred stimulus; and (d) the red switch in the left position linked with the non-preferred stimulus and the blue switch in the right position linked with the preferred stimulus.

The modes of engagement and involvement in the activity remained the same as in Phase 1, with two differences: (1) before the start of each session, the subject concretely experienced, two times, the consequence associated with the pressure of each switch through the provision for each of them of a total physical support; and (2) in an error-correction procedure, hand-to-hand physical guidance was provided in the case of an inaccurate choice behavior, operationalized as pression, three times, of the switch connected to the non-preferred (Level 1) or neutral stimulus (Level 2) without self-correcting. Self-correcting behavior was defined as pressing the switch connected to the preferred stimulus within 7 seconds following incorrect choice behavior. In the case of zero occurrence of the behavior or three cases of inaccurate choice, support was provided. The procedure was repeated 10 times for each song.

Prompting, fading, and time delay techniques as well as EO manipulations were arranged in Phase 2 and 3 in the same manner that they were done during learning step 1.

In each session, of 10 trials each, the occurrence of target behavior and error behavior was recorded, as well as the level of support provided. The ratio between the choices of the preferred stimulus in relation to the number of opportunities provided is therefore an index of the magnitude of the target behavior observed throughout the intervention. Its observation was carried out by assigning different values to more approximate occurrences (e.g., switch pressure connected to the non-preferred stimulus and then autonomous correction of the action) and occurrences where support had to be provided.

The reaching criterion was defined as at least 80% of the accurate switch pressure responses, within a maximum latency of 7 seconds, for three consecutive sessions.

Phase 3: Subjective Satisfaction

Starting from the assumption that the supports we provided in daily practice were as salient as possible to meet the person’s needs in terms of QoL, the validation of the entire intervention can only find expression in the impact that this intervention has had in the person’s daily life, with particular reference to the domains of emotional well-being and self-determination.

Consequently, construction of spaces in which behavioral repertoires could be effectively exercised and within them the occurrence of behavior indicators of emotional well-being was arranged in the last intervention phase. Opportunities of autonomous listening to music were included in the day’s programing. Levels of interaction with the switches and the indicators of happiness were observed and recorded, comparing the choice of preferred stimuli with neutral or non-preferred ones. Interaction levels were measured by detecting the on/off behavior of soundtracks and listening time, through a 12-minute, whole interval sample measurement.

The happiness indicators were coded following the selection process indicated by Petry and Maes (2006) that provides an intersubjectively shared individual happiness profile that in the case of A. included smiles, loud laughter, upper limb movement, vocalization, head twisting, jerking, and facial mimicry.

Results

Below are illustrated the data obtained through the observation of the responses provided by the subject through the different phases of the intervention and in the different training sessions.

Inter-Rater Agreement

The mean inter-rater agreement was 93.2%.

Phase 1: Switch Pressure Learning

As can be seen from the graph in Figure 2, the subject reached the mastering criterion of 14 out of 15 autonomous responses for three consecutive times from the 10th session onward. Of particular note is the fading trend of support level provided, that moves rapidly from total physical mode to partial physical prompts, with a gradual reduction at the same time as the progressive development of independent behavior (see in the graph the line that corresponds to the linear relationship between the variables).

Figure 2.

Ability to use a switch. Accuracy (Black bar) and support type (Gray bar) per session.

The significance of this negative correlation between the two variables is confirmed by Pearson’s r scores of −.98 in Phase 1. A significance test on r was performed with reference to Student’s t distribution, whereby the t calculated was larger than the critical t (|−27,8785954514457| >|2,131|). Consequently it was too unlikely that what was observed was the result of the fact that the null hypothesis was true, and we therefore reject the null hypothesis. The two variables have a significant linear correlation.

Phase 2: Choice Behavior Learning

The reaching of the target behavior as previously defined occurred for both Level 1 (session 22) and Level 2 (session 29) (Figure 3).

Figure 3.

Switch training data: probe session, baselines, accuracy and support need per session. Phase 1 (First Panel), Phase 2.1 (Second Panel), Phase 2.2 (Third Panel).

Choice behavior was operationalized as switch pressure linked with the preferred stimulus (selected from two switches). As the graphic shows, target behavior was maintained in correspondence with a significant and progressive decrease in the support provided: as the support provided decreased, the frequency of occurrence of the target behavior increased. The significance of this negative correlation between the two variables is confirmed by Pearson’s r scores of −.98 in Phase 1, −.83 for Level 1 Phase 2, and −.99 for Level 2 Phase 2. A significance test on r was performed with reference to Student’s t distribution, whereby t calculated was larger than the critical t (|−7,08218185664778| >|2,074| for Phase 2.1; |−28,7744829428532| >|2,201| for Phase 2.2). Consequently we again rejected the null hypothesis. The two variables have a significant linear correlation.

In Figure 4, it can also be observed how with the number of inaccurate responses, the pressure behavior of the switch connected to the non-preferred stimuli (non-target responses) gradually decreased until it became a punctiform eventuality in proceeding with the learning intervention.

Figure 4.

Switch training data: comparison between target and non-target response.

Considering the data related to both levels of Phase 2, there was a significant increase in self-correction behavior, defined as pressing the switch connected to the preferred stimulus within 7 seconds following incorrect choice behavior (Figure 5). The self-correction behavior could be considered a clear indicator of the ability to manage the switch in terms of self-changing the behavior according to the consequences associated with the activation of the two switches. The response rate was directly related to the slope of the cumulative frequency graph—7.145—which means that the number of responses emitted increased by seven units for each session.

Figure 5.

Cumulative count of self-correction behavior occurrence.

Phase 3: Subjective Satisfaction

Outcome evaluation also considered QoL indicators of subjective well-being, within the emotional well-being domain in particular. The sample basis observation during the interval of time of free access with sound stimulation showed an occurrence of behaviors index of happiness on average for 81% of the observation intervals and to a significantly greater extent compared to behaviors indicating a neutral state (Figure 6).

Figure 6.

Indicators of happiness.

Discussion

The objectives of learning and maintaining the behaviors to access the preferred stimulus in the different conditions have been achieved. Phase 1, “learning of pressure behavior” in which a switch has been connected to a preferred stimulus, verifies the adequacy and effectiveness of the technological support in order to teach voluntary pressure behaviors to activate a stimulus; Phase 2, “learning the repertoire of choice,” in which two switches were connected to different stimuli, first aversive-preferred, then neutral-preferred, confirms the evidence on the adequacy of the selected teaching according to the review by Roche et al. (2015); Phase 3, “subjective satisfaction,” in which two switches were connected to highly preferred stimuli, highlights the possibility that the intervention had an outcome on happiness indices.

The results support those of previous studies on AT-based programs to promote functional and choice behavior (Lancioni, 2018; Lancioni et al., 2014; Stasolla et al., 2015; Stasolla et al., 2019b). It is important to underline how the acquisition of pressure behavior, obtained in Phase 1, constitutes an extremely significant evolution if considered in the ecological-existential perspective of an adult subject with high levels of support needs. The learning and the spontaneous emission of this behavior in fact allowed the subject to pass from a “responding condition” (in which the stimulations he received were completely under the control of the environment) to an “operating condition” (in which, probably due to the first time, he became able to adaptively interact with his environment, modifying it in order to obtain the desired stimuli).

The results obtained in Phase 2, in which the antecedent variables of the position and color of the switches were combined with the consequences of the pressure behavior, allowed us to affirm that choice behaviors were learned. The occurrence percentages of the target behavior in fact reached the mastery criteria set for the various conditions. The significant increase in self-correction behaviors could also have been an indicator of the progressive acquisition of the ability to explore and self-regulate the behavior of choice for control and interaction with the environment. These results confirm the effectiveness of the switch technology to support and build opportunities of operating autonomous requests for preferred stimuli (Roche et al., 2015; Stasolla et al., 2015, 2018, 2019b).

The autonomous use of the switches and self-regulation of pressure to make choices are indicators of the main components of self-determination that it has been possible to promote. By issuing the learned behaviors, the subject began to experience the condition of being the causal agent (Shogren et al., 2017, 2020) of events and happenings relevant for himself.

Furthermore, the detection of happiness indicators (Lancioni et al., 2005b; Stasolla & Caffò, 2013) allowed us to highlight that the intervention also produced a positive impact not only on the functional and adaptive variables but also on the personal outcomes and in general on the person’s QoL.

At the same time, the study has some limitations. The balance between adherence to methodological standards and the constraints linked to the implementation of interventions within the services resulted in compromise choices in the planning and implementation of interventions. First of all, no systematic pre-session preference measurements were carried out; secondly, a baseline was not produced that could give evidence of a significant difference in the occurrence of pre-intervention happiness indicators; and finally, it should be noted that teaching new skills does not allow the design of experimental inversion designs, nor is it possible to control the independent role of social attention, as it is intrinsically conveyed by the provision of supports.

In summary, the work confirms the effectiveness of switch training in promoting functional operant behavior to choice expression in the daily life context of people with SMD. Specifically, two new repertoires were acquired: operant behaviors of switch pressures and behaviors of choice between two concurrent stimuli. Subjective satisfaction measures underlined the positive effects on personal outcomes and QoL. Deepening the reflections already present in the literature and extending them with respect to three variables: population with greater level of impairment, using motor responses of the limbs and applying in adult age.

In conclusion, we obtained encouraging experimental evidence regarding the possibility of increasing unprecedented choice behaviors in everyday contexts using switches. We anticipate that future research objectives could include providing further evidence on the efficacy and replicability of the treatment carried out, and evaluating new combinations of responses through technological aids to further promote personal development and self-determination in people with severe disabilities.

Footnotes

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Ethical Approval

The research procedures were applied in accordance with: European Responsible Committee on Human Experimentation, the Helsinki Declaration (1983) and the Single Regional Ethics Committee (CEUR).

ORCID iD

Simone Zorzi

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