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

Comparison of synchronous reinforcement and accumulated reinforcement for increasing on-task behavior in preschoolers

In synchronous-reinforcement schedules, the duration of behavior directly controls the duration of reinforcement on a moment-to-moment basis. We replicated and extended Diaz de Villegas et al. (2020) by comparing the effects of synchronous reinforcement with two accumulated-reinforcement schedules for increasing on-task behavior for seven preschoolers. One accumulated schedule was the same as the one used in Diaz de Villegas et al. and did not include tokens, whereas the other accumulated schedule included the delivery of tokens within session. Furthermore, we assessed preference for the three reinforcement schedules. The results showed that synchronous reinforcement was effective for increasing on-task behavior for all seven participants. Furthermore, it was most effective for increasing on-task behavior for three out of seven participants and preferred by all participants. For some participants, other schedules were also similarly effective. The results are discussed with respect to implications for application.

Teaching Individuals to Signal for Assistance in a Timely Manner

The study describes the adaptive-switch performances of 8 adults with severe multiple impairments. Each was given a series of progressively more difficult discrimination tasks that, if solved, would require the participant to close the switch to activate a device that was not operating or to stay away from the switch if the device was operating. Then in a 2-choice format, a preference test was conducted by providing 2 devices simultaneously that could be activated or deactivated by closure or release of the switch. Finally, a preferred device was activated and then surreptitiously deactivated. Switch closures in this contingency activated a speech-generating device that played the message, "Help me." All 8 participants learned to control devices using their adaptive switch, but only 4 participants learned to make a request for help. Reasons for the different performances across learners and nonlearners are discussed.

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.

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.

Innovation of a reinforcer preference assessment with the difficult to test

In this study, we continued evaluation of a two-choice preference assessment aimed at identifying a hierarchy of reinforcers for individuals with only one voluntary motor sequence-closing and releasing an adaptive switch. We assessed preferences among types of sensory stimulation in 6 adults with multiple profound impairments using concurrent synchronous reinforcement contingencies. Pre-experimental assessments with various types of stimulation led to the selection of music (A), vibration (B), and either olfactory or visual stimulation (C) as the 3 modalities for continued testing. Each participant received opportunities for familiarization with each type of stimulation in blocks of six 20-min sessions in which the closure of an adaptive switch produced the stimulation for as long as the switch remained closed. Next, participants could choose between pairs of types of stimulation in blocks of 12 sessions. In the first 6 of the 12 sessions, switch closure activated one type (e.g., A) and switch release activated the contrasted type (e.g., B). In the second 6 sessions, the contingencies were reversed. Two additional 12-session blocks completed all possible contrasts (AB, BC and AC). Four of the 6 participants showed distinct preferences in these two-choice tests with indications of preference hierarchies. The results demonstrate a method for obtaining indications of relative preference for potentially reinforcing stimuli from individuals without communication and without the abilities to act on more than one switch.

A learning setup for a post-coma adolescent with profound multiple disabilities involving small forehead movements and new microswitch technology

PURPOSE

A learning setup was arranged for an adolescent with profound multiple disabilities and a diagnosis of vegetative state. Signs of learning by the adolescent would underline an improvement in his immediate situation with potential implications for his general prospect, and could help revise his diagnosis.

METHOD

The response adopted in the learning setup was forehead skin movement. The microswitch technology used for detecting such a response consisted of (a) an optic sensor (i.e., barcode reader), (b) a small tag with horizontal bars attached to the participant's forehead, and (c) an electronic control system that activated stimuli in relation to the participant's forehead responses. The study followed an ABABACAB sequence, in which A represented baseline periods, B intervention periods with stimuli contingent on the response, and C a control condition with stimuli presented non-contingently.

RESULTS

Data showed that the level of responding during the B phases was significantly higher than the levels observed during the A phases as well as the C phase, indicating clear signs of learning.

CONCLUSIONS

Intervention strategies based on a learning format and suitable technology might be useful to improve the situation and prospect of persons with profound multiple disabilities and a diagnosis of vegetative state.

Increasing Communication in Children With Concurrent Vision and Hearing Loss

Nine children with complex communication needs and concurrent vision and hearing losses participated in an intervention program aimed at increasing intentional prelinguistic communication. The intervention constituted a pilot, descriptive study of an adapted version of prelinguistic milieu teaching, hence referred to as A-PMT. In A-PMT, natural gestures and vocalizations were targeted in child-focused, one-on-one activities conducted by a member of the project staff. Adaptations included using more physical prompts than in other forms of PMT and using means other than directed eye gaze to determine directionality of gestures. All nine participants increased their rates of initiated, intentional communication substantially during the course of intervention; in addition, each participant acquired new forms of natural gestures. Results were limited primarily to requests (as opposed to other communication functions). Discussion centers on how to promote more generalized communication developments in future implementations of the program.

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.

Promoting foot–leg movements in children with multiple disabilities through the use of support devices and technology for regulating contingent stimulation

The present study assessed the possibility of promoting pre-ambulatory foot-leg movements in children with multiple disabilities by motivating their action through contingent stimulation combined with a support device. Two children aged 10 and 8 years participated. Microswitch technology (i.e., pressure sensors under the shoes or optic sensors at the front-inner side of the shoes) served for detecting the foot-leg movements and providing contingent stimulation on their occurrence. Sensor activation produced 5 s of stimulation during intervention. Data showed that both children had significant increases in foot-leg movements during the intervention phases. Implications of the data in terms of skill acquisition and further intervention prospects are 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.

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.