Data tended to be positive with increases in the participants' indices of happiness, but some failures also occurred. The outcomes were discussed in relation to (a) methodological issues, such as designs of the studies, length of the intervention, and number of participants, and (b) personal and practical implications of the procedures. Some suggestions for future research (particularly focused on extending evidence and overcoming present methodological weakness) were also examined.

All students showed an increase in the frequency of the target response during Intervention I and in the percentage of times the response occurred in combination with appropriate posture during Intervention II. These changes lasted over time. The importance of microswitch clusters to enhance the performance of students with multiple disabilities was underlined.

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.

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.

We assessed the effects of automatically delivered favorite stimulation on engagement and indices of happiness of two adults with multiple disabilities during their use of a stationary bicycle. The participants typically received four 5-min. sessions per day over a period of about 3.5 mo. Analysis showed that one participant had a significant increase in both those measures while the other participant had a significant increase in engagement during the intervention phases of the study (when the stimulation was present) as opposed to the baseline periods (when the stimulation did not occur). Implications of the findings are discussed.