Biomedical Engineering Reference
In-Depth Information
the participant's headrest, which triggered vocal systems calling different caregivers. The
caregivers interacted with the participant and presented him different stimuli. The inter-
vention program continued with the simultaneous availability of the microswitch and
VOCA systems. At that point, the participant could perform any of the responses acquired
(choosing at any occasion among four different options). Data showed that he was suc-
cessful in acquiring the microswitch and VOCA responses. The overall frequency of the
microswitch responses was somewhat higher than that of the VOCA responses.
18.5 Discussion
18.5.1 Outcome of the Studies
The positive results generally reported by the studies using microswitches and related
forms of technology such as VOCAs underline the importance of adopting these forms
of assistive technology for persons with severe/profound multiple disabilities (Lancioni
et al. 2009a, 2009b, 2009c; Sigafoos et al. 2009; Shih et al. 2010). Obtaining a successful
outcome in intervention programs such as those examined in this overview is much
more likely if a number of conditions are met. One of those conditions concerns the
response requirement (demand), which should be within easy reach for the partici-
pant. More specifically, the likelihood of success is greater if the response difficulty is
moderate (i.e., if the response is in the person's repertoire and requires a fairly low
level of effort to be performed) (Lancioni et al. 2005b, 2008b, 2010d). A second condition
concerns the stimulus events available for the participant's response(s). These events
should have a reinforcing power (i.e., should be highly preferred/attractive) and their
positive/attractive value for the participant should exceed the efforts required of him or
her to perform the response(s) (Kazdin 2001). A third condition concerns the interven-
tion length. This length needs to be tailored to the participant's learning characteristics
and essentially should be significantly longer for the participants with a more severe
(disadvantaged) condition (Kazdin 2001; Lancioni et al. 2001a, 2009a; Saunders et al.
2003; Catania 2007).
The positive outcomes, as documented above (i.e., in terms of participants' response
frequencies; see review of the studies), are the most immediate and common form of evi-
dence. Other apparently critical pieces of evidence, which were recorded only in some
of the studies, could be (1) the indices of happiness or unhappiness of the participants,
and (2) the opinion of staff personnel, family members, or other raters about the tech-
nology, its application impact and overall effects (Lancioni et al. 2006d, 2006e, 2007d,
2008b; Dillon and Carr 2007). For example, Lancioni et al. (2006d) assessed the mood
of the three children involved in a microswitch-based study, in which each participant
(child) had a microswitch to use for producing brief periods of preferred stimulation.
The results showed that two of the participants had clear increases in indices of hap-
piness during the intervention. The third participant had a decrease (a virtual elimi-
nation) of indices of unhappiness (i.e., frowning and crying) during the intervention.
Similarly, Lancioni et al. (2007d) explored the mood of nine participants ranging in age
from about 4 to about 19 years during the baseline and intervention with microswitch-
based programs. The performance of microswitch-related responses during the inter-
vention phases allowed the participants to access brief periods of preferred stimulation.
