Microswitch- and VOCA-assisted programs for two post-coma persons with minimally conscious state and pervasive motor disabilities.
A tiny switch that turns on music or a voice device can give non-verbal, minimally conscious adults immediate control over their world.
01Research in Context
What this study did
Two adults who had been in a coma were now in a minimally conscious state.
They could not move or speak.
The team gave each person a small switch they could hit with any tiny body part.
Hitting the switch turned on a VOCA (voice-output device) that played music, showed a video, or called the caregiver.
Sessions ran like an ABAB design: first baseline, then switch on, then off, then on again.
What they found
Both adults quickly learned to hit the switch.
Their switch presses and VOCA use shot up in the "on" phases and dropped in the "off" phases.
Caregivers saw clear signs the adults were choosing on purpose.
The setup gave them real control over sound, pictures, and people.
How this fits with other research
Sarber et al. (1983) tried the same idea 26 years earlier.
They used only music with patients who were still in a vegetative state.
Results were weak for the two people who had been comatose longest.
The new study adds a switch and a VOCA, targets people who are already minimally conscious, and gets strong effects.
LAller et al. (2023) push the idea even further.
They are teaching non-verbal students with ID to read using AAC devices.
Together the papers show: once you give reliable access, you can move from simple music to full messages and even academics.
Why it matters
If you work with adults who are locked in after brain injury, try a microswitch linked to a VOCA.
Start with one loved song or video.
Watch for any tiny movement that can hit the switch.
When the client sees that their move brings the reward, responses usually grow fast.
You will have a quick, low-cost way to test awareness and give the person a voice.
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02At a glance
03Original abstract
Intervention programs, based on learning principles and assistive technology, were assessed in two studies with two post-coma men with minimally conscious state and pervasive motor disabilities. Study I assessed a program that included (a) an optic microswitch, activated via double blinking, which allowed a man direct access to brief music intervals, and (b) a voice output communication aid (VOCA) with two channels, activated via different hand-closure movements, which allowed the man to call his mother and a research assistant who provided stimulation events. Study II assessed a program that included (a) a pressure microswitch, activated via head movements, which allowed a man direct access to video-clips and music, and (b) a VOCA device, activated via prolonged eyelid closure, which allowed the man to call the caregiver (i.e., a research assistant) who provided attention and sung to him. Each of the two participants had significant increases in both microswitch- and VOCA-related responses during the intervention phases of the studies. Moreover, purposeful choice seemed to occur between the two VOCA responses in Study I. Implications of the findings for improving the situation of post-coma persons with minimally conscious state and pervasive motor disabilities are discussed.
Research in developmental disabilities, 2009 · doi:10.1016/j.ridd.2009.07.006