Use of Laser Pointer for Sustaining Ambulation

We next looked at using the laser pointer alone to both initiate and sustain ambulation. As far as we know, no previous study has looked at this stimulus source as a cue for kinesia paradoxa.

T.R. was accustomed to stepping over visual cues. This poses two problems when used in conjunction with the laser pointer. The first is that when one steps on the spot, it will appear on top of one's foot, which destroys the illusion of an obstacle needing to be stepped over. At some inconvenience, this can be dealt with by turning the laser pointer off at the appropriate moment.

A more serious problem is that after one has stepped over the laser pointer spot one no longer has a visual cue in front of one. Consequently, one has to stop to redirect the laser pointer.

Under the guidance of one of the researchers (D.A.), T.R. learned to step to the laser pointer spot, rather than over it. This kept the laser pointer spot continually in front of him, and therefore allowed the smoothest gait we had seen to this point in the study with non-tangible cues.

A drawback of the laser pointer discovered at this point was that it is not visible outside in bright sunlight.