Abstract: Objectives:Traditional habilitation recommends the use of single switch control and simple computer games as pre-training of cause-effect relationships and joystick control before training in use of a powered wheelchair. Findings from studies of individuals at an early developmental level driving a powered wheelchair suggest it may be more effective to reverse order. Methods:We studied the outcome of powered wheelchair activity in context (self-directed locomotion). Participants included 40 disabled individuals and 17 typically developed infants functioning at an early developmental level. The activity in the wheelchair was paralleled with the use of single switch controls connected both to toys and to a computer with simple “press-action” software. Results:The cognitive understanding of the simple cause-effect (use of joystick causes the effect of motion of the wheelchair) developed earlier than the understanding (press on single switch causes activation of toy or apparatus). Conclusion:The recommendation to use single switch controls as pre-training for driving a powered wheelchair corresponds with individuals with quite good cognitive function but not with individuals who function at an early developmental level. For individuals with severe or profound mental retardation the possibilities to understand cause-effect relationships are found in tools that affect all their senses, their whole body. A powered wheelchair is such a tool. When the individual activates the joystick, the wheelchair moves, affecting all senses and the individual’s position in space. This event provides arousal, interest and motivation to further manipulate and explore the cause of the effect.
Keywords: cause-effect relationships, powered wheelchair, single switch control, early developmental level, mental retardation, visual impairment
