RESNA 27th International Annual Confence

Technology & Disability: Research, Design, Practice & Policy

June 18 to June 22, 2004
Orlando, Florida


Denis Anson, MS, OTR; Cheryl Ames, OTS;
Lynn Fulton, OTS;
Megan Margolis,OTS; Maria Miller, OTS
College Misericordia
301 Lake St.
Dallas, PA 18612.


The purpose of this study was to determine the age at which children are able to use patterns of switch closures to produce desired responses in the environment. Fifty-two typically-developing children, between the ages of 2 and 8, were instructed to activate specific toys by pressing two large, colored switches in indicated patterns. Testing involved 1, 2, and 3-step patterns. By age 4, most children had both the cognitive and motor capacity to generate specific patterns for control of their environment. By the age of 5, all of the children were 100% successful. The results of this study indicate that by the age of 5, children have the cognitive ability to use patterns of switch closures to produce desired responses in the environment.


For the very young child, early development is fostered through play as the child learns new skills through exploration. By 6 months of age, infants have only a primitive understanding of cause and effect, but by 10 months they are able to recognize that their actions can make things occur in the outside world(1). Later, as the child develops a behavioral repertoire, his/her exploration of the environment involves more possibilities.

EADLs range from low to high technology and from basic to complex. One example of a basic EADL is a simple switch that activates a single device when pressed (5,2). Today, switch adapted toys are commonly used to provide control for children with physical limitations. Instead of becoming frustrated at the inability to retrieve a toy, a child would use switches to control desired toys, engage in the occupation of play, and ultimately achieve greater independence (8). Typically developing children quickly learn that different motor behaviors result in different environmental responses. Children with disabilities need to learn the same lesson, and develop a behavioral repertoire that produces a variety of outcomes. However, simply increasing the number of switches beyond a very few would be cumbersome, and would probably not provide an adequate solution.

Experience in text generation has shown that patterned closures of a relatively few switches (e.g. Morse code) can be used to allow individuals to use only a few switches to generate a large number of options. Early studies have shown that children with the ability to use language at the third grade level can use Morse for language (9). Although it has many applications, Morse code is not generally used with very young children because of its traditional utilization as a tool to generate language. It seems possible that simpler, non-language applications of switch patterning could be usable at a younger age. Patterned switch closures could conceivably allow a wide range of options for a child with very limited motor control (10, 11, 12).

The purpose of this study is to determine the age at which typically developing children are able to use patterns of switch closures to produce desired responses in the environment.



The convenience sample consisted of 52 typically-developing children divided into seven age categories. These children were all full-term children with no identified developmental disabilities. They had vision adequate to see the provided cues, and sufficient auditory acuity to follow spoken directions. Because of the rapid rate of growth and maturation of the brain in this age population, the children were grouped into twelve-month age intervals. During the study, ten two-year-olds, ten three-year-olds, eleven four-year-olds, eleven five-year-olds, five six-year-olds, two seven-year-olds, and three eight-year-olds were tested.

Control System

Because no available EADL system provided Morse code control, we created this function for our study. The control system was based on an HP Pavilion n5420 notebook computer system with a color video display. This computer ran the X-10 ActiveHome Control1 software to control power modules used to power the stimulus devices (toys). Because the Home Control software does not have a keyboard interface, it could not be directly controlled by Morse input, so we also used a macro-program, mgSimplify2, to translate keyboard commands to mouse movements and mouse clicks. Keyboard input was provided by Darci USB3, a Morse code device that connected to the laptop via the USB ports. Input to the Darci USB was provided by two “Big Red” switches4, one blue and one red. The “dah” switch was labeled with a large square corresponding to the visual cues provided to operate specific switch toys.

Controlled Devices

The study used a set of eight “power-adapted” toys. These toys were originally battery powered, but were adapted, in a manner similar to that for constructing “switch adapted” toys, to draw their power from an external power supply. These power supplies were connected through X-10 switching modules to allow the toys to be controlled remotely by the laptop computer.


Each child was seated at a table and told that they were going to be playing a game with big buttons and toys. The child sat at the table in front of the two switches, which were positioned at a comfortable distance from the child and with the toys positioned out of reach of the child and directly in front of the switches, 12 inches apart. Each toy had a card showing the pattern for its activation, as a series of red circles and blue squares, placed immediately in front of the toy and clearly visible to the child.

During the testing, the researcher pointed to the target toy and said, “Can you make the [elephant, robot, pig…] go?” If the child did not respond within 10 seconds, the second cue, “Make this [elephant, robot, pig…] go!” was given. If the child activated the correct toy, the trial was counted as a success. If the child did not respond within 10 seconds of the second cue, or activated the wrong toy, the trial was counted as a failure. At each level, the child was given up to 10 trials. If the child activated the correct toy at least 8 times (80% success), they advanced to the next level of training. If they did not achieve 80% success, they were dismissed from testing.

In the first level of testing, the child could activate one of two toys by pressing the appropriate switch one time. At the second level of testing, the child could activate one of three toys by pressing the switches in a two-step pattern selected for that toy (e.g. “circle-square” makes the elephant go). At the third level, the child could activate each of three toys using a three-step pattern.


There was no difference in performance based on gender at any of the age levels. The length of practice time was child specific and was dependent on the child's attention span and interest level.

Table 1. Percentage of Subjects Meeting Criteria for Success at Each of the Three Levels

Age Level

No. of children tested

% Successful


Level I

Level II

Level III

2 years





3 years





4 years





5 years





6 years





7 years





8 years





In this study, two-year-olds consistently demonstrated an understanding of cause and effect interaction with objects and a one-to-one correspondence between controls and devices, but their attending or motor skills were inadequate to achieve success past the first level. The three-year-old children demonstrated an emerging understanding of patterns, but still failed to consistently utilize the cue cards. Of the ten children tested, 50% were successful with two step control sequences and 20% were successful with three step commands. The results of this study indicate that a four-year-old, using modern technology and Morse code, has the cognitive ability to acquire a higher level of independence by effectively controlling their environment. In addition, by this age the children had the motor capacity to generate specific patterns for control of their environment and switch-control was no longer an issue. Of the eleven four-year-olds tested, 91% were successful in producing two step commands and 82% were successful with three step control sequences.

All children in the study of at least five-years of age were able to successfully master all three control strategies. It was noted that the five-year-olds appeared less enthusiastic in the first two stages, but became excited by the challenge presented with the three-step patterns. Five six-year-olds, two seven-year-olds, and three eight-year-olds also participated in the study and they all successfully completed all levels. The tasks were very easy for them and they appeared bored throughout the testing. The 100% success rate at the five-year-old level predicted the success of children above this age.


This study supports the use of patterns rather than devices to control EADL devices for individuals with severe motor impairments and for those with significant cognitive impairment. An individual with the physical capacity to produce only two volitional movements could still use those very limited movements to control a wide array of devices in the environment. The findings of this study suggest that children can learn to use patterns of behavior rather than simple behaviors to control their environment.


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  6. Reeson, D. J., & Ryan, M. (1988). Computer microtechnology for a severely disabled preschool child. Child: Care, Health, and Development, 14, p. 93-104.
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  10. Anson, D. K. (1997). Alternative computer access a guide to selection. Philadelphia: F. A. Davis.
  11. Jarus, T. (1994). Learning Morse code in rehabilitation: visual, auditory, or combined method? British Journal of Occupational Therapy, 57, 127-130.
  12. Wellings, D. J., & Unsworth, J. (1997, August 16). Environmental control systems for people with a disability: An update. British Medical Journal, 315, 409-413.

SMARTHOME, Inc., 16542 Millikan Avenue, Irvine, CA 92606, United States,

mgSimplify, 22298 Davenrich, Salinas, CA 93908, United States,

The Darci Institute of Rehabilitation Engineering, 810 W. Shepard Lane, Farmington, UT 84024, United States,

Ablenet, Inc., 1081 Tenth Ave SE, Minneapolis, MN, 55414, United States,

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