Traumatic Brain Injury &
bbbbbbAssistive Technology
 
 

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ABSTRACT     Levine, S.P., Horstmann, H.M., Kirsch, N.L. (1992).  Performance considerations for people with cognitive impairment in accessing assistive technologies. The Journal of Head Trauma Rehabilitation,7 (3), 46-58. _____________________________________________________________________                                    Purpose     The purpose of this article is to highlight how cognitive and perceptual deficits associated with traumatic brain injury can affect an individual’s ability to operate assistive technologies, in an attempt to facilitate the development of improved criteria for the selection and the design of such devices. The article is divided into three sections. First, it reviews the cognitive and perceptual deficits associated with TBI and how those deficits affect user performance. Second, it provides examples of assistive technology techniques to focus on the cognitive and perceptual requirements needed for their operation.  Finally, the article presents a model for how to analytically assess user performance for a specific assistive technology system. This abstract outlines basic points from the article.   Review of Cognitive and Perceptual Deficits in TBI and  How They Affect Technology Use  Attention- Deficits in attention may impair an individual’s ability to learn to use an assistive technology system as well as limit the level of skill that can be achieved. Orientation-This is an individuals’ appreciation of passage of events, and awareness of self and place. Orientation is needed prior to use of, and for motivation to use an assistive technology system. Memory-Deficits in memory can affect performance. For example, an individual may forget what the message is before completely entering it into a  communication system.  Deficits in memory may also affect an individual’s ability to retrieve information from a device. Problem solving-Limitations in problem solving can affect an individual’s ability to recover from simple errors while using a device as well as will limit the degree of independence that can be achieved with the system.  An individual’s ability to learn and use assistive technologies may be affected by limitations in understanding concepts (category membership, similarities, etc.).  Perceptual and analytic abilities-This includes nonverbal thinking skills that require interpretation or manipulation of spatial and congifural information. Deficits in this area may affect an individuals' ability to safely maneuver a wheelchair through his/her environment, or to find and select pictures on the display of an augmentative communication system. Social reasoning-This includes the ability to recognize and/or engage in socially appropriate behavior, to see things from another’s perspective, and to respond differently to particular social behaviors according to the context in which they occur. An example of a deficit in social reasoning would  include an individual’s inability to judge the danger of driving their powered wheelchair very close to  another person.  Executive abilities-This includes the ability to plan, organize, and form strategies for problem solving, and then self-evaluating how a task is carried out. Deficits in executive abilities affects an individual’s understanding of how the assistive technology can be useful, as well as affects an individual’s ability to initiate the use of their device, and to determine how the device could be used more efficiently.     Examples of Assistive Technology Systems and the Cognitive and Perceptual Skills Needed to Operate Them Example #1     Many augmentative communication devices use "scanning" that accepts input from a switch.  The cognitive and perceptual skills needed to successfully use a scanning device include: -understanding the selection strategy -responding appropriately to visual cues, under specified time constraints -keeping the message context, word, and specific icon in mind -visually searching the letter array and identifying the location of the desired icon -for operation of multiple levels of scanning, the individual must also remember or determine the current level as well as methods for changing between levels   Example #2     One common type of power wheelchair control for people with severe motor limitations is "sip-and-puff" control.  In this system, the switches are activated when the individual produces air pressure with their mouth movement. The cognitive requirements necessary to use this system include the individual’s understanding of the different levels of sips and puffs and how they relate to the speed and direction of the wheelchair. It may be difficult for the user to develop automaticity and therefore may require a high level of concentration while operating. This may cause distraction for the individual when they must perform tasks simultaneously, such as perceiving and avoiding obstacles while driving the wheelchair, and controlling the "sip-and-puff." Modeling of Performance      In the remainder of the article, an augmentative communication technique called "word prediction" is presented in an attempt to illustrate how an assessment can be made of the cognitive, perceptual, and motor skills required for its use. A trade-off involved in word prediction is that decreasing the number of movements in typing may increase the time required to make each selection because of the increase in cognitive and perceptual requirements. To determine what effect this trade-off has on overall performance (i.e., is word prediction time saving or actually time consuming when perceptual and cognitive deficits are involved), the article addresses three main questions through analytical research:     What are the factors that contribute to an increase in selection time? What are the time requirements associated with each of these factors? Can a crossover point between rate enhancement and rate inhibition be defined? Implications     The examples in this article and the modeling example for measurement of benefits versus costs of enhancing motor abilities when cognitive and perceptual deficits are involved, present practical implications. First of all, they help increase clinicians and users awareness of costs that may be introduced with various devices. These examples may also provide balance to manufacturers’ claims that a device increases efficiency/ability for anyone who uses it, they can help users make more informed decisions, and may help to produce significant design improvements for various devices. Research of tradeoffs can help to produce a better understanding by both technology developers and clinicians about the issues surrounding optimization of performance with assistive technology.