Biofeedback

Description of the Strategy

Biofeedback is the process of monitoring some biological event with an instrument designed to provide real-time information about the activity of that event to the person being monitored. In the clinical setting, it is the therapist's responsibility to know what biological event should be monitored and fed back to the client. The therapist must also help the person use the information correctly to change behavior.

The strategy is to use a sensor to measure some biological process. Sensors may be electrodes, such as an EKG electrode, or a temperature probe, or a specifically designed sensor used for detecting an ongoing biological process. Sensors must be able to detect small changes in the physiology in real time and continuously.

The sensor is connected to an instrument through which the physical event is changed into some display that is meaningful to the person being monitored. This display is the feedback signal. It is the task of the person to relate the changes in the display to what they might be doing that is changing their physiology. Today, most instruments use computers and specialized software to generate the display on the video screen and/or generate an audio signal that relates the level of the activity of the physiological event. The necessary feature of the monitoring process is that the equipment is sensitive to small changes in the biological event so that even small changes can be displayed as major changes on the display. An example is the equipment used today to measure finger skin temperature, which can detect a 10th of a degree or smaller change in skin temperature. While most people can tell you whether their hands feel cold or warm, few, unless previously trained in skin temperature regulation, can accurately tell you whether their finger skin temperatures have changed one or two degrees. Yet the sensitivity provided by the system can let persons know not only whether they have relaxed a small amount, which will cause an increase in finger skin temperature, but also that they are starting to do the correct response. The provision of this very sensitive feedback signal allows the person to gain control over the biological process by building on these small changes.

Clinical biofeedback requires accurate measurement of various physiological processes while providing client feedback that is sensitive to small changes in their physiology. It is necessary to also provide instructions to the client about proper interpretation of the feedback signal and to emphasize why changing the physiology will treat the condition. Generalization of what is learned in the clinic to the client's home, work, and social environments is also necessary.

Most biofeedback systems are computer interfaced so the feedback signal can be both visual and auditory. The visual feedback is limited only by the type of graphics available on the computer. The signal can be as simple as a line graph, in which the status of the physiology is depicted by a line that moves across the screen at some predetermined speed and the height of the line carries information about the level of the physiological event. This is one of the simplest types of feedback and looks like a typical graph. In other instances, feedback may be entertaining. This type of feedback is often a video game in which the progress of the game is based upon the level of the physiological event. An example would be to have a puzzle in which the pieces are arranged out of order on the display and the pieces start coming together when the [Page 180]physiological event reaches predetermined levels. In these instances, feedback is not only informative, but provides an incentive for the client to change physiology in order to “play” such games.

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