Psychophysiological Stress Profiling (PSP) Copyright 1995 Rob Kall,excerpted from the soon to be published Encyclopedia of Biofeedback with permission of the publisher
Stress profiling starts with a baseline and then subjects an individual to different kinds of stressors while monitoring a number of psychophysiological and other parameters. After each stressor a recovery period is allowed. The goal of the PSP is to identify stressors which produce stronger reactions and/or psychophysiological systems or behaviors which are excessively reactive. The pattern of system activation and the pattern of recovery orlack of it can be useful predictors of response to different biofeedback interventions to minimize excessive reactions and increase skills for coping with stressors which had caused excessive reactions.
The following sequence is a generic sequence which most stress profiles are based upon,. Different stressors can be incorporated as the need dictates.
Working with a post injury patient one might consider aversive imagery of the injury activity and related activities. And if pain is present, then imagery of situations which activate or exagerate the pain. If the client is an athlete, then high pressure situations, situations where poor performance has occurred, activities in which injuries have occurred or where unknown factors threaten might be considered as sources of imagery.
The basic PSP Model
Pain/Injury General PSP
The above general protocol is designed for assessing pain, stress, anxiety, post-traumatic-stress aand related clients. The goal is to identify significant stressors and the psychophysiological response patterns they elicit. The following discussion will explore what different findings for the different conditions and the interaction between the conditions suggest in the way of interpretation and and treatment planning.
You can use as few or as many signals as you wish to in evaluating your client's response to stressors. Typical signals collected include:
EMG wide frontalis placement
EMG Upper Trapezius
EMG low back
non-dominant hand temperature or skin condcutance/EDG/EDR/GSR respiration rate, thoracic excursion level, abdominal excursion level pulse/heart rate blood pulse volume (Photoplethysmograph)
Less common signals which can be used:
EEG frequency /amplitude
EMG median or mean frequency
variability of any signal
proportion between two signals (bilateral, antagonist muscles, bilateral EEG,
Pain/Injury General PSP
The first step of a stress profile is to establish a baseline. Before you get an "official" baseline for the PSP it is important to make sure the client's psychophysiology has stabilized from dramatic temperature differences outside the office, activity level (if, for example, the client ran to the office and had a rapid heart beat and was sweating profusely and
breathing fast and shallowly.) It is essential to allow the client to reach some stabilization. Usually this means sitting quietly for some time.
Different people have stated varying guidelines. The ideal is for the client to reach some stable level within the new environment. This could take as long as 15 or more minutes. If you do not wait, it is possible the findings will be tainted and misleading or dampened by the previous stimuli.
Once you are confident the effects of external stimuli, those stimuli the client had experienced outside the training environment, are worn off or stabilized, you can record baseline readings for a fixed period of time. usually the baseline period is the same or perhaps a bit longer than the average time period for each of the following stressor and recovery
One important decision to make is whether the whole PSP should be performed with eyes open or closed. It is difficult to make comparisons between phases of the PSP if some are with eyes open and some closed. The same is true for
any activities which cause muscle activity or changes in energy level.
Talking or strenuous movement, for example, produces EMG activity which is no stress related, so it is impossible to compare recovery periods or other stressor periods with those active phases. Forthis reason, my own approach is
to only record data with eyes closed and when no activity is occurring.
During times of activity or talking, data storage is paused. Once the activity or talking ceases, the recording can continue.
Evaluating the baseline information takes some practice and experience. Some parameters have normal readings across individuals to some extent, such as frontalis muscle activity. But even then it is necessary to consider the filter bandpass frequency for the instrumentation and o a mild extent for the frontalis, percent body fat. Body fat is more important when considering electrode placements over areas where excess adipose tissue tends to accumulate. When using a narrow, 100-200 Hz bandpass on the frontalis, a relaxed baseline is under three, even under two or 1.5 microvolts with eyes open. Using a wider bandpass, normal, relaxed readings are under 4 or 5 microvolts.
I invite other PSP users to send me descriptions of their approaches to conceptualizing, implementing and interpreting PSPs. I can be reached at FUTUREHEALTH 211 N. Sycamore, Newtown, PA 18940, 215-504-1700 fax 215-860-5374
or at firstname.lastname@example.org