The paper recommends an acceptable methodolog> for recording electrodermal activity which reflects a consensus of experts in the field. These recommendations are presented with a minimum of technical discussion in order to maximize their usefulness to investigators who are not specialists in this area.For most purposes, skin conductance (SC) is to be preferred over skin potential (SP). It is recommended that SC be recorded from palmar sites with silver-silver chloride electrodes and an electrode paste consisting of a sodium chloride electrolyte in a neutral ointment cream medium. The area of contact with the skin should be controlled and time allowed for stabilization ofthe skin-electrode paste interface. Electrode bias potentials and polarization should be monitored during use. Signal conditioning is achieved by the application of a constant 0.5 volt across the electrodes and measurement of the resultant current flow by amplifying the voltage developed across a small resistor in series with the skin. The measurement ofthe amplitude-or even the detection-of small responses requires some form of tonic level control, permitting an adjustment of the tonic level. A circuit is provided for signal conditioning and tonic levei control.SP can be recorded with the same electrodes and electrode paste, unless the results are to be related to the British work on SP level, in which case the original potassium chloride electrolyte in an agar medium should be used. SP recordings require that one of the electrodes be placed over an inactive reference site, preferably over the ulnar bone near the elbow. No external voltage is applied, but some form of tonic level control may be needed. Electrodes need to be checked for bias potentials but not polarization. DESCRIPTORS: Skin conductance measurement. Skin potential measurement, Electrodermal measurement.The investigator who wishes to record electrodermal activity is faced with a bewildering number of choices as to the methodology to be employed. In some cases the alternatives are equally acceptable, whereas in other cases a poor choice can produce invahd results. At the request of the Editor, David Shapiro, a committee was formed for the purpose of setting forth an acceptable methodology for recording electrodermal activity which reflects a consensus Address requests for reprints either to Don C. Fowles. Department of Psychology. The University of Iowa. Iowa City. Iowa 52242; or (for requests from Europe) to Peter H. Venables. Department of Psychology. University of York. Heslington. York. YUl 5DD. England. of experts in the field.' It is hoped that doing so will accomplish two purposes: 1) to provide guidance for those investigators who are not experts in electrodermal methodology, and 2) to foster some degree of standardization. This second purpose should not. however, be overemphasized, as it is not our intention to dictate a specific method to seasoned investigators who have good reasons for using other techniques. Nevertheless, some degree of standardization is desira...

Heart rate variability biofeedback had strong long-term influences on resting baroreflex gain and pulmonary function. It should be examined as a method for treating cardiovascular and pulmonary diseases. Also, this study demonstrates neuroplasticity of the baroreflex.

No abstract

Recent evidence, particularly in research on the skin conductance orienting response (SCOR) in schizophrenia, suggests that differences in scoring criteria may be important sources of error and variability in studies of electrodermal responses to discrete stimuli and their habituation. Although a wide variety of response latency criteria have been used in published studies, empirical evidence suggests that responses occur in a narrow and early post‐stimulus time window. Data are presented demonstrating that the intra‐subject variability of response latency is low when responses are scored within a narrow time window, but that broader time windows include more variable‐latency responses that may represent spontaneous activity. The commonly‐used criterion of three no‐response trials as an habituation endpoint may also introduce contamination by spontaneous activity; available evidence favors a two‐trials criterion. Analyses such as the ones presented here permit testing of the specificity of scoring criteria for responses elicited by experimental stimuli.

Two experiments compared finger plethysmograph (FP) to electrocardiogram (ECG) in providing accurate heart periods for use in heart rate variability (HRV) calculations. In Experiment 1, simultaneous ECG and FP recordings were taken from 16 healthy subjects at rest. In Experiment 2, 10 additional healthy subjects were recorded at rest and during the Stroop Color-Word Test. In both studies, high correlations were found between FP-derived and ECG-derived band variance for high and low frequency HRV at rest. But, during the Stroop task, correlations were strongly diminished. In addition, under both conditions, HRV measures were significantly higher using the FP signal. Thus, FP may be adequate for determining HRV at rest, but, for experimental use, ECG may still be recommended. Nonetheless, further studies that include test-retest reliability assessment of both data collection techniques are warranted before a more certain determination can be made.

The hot flush (or flash) is the most widely reported menopausal symptom. Anecdotal reports suggest that women experience more hot flushes when stressed. Although stress may actually trigger hot flushes, another possibility is that women under stress may be more aware of the physiological changes associated with flushes and, therefore, more likely to report them. The goal of this study was to test these hypotheses by investigating the association between stress and both objective (i.e., physiologically recorded) and subjective hot flushes. Twenty-one postmenopausal women who reported having frequent hot flushes each underwent psychophysiological monitoring during stressful and nonstressful laboratory sessions. Significantly more objective flushes were recorded during the stress session than during the nonstress session. The stress manipulation, however, did not affect subjects' propensity to report flushes. These results suggest that the observed association between reported hot flushes and stress is not due to changes in report bias. The physiological mechanisms through which stress may stimulate hot flushes are discussed.

Interpretation of cutaneous electrical measurements in terms of structure or function requires special techniques for identifying the separate contributions of the various elements. Resistance measures have different implications depending upon whether the subject is sweating and whether the electrode preparation is wet or dry. Microelectrode measurement indicates that the stratum corneum and other epidermal layers represent a significant pathway for ion conductance. Impedance measurement allows estimation of skin capacitance and of the thickness of the capacitative element. When applied to data on excised stratum corneum, this analysis indicates the presence of a relatively impermeable layer less than 2 microns thick, a conclusion subject to some doubt because of uncertainty over the dielectric constant of wet keratin. The use of impedance measurement with closely spaced electrodes gives an indication of the hydration of the superficial horny layer and also demonstrates reabsorption of sweat from this region. Potential measurement at the surface reflects the relative internal resistance of two parallel sources, the sweat glands and an "epidermal generator."

To distinguish between goal‐orientation and the attending activation as causes of acceleration of electrodermal recovery, 16 subjects were examined during task performance and during an activating, non‐task condition, cold pressor. Recovery limb time constants (tc) were significantly related to two activation measures, electrodermal frequency (EF) and skin conductance level (SCL). EF, SCL, and change in log conductance were similar for cold pressor and mirror tracing despite significant differences in tc values. Since, in addition, tc decreased with better performance and with increasing task complexity, goal‐orientation is considered the primary determinant of acceleration of recovery. There are characteristic individual differences in recovery rate which are relatively stable over 5 consecutive weeks. Rate constant, the reciprocal of tc, has more uniform variance and is preferred for parametric statistical analysis. A warning of shock introduced during a reaction time series caused slowing of recovery. This coupled with slow recovery during cold pressor suggests that enhanced electrodermal activity with retarded recovery may signal a defensive reaction.