Electrodermal Measurements Research Articles

Electrodermal Activity of Auricular Acupoints in Pediatric Patients With Functional Abdominal Pain Disorders.

Functional abdominal pain disorders (FAPD) affect approximately 13.5% of children. Pharmacotherapy is often ineffective, leaving providers, and families seeking adjunctive therapies. Auriculotherapy provides treatment for pain and other symptoms, without a defined protocol for FAPD. A handheld point-finder device measuring transdermal electrical current determines active acupoints, with a higher current indicating a more active acupoint. Our objectives were to determine auricular acupoint (AA) activity in FAPD and to assess participants' attitudes towards auriculotherapy. This is a prospective double-blind study evaluating the electrodermal activity of AAs in pediatric-aged female participants with FAPD compared to healthy controls (HC). Participants completed surveys regarding demographics and interest in auriculotherapy. The electrodermal assessment evaluated 20 AAs per ear using a point-finder device. Each AA current measurement was analyzed by average relative rank and median, with a median current measurement ≥50 μA considered active. We enrolled 46 female participants, 22 FAPD (mean age 15.8 years) and 24 HC (mean age 15.4 years). In FAPD, 12 of 40 AAs were active, of which only six were also active in HC. Comparison of median current and average ranking between participants demonstrated consistency. In the post-assessment survey, 86.4% of FAPD expressed interest in receiving auricular acupressure and 68.2% would travel to the clinic solely for treatment. Based on electrodermal measurements, we propose a treatment protocol using auriculotherapy for FAPD symptom-management. We demonstrated there is considerable patient interest in auriculotherapy. Further studies are needed to confirm the findings in a larger sample size and validate the efficacy of this treatment protocol.

Examination of electrodermal and cardio-vascular reactivity in virtual reality through a combined stress induction protocol

In this study, task-related stress induction through Stroop task and social stress induction protocol based on elements of Trier Social Stress Test are examined. The aim of the paper is to find the optimal combination of social and task-related stress to be used to consistently and reliably induce a stressful reaction. In total 16 healthy subjects participated in this study that seeks to find and compare the different stressors and their relation to physiological reactivity. Our findings show that electrodermal activity measurements are suitable when using a combination of stressors while heart rate and Root Mean Square of the Successive Differences highlight a greater reactivity to task-stress.

The Power of the Omega Points and Their Direct and Reciprocal Meanings: A Clinical Monocentric Prospective Study of 250 Cases.

Objective: Three Omega points on the human auricle were first described by Paul Nogier, MD, of France. Each Omega point theoretically represents a different embryologic tissue layer, with a correspondence to specific physical body attributes and certain emotional developments. Maurice Verdun, MD, and René J. Bourdiol, MD, developed the use of distinguishable anthropobiometric parameters and specific psychologic tests to classify a large clinical population into 4 categories that have both somatic and emotional features. The categories were: (1) normosome (normal); (2) leptosome (willowy); (3) pycnosome (rotund); and (4) athletosome (athletic). Dr. Bourdiol hypothesized that these biopsychomorphotypologic variations resulted from subtle overexpression of one of the three embryologic tissues during embryological development. Dr. Nogier and David Alimi, MD, both theorized that the three embryologic tissue layers are represented on the external ear by the 3 different Omega points: (1) Omega; (2) Omega 1; and (3) Omega 2. The expression of these points can be found by their electrodermal potentials. The aim of this survey was to find a unifying method to determine if all the clinical assessments observed from varied disciplines and different researchers could lead to a consistent theoretical perspective on the embryologic basis for auriculotherapy. Materials and Methods: The electrodermal potential of the 3 auricular Omega points were measured on 250 patients who requested auriculotherapy since the beginning of this survey, which began in February 2010. The patients were classified as normosome, pycnosome, leptosome, athletosome, athleto-leptosome, athleto-pycnosome, and dysmorphic. Electrodermal measurements of the Omega points on individual patients were compared to the phenotypical expression related to the theoretical expression of the embryologic tissues. Results: There was a prominent concordance between overexpression of an Omega point and the morphotype of an individual patient in 90% of the cases. In particular, there was a concordance between overexpression of an Omega point and the psychoemotional type in 92.4% of the cases. Conclusions: The clinical assessments of Drs. Verdun, Bourdiol, Nogier, and Alimi were supported by the electrophysiologic measurements of auricular reflex points. The original hypothesis of Dr. Bourdiol regarding anthropobiometric qualities was in concordance with the data obtained in this research. The Omega points have not only fundamental correspondences related to anatomical and physiologic embryogenesis but also are connected to a more-abstract significance related to a person's higher-order cognitive and emotional development.

A Guide to Cleaner Electrodermal Activity Measurements

Valid electrodermal measurements ensure the integrity of client assessment and biofeedback training. Accurate measurements require understanding of the signal and potential artifacts (sources of contamination) and developing “bulletproof procedures.” Peper, Shaffer, and Lin have recommended the following guidelines for ensuring accurate psychophysiological monitoring: (a) understand the physiological mechanisms that generate the signal, (b) always record and inspect the raw signal because this will allow you to identify artifact, (c) question whether displayed values make sense (e.g., skin conductance levels that rapidly fluctuate, exceed 40 μS/cm2, or fall below 1 μS/cm2 should be suspect in a client who is sitting quietly), (d) recognize the appearance of common artifacts and how they alter derived measurements, and (e) intentionally create artifacts so that you can better recognize them (e.g., rhythmically move the fingers attached to a skin sensor, loosening or tightening the sensors if they are attached with the Velcro® finger straps, and review both the raw signal and calculated skin conductance values). This article reviews the anatomy and physiology, measurement procedures, sources of common artifacts and their control, tracking test for recording electrodermal activity, and common response patterns.

Application of photoluminescent bioceramic material for different chronic illnesses by selecting "trigger points" and "propagated sensation along meridians" phenomenon.

To investigate the practicability on the processes of selecting "local tenderness skin points (trigger points)" and "propagated sensation along meridians" (PSM) phenomenon, and to find out the corresponding abnormal meridian channel in different illnesses. Ten patients with different kinds of chronic illnesses were administered photoluminescent bioceramic material (PLB) irradiations on meridians. The processes of selecting trigger points and PSM phenomenon were carried out on 80% (8/10) of the cases to find out the corresponding abnormal meridian channel in different illnesses. There were 8 cases identified by trigger points selection; 3 cases identified by PSM; 2 were not identified by either trigger points or PSM. These 2 cases were tested with electrodermal measurements of the 24 Ryodoraku meridian points to select their corresponding abnormal meridian channels for PLB irradiations. Objective and subjective Clinical improvements after PLB irradations were recorded. After PLB treatment, patients showed different noticeable improvements upon clinical observations. The most significant improvements were noticed shortly after subacute stage at 3-5 months durations of illnesses. Objective measurements showed a clinical improvement of 43.8%. To explain our clinical observations, we simply deduced that PLB treatment induced or promoted fluid/water diffusion along meridian channels. There was a gradually dredging of the meridian channels thus relieving stagnation and a vital change in the flow of dynamic patterns of meridians. This conforms to, or validates, the old traditional Chinese theory of "Bu Tong Ze Tong" and "Tong Ze Bu Tong", that is, where there is obstruction, there is pain; where there is no obstruction, there is no pain.

Inter-operator Variability of Electrodermal Measure at Jing Well Points using AcuGraph 3

Recent studies have found that many factors, both biological and operator induced, influence electrodermal measurements. Here, we report on operator variability for a series of measurements made by four operators at Jing-Well points on 132 individuals of both sexes (68 males and 64 females) by using the AcuGraph 3 ‘Digital Meridian Imaging Tool’: Operator 1 (16 males, 12 females), Operator 2 (18 males, 13 females), Operator 3 (15 males, 21 females), and Operator 4 (19 males, 18 females). The individuals studied were attending a yoga therapy program for type 2 diabetes mellitus and were assessed on the 1st day of treatment. Large inter-operator variations in overall acumeridian energy readings were observed. For individual meridians, the AcuGraph 3 measure differed by up to 42 points for minimum values and 67 points for maximum values. After normalization, the data showed similar patterns between different acumeridians. This suggested that variations were caused by operators applying different pressures when making measurements. Thus, inter-operator variability should be considered when interpreting electrodermal measurements made by several different operators. Unless inter-operator variability is taken into account, actual values may not have meaning; only then can readings for the same population taken by different operators be evaluated correctly.

Effects of yoga practice on acumeridian energies: Variance reduction implies benefits for regulation

Background and Objective:This paper concerns mechanisms responsible for the efficacy of yoga medicine, traditionally attributed to the enlivenment of prana. Our strategy was to investigate levels of Qi in acupuncture meridians, since Qi is usually considered equivalent to prana.Materials and Methods:Electrodermal measurements at acumeridian endpoints (Tsing points) were made on 32 healthy individuals, pre and post 3 weeks yoga lifestyle program using AcuGraph 3 (an instrument in wide use). A previous study found that inherent errors prevent AcuGraph from precisely evaluating Qi energies in single meridians, so group results are reported: (a) Energy levels, (b) energy stability, and (c) energy balance between (i) Yin/Yang meridians, (ii) upper and lower, and (iii) left and right regions of the body.Results:Significant improvements were observed in all but energy stability, supporting the ideas that yoga enlivens prana, and that balance in meridians constitutes health. For balance variables, the study observed shifts toward normal at both ends of variable distributions, reducing standard deviations: post-intervention percentages of subjects with values in the ‘healthy’ range increased.Conclusion:Yoga improved regulation of Qi levels in acumeridian meridians as well as increasing them.

Publication recommendations for electrodermal measurements

This committee was appointed by the SPR Board to provide recommendations for publishing data on electrodermal activity (EDA). They are intended to be a stand-alone source for newcomers and experienced users. A short outline of principles for electrodermal measurement is given, and recommendations from an earlier report (Fowles et al., ) are incorporated. Three fundamental techniques of EDA recording are described: (1) endosomatic recording without the application of an external current, (2) exosomatic recording with direct current (the most widely applied methodology), and (3) exosomatic recording with alternating current-to date infrequently used but a promising future methodology. In addition to EDA recording in laboratories, ambulatory recording has become an emerging technique. Specific problems that come with this recording of EDA in the field are discussed, as are those emerging from recording EDA within a magnetic field (e.g., fMRI). Recommendations for the details that should be mentioned in publications of EDA methods and results are provided.

Chronic Disease: Are We Missing Something?

Chronic Disease: Are We Missing Something?

Electrodermal measurements for monitoring the effects of a qigong workshop.

Electrodermal measurements with a Ryodoraku instrument were used to monitor the effects of a 2-day qigong workshop on the body energy of participants. Measurements were made of the relative electrical conductivity of 24 acupuncture points on the wrists and feet of 29 subjects. Each subject was measured in the morning and afternoon of each day, and the subjects served as their own control. The standard deviation of the mean values of the Ryodoraku responses of individuals and of the group were less in the afternoons than in the mornings with p-values of 0.004 and 0.0001 for the first and second days, respectively. The decreases in the values of the standard deviations indicate that the balance of the body energy of individuals and the group had improved, presumably as a result of the workshop. We also found that all Ryodoraku responses were significantly greater in the afternoons than in the mornings, a result that is attributed to a circadian rhythm. The improved balance of qi energy in the body of the participants indicates that qigong practice has the potential to improve health. Electrodermal measurements for monitoring Eastern and Western therapies are discussed.

Gender differences in cardiovascular and electrodermal responses to public speaking task: the role of anxiety and mood states

Gender moderates psychophysiological responses to stress. In addition to the hormonal background, different psychological states related to social stressors, such as anxiety and mood, could affect this response. The purpose of this study was to examine the existence of gender differences in the cardiovascular and electrodermal responses to a speech task and their relationship with anxiety and the mood variations experienced. For this, non-specific skin conductance responses (NSRs), heart rate (HR), and finger pulse volume (FPV) were measured at rest, and during preparation, task and recovery periods of an academic career speech in undergraduate men ( n=15) and women ( n=23), with assessment of changes in the state version of the State–Trait Anxiety Inventory (STAI-S) and in the Profile of Mood States (POMS) questionnaires. Men and women did not differ in trait anxiety, hostility/aggressiveness, or in the appraisal of the task, which were evaluated with the trait version of the State–Trait Anxiety Inventory (STAI-T), the Buss and Durkee Hostility Inventory (BDHI), and a self-report elaborated by ourselves, respectively. Women had higher FPV in all periods except during the task, and were more reactive to the stressor in state anxiety, and in the amplitude of NSRs. No gender differences for HR and for the frequency of NSRs were found. Anxiety and mood states were differently related to cardiovascular and electrodermal measurements in men and women. Further studies should consider the hormonal variations in addition to the psychological dimensions, in order to offer a more integrative perspective of the complex responses to stress.

The use of DC electrodermal potential measurements and healer's felt sense to assess the energetic nature of qi.

Because DC electrodermal potential measurements do not involve introducing a current into the body, it was postulated that temporal fluctuations in DC potential values on acupoints would be a useful method for assessing the subtle energetic changes of qi. DC potential measurements from acupoints and nonacupoints were therefore compared when energy healing practitioners were in an external focus state, were healing at a distance (external qi), or were self-healing (internal qi). The results show statistically significant differences between measurements obtained on and off acupoints and between external focus and healing states. Subjects' report of felt sense of the flow of qi moving in their body also correlated with DC potential readings, but only those readings taken on acupoints. The results support the hypothesis that pattern information from temporal fluctuations in DC potential electrodermal measurements reflects the movement and/or amount of a physical, electrical activity that corresponds to the traditional Eastern concept of qi circulating in the body.

Cognitive performance, electrodermal activity, self-rated mood and symptomatology in medicated and unmedicated anxiety disorder patients

A comparison was made between medicated and unmedicated anxiety disorder patients referred to an anxiety clinic for evaluation because prior treatment had been without effect. Thirty patients, half of whom were medicated (mostly benzodiazepines and antidepressants), and twelve healthy controls were included in the analysis. The groups were compared on self-report questionnaires, cognitive performance tests, and electrodermal measurements. On cognitive tests, delayed memory of both verbal and visual material was significantly poorer in the anxiety patients compared with controls. On immediate recall and subsequent learning in the visual test, the medicated patients were the most affected. No differences between medicated and unmedicated patients were found on autonomic responding, psychiatric symptomatology and psychological trait and state variables. Electrodermal responding and trait anxiety scores, however, were more reliable in the medicated group, as indicated by 1 week test-retest correlations. Although speculative, it is suggested that the response pattern in the medicated group to some extent could compromise a subsequent psychological treatment programme.

Electrodermal lability and hypertension

Thirty-nine (39) middle-aged subjects with mild to moderate hypertension (WHO stages I–II) and 35 healthy normotensive controls from a community sample participated in this psychophysiological study, the aim of which was to study whether the electrodermal lability as an indicator of increased sympathetic activity is related to hypertension. Resting blood pressure was measured by using a mercury sphygmomanometer. Electrodermal activity was recorded with a constant voltage circuit. Bipolar skin electrodes were placed on the palmar side of the middle phalanges of the index and middle fingers of both hands. Six years after the electrodermal measurements, the possible use of reimbursed antihypertensive medication was checked in both groups, and blood pressure re-measured in the control group. Multivariate analysis controlling for age, gender and body mass showed that the electrodermal lability was increased in the hypertensive as compared to the normotensive group. This supports the hypothesis that the sympathetic nervous system tonus is increased at least, in some middle-aged subjects with mild to moderate hypertension.

Electrodermal lability in anxiety disorders.

Twenty-eight anxiety patients, aged below 50 years, were diagnosed according to DSM-III-R criteria (panic disorder with and without agoraphobia, generalised anxiety disorder, and anxiety disorder not otherwise specified). The patients were characterised by high levels of state and trait anxiety and neuroticism, compared with the controls. However, there were no differences between patients and controls in electrodermal habituation rate, non-specific activity, or skin resistance level. When the patients were divided into electrodermally labile and stable subjects, significant differences were found between patients and controls in both electrodermal activity and Eysenck's personality dimensions. The labile patients were more introverted and attained higher psychoticism scores than either the stable patients or controls. Duration of anxiety symptoms removed the difference found in extroversion, but not in any other variable. The results are discussed in relation to the utility of electrodermal measurements in validation of diagnostic entities. It is concluded, that from the psychophysiological point of view, anxiety disorders may be examined within a dimensional framework.

A practical and experimental comparison of electrolytic gels used in electrodermal measurements

A practical and experimental comparison of electrolytic gels used in electrodermal measurements

Committee report. Publication recommendations for electrodermal measurements.

ABSTRACTThe paper recommends an acceptable methodology 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 of the 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 of the 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 level 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.

Electrolyte medium effects on measurements of palmar skin potential.

ABSTRACTTwo experiments with 12 subjects each compared skin potential recordings taken simultaneously with four different electrolytes. These were polyethylene glycol, hydrated agar (at a site presoaked with water), fresh agar (i.e., not presoaked), and Unibase. The glycol controlled epidermal hydration at a minimal level, while presoaking produced a high level of hydration at the hydrated agar site. Fresh agar and Unibase represented normal recording conditions for these two electrolytes which have been recommended as “standard” for electrodermal measurements. This design permitted a comparison of two standard electrolytes with each other and with recordings from hydrated and unhydrated sites. These comparisons were made for both monophasic negative SPRs and positive SPRs and the prestimulus levels associated with each.The results replicated previous studies in showing a large effect of epidermal hydration on skin potential measurements. Recordings with agar and Unibase did not differ significantly. The effects of hydration were interpreted in terms of a reduction in the resistance of the stratum corneum and of alterations in the functioning of the dermal and epidermal membranes as a result of blockage of the sweat gland pore. In the light of this interpretation, it was suggested that both agar and Unibase substantially alter the functioning of the sweat glands under some conditions, and neither may be entirely suitable for skin potential measurements.

The orienting response as an index of mass communication effect.

ABSTRACTA study is described of the contribution of the electrodermal response to the measurement of broadcast communication effect. A 2 × 2 mixed between‐within groups design was employed. The within groups variable was radio commercial content, while the between groups variable was production style. Electrodermal measurements included average log conductance change, number of responses, and recovery half time. Comparison measures included retention test, interestingness scales, and semantic differentials. Only average log conductance change significantly discriminated stimuli on both between and within groups variables. An explanatory model incorporating Sokolov's notion of the neuronal model and the Deutsch and Deutsch model for attention is offered.