Electrodermal activity (EDA) is the property of the human body that causes continuous variation in the electrical characteristics of the skin. Historically, EDA has also been known as skin conductance, galvanic skin response (GSR), electrodermal response (EDR), psychogalvanic reflex (PGR), skin conductance response (SCR), sympathetic skin response (SSR) and skin conductance level (SCL). The long history of research into the active and passive electrical properties of the skin by a variety of disciplines has resulted in an excess of names, now standardized to electrodermal activity (EDA).
The traditional theory of EDA holds that skin resistance varies with the state of sweat glands in the skin. Sweating is controlled by the sympathetic nervous system, and skin conductance is an indication of psychological or physiological arousal. If the sympathetic branch of the autonomic nervous system is highly aroused, then sweat gland activity also increases, which in turn increases skin conductance. In this way, skin conductance can be a measure of emotional and sympathetic responses. More recent research and additional phenomena (resistance, potential, impedance, and admittance, sometimes responsive and sometimes apparently spontaneous) suggest that EDA is more complex than it seems, and research continues into the source and significance of EDA.
In 1849, Dubois-Reymond in Germany first observed that human skin was electrically active. He immersed the limbs of his subjects in a zinc sulfate solution and found that electric current flowed between a limb with muscles contracted and one that was relaxed. He therefore attributed his EDA observations to muscular phenomena. Thirty years later, in 1878 in Switzerland, Hermann and Luchsinger demonstrated a connection between EDA and sweat glands. Hermann later demonstrated that the electrical effect was strongest in the palms of the hands, suggesting that sweat was an important factor.
Vigouroux (France, 1879), working with emotionally distressed patients, was the first researcher to relate EDA to psychological activity. In 1888, the French neurologist Féré demonstrated that skin resistance activity could be changed by emotional stimulation and that activity could be inhibited by drugs.
In 1889 in Russia, Ivane Tarkhnishvili observed variations in skin electrical potentials in the absence of any external stimuli, and he developed a meter to observe the variations as they happened in real time.
The scientific study of EDA began in the early 1900s. One of the first references to the use of EDA instruments in psychoanalysis is the book by C. G. Jung entitled Studies in Word Analysis, published in 1906. Jung and his colleagues used the meter to evaluate the emotional sensitivities of patients to lists of words during word association. Jung was so impressed with EDA monitoring, he allegedly cried, "Aha, a looking glass into the unconscious!" Jung described his use of the device in counseling in his book, Studies in Word Association, and such use has continued with various practitioners.
The controversial Austrian psychoanalyst Wilhelm Reich also studied EDA in his experiments at the Psychological Institute at the University of Oslo, in 1935 and 1936, to confirm the existence of a bio-electrical charge behind his concept of vegetative, pleasurable "streamings".
By 1972, more than 1500 articles on electrodermal activity had been published in professional publications, and today EDA is regarded as the most popular method for investigating human psychophysiological phenomena. As of 2013, EDA monitoring was still on the increase in clinical applications.
Skin conductance is not under conscious control. Instead, it is modulated autonomously by sympathetic activity which drives human behavior, cognitive and emotional states on a subconscious level. Skin conductance, therefore, offers direct insights into autonomous emotional regulation.
Human extremities, including fingers, palms, and soles of feet display different bio-electrical phenomena.They can be detected with an EDA meter, a device that displays the change electrical conductance between two points over time. The two current paths are along the surface of the skin and through the body. Active measuring involves sending a small amount of current through the body.
Some studies include the human skin's response to alternating current, including recently deceased bodies.
There is a relationship between emotional arousal and sympathetic activity, although the electrical change alone does not identify which specific emotion is being elicited. These autonomic sympathetic changes alter sweat and blood flow, which in turn affects GSR and GSP. The amount of sweat glands varies across the human body, being highest in hand and foot regions (200–600 sweat glands per cm2). The response of the skin and muscle tissue to external and internal stimuli can cause the conductance to vary by several microsiemens. A correctly calibrated device can record and display the subtle changes.
The combined changes between electrodermal resistance and electrodermal potential make up electrodermal activity. Galvanic skin resistance (GSR) is an older term that refers to the recorded electrical resistance between two electrodes when a very weak current is steadily passed between them. The electrodes are normally placed about an inch apart, and the resistance recorded varies according to the emotional state of the subject. Galvanic skin potential (GSP) refers to the voltage measured between two electrodes without any externally applied current. It is measured by connecting the electrodes to a voltage amplifier. This voltage also varies with the emotional state of the subject.
A painful stimulus such as a pinprick elicits a sympathetic response by the sweat glands, increasing secretion. Although this increase is generally very small, sweat contains water and electrolytes, which increase electrical conductivity, thus lowering the electrical resistance of the skin. These changes in turn affect GSR. Another common manifestation is the vasodilation (dilation) of blood vessels in the face, referred to as blushing, as well as increased sweating that occurs when one is embarrassed.
EDA is highly responsive to emotions in some people. Fear, anger, startled response, orienting response, and sexual feelings are among the reactions that may be reflected in EDA. These responses are utilized as part of the polygraph or lie detector test.
EDA in regular subjects differs according to feelings of being treated fairly or unfairly, but psychopaths have been shown to manifest no such differences. This indicates that the EDA record of a polygraph may be deceptive in a criminal investigation.
EDA is a common measure of autonomic nervous system activity, with a long history of being used in psychological research. Hugo D. Critchley, Chair of Psychiatry at the Brighton and Sussex Medical School states, "EDA is a sensitive psychophysiological index of changes in autonomic sympathetic arousal that are integrated with emotional and cognitive states." Many biofeedback therapy devices utilize EDA as an indicator of the user's stress response with the goal of helping the user to control anxiety. EDA is used to assess an individual's neurological status without using traditional, but uncomfortable and expensive, EEG-based monitoring.
Oftentimes, EDA monitoring is combined with the recording of heart rate, respiratory rate, and blood pressure, because they are all autonomically dependent variables. EDA measurement is one component of modern polygraph devices, which are often used as lie detectors.
External factors such as temperature and humidity affect EDA measurements, which can lead to inconsistent results. Internal factors such as medications and hydration can also change EDA measurements, demonstrating inconsistency with the same stimulus level. Also, the classic understanding has treated EDA as if it represented one homogeneous change in arousal across the body, but in fact different locations of its measurement can lead to different responses; for example, the responses on the left and right wrists are driven by different regions of the brain, providing multiple sources of arousal; thus, the EDA measured in different places on the body varies not only with different sweat gland density but also with different underlying sources of arousal. Lastly, electrodermal responses are delayed 1–3 seconds. These show the complexity of determining the relationship between EDA and sympathetic activity. The skill of the operator may be a significant factor in the successful application of the tool.
Electrodermal activity (EDA) is now the preferred term for changes in electrical conductance of the skin, including phasic changes that have been referred to as galvanic skin responses (GSR)
By 1906 [Jung] was using GSR and breath measurement to note changes in respiration and skin resistance to emotionally charged worlds. Found that indicators cluster around stimulus words which indicate the nature of the subject's complexes...Much later L. Ron Hubbard used this approach in Scientology's "auditing," using the "e-meter" (a galvanic skin response indicator) to discern the presence of complexes.
Current research using the skin's electrical activity as a communications medium between patient and therapist looks promising in such stress problems as drug abuse, alcoholism, neuroses and other tension states.
Affectiva is an emotion measurement technology company that grew out of MIT's Media Lab. Affectiva has developed software to recognize human emotions based on facial cues or physiological responses. Among its commercial applications, this emotion recognition technology is used to help brands improve their advertising and marketing messages. Another major application has been in political polling. In 2011, the company partnered with Millward Brown, a unit of the Kantar Group, the market research, insight and consultancy division of WPP plc, a London-based advertising and public relations conglomerate.Auditing (Scientology)
In the Church of Scientology, auditing is a process wherein the auditor takes an individual, known as a "preclear", through times in their life and gets rid of any hold negative situations have on them. Auditing began as an integral part of the Dianetics movement and has since, with the E-meter, become a core practice in Scientology. Auditing is defined by the Church as "the application of Dianetics or Scientology processes and procedures to someone by a trained auditor. One formal definition of auditing is the action of asking a person a question (which he can understand and answer), getting an answer to that question and acknowledging him or her for that answer." Auditing is considered "a technical measure," that according to the Church, "lifts the burdened individual, the 'preclear,' from a level of spiritual distress to a level of insight and inner self-realization." The process is meant to bring the individual to clear status.
According to scholar Eric Roux, auditing is one of the "core practices" of Scientology. The primary aim of auditing in Scientology doctrine is to rediscover an individual's natural abilities, while understanding that one is a spiritual being.
Some auditing actions use commands, for example "Recall a time you knew you understood someone," and some auditing actions use questions such as, "What are you willing for me to talk to others about?"Body reactivity
Body reactivity is usually understood as the body's ability to react in a proper way to influence the environment. Resistance of an organism is its stability under the influence of pathogenic factors.The body reactivity can range from homeostasis to a fight or flight response. Ultimately, they are all governed by the nervous system.Dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is an organic chemical of the catecholamine and phenethylamine families that plays several important roles in the brain and body. It is an amine synthesized by removing a carboxyl group from a molecule of its precursor chemical L-DOPA, which is synthesized in the brain and kidneys. Dopamine is also synthesized in plants and most animals. In the brain, dopamine functions as a neurotransmitter—a chemical released by neurons (nerve cells) to send signals to other nerve cells. The brain includes several distinct dopamine pathways, one of which plays a major role in the motivational component of reward-motivated behavior. The anticipation of most types of rewards increases the level of dopamine in the brain, and many addictive drugs increase dopamine release or block its reuptake into neurons following release. Other brain dopamine pathways are involved in motor control and in controlling the release of various hormones. These pathways and cell groups form a dopamine system which is neuromodulatory.
In popular culture and media, dopamine is often seen as the main chemical of pleasure, but the current opinion in pharmacology is that dopamine instead confers motivational salience; in other words, dopamine signals the perceived motivational prominence (i.e., the desirability or aversiveness) of an outcome, which in turn propels the organism's behavior toward or away from achieving that outcome.Outside the central nervous system, dopamine functions primarily as a local paracrine messenger. In blood vessels, it inhibits norepinephrine release and acts as a vasodilator (at normal concentrations); in the kidneys, it increases sodium excretion and urine output; in the pancreas, it reduces insulin production; in the digestive system, it reduces gastrointestinal motility and protects intestinal mucosa; and in the immune system, it reduces the activity of lymphocytes. With the exception of the blood vessels, dopamine in each of these peripheral systems is synthesized locally and exerts its effects near the cells that release it.
Several important diseases of the nervous system are associated with dysfunctions of the dopamine system, and some of the key medications used to treat them work by altering the effects of dopamine. Parkinson's disease, a degenerative condition causing tremor and motor impairment, is caused by a loss of dopamine-secreting neurons in an area of the midbrain called the substantia nigra. Its metabolic precursor L-DOPA can be manufactured; Levodopa, a pure form of L-DOPA, is the most widely used treatment for Parkinson's. There is evidence that schizophrenia involves altered levels of dopamine activity, and most antipsychotic drugs used to treat this are dopamine antagonists which reduce dopamine activity. Similar dopamine antagonist drugs are also some of the most effective anti-nausea agents. Restless legs syndrome and attention deficit hyperactivity disorder (ADHD) are associated with decreased dopamine activity. Dopaminergic stimulants can be addictive in high doses, but some are used at lower doses to treat ADHD. Dopamine itself is available as a manufactured medication for intravenous injection: although it cannot reach the brain from the bloodstream, its peripheral effects make it useful in the treatment of heart failure or shock, especially in newborn babies.E-meter
The E-meter is an electronic device for displaying the electrodermal activity (EDA) of a human being. The device is used for auditing in Scientology and divergent groups. The efficacy and legitimacy of Scientology's use of the E-meter has been subject to extensive debate and litigation and in accordance with a federal court order, the Church of Scientology now publishes disclaimers in its books and publications declaring that the E-meter "by itself does nothing" and that it is used specifically for spiritual purposes.Such devices have been used as a research tool in many human studies, and as one of several components of the Leonarde Keeler's polygraph (lie detector) system, which has been widely criticized as ineffective or pseudoscientific by legal experts and psychologists.Frisson
Frisson (French for 'shiver'), also known as aesthetic chills, musical chills, and colloquially as a skin orgasm, is a psychophysiological response to rewarding auditory and/or visual stimuli that induces a pleasurable or otherwise positively-valenced affective state and transient paresthesia (skin tingling or chills), sometimes along with piloerection (goose bumps) and mydriasis (pupil dilation). The sensation commonly occurs as a mildly to moderately pleasurable emotional response to music with skin tingling; piloerection and pupil dilation do not necessarily occur in all cases. The psychological component (i.e., the pleasurable feeling) and physiological components (i.e., parasthesia, piloerection, and pupil dilation) of the response are mediated by the reward system and sympathetic nervous system, respectively. The stimuli that produce this response are unique to each individual.
Frisson is of short duration, lasting only a few seconds. Typical stimuli include loud passages of music and passages—such as appoggiaturas and sudden modulation—that violate some level of musical expectation. During a frisson, a sensation of chills or tingling felt on the skin of the lower back, shoulders, neck, and/or arms. The sensation of chills is sometimes experienced as a series of 'waves' moving up the back in rapid succession and commonly described as "shivers up the spine". Hair follicles may also undergo piloerection.It has been shown that some experiencing musical frisson report reduced excitement when under administration of naloxone (an opioid receptor antagonist), suggesting musical frisson gives rise to endogenous opioid peptides similar to other pleasurable experiences. Frisson may be enhanced by the amplitude of the music and the temperature of the environment. Cool listening rooms and cinemas may enhance the experience.Implicit data collection
Implicit data collection is used in human–computer interaction to gather data about the user in an implicit, non-invasive way.Neuro-Information-Systems
Neuro-Information-Systems (NeuroIS) is a subfield of the information systems (IS) discipline, which relies on neuroscience and neurophysiological knowledge and tools to better understand the development, use, and impact of information and communication technologies. The field has been formally established at the International Conference on Information Systems (ICIS) in 2007.Physioeconomics
Physioeconomics (or physio-economics) is an extension of experimental economics research that collects physiological parameters in addition to recording behavior. These measures can include skin conductance, blood pressure and the pulse of the subject. Experiments typically present subjects with economic decisions in a game–like context.
The term has also been used by Philip M. Parker in his book Physioeconomics to refer to his theory of the physiological basis of economics, according to which the equatorial paradox (that countries further from the equator have higher GDP per capita) is explained by the pressure on humans located in cold climates to restore their physiological homeostasis, for example by agriculture and wealth-creation.Psychophysiological economics
Psychophysiological economics is a field of study focused on the assessment and evaluation of psychological and physiological events as factors shaping consumer economic behavior. Psychophysiological economists believe that behavior and cognitive processing are indivisible and that behavioral, cognitive, and physiological tools and techniques can be combined to create interventions that improve the economic well-being of consumers.
Psychophysiological economics differs from behavioral economics by focusing on direct measures of physiological change and observational data, in addition to attitudinal measurement. Psychophysiological economics also differs from functional magnetic resonance imaging, which is typically applied exclusively to the study of brain activity. Psychophysiological economics emphasizes the role of the peripheral nervous system as it relates to shaping economic behavior.
The peripheral nervous system includes the spinal and cranial nerves. Of specific relevance is the Autonomic Nervous System (ANS). The ANS regulates glands and other internal organs (visceral structures). Visceral structures control involuntary physiological activities and behavior. Psychophysiological economics researchers directly measure the sympathetic nervous system as a person responds to stressor within the environment.Psychophysiology
Psychophysiology (from Greek ψῡχή, psȳkhē, "breath, life, soul"; φύσις, physis, "nature, origin"; and -λογία, -logia) is the branch of psychology that is concerned with the physiological bases of psychological processes. While psychophysiology was a general broad field of research in the 1960s and 1970s, it has now become quite specialized, and has branched into subspecializations such as social psychophysiology, cardiovascular psychophysiology, cognitive psychophysiology, and cognitive neuroscience.Reward system
The reward system is a group of neural structures responsible for incentive salience (i.e., motivation and "wanting", desire, or craving for a reward), associative learning (primarily positive reinforcement and classical conditioning), and positively-valenced emotions, particularly ones which involve pleasure as a core component (e.g., joy, euphoria and ecstasy). Reward is the attractive and motivational property of a stimulus that induces appetitive behavior, also known as approach behavior, and consummatory behavior. In its description of a rewarding stimulus (i.e., "a reward"), a review on reward neuroscience noted, "any stimulus, object, event, activity, or situation that has the potential to make us approach and consume it is by definition a reward." In operant conditioning, rewarding stimuli function as positive reinforcers; however, the converse statement also holds true: positive reinforcers are rewarding.Primary rewards are a class of rewarding stimuli which facilitate the survival of one's self and offspring, and include homeostatic (e.g., palatable food) and reproductive (e.g., sexual contact and parental investment) rewards. Intrinsic rewards are unconditioned rewards that are attractive and motivate behavior because they are inherently pleasurable. Extrinsic rewards (e.g., money or seeing one's favorite sports team winning a game) are conditioned rewards that are attractive and motivate behavior, but are not inherently pleasurable. Extrinsic rewards derive their motivational value as a result of a learned association (i.e., conditioning) with intrinsic rewards. Extrinsic rewards may also elicit pleasure (e.g., euphoria from winning a lot of money in a lottery) after being classically conditioned with intrinsic rewards.Survival for most animal species depends upon maximizing contact with beneficial stimuli and minimizing contact with harmful stimuli. Reward cognition serves to increase the likelihood of survival and reproduction by causing associative learning, eliciting approach and consummatory behavior, and triggering positively-valenced emotions. Thus, reward is a mechanism that evolved to help increase the adaptive fitness of animals.Roland Clark Davis
Roland Clark Davis (December 20, 1902– February 23, 1961) was an American psychologist recognized for his innovation in instrumentation and measurement of electrophysiological phenomena. Davis contributed to the measurement of electrodermal activity, gastric reflexes, and muscle action potentials. Davis published over 70 articles on psychophysiology and related topics across a 30-year career and mentored many graduate students at Indiana University Bloomington from 1931 through 1961.Rosalind Picard
Rosalind Wright Picard (born May 17, 1962) is an American scholar who is Professor of Media Arts and Sciences at MIT, founder and director of the Affective Computing Research Group at the MIT Media Lab, and co-founder of the startups Affectiva and Empatica. In 2005, she was named a Fellow of the Institute of Electrical and Electronics Engineers.Picard is credited with starting the branch of computer science known as affective computing with her 1997 book of the same name. This book described the importance of emotion in intelligence, the vital role human emotion communication has to relationships between people, and the possible effects of emotion recognition by robots and wearable computers. Her work in this field has led to an expansion into autism research and developing devices that could help humans recognize nuances in human emotions.Scientology
Scientology is a body of religious beliefs and practices launched in May 1952 by American author L. Ron Hubbard (1911–86). Hubbard initially developed a program of ideas called Dianetics, which was distributed through the Dianetics Foundation. The foundation soon entered bankruptcy, and Hubbard lost the rights to his seminal publication Dianetics: The Modern Science of Mental Health in 1952. He then recharacterized the subject as a religion and renamed it Scientology, retaining the terminology, doctrines, the E-meter, and the practice of auditing. Within a year, he regained the rights to Dianetics and retained both subjects under the umbrella of the Church of Scientology.Hubbard describes the etymology of the word "Scientology" as coming from the Latin word scio, meaning know or distinguish, and the Greek word logos, meaning "the word or outward form by which the inward thought is expressed and made known". Hubbard writes, "thus, Scientology means knowing about knowing, or science of knowledge".Hubbard's groups have encountered considerable opposition and controversy. In January 1951, the New Jersey Board of Medical Examiners brought proceedings against Dianetics Foundation on the charge of teaching medicine without a license. Hubbard's followers engaged in a program of criminal infiltration of the U.S. government.Hubbard-inspired organizations and their classification are often a point of contention. Germany classifies Scientology groups as an "anti-constitutional sect". In France, they have been classified as a dangerous cult by some parliamentary reports.Sexual jealousy
Sexual jealousy is a special form of jealousy in sexual relationships, based on suspected or imminent sexual infidelity. The concept is studied in the field of evolutionary psychology.Space opera in Scientology
Church of Scientology founder L. Ron Hubbard included space opera narratives in his writings, wherein thetans (the name given to human souls) were reincarnated periodically over quadrillions of years, retaining memories of prior lives, to which Hubbard attributed complex narratives about life throughout the universe. The most controversial of these myths is the story of Xenu, to whom Hubbard attributed responsibility for many of the world's problems.
Some space opera doctrines of Scientology are only provided by the church to experienced members, who church leaders maintain are the only ones able to correctly understand them. Several former members of the church have exposed these secret documents, leading to lengthy court battles with the church, which failed to keep the secret. Critics of the church have noted that some of the narratives are scientifically impossible, and have thus assailed the church as untrustworthy for teaching them. The space opera teachings have also been satirized in popular culture. Scholars of religion have described the space opera narratives as a creation myth designed to encourage reverence of Hubbard as a supreme messenger. Several academics have drawn attention to the similarity of the space opera myths to themes of the 1950s Cold War culture in which they were constructed.Volney Mathison
Volney G. Mathison, also known by the pseudonym Dex Volney (August 13, 1897 – January 3, 1965), was an American chiropractor, writer, and inventor of the first E-meter used by the Church of Scientology.