Galvanic Skin Response (GSR)
Electro Dermal Activity (EDA)
Our main sensor for measuring emotional reactions, the GSR is by far the most reliable bio-sensor for measuring a person's emotional state, and emotional reaction to stimuli.
Sweating serves a function in regulating body temperature by transporting more blood to the skin. If you feel warm, you might begin to sweat. These reactions are autonomous bodily reactions, but they are not exclusively limited to heat regulation. The sympathetic nervous system - or the human's inherent fight or flight reactions - activates different physiological responses, such as increased heart rate and sweat gland activity. The intensity of the reaction determines the extent of the person's sweat response.
In simple terms, GSR is about measuring the sweat activity induced by reactions from the sympathetic nervous system. This is most often done through sensors on the hands or the feet of the person, as these spots are unobtrusive and have inherently more sensitive sweat glands.
We use sensors strapped to two fingers on the user.
GSR is measured through electrodes emitting a very low current through two points. Higher moisture leads to higher conductivity between the electrodes, and thus an emotional response can be measured.
We measure this reaction as Skin Conductivity Response (SCR). On average, it takes about 1-5 seconds for an emotional reaction from stimuli to register. This is taken into account during the calibration before the test starts. Before the test begins, flashing lights or other stimuli are shown to measure how many seconds the person takes to react to stimuli. This is what we call SCR Latency.
The SCR itself can be measured as a reaction for about 10-30 seconds. However, the tonic component variation, which is the gradual increase and decrease of stress levels, can be measured starting from 10 seconds and may take several minutes to return to normal rest values.
Autonomic Nervous System
Sympathetic Nervous System (SNS)
The sympathetic nervous system is responsible for the body's "fight or flight" response to stress. When the body perceives a threat or danger, the sympathetic nervous system activates to prepare the body for action. This can cause the heart rate and blood pressure to increase, the pupils to dilate, and the lungs to take in more air. Other effects of sympathetic nervous system activation include the release of adrenaline and other stress hormones, decreased digestion, and increased sweating.
Parasympathetic Nervous System
The parasympathetic nervous system is responsible for the body's "rest and digest" response. This system is activated when the body is in a relaxed state, such as during sleep or after a meal. The parasympathetic nervous system helps to conserve and restore energy by slowing down heart rate and breathing, increasing digestion, and promoting relaxation.
Valence & Arousal
Valence and Arousal are two dimensions commonly used to describe and measure the emotional content of various stimuli.
Refers to the degree of pleasantness or unpleasantness of an emotional experience. It ranges from a negative to positive.
Valence is a fundamental aspect of emotional experience that influences how we perceive and respond to the world around us. For example, positive valence is associated with emotions such as happiness, joy, and contentment, while negative valence is associated with emotions such as sadness, anger, and fear.
Valence can be influenced by a variety of factors, including situational context, personal beliefs and values, and differences in individual personality and mood. In addition, valence can interact with other aspects of emotional experience, such as arousal, to produce complex and nuanced emotional responses.
Valence is an important concept in a variety of fields, including psychology, neuroscience, and marketing. In psychology, valence is often used to study emotional processes, such as emotion regulation, empathy, and emotional intelligence. In neuroscience, valence is used to investigate the neural mechanisms underlying emotional experience, such as the amygdala and prefrontal cortex. In marketing, valence is used to understand how consumers respond to different products and advertisements.
Refers to the level of activation or intensity of an emotional experience. It ranges from low arousal (tiresome, drowsy etc.) to high arousal (fear, astonishment etc.)
Arousal can be triggered by a variety of stimuli, such as exciting or challenging situations, physical exercise, or emotional events. It can also be modulated by individual differences, such as personality traits, mood, and cognitive appraisal of a situation.
Research has shown that arousal plays an important role in shaping cognitive, affective, and behavioral responses to emotional experiences. For example, high levels of arousal can enhance attention, memory, and decision-making, but can also impair performance in complex or demanding tasks. In terms of affective responses, high arousal is often associated with positive emotions such as happiness, excitement, and joy, as well as negative emotions such as fear, anger, and anxiety.