Affective Computation: is computing that relates to, arises from, or deliberately influences emotion or other affective phenomena.
Physiological: in general, physiology is a branch of biology that deals with the functions of activities of life. With respect to affective computing, physiological affect in general refers to responses that come from the body, more especially those associated with the autonomic nervous systems. Although brain activity is in essence physiological, the field of neurophysiology provides a more specific view of brain function and the term “physiological” is usually used to refer to other types of bodily responses.
Emotion: A term used colloquially to reflect a wide range of affective responses (feelings, mood, disposition, etc.). In emotion theory, emotions are generally perceived as short term affective responses and are often perceived as both “basic” versus “social/moral/higher-order” emotions, where the first category is more often tied with primary physiological responses.
Heart Rate Variability: A term used to describe how successive heart beats differ from one another (e.g. how the lengths of the intervals between successive heart beats vary). The term heart rate variability is used to describe a number of metrics, some of which are calculated in the time domain and others of which are calculated in the frequency domain.
Galvanic Skin Response: (also commonly referred to as electrodermal activity (EDR) or Skin Conductance) is a commonly measured physiological metric that measures a person’s sweat levels by measuring the conductance of the skin. The skin is normally an insulator, but sweat is ionic and conducts electricity so that when a person starts sweating their skin conductivity increases. This phenomena is most often measured by placing two electrodes on two adjacent fingers and measuring the voltage in response to a small injection current that runs between the two electrodes across the skin of the palm of the hand where many of the most emotionally reactive sweat glands are found.
Signals: A signal is a time varying response that communicates information about phenomena. In the context of physiological affective computing, a signal is usually a two dimensional time-voltage signal, measured from some part of the body. For example, a skin conductance signal conveys information about how a person’s sweat level changes over time and a heart rate signal conveys information about how a person’s heart rate changes over time.
Sensing: using a physical instrument to detect a physical stimulus. In affective computing, sensing is used to capture information that can be used by a computer to incorporate into algorithms, for example to sense skin conductance, a GSR sensor is used and to sense heart rate a heart rate sensor (ECG, BVP) is used.