Depersonalization-derealization disorderDepersonalization-derealization disorder (DPDR, DPD) is a mental disorder in which the person has persistent or recurrent feelings of depersonalization and/or derealization. Depersonalization is described as feeling disconnected or detached from one's self. Individuals may report feeling as if they are an outside observer of their own thoughts or body, and often report feeling a loss of control over their thoughts or actions. Derealization is described as detachment from one's surroundings.
Personal identityPersonal identity is the unique numerical identity of a person over time. Discussions regarding personal identity typically aim to determine the necessary and sufficient conditions under which a person at one time and a person at another time can be said to be the person, persisting through time. In philosophy, the problem of personal identity is concerned with how one is able to identify a single person over a time interval, dealing with such questions as, "What makes it true that a person at one time is the same thing as a person at another time?" or "What kinds of things are we persons?" In contemporary metaphysics, the matter of personal identity is referred to as the diachronic problem of personal identity.
Functional disorderFunctional disorder is an umbrella term for a group of recognisable medical conditions which are due to changes to the functioning of the systems of the body rather than due to a disease affecting the structure of the body. Functional disorders are common and complex phenomena that pose challenges to medical systems. Traditionally in western medicine, the body is thought of as consisting of different organ systems, but it is less well understood how the systems interconnect or communicate.
Alice in Wonderland syndromeAlice in Wonderland syndrome (AIWS), also known as Todd's syndrome or dysmetropsia, is a neurological disorder that distorts perception. People may experience distortions in their visual perception of objects, such as appearing smaller (micropsia) or larger (macropsia), or appearing to be closer (pelopsia) or farther (teleopsia) than they are. Distortion may also occur for senses other than vision. The cause of Alice in Wonderland syndrome is currently unknown, but it has often been associated with migraines, head trauma, or viral encephalitis caused by Epstein–Barr virus infection.
Integrated information theoryIntegrated information theory (IIT) attempts to provide a framework capable of explaining why some physical systems (such as human brains) are conscious, why they feel the particular way they do in particular states (e.g. why our visual field appears extended when we gaze out at the night sky), and what it would take for other physical systems to be conscious (Are other animals conscious? Might the whole Universe be?).
SentienceSentience is the ability to experience feelings and sensations. The word was first coined by philosophers in the 1630s for the concept of an ability to feel, derived from Latin sentiens (feeling), to distinguish it from the ability to think (reason). In modern Western philosophy, sentience is the ability to experience sensations. In different Asian religions, the word "sentience" has been used to translate a variety of concepts. In science fiction, the word "sentience" is sometimes used interchangeably with "sapience", "self-awareness", or "consciousness".
