Artificial human companions have been proposed as one means of assisting the elderly in maintaining an acceptable standard of life. Senior citizens make up an increasing percentage of the population in the Western nations, and, according to Judith Masthoff of the University of Brighton, they tend to live alone and have a limited social network. Studies also show that those elderly living in such circumstances have an increased risk of developing depression and dementia, and have a shorter life span than more socially connected seniors.

A humanoid robot is a robot with its overall appearance based on that of the human body. In general humanoid robots have a torso with a head, two arms and two legs, although some forms of humanoid robots may model only part of the body, for example, from the waist up. Some humanoid robots may also have a 'face', with 'eyes' and 'mouth'. Androids are humanoid robots built to resemble a male human, and Gynoids are humanoid robots built to resemble a human female.

An android is a robot designed to resemble a human, usually both in appearance and behavior. The word derives from the Greek andr-, meaning "man, male", and the suffix -eides, used to mean "of the species; alike" (from eidos "species"). The term was first mentioned by Albertus Magnus in 1270 and was popularized by the French writer Villiers in his 1886 novel L'Ève future, although the term "android" appears in US patents as early as 1863 in reference to miniature humanlike toy automations.[3]

Gynoid (from Greek γυνη, gynē - woman) is a term used to describe a robot designed to look like a human female, as compared to an android modeled after a male. The term is not common, however, with android often being used to refer to both "sexes" of robot. The portmanteaus fembot (female robot) and feminoid (female android) have also been used; the latter sparingly. The term "Gynoids" was created by the female British SF writer, Gwyneth Jones, and developed by another British SF writer, Richard Calder.

Android science is a new interdisciplinary framework for studying human interaction and cognition based on the premise that a very humanlike robot (that is, an android) can elicit human-directed social responses in human beings. The android's ability to elicit human-directed social responses enables researchers to employ an android in experiments with human participants as an apparatus that can be more precisely controlled than a human actor.

The uncanny valley is a hypothesis about robotics concerning the emotional response of humans to robots and other non-human entities. It was introduced by Japanese roboticist Masahiro Mori in 1970, although drawing heavily on Ernst Jentsch's concept of "the uncanny," identified in a 1906 essay, "On the Psychology of the Uncanny." Jentsch's conception is famously elaborated upon by Sigmund Freud in a 1919 essay, simply entitled "The Uncanny" ("Das Unheimliche"). A similar problem exists in realistic 3D computer animation.

Cognitive science is most simply defined as the scientific study either of mind or of intelligence (e.g. Luger 1994). It is an interdisciplinary study drawing from relevant fields including psychology, philosophy, neuroscience, linguistics, anthropology, computer science, biology, and physics. The term cognitive science was coined by Christopher Longuet-Higgins in his 1973 commentary on the Lighthill report, which concerned the then-current state of Artificial Intelligence research. In the same decade, the journal Cognitive Science and the Cognitive Science Society began.

The modern definition of artificial intelligence (or AI) is "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions which maximizes its chances of success. John McCarthy, who coined the term in 1956,defines it as "the science and engineering of making intelligent machines." Other names for the field have been proposed, such as computational intelligence,[4] synthetic intelligence or computational rationality. The term artificial intelligence is also used to describe a property of machines or programs: the intelligence that the system demonstrates.

AI research uses tools and insights from many fields, including computer science, psychology, philosophy, neuroscience, cognitive science, linguistics, operations research, economics, control theory, probability, optimization and logic.[7] AI research also overlaps with tasks such as robotics, control systems, scheduling, data mining, logistics, speech recognition, facial recognition and many others.