The belief, first proposed in the eighteenth century, that intellectual abilities could be divined by studying bumps found on the skull. The assumption was that particular areas of the BRAIN dealt with particular abilities and that the larger the area (and therefore the larger the bump on the skull surrounding it) the greater the ability. Phrenology is now regarded as pseudo-scientific, though it did help establish the link between brain and BEHAVIOUR.

The impression of seeing apparent movement. In its simplest form two lights flashed on and off in quick succession, with the right time interval between the flashes, will induce people to perceive the light as moving between two points. This ILLUSION is the basis for our PERCEPTION of movement in films, cartoons and neon light displays. It was discovered at the beginning of the twentieth century by the first GESTALT PSYCHOLOGISTS, shortly after the film industry was created.

The level of cognitive ability attained in the second of PIAGET S STAGES of development from about 2 to 7 years of age. At this stage the child’s thought is intuitive rather than logical and is characterised by MAGIC THINKING. ANTHROPOMORPHISM and EGOCENTR1CITY.

The sensation of ‘feeling’ in a limb that has been amputated. Two complementary reasons for this PHENOMENON have been suggested; the existing SELF-IMAGE or body schema in an adult takes a long time to adjust to a sudden physical change and the neural links built up between the amputated limb and the BRAIN may still exist in some form.

The EVOLUTION and development of a species. Contrast With ONTOGENY.

A detailed example or MODEL.

See CONNECTIONISM.

A stage of sleep during which there is a great deal of electrical activity in theBRAIN while the muscles are very relaxed and the sleeper is difficult to rouse. The BRAIN WAVES recorded during this phase resemble the pattern found in someone awake. There is often a great deal of the RAPID EYE MOVEMENTS associated with dreaming.

A PSYCHOSIS characterised by DELUSIONS, especially delusions of grandeur and delusions persecution. Apart from such delusions, which may be vigorously and even plausibly defended, a paranoiaccan often behave quite normally.

See INTERMITTENT REINFORCEMENT.