The nature of the relationship between an animal’s behaviour and the reinforcing agent that is contingent upon it. This might be continuous reinforcement or partial reinforcement.

Regular structure within a polypeptide chain. There are two main types: the α-helix and the β-sheet.

A family of enzymes involved in the processing/proteolysis of APP.

A term that refers to the capacity of an individual to set goals and to meet them. A capacity to obtain satisfaction in realising ambitions.

Memory that includes general knowledge of the world acquired through education and experience, including the use of language.

Extracellular structures composed of complex and incompletely characterised molecular and cellular constituents. Amyloid β peptide, produced by proteolytic cleavage of APP, and ApoE are the major components of the plaques.

Neurons that convey information to the central nervous system.

An adjective describing a neuron that synthesises, stores and releases serotonin or a synapse at which serotonin is the neurotransmitter.

One of the brain’s neurotransmitters.

A procedure whereby an experimenter rewards successive approximations to a desired operant response. For example, if lever-pressing is the desired operant, an experimenter might offer reward for first touching the lever and then for lowering the lever slightly. Finally, reward would be given only for fully lowering the lever.