Observational Learning: see vicarious learning.
Obsessive-Compulsive Disorder (OCD): a serious condition characterised by undesirable – sometimes highly-disturbing – and intrusive thoughts and compulsive, often ritualistic behaviours. The behaviours, though not always obviously so, serve to compensate for, control or distract from the unwanted thoughts. Clare W Graves saw OCD as the result of emerging BLUE fighting back the impulses of RED which would fit with Carl Gustav Jung’s assertion that OCD was the intrusion into consciousness of threatening sexual and aggressive ideas being warded off through ritualistic behaviours and/or repeated verbal incantations.At a biological level OCD has been associated with problems in the caudate nucleus affecting signalling between the orbitofrontal cortex and the thalamus.
Oestregen: oestrogens are a group of compounds named for their importance in the oestrous cycle of humans and other animals. They are the primary female sex hormones.
While oestrogens are present in both men and women, they are usually present at significantly higher levels in women of reproductive age. They promote the development of female secondary sexual characteristics, such as breasts, and are also involved in the thickening of the endometrium and other aspects of regulating the menstrual cycle. In males, oestrogen regulates certain functions of the reproductive system important to the maturation of sperm and may be necessary for a healthy sex drive.
Operant Conditioning: first identified conceptually by Edward Thorndike (1932), this is leaning through the consequnces of behaviour – either reinforcement (reward) or punishment. (Thorndike talked of “stamping in” and “stamping out” behaviour.) See also Behaviourism.Orbitofrontal Cortex: a part of the frontal lobe of the cerebral cortex associated with learning.