Frequency Law  

In the doctrine of associationism, a law where mental elements that frequently occur together tend to become associated.

Eidetic Image

A mental image or memory that is extraordinarily clear and vivid , as though actually being perceived, which is caused through a previously perceived stimulus.

Stimulus

Any event, agent, or influence which is internal or external, that excites or is capable of exciting a sensory receptor and causes a response in a organism. Another name for Stimulus is Stimuli. 

Placebo

An assumedly inactive substance or dummy treatment administered to a control group to serve as a baseline for comparison of the effects of an active drug or treatment. 

Interdependence Theory

A theory that seeks to analyse the causal determinants of dyadic social behavior by providing a systematic classification of certain key properties of interpersonal situations or interactions and of the individuals' responses to them.

Deindividuation 

A psychological state characterized by loss of the sense of individuality and a submerging of personal identity and accountability in a group. 

Deduction

The form of reasoning characteristic of logic and mathematics in which a conclusion is inferred from a set of premises that logically imply it.

Extraversion

One of the Big Five personality factors, ranging from extreme extraversion, characterized by traits such as sociability and assertiveness, to extreme introversion, characterized by reserve and passivity. 

Hybrid

In genetics, the offspring of a cross between genetically dissimilar forms, such an organism being necessarily sterile if the cross is between different species: also, a molecule of DNA composed of portions from different organisms. 

Inadequate Stimulus

A term sometimes used for a stimulus that is incapable of evoking a response from an organism, such as visible light or sound that is too faint for the visual or auditory receptors to detect. It is an oxymoron and is avoided in careful usage.

Interpretation

The act or process of explaining, elucidating , or clarifying, or the product of activity. In psychoanalysis, a process of decoding the latent meaning of a patient's speech and actions, thereby revealing unconscious.

Consciousness

The state of being conscious. The normal mental condition of waking state of humans, characterized by experience of perceptions, thoughts, feelings, awareness, of the external world, and often in humans self-awareness. 

Unconscious

Lacking consciousness or awareness of mental experiences such as perceptions, thoughts, or emotions: lacking deliberate intention. In psychoanalysis, a part in the mind containing repressed instincts and their representative wishes, ideas, and images that are not accessible to direct examination, its functions being governed by the mechanisms of the primary process, especially condensation and displacement. The operation of repression prevents the contents of the unconscious from entering either consciousness or the preconscious, and a barrier of censorship exists between the unconscious and the preconscious-conscious system.  

Reference

Colman, M. A. (2006). A dictionary of psychology (2nd Ed.). New York, NY; Oxford University Press.