Schema (psychology)

A schema (pl. schemata), in psychology and cognitive science, is a mental structure that represents some aspect of the world. People use schemata to organize current knowledge and provide a framework for future understanding. Examples of schemata include stereotypes, social roles, scripts, worldviews, and archetypes. In Piaget's theory of development, children adopt a series of schemas to understand the world.

The importance of schemata for thought cannot be overstated. Sufferers of Korsakov's syndrome are unable to form new memories, and must approach every situation as if they had just seen it for the first time. Many sufferers adapt by continually forcing their world into barely-applicable schemata, often to the point of incoherence and self-contradiction.

Thought using schemas
Schemas are an effective tool for understanding the world. Through the use of schemata, most everyday situations do not require effortful thought -- automatic thought is all that is required. People can quickly organize new perceptions into schemas and act effectively without effort. For example, most people have a stairway schema and can apply it to climb staircases they've never seen before.

However, schemas can influence and hamper the uptake of new information (proactive interference), such as when existing stereotypes, giving rise to limited or biased discourses and expectations (prejudices) may lead an individual to 'see' or 'remember' something that has not happened because it is more believable in terms of his/her schema: for example, if a well-dressed businessman draws a knife on a Rastafarian, the schemas of onlookers may (and often do) lead them to 'remember' the Rastafarian pulling the knife. Such distortion of memory has been demonstrated. See Background research below.

Schemas are often related to one another, and multiple conflicting schemata can be applied to the same information. Schemata are generally thought to have a level of activation, which can spread among related schemata. Which schema is selected can depend on factors such as current activation, accessibility, and priming.

Accessibility is how easily a schema comes to mind, and is determined by personal experience and expertise. This can be used as a cognitive shortcut; it allows the most common explanation to be chosen for new information. See availability heuristic.

With priming, a brief imperceptible stimulus temporarily provides enough activation to a schema so that it is used for subsequent ambiguous information. Although this may suggest the possibility of subliminal messages, the effect of priming is so fleeting that it is difficult to detect outside laboratory conditions. Furthermore, the mere exposure effect -- which requires consciousness of the stimuli -- is far more effective than priming.

Background research
The original concept of schemata is linked with that of reconstructive memory as proposed and demonstrated in a series of experiments by Bartlett (1932). By presenting participants with information that was unfamiliar to their cultural backgrounds and expectations and then monitoring how they recalled these different items of information (stories, etc.), Bartlett was able to establish that individuals' existing schemata and stereotypes influence not only how they interpret 'schema-foreign' new information but also how they recall the information over time. One of his most famous investigations involved asking participants to read a Native American folk tale, "The War of the Ghosts", and recall it several times up to a year later. All the participants transformed the details of the story in such a way that it reflected their cultural norms and expectations, i.e. in line with their schemata. The factors that influenced their recall were:
 * Omission of information that was considered irrelevant to a participant;
 * Transformation of some of the detail, or of the order in which events etc were recalled; a shift of focus and emphasis in terms of what was considered the most important aspects of the tale;
 * Rationalisation: details and aspects of the tale that would not make sense would be 'padded out' and explained in an attempt to render them comprehensible to the individual in question;
 * Cultural shifts: The content and the style of the story were altered in order to appear more coherent and appropriate in terms of the cultural background of the participant.

Bartlett's work was crucially important in demonstrating that long-term memories are neither fixed nor immutable but are constantly being adjusted as our schemata evolve with experience. In a sense it supports the existentialist view that we construct our past and present in a constant process of narrative/discursive adjustment, and that much of what we 'remember' is actually confabulated (adjusted and rationalised) narrative that allows us to think of our past as a continuous and coherent string of events, even though it is probable that large sections of our memory (both episodic and semantic) are irretrievable to our conscious memory at any given time.

Modification of schemas
New information that falls within an individual's schema is easily remembered and incorporated into their worldview. However, when new information is perceived that does not fit a schema, many things can happen. The most common reaction is to simply ignore or quickly forget the new information. This can happen on a deep level -- frequently an individual does not become conscious of or even perceive the new information. However, when the new information cannot be ignored, existing schemas must be changed.

Assimilation is reuse of schemata to fit the new information. For example, when an unfamiliar dog is seen, a person will probably just assimilate it into their dog schema. However, if the dog behaves strangely, and in ways that don't seem dog-like, there will be accommodation as a new schema is formed for that particular dog.