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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Body schema | 1/3 | https://en.wikipedia.org/wiki/Body_schema | reference | science, encyclopedia | 2026-05-05T15:12:55.941468+00:00 | kb-cron |
Body schema is an organism's internal model of its own body, including the position of its limbs. The neurologist Sir Henry Head originally defined it as a postural model of the body that actively organizes and modifies 'the impressions produced by incoming sensory impulses in such a way that the final sensation of body position, or of locality, rises into consciousness charged with a relation to something that has happened before'. As a postural model that keeps track of limb position, it plays an important role in control of action. It involves aspects of both central (brain processes) and peripheral (sensory, proprioceptive) systems. Thus, a body schema can be considered the collection of processes that registers the posture of one's body parts in space. The schema is updated during body movement. This is typically a non-conscious process, and is used primarily for spatial organization of action. It is therefore a pragmatic representation of the body’s spatial properties, which includes the length of limbs and limb segments, their arrangement, the configuration of the segments in space, and the shape of the body surface. Body schema also plays an important role in the integration and use of tools by humans. Body schema is different from body image; the distinction between them has developed over time.
== History == Henry Head, an English neurologist who conducted pioneering work into the somatosensory system and sensory nerves, together with British neurologist Gordon Morgan Holmes, first described the concept in 1911. The concept was first termed "postural schema" to describe the disordered spatial representation of patients following damage to the parietal lobe of the brain. Head and Holmes discussed two schemas (or schemata): one body schema for the registration of posture or movement and another body schema for the localization of stimulated locations on the body surface. "Body schema" became the term used for the "organized models of ourselves". The term and definition first suggested by Head and Holmes has endured nearly a century of research with clarifications as more has become known about neuroscience and the brain.
== Properties == Neuroscientists Patrick Haggard and Daniel Wolpert have identified seven fundamental properties of the body schema. It is spatially coded, modular, adaptable, supramodal, coherent, interpersonal, and updated with movement.
=== Spatial encoding === The body schema represents both position and configuration of the body as a 3-dimensional object in space. A combination of sensory information, primarily tactile and visual, contributes to the representation of the limbs in space. This integration allows for stimuli to be localized in external space with respect to the body. An example by Haggard and Wolpert shows the combination of tactile sensation of the hand with information about the joint angles of the arm, which allow for rapid movements of said arm to swat a fly.
=== Modular === The body schema is not represented wholly in a single region of the brain. Recent fMRI (functional Magnetic Resonance Imaging) studies confirm earlier results. For example, the schema for feet and hands are coded by different regions of the brain, while the fingers are represented by a separate part entirely.
=== Adaptable === Plastic changes to the body schema are active and continuous. For example, gradual changes to the body schema must occur over the lifetime of an individual as they grow and absolute and relative sizes of body parts change over their life span. The development of the body schema has also been shown to occur in young children. One study showed that with these children (9-, 14-, and 19-month-olds), older children handled spoons so as to optimally and comfortably grip them for use, whereas younger children tended to reach with their dominant hand, regardless of the orientation of the spoon and eventual ease of use. Short-term plasticity has been shown with the integration of tools into the body schema. The rubber hand illusion has also shown the rapid reorganization of the body schema on the timescale of seconds, showing the high level of plasticity and speed with which the body schema reorganizes. In the Illusion, participants view a dummy hand being stroked with a paintbrush, while their own hand is stroked identically. Participants may feel that the touches on their hand are coming from the dummy hand, and even that the dummy hand is, in some way, their own hand.
=== Supramodal === By its nature, body schema integrates proprioceptive, (the sense of the relative position of neighbouring parts of one's body), and tactile information to maintain a three-dimensional body representation. However, other sensory information, particularly visual, can be in the same representation of the body. This simultaneous participation means there are combined representations within the body schema, which suggests the involvement of a process to translate primary information (e.g. visual, tactile, etc.) into a single sensory modality or an abstract, amodal form.
=== Coherent === The body schema, to function properly, must be able to maintain coherent organization continuously. To do so, it must be able to resolve any differences between sensory inputs. Resolving these inter-sensory inconsistencies can result in interesting sensations, such as those experienced during the Rubber Hand Illusion.
=== Interpersonal === It is thought that an individual's body schema is used to represent both one's own body and the bodies of others. Mirror neurons are thought to play a role in the interpersonal characteristics of body schema. Interpersonal projection of one's body schema plays an important role in successfully imitating motions such as hand gestures, especially while maintaining the handedness and location of the gesture, but not necessarily copying the exact motion itself.