- The term hyposchematia comes from the Greek words hupo (below, beneath) and schema (form, scheme, topographic map). It translates roughly as 'insufficiently detailed mapping of space'. The term hyposchématie was introduced in or shortly before 1905 by the French neurologist Pierre Bonnier (1861-1918) to denote a variant of " aschematia characterized by an underestimation of the space occupied by some part of the body. Today the term hyposchematia is used to denote a left (i.e. contralesional) shrinkage of object representations due to a lesion of the right parietal lobe. Because of its subjective nature, hyposchematia cannot be observed directly in the affected individual. However, the presence of the condition may be inferred from drawings made by these individuals. The left side of a clock characteristically is smaller than the right side, and the petals on the left side of a daisy tend to be both smaller and less numerous than on the right. Hyposchematia is considered a productive, subconscious manifestation ofneglect. It is usually classified as a "body schema illusion. The term hyposchematia was used by Bonnier in opposition to the terms "hyperschematia and " paraschematia.ReferencesBonnier, P. (1905). L'aschématie. Revue Neurologique, 13, 605-609.Rode, G., Michel, C., Rossetti, Y., Boisson, D., Vallar, G. (2006). Left size distortion (hyper-schematia) after right brain damage. Neurology, 67, 1801-1808.
Dictionary of Hallucinations. J.D. Blom. 2010.