Dyslexia subtype with simultaneous processing of intraobject spatial relations in an "ecological syndrome".

Abstract

Three interrelated phenomena of a global visuospatial representation are discussed within the context of a subtype of "spatial dyslexia" as part of an "ecological syndrome." Results from a new test, Draw-A-Person-With-Face-In-Front (using simple measurement and requiring no graphic or aesthetic skills) showed in a third of 269 Australian Aboriginal school children a deficient representation of spatial relations within the natural pattern of the upper part of the human face. The test performance apparently is an indicator of a similarly deficient representation of the spatial relations within written signs (single letters, short, isolated functional words, and novel or "nonwords" lacking strong semantic association and imageability). The test discriminates between two modes of visuospatial pictorial (and implied mental) representation, a simultaneous and merely "interobject"-related global kind vs a successive and "intraobject"-related one. Further support for such conceptualizing is found in a positive correlation between certain low literacy skills and the specific results (in 6000 examined cases) on the new drawing test. Both inabilities implicate a simultaneous global mode of visuospatial processing, which early in life promptly elicits the infants' indiscriminate automatic "smiling response" and appears to be resorted to still later in life by persons with "spatial dyslexia." Such conceptualizing interrelates with the so far puzzling difference between "literal alexia" vs "verbal alexia" known to neuropathology (not implicated in the present cases but pointing to an underlying structuring process shared by pathological and by "ecological syndromes" alike).