The Japanese journal of neuropsychology

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ArticleTitle	Object orientation agnosia: Cognition of object orientation in three dimensional orientation change
Language	J
AuthorList	Takashi Nogawa¹⁾, Hajime Hirabayashi¹⁾ and Hiromasa Kotaki²⁾
Affiliation	¹⁾Department of Clinical Psychology, Kakeyu-Misayama Rehabilitation Center, Kakeyu Hospital ²⁾Department of Speech Therapy, Nara City Hospital
Publication	Japanese Journal of Neuropsychology: 32 (4), 347-360, 2016
Received	Aug 7, 2015
Accepted	Mar 17, 2016
Abstract	Object orientation agnosia involving the orientation of two-dimensional material has been studied, but little is known about problems in three-dimensional orientation. In this study, we conducted orientation identification and discrimination tasks using photographs taken from various angles of a teapot to a patient with object orientation agnosia. She showed normal performance with front/rear/top/bottom orientation, could not identify right and left sides, and performed poorly with oblique views. Discrimination of orientation change in two-dimensional linear transformation such as upright/inverted, mirror, and upright/rotated images tended to be significantly worse than orientation discrimination front/rear/top/bottom views each other, and lower than including the left/right sides are direction changes in the three dimensional space. Therefore, discrimination of orientation change in two dimensional linear transformation and in the three dimensional space show differences in difficulty or involve different processes. Based on the patient's performance, we propose the following processes of cognition orientation for normally functioning individuals: front/rear/top/bottom locations are included in the initial mental representation and described adequately by language. Right/left orientations are (1) first described as side locations and then (2) calculated to distinguish between them as necessary. Oblique orientation is (1) usually described only vaguely, and then (2) calculated from axes as necessary. In discriminating orientations in two dimensional linear transformation, (1) axes are extracted, (2) redefined to another coordinate system, and (3) compared with each other. The patient showed normal performance in the first steps of all these processes, but showed impairment in later steps which require more advanced spatial information processing for additional computation as well as a detailed description and redefinition of the coordinates. In addition, the level of the morphological similarity of views was considered a factor affecting the orientation judgment.
Keywords	agnosia for object orientation, three-dimension, coordinate system, intrinsic axis, internal representation