Orientation agnosia (OA) defines the difficulty of correctly
reproducing, describing and recognizing the spatial orientation
(typically the correct cardinal axis) of visually presented
objects. The orientation difficulty is independent of the original
orientation of the object (vertical or horizontal), and has
been reported for drawings of real objects (like a house or a
kangaroo), and for meaningless stimuli (such as the Rey
Complex Figure). The term orientation agnosia is used only for
substantial (and ideally repeatable) misorientations, of which
dramatic rotations of 90 or 180 have often been reported.
Object orientation can be assessed in several ways: examples
include copying an image directly, drawing a picture
from memory, verbally describing the object's orientation, or
choosing the stimulus orientation from among alternatives.
Thus, while the phenomenon has been described as ‘rotated
drawing’, it also appears when assessed using methods other
than drawing.
Orientation agnosia is a selective disorder that dissociates
from constructional apraxia and visual object agnosia. Thus,
despite substantial orientation errors, patients are able to
accurately reproduce and name visually presented objects,
suggesting that the processing of shape information is more
intact.
The label “Orientation agnosia” applies only when the
orientation errors cannot be attributed to aphasia, sensorymotor
impairments, intelligence deficits or any other disorders
that could prevent task completion.