The Hooper Visual Organization Test (VOT), a commonly applied
neuropsychological test of visual spatial ability, is used for
assessing patients with suspected right hemisphere, or parietal lobe
involvement. A controversy has developed over whether the inferences of
this test metric can be assumed to involve global, lateralized, or
regional functionality. In this study, the characteristic visual
organization and object naming aspects of the VOT task presentation
were adapted to a functional MR imaging (fMRI) paradigm to probe the
neuroanatomic correlates of this neuropsychological test. Whole brain
fMRI mapping results are reported on a cohort of normal subjects.
Bilateral fMRI responses were found predominantly in the posterior
brain, in regions of superior parietal lobules, ventral
temporal-occipital cortex, and posterior visual association areas, and
to a lesser extent, the frontal eye fields bilaterally, and left
dorsolateral prefrontal cortex. The results indicate a general brain
region or network in which VOT impairment, due to its visuospatial and
object identification demands, is possible to be detected. Discussion
is made of interpretive limitations when adapting neuropsychological
tests to fMRI analysis. (JINS, 2004, 10,
939–947.)
Measuring visual form discrimination with blur thresholds
