Jh. Kempen et al., EFFECT OF VISUAL IMPAIRMENT ON NEUROPSYCHOLOGICAL TEST-PERFORMANCE, Neuropsychology, development, and cognition. Section A, Journal of clinical and experimental neuropsychology, 16(2), 1994, pp. 223-231
Three vision-dependent neuropsychological tests of visual processing -
Benton's Facial Recognition (FR), Judgment of Line Orientation (JLO),
and Visual Form Discrimination (VFD) - were administered to subjects
on the same day as routine ophthalmic examination. Seventeen subjects
had Jaeger near vision of J5 (analogous to 20/50) or worse resulting f
rom refractive error, while 13 control subjects had normal near vision
of J1. Neuropsychological test scores of thesegroups were compared wi
th each other and also the published standardization group for each te
st. Low near-vision subjects' performances on FR and VFD were signific
antly poorer than both control group subjects and standardization grou
p subjects, but performance on JLO was not significantly altered. Thes
e results demonstrate that visual impairment can result in unexpectedl
y low scores on certain tests of visual processing, which suggests tha
t poor vision might alsoaffect results of other neuropsychological tes
ts that involve vision, such astests of visual processing and tests wh
ich use vision as a vehicle to delivertest stimuli to the relevant por
tions of the cortex. We therefore strongly urge examiners to secure co
ntrol over potential bias resulting from reduced vision by instituting
routine near visual acuity testing of all subjects prior to or during
neuropsychological assessment.