Spatial vision in Alzheimer's disease. General findings and a case report
M. J. Nissen, S. Corkin, F. S. Buonanno, J. H. Growdon, S. H. Wray and J. Bauer
Visual contrast sensitivity to sinusoidal gratings of five spatial
frequencies was measured in 15 patients with Alzheimer's disease and in
eight control subjects. Contrast sensitivity thresholds were elevated at
all frequencies in 14 patients compared with control subjects. The 15th
patient was unique: she had an impairment in object and face recognition so
severe that she could not recognize her husband visually. Her sensitivity
to low and intermediate frequencies was markedly reduced in relation to
that of other patients, whereas her sensitivity to the highest frequency
tested equaled theirs. These observations emphasize the importance of low
spatial frequency information for visual object and face recognition.
