Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642-0673, USA.
J Alzheimers Dis. 2012;31(3):613-21. doi: 10.3233/JAD-2012-112201.
We tested whether visual processing impairments in aging and Alzheimer's disease (AD) reflect uniform posterior cortical decline, or independent disorders of visual processing for reading and navigation. Young and older normal controls were compared to early AD patients using psychophysical measures of visual word and motion processing. We find elevated perceptual thresholds for letters and word discrimination from young normal controls, to older normal controls, to early AD patients. Across subject groups, visual motion processing showed a similar pattern of increasing thresholds, with the greatest impact on radial pattern motion perception. Combined analyses show that letter, word, and motion processing impairments are independent of each other. Aging and AD may be accompanied by independent impairments of visual processing for reading and navigation. This suggests separate underlying disorders and highlights the need for comprehensive evaluations to detect early deficits.
我们测试了在衰老和阿尔茨海默病（AD）中视觉处理损伤是否反映了后皮质的均匀衰退，或者是否反映了阅读和导航的视觉处理的独立障碍。我们将年轻和老年正常对照组与早期 AD 患者进行了比较，使用了视觉文字和运动处理的心理物理测量方法。我们发现，与年轻正常对照组相比，年长正常对照组和早期 AD 患者的字母和单词辨别知觉阈值升高。在整个受试者组中，视觉运动处理的阈值呈递增模式，其中对放射状图案运动感知的影响最大。综合分析表明，字母、单词和运动处理障碍彼此独立。衰老和 AD 可能伴随着阅读和导航的视觉处理的独立障碍。这表明存在不同的潜在障碍，并强调需要进行全面评估以发现早期缺陷。
