Owsley C, Burton-Danner K, Jackson G R
Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, AL 35294-0009, USA.
Gerontology. 2000 Nov-Dec;46(6):300-5. doi: 10.1159/000022181.
Previous studies indicate that older adults, like young adults, can efficiently search for a briefly presented visual target defined by a single salient feature presented amidst background distractors. However, little is known about older adults' ability to identify the spatial location of targets during this aspect of preattentive processing.
This study examined the extent to which older adults exhibit localization problems during feature search for a target with high conspicuity. Their performance was compared to that of younger adults.
Twenty older adults (mean age 70 years, 8 men and 12 women) and 20 younger adults (mean age 25 years, 6 men and 14 women) with good central and peripheral vision were tested. Subjects were asked to indicate via a computerized touch-screen the location of a briefly presented (80 ms) target presented amidst distracting stimuli (set size 8, 16, or 32). Targets were presented at either 10 degrees, 20 degrees, or 30 degrees eccentricity. The dependent measures were percent correct localization and, for trials in which there were errors, the spatial magnitude of the error.
Compared to young adults, older adults committed more localization errors during feature search, a problem which was accentuated with increasing target eccentricity. In addition, older adults' mislocalizations deviated from the correct location by greater distances.
Older adults have spatial localization problems in preattentive processing during feature search, which could be detrimental to the guidance and deployment of visual attention.
先前的研究表明，老年人与年轻人一样，能够有效地在由背景干扰物中呈现的单个显著特征所定义的短暂呈现的视觉目标中进行搜索。然而，对于老年人在这种前注意加工过程中识别目标空间位置的能力，我们知之甚少。
本研究考察了老年人在对具有高显著性的目标进行特征搜索时出现定位问题的程度。将他们的表现与年轻人进行比较。
测试了20名老年人（平均年龄70岁，8名男性和12名女性）和20名年轻人（平均年龄25岁，6名男性和14名女性），他们的中央和周边视力良好。受试者被要求通过计算机触摸屏指出在干扰刺激（集合大小为8、16或32）中短暂呈现（80毫秒）的目标的位置。目标呈现于10度、20度或30度的偏心度处。因变量测量指标为定位正确的百分比，对于出现错误的试验，测量错误的空间大小。
与年轻人相比，老年人在特征搜索过程中出现更多的定位错误，随着目标偏心度的增加，这个问题更加突出。此外，老年人的错误定位偏离正确位置的距离更大。
老年人在特征搜索的前注意加工过程中存在空间定位问题，这可能对视觉注意的引导和部署产生不利影响。
