Allen Philip A, Bucur Barbara, Grabbe Jeremy, Work Tammy, Madden David J
Department of Psychology, The University of Akron, Akron, Ohio 44325-4301, USA.
Exp Aging Res. 2011 May;37(3):261-92. doi: 10.1080/0361073X.2011.568805.
It is presently unclear as to why older adults take longer than younger adults to recognize visually presented words. To examine this issue in more detail, the authors conducted two word-naming studies (Experiment 1: 20 older adults and 20 younger adults; Experiment 2: 60 older adults and 60 younger adults) to determine the relative effects of orthographic encoding (case type), lexical access (word frequency), and phonological regularity (regular vs. irregular phonology). The hypothesis was that older adults attempt to compensate for sensory and motor slowing by using progressively larger perceptual units (holistic encoding). However, if forced to use smaller perceptual units (e.g., by using mixed-case presentation), it was predicted that older adults would be particularly challenged. Older adults did show larger case-mixing effects than younger adults (suggesting that older adults' performances were especially poor when they were forced to use smaller perceptual units), but there were no age differences in word frequency or phonological regularity even though both age groups showed main effects for these variables. These results suggest that lexical access skill remains stable in the addressed (orthographic/semantic) and assembled (phonological) routes over the life span, but that older adults slow down in recognizing words because it takes them longer to normalize (perceptually "clean up") noisier sensory information.
目前尚不清楚为何老年人识别视觉呈现的单词比年轻人花费的时间更长。为了更详细地研究这个问题，作者进行了两项单词命名研究（实验1：20名老年人和20名年轻人；实验2：60名老年人和60名年轻人），以确定正字法编码（大小写类型）、词汇通达（词频）和语音规则性（规则语音与不规则语音）的相对影响。假设是老年人试图通过使用逐渐增大的感知单元（整体编码）来补偿感觉和运动的减慢。然而，如果被迫使用较小的感知单元（例如，通过使用混合大小写呈现），预计老年人会面临特别大的挑战。老年人确实比年轻人表现出更大的大小写混合效应（这表明当老年人被迫使用较小的感知单元时，他们的表现特别差），但在词频或语音规则性方面没有年龄差异，尽管两个年龄组在这些变量上都显示出主效应。这些结果表明，在整个生命周期中，词汇通达技能在已处理的（正字法/语义）和组合的（语音）路径中保持稳定，但老年人识别单词的速度较慢，因为他们需要更长的时间来规范化（在感知上“清理”）更嘈杂的感觉信息。
