Adult age differences in visual word recognition: semantic encoding and episodic retention.

The present experiment examined adult age differences in semantic priming effects and subsequent episodic retention for visually presented words. Twenty-four young (18-22 years) and 24 older (58-74 years) adults participated. In a lexical decision task, each of the word targets was presented as the final item of a sentence context (i.e., a prime) that was either semantically congruous, incongruous, or neutral with regard to the target. The perceptual difficulty of the target was also varied. The semantic priming effects in lexical decision RT were equivalent in magnitude for the young and older adults. The RT data appeared to represent a generalized, age-related slowing in the speed of information processing. In unexpected tests of recall and recognition for the target words, the older adults performed significantly worse than the young adults. The present results indicate that age-related deficits in episodic memory are not accompanied by substantial changes in semantic encoding ability.