Automatic semantic priming with various category relations in Alzheimer's disease and normal aging.

Abstract

The 6 experiments reported here tested the effects of various category relations on automatic semantic priming in 20 Alzheimer's disease (AD), 20 older control, and 22 younger control subjects. The tasks were either word pronunciation or lexical decision; the prime-target stimulus-onset asynchrony (SOA) was always 250 ms. A variety of category relationships between prime and target were examined: highly associated category comembers, subordinate-superordinate or superordinate-subordinate pairs, and pairs selected on the basis of category typically to form typical-typical, atypical-typical, typical-atypical, and atypical-atypical pairings. Both for AD versus older control subjects and for older versus younger control subjects, no significant group differences were found in the magnitude of overall semantic priming or in the effects on priming of factors pertaining to the prime-target relationship.

Aging Influences the Neural Correlates of Lexical Decision but Not Automatic Semantic Priming

“…Also consistent with previous findings, older adults showed comparable behavioral semantic priming effect sizes as young adults (Howard 1983;Madden 1986;Ober et al 1991). The present study explored the functional neuroanatomic correlates of these frequently observed behavioral findings.…”

“…However, strategic processes required to complete the LD task can be reduced substantially when the target word is preceded by a semantically related prime word (e.g., bread--butter) (Posner and Snyder 1975;Neely 1977). Under these conditions, older adults tend to show comparable semantic priming effect sizes as young adults (Howard 1983;Madden 1986;Ober et al 1991). These findings suggest that older adults require more time to perform LDs than young adults under effortful conditions that emphasize strategic processes (unprimed conditions) but retain cognitive mechanisms that enable facilitation of LD (semantically primed conditions).…”

Convergent behavioral and neuropsychological evidence for a distinction between identification and production forms of repetition priming.

“…These dissociations in patients with neurological disease indicate that different neural systems support identification and production priming. Indeed, AD patients often show intact priming on identification tasks, including word and nonword identification (e.g., Fleischman et al, 1995;Keane et al, 1991Keane et al, ,1994, lexical decision (Balota & Ferraro, 1996;Ober & Shenault, 1988;Ober, Shenault, Jagust, & Stillman, 1991), picture naming (Experiment 1 in the present study ;Mitchell, 1988;Sullivan, Faust, & Balota, 1995), word naming (Balota & Duchek, 1991;Ober et al, 1991), and incomplete-picture identification (when compared with amnesic patients, Gabrieli et al, 1994). Conversely, AD patients often show impaired priming on production tasks, including word-stem completion (Experiment 1 in the present study; Gabrieli et al, 1994;Heindel et al, 1989;Keane et al, 1991;Salmon et al, 1988;Shimamura et al, 1987), word-association production (Brandt et al, 1988;Carlesimo et al, 1995;Salmon et al, 1988), and categoryexemplar production (Experiment 3 in the present study; Monti et al, 1996).…”

Memory, brain and aging: The good, the bad and the promising

“…A reduction in response time, when associative and semantic linkages are present versus absent, comprises the semantic priming effect. With semantic priming tasks, the preservation of a wide variety of semantic knowledge about objects and their relationships has been demonstrated, not only for healthy elderly adults but also for patients with Alzheimer's disease (Ober 2002;Ober et al 1991).…”