PubMed Health⌕ Search

Biomedical subjects

Tanara Bowie

Publications and source records attributed to Tanara Bowie.

3 recordsLinked to original sources

Differential age effects in semantic and episodic memory.

Results from 4 experimental tasks and 8 data sets (the 4 tasks involved either multiple sessions or different stimuli) as well as a vocabulary test conducted on the same 80 participants (40 younger and 40 older adults) are reported. The authors employed 2 semantic memory tasks (lexical decision and multiplication verification) using data from 2 sessions (for a total of 4 semantic data sets) and 2 episodic memory tasks (hybrid visual search and memory search with digits and with words as stimuli). Factor analyses using slope and intercept data from the 8 experimental data sets indicated the presence of 3 latent factors: a single intercept factor for both episodic and semantic tasks and separate slope factors for episodic and semantic tasks. A structural equation model with paths from age to 3 different 1st-order latent factors (episodic central processes, semantic central processes, and combined episodic and semantic peripheral processes) fit better than general factor models. These data are consistent with a theoretical framework in which there are age-related dissociations between peripheral and central processes across semantic and episodic memory.

Adolescent↗

Differential age effects in semantic and episodic memory, Part II: Slope and intercept analyses.

This study tested for dissociations between age-related slowing in peripheral and central processes across semantic and episodic memory tasks. We report the mixed-model analysis of variance (ANOVA) results using reaction time (RT), error, and data from four different experimental tasks and eight data sets (the four tasks involved either multiple sessions or different stimuli) conducted on the same 80 participants (40 younger and 40 older adults). An earlier paper (Allen, Sliwinski, Bowie, & Madden, in press) reported the factor analysis and structural equation modeling results of this study. We employed two semantic memory tasks (lexical decision and multiplication verification) using data from two different sessions (for a total of four semantic data sets), and two episodic memory tasks (hybrid visual search and memory search with digits and with words as stimuli). For RT analyses, we found Age x Task interactions for all four episodic memory data sets, but no Age x Task interactions for the four semantic memory data sets. Also, the intercept (assumed to index peripheral processes) and slope (assumed to index central processes) analyses demonstrated that older adults (relative to younger adults) showed both intercept and slope decrements for episodic memory tasks, but only intercept decrements for semantic memory tasks. These data are consistent with a theoretical framework in which there are age-related dissociations between peripheral and central processes across semantic and episodic memory.

Adolescent↗

An emotional mediation theory of differential age effects in episodic and semantic memories.

Although there is a large decrement in central episodic memory processes as adults age, there is no appreciable decrement in central semantic memory processes (Allen et al., Journal of Gerontology: Psychological Sciences, 57B, P173-P186, 2002; Allen et al., Experimental Aging Research, 28, 111-142, 2002; Mitchell, Journal of Experimental Psychology: Learning, Memory, and Cognition, 15, 31-49, 1989). The authors develop a theory of episodic memory's connections to cognitive, emotional, and motivational systems to explain these differential age effects. The theory is discussed within the context of the cognitive neuroscience research regarding limbic system connectivity in conjunction with Damasio's notion of somatic markers (Descartes' error: Emotion, reason, and the human brain, New York: Grosset/Putnam, 1994). The central hypothesis is that elements of limbic system circuitry, including portions of the medial temporal lobes and frontal cortex, are associated with both working and long-term episodic memory performance, and by extension, with the capacity to engage in emotion-guided, self-regulatory processes that depend heavily on episodic memory. In contrast, the semantic memory system may have less shared interface with episodic and affective networks (i.e., the limbic-related system), and therefore remain independent of neurocognitive changes impacting emotional states and episodic-type memory processes. Accordingly, this framework may account for the pattern of age-related declines in episodic relative to semantic memory, particularly if older adults experience less emotional activation, and therefore fewer somatic markers, than younger adults. An initial empirical examination of this emotional mediation theory is presented, using preexisting data that include indicators of age, chronic tendency to focus on negative emotional stimuli (neuroticism), and working memory performance.

Adolescent↗