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- Marklund, Petter, 1968-
(author)
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Shared component processes in working memory and long-term memory : Insights from functional brain imaging
- 2004
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Licentiate thesis (other academic/artistic)abstract
- Marklund, P. (2004). Shared component processes in working memory and long-term memory: Insights from functional brain imaging. Department of Psychology, Umeå University, S-901 87 Umeå SwedenRecent findings from functional neuroimaging studies have shown pronounced similarities in the functional brain activity patterns associated with tests of various cognitive functions. This thesis investigates shared component processes in working memory and declarative long-term memory. Study 1 showed a common pattern of increased activity in four anatomically distinct regions in prefrontal cortex during three tests each of working memory, episodic memory, and semantic memory. Such similarities may reflect shared demands on working-memory processes across all tests or increased demands on attentional mechanisms. Study 2 was designed to dissociate these possibilities by measuring sustained and transient brain activity during tests of working memory, long-term memory and sustained attention. The results provided support for the notion that one basis for overlapping activations is increased attentional demands, but some activity seems to reflect cognitive control related to mnemonic processes. Taken together, the results indicate that it is critical for taxonomies of cognitive functions to consider similarities in underlying cognitive and associated neurobiological component processes.
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| 2. |
- Sundström, Anna, 1969-, et al.
(author)
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APOE influences on neurosychological function after mild head injury : within-person comparisons
- 2004
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In: Neurology. - Minneapolis, Minn : Lancet Publications Inc.. - 0028-3878 .- 1526-632X. ; 62:11, s. 1963-1966
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Journal article (peer-reviewed)abstract
- Objective: To examine the relationship between neuropsychological outcome following mild head injury (MHI) and APOE genotype. Methods: Data from a population-based longitudinal study (n = 3,500) were used to identify 34 adults who experienced MHI during the course of the study. Their pre- and postinjury performances on a battery of nine neuropsychological tests were compared within person, and the postinjury performance was compared with that of age- and gender-matched control subjects. Results: The within-person comparisons showed that participants with at least oneAPOE ε4 allele (n = 11) had a significantly decreased postinjury performance on three of the tests, whereas the postinjury performance for APOE ε4-negative participants (n = 23) was unchanged. There was no significant difference in postinjury performance between participants with/without the ε4 allele, and neither group was impaired relative to controls. Conclusions: APOE genotype may influence the outcome following an MHI. Pre/postinjury within-person comparisons seem more sensitive than control group comparisons for detecting injury-related effects.
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