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ISSN 0439-755X
CN 11-1911/B

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    30 November 2009, Volume 41 Issue 11 Previous Issue    Next Issue

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    Cognition in Preclinical Dementia: Current Knowledge and Future Prospects
    Lars Bä,ckman
    2009, 41 (11):  1040-1048. 
    Abstract ( 1057 )  
    In this article, I discuss the cognitive transition from normal aging to dementia -- a period often referred to as the preclinical phase of dementia. Research shows marked preclinical cognitive deficits several years before diagnosis in both Alzheimer´s disease and vascular dementia. The most pronounced prodromal impairment is observed for measures of episodic memory, speed, and executive functioning. The global nature of the impairment is consistent with neurobiological evidence that multiple lesions in limbic and neocortical regions. Despite large mean-level differences between cases and controls long before diagnosis, the performance distributions for the two groups overlap to a large degree. An important task for future research is to find means by which to decrease this overlap. This could be accomplished by combining cognitive and other (e.g., brain-based, genetic, clinical, social) markers into the prediction models. Other pressing issues for future research include (a) delineating the point at which precipitous decline normally occurs during the preclinical period; (b) asesssing individual differences in rate of change from preclinical to clinical dementia; and (c) determining how the strength of the association between a certain factor and subsequent dementia varies as a function of time to diagnosis.
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    Differential Age and Sex Effects in Semantic Recognition of Odors and Words

    Maria Larsson, Margareta Hedner, and Jonas Olofsson
    2009, 41 (11):  1049-1053. 
    Abstract ( 1480 )  
    This study examined the impact of age and sex on olfactory function as determined by a cued odor identification test and on semantic knowledge as indexed by a vocabulary test using a large population-based sample. 1497 healthy adults varying in age from 35 to 95 years were assessed in odor identification and in vocabulary proficiency. The results showed that aging exhibited negative repercussions on performance in both tests, although the age effect was stronger in the olfactory task. Corroborating previous observations, females identified more odors than men irrespective of age. The implications of the findings are discussed.
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    Maintenance and Manipulation in Working Memory: Differential Ventral and Dorsal Frontal Cortex fMRI Activity
    Sara Pudas, Jonas Persson, L-G Nilsson &, Lars Nyberg
    2009, 41 (11):  1054-1062. 
    Abstract ( 1259 )  
    A verbal working memory protocol was designed and evaluated on a group of healthy younger adults in preparation for a large-scale functional magnetic resonance (fMRI) study on aging and memory. Letters were presented in two critical conditions: (i) maintenance, in which letters were to be memorized and kept in mind over a four second interval, and (ii) manipulation, in which letters were shifted forward in alphabetical order, and the new order was kept in mind. Analyses of fMRI data showed that the protocol elicited reliable activation in the frontal cortex, with manipulation producing more extensive activation patterns, both in whole-brain analyses and in predefined regions of interest (ROIs). There was also a distinction between dorsal and ventral lateral prefrontal regions, such that manipulation elicited more dorsolateral prefrontal activation. The protocol also elicited activation in various subcortical areas, previously associated with working-memory tasks. It was concluded that this working memory protocol is appropriate for investigating age-related changes in frontal-cortex functioning.
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    Preserved Cross-modal Priming and Aging: A Summary of Current Thoughts
    Soledad Ballesteros and Julia Mayas
    2009, 41 (11):  1063-1074. 
    Abstract ( 1051 )  
    Research on within-modal repetition priming suggests that this form of implicit memory is preserved in older adults not only for visual stimuli but also for stimuli presented to other perceptual modalities (e.g., touch, audition, and olfaction). Fewer studies, however, have examined whether priming is modality specific. Studies conducted with young adults have shown that cross-modal (vision-to-touch and touch-to-vision) transfer was similar in magnitude than within-modal transfer (vision-to-vision and touch-to-touch). A recent study further investigated whether cross-modal priming between these perceptual modalities is preserved in older adults. The results suggest that cross-modal priming between vision and touch is preserved and symmetric in both, young adults and older adults. Moreover, within-modal and cross-modal priming for ecological sounds and pictures is preserved with age. These behavioural findings and other recent neuroscience results suggest that cross-modal priming occurs in posterior extrastriate occipital areas that are preserved in aging. Future directions for research in this area include the performance of well designed cross-modal priming studies conducted in normal elderly and Alzheimer´s disease patients using different perceptual modalities, familiar and novel stimuli combining behavioural and brain imaging measures, and the inclusion of well designed priming tasks in programs directed to improving memory functions in the elderly.
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    Is Memory Impaired in Seasonal Affective Disorder? A Review of Literature
    Erik Nilsson
    2009, 41 (11):  1075-1080. 
    Abstract ( 1536 )  
    Seasonal Affective Disorder (SAD) has symptoms similar to those of mild to moderate clinical depression, and is common in places where there is seasonally less natural light. A probable cause of the disorder is deficient regulation of melatonin secretion. In contrast to what is the case in non-seasonal depression, memory impairments in SAD are insufficiently studied. Similar impairments to those shown in non-seasonal depression have been shown, but studies are generally to small for reaching statistical significance, and tests employed lack resolution to describe impairments in sufficient detail. A review of available literature is herein reported.
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    Sex Differences in Cognitive Functions
    Agneta Herlitz and Johanna Lovén
    2009, 41 (11):  1081-1090. 
    Abstract ( 1831 )  
    Here, we present an overview of sex differences in cognitive functions with a special focus on sex differences in episodic memory. Results show that women perform at a substantially higher level than men on verbal production, episodic memory, and face recognition tasks. Men perform at a higher level on visuospatial tasks, including visuospatial episodic memory tasks. The popular hypothesis that steroid hormones affect the magnitude of sex differences in cognitive functions is critically discussed, and the conclusion is that neither endogenous testosterone nor estradiol affect cognitive sex differences substantially.
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    Long-term Stability and Variability in Memory Compensation among Older Adults: Evidence from the Victoria Longitudinal Study

    Roger A. Dixon, Cindy M. de Frias
    2009, 41 (11):  1091-1101. 
    Abstract ( 1454 )  
    Two memory status groups were derived from a parent sample of older adults participating in the Victoria Longitudinal Study (VLS) in Canada. A not impaired control (NIC) group and a mild memory deficit (MMD) group were compared at baseline and longitudinally (over five waves or 12 years) regarding their use of memory compensation techniques in everyday life. We used multi-level modeling (covarying age and education) to examine baseline level differences and long-term change patterns. Baseline results showed that the MMD participants reported greater recent increases in memory compensation strategy use in everyday life. Longitudinal results showed notable 12-year stability in memory compensation use, but group-related differences in the compensatory mechanism of effort. The covariate of education (potentially a marker of cognitive reserve) was associated with differential change in three memory compensation strategies over time.
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    The Center of Lifespan Psychology at the Max Planck Institute for Human Development: Conceptual Agenda and Illustration of Research Activities
    Shu-Chen Li, Martin Lö,vdén, Sabine Schaefer, Florian Schmiedek, Yee Lee Shing, Markus Werkle-Bergner, and Ulman Lindenberger
    2009, 41 (11):  1102-1122. 
    Abstract ( 679 )  
    Founded in 1981 by the late Paul B. Baltes, the Center for Lifespan Psychology at the Max Planck Institute for Human Development has helped to establish lifespan psychology as a distinct conceptual approach within developmental psychology. Since 2004, the Center has extended its research program into developmental behavioral neuroscience. Work at the Center is guided by three propositions: (i) to study lifespan changes in behavior as interactions among maturation, learning, and senescence; (ii) to develop theories and methods that integrate empirical evidence across domains of functioning, timescales, as well as behavioral and neuronal levels of analysis; (iii) to identify mechanisms of development by exploring age-graded differences in plasticity. The Center continues to pay special attention to the age periods of late adulthood and old age, which offer unique opportunities for innovation, both in theory and practice. At the same time, it has intensified its interest in early periods of ontogeny including infancy and early childhood. In this article we report recent findings from four research projects focusing on sensory and cognitive development at behavioral and neural levels of analysis.
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