Browsing by Subject "Hippocampus"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Open Access
    Acute psychosocial stress enhances visuospatial in healthy males
    (SAGE Publications, 2013) Human, Robyn; Thomas, Kevin G F; Dreyer, Anna; Amod, Alysaa R; Wolf, Pedro S A; Jacobs, W Jake
    Previous research demonstrates that stress can disrupt a number of different cognitive systems, including verbal memory, working memory, and decision-making. Few previous studies have investigated relations between stress and visuospatial information processing, however, and none have examined relations among stress, visuospatial memory performance, and planning/ organisation of visuospatial information simultaneously. In total, 38 undergraduate males completed the copy trial of the Rey-Osterrieth Complex Figure Test. Those assigned randomly to the Stress group (n = 19) were then exposed to a laboratory-based psychosocial stressor; the others were exposed to an equivalent control condition. All then completed the delayed recall trial of the Rey-Osterrieth Complex Figure Test. Physiological and self-report measures of stress indicated that the induction manipulation was effective. Our predictions that control participants, relative to stressor-exposed participants, (a) take less time to complete the Rey-Osterrieth Complex Figure Test recall trial, (b) reproduce the figure more accurately on that trial, and (c) show better planning and more gestalt-based organisational strategies in creating that reproduction were disconfirmed. At recall, those with higher circulating cortisol levels (measured post-stress-induction) completed the drawing more accurately than those with lower circulating cortisol levels. Otherwise stated, the present data indicated that exposure to an acute psychosocial stressor enhanced visuospatial memory performance in healthy males. This data pattern is consistent with a previously proposed inverted U-shaped relationship between cortisol and cognition: Under this proposal, moderate levels of the hormone (as induced by the current manipulation) support optimal performance, whereas extremely high and extremely low levels impair performance.
  • Thumbnail Image
    Item
    Open Access
    BDNF polymorphisms are linked to poorer working memory performance, reduced cerebellar and hippocampal volumes and differences in prefrontal cortex in a Swedish elderly population
    (Public Library of Science, 2014) Brooks, Samantha J; Nilsson, Emil K; Jacobsson, Josefin A; Stein, Dan J; Fredriksson, Robert; Lind, Lars; Schiöth, Helgi B
    BACKGROUND: Brain-derived neurotrophic factor (BDNF) links learning, memory and cognitive decline in elderly, but evidence linking BDNF allele variation, cognition and brain structural differences is lacking. METHODS: 367 elderly Swedish men (n = 181) and women (n = 186) from Prospective Investigation of the Vasculature in Uppsala seniors (PIVUS) were genotyped and the BDNF functional rs6265 SNP was further examined in subjects who completed the Trail Making Task (TMT), verbal fluency task, and had a magnetic resonance imaging (MRI) scan. Voxel-based morphometry (VBM) examined brain structure, cognition and links with BDNF. RESULTS: The functional BDNF SNP (rs6265,) predicted better working memory performance on the TMT with positive association of the Met rs6265, and was linked with greater cerebellar, precuneus, left superior frontal gyrus and bilateral hippocampal volume, and reduced brainstem and bilateral posterior cingulate volumes. CONCLUSIONS: The functional BDNF polymorphism influences brain volume in regions associated with memory and regulation of sensorimotor control, with the Met rs6265 allele potentially being more beneficial to these functions in the elderly.