Examining if being overweight really confers protection against dementia: Sixty-four year follow-up of participants in the Glasgow University alumni cohort study

BACKGROUND: Recent large-scale studies suggest that obesity and overweight may confer protection against future dementia. This observation could, however, be generated by reverse causality. That is, weight loss in the incipient phase of dementia ascribed to diminished self-care, including sub-optimal nutrition, would have the effect of generating such an inverse association. One approach to circumventing this problem would be to measure weight in a population which is young enough to be free of the symptoms of dementia which is then followed up for dementia occurrence over many decades. METHODS: In a prospective cohort study, body mass index, and other potential risk factors, were measured in 9547 male university undergraduates (mean age 20.5 years) in 1948-68 who were then linked to national mortality registers. RESULTS: Of 2537 deaths over a mean of 50.6 years follow up, 140 were ascribed to dementia. There was no association between overweight and future dementia deaths (age-adjusted hazard ratio; 95 % confidence interval: 0.93; 0.49, 1.79). CONCLUSION: In this cohort study of former university students, being overweight in youth did not confer protection against later dementia death

Line orientation adaptation: local or global?

Prolonged exposure to an oriented line shifts the perceived orientation of a subsequently observed line in the opposite direction, a phenomenon known as the tilt aftereffect (TAE). Here we consider whether the TAE for line stimuli is mediated by a mechanism that integrates the local parts of the line into a single global entity prior to the site of adaptation, or the result of the sum of local TAEs acting separately on the parts of the line. To test between these two alternatives we used the fact the TAE transfers almost completely across luminance contrast polarity [1]. We measured the TAE using adaptor and test lines that (1) either alternated in luminance polarity or were of a single polarity, and (2) either alternated in local orientation or were of a single orientation. We reasoned that if the TAE was agnostic to luminance polarity and was parts-based, we should obtain large TAEs using alternating-polarity adaptors with single-polarity tests. However we found that (i) TAEs using one-alternating-polarity adaptors with all-white tests were relatively small, increased slightly for two-alternating-polarity adaptors, and were largest with all-white or all-black adaptors. (ii) however TAEs were relatively large when the test was one-alternating polarity, irrespective of the adaptor type. (iii) The results with orientation closely mirrored those obtained with polarity with the difference that the TAE transfer across orthogonal orientations was weak. Taken together, our results demonstrate that the TAE for lines is mediated by a global shape mechanism that integrates the parts of lines into whole prior to the site of orientation adaptation. The asymmetry in the magnitude of TAE depending on whether the alternating-polarity lines was the adaptor or test can be explained by an imbalance in the population of neurons sensitive to 1st-and 2nd-order lines, with the 2nd-order lines being encoded by a subset of the mechanisms sensitive to 1st-order lines

Cognitive Reserve and the Prevention of Dementia: the Role of Physical and Cognitive Activities

Purpose of Review: The article discusses the two most significant modifiable risk factors for dementia, namely, physical inactivity and lack of stimulating cognitive activity, and their effects on developing cognitive reserve. Recent Findings: Both of these leisure-time activities were associated with significant reductions in the risk of dementia in longitudinal studies. In addition, physical activity, particularly aerobic exercise, is associated with less age-related gray and white matter loss and with less neurotoxic factors. On the other hand, cognitive training studies suggest that training for executive functions (e.g., working memory) improves prefrontal network efficiency, which provides support to brain functioning in the face of cognitive decline. Summary: While physical activity preserves neuronal structural integrity and brain volume (hardware), cognitive activity strengthens the functioning and plasticity of neural circuits (software), thus supporting cognitive reserve in different ways. Future research should examine whether lifestyle interventions incorporating these two domains can reduce incident dementia

Hvordan forstå og håndtere barn som avviser en forelder: En systematisk kartleggingsoversikt

Hovedbudskap: Samlivsbrudd er en alvorlig hendelse i barns liv. I enkelte tilfeller skjer det at barn motsetter seg samvær med en av (eller begge) foreldrene i etterkant av foreldrenes samlivsbrudd. Samværsvegring betyr at et barn over tid uttrykker sterk motstand mot samvær med en (eller begge) foreldrene. Hensikten med dette prosjektet er å kartlegge og beskrive forskningen som fins om årsaker til samværsvegring, og kliniske verktøy og/eller tiltak for å identifisere, forebygge og håndtere samværsvegring. For å identifisere relevante studier fra 2000 til 2020 utførte en bibliotekar søk i internasjonale litteratur-databaser, inkludert MEDLINE, EMBASE og PsycINFO. To medarbeidere vurderte uavhengig av hverandre studienes relevans i henhold til inklusjonskriteriene. Vi inkluderte én oversikt og 54 primærstudier. De fleste var fra USA (n=38), var tverrsnittstudier (n=23) og hadde som deltakere barn eller voksne som uttalte seg om når de var barn (n=45). De fleste studiene undersøkte foreldrefremmedgjøring (n=48). Studiene rapporterte at den underliggende motivasjonen bak foreldre-fremmedgjøring varierer og at strategiene som er brukt er mange og varierte. I studiene ble det hevdet mulige sammenhenger mellom samværsvegring eller foreldrefremmedgjøring og negative utfall. Vi fant spesifikke verktøy for identifisering av: ulike årsaker til samværsvegring (n=1) eller eksponeringsgrad av foreldrefremmedgjøring (n=10), risikovurdering av foreldrefremmedgjøring (n=1), samt tiltak for å håndtere samværsvegring (n=2) og foreldrefremmedgjøring (n=3). Denne kartleggingsoversikten fant at det er behov for mer empirisk forskning på samværsvegring utover det som fins av forskning om foreldrefremmedgjøring, studier fra andre land enn USA og studier med design som kan måle effekt av tiltak