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BackgroundWhile obesity has been shown to be a risk factor for Alzheimer's disease, the potential mechanisms underlying this risk may be clarified with better understanding of underlying physiology in obese persons.ObjectiveTo identify patterns of cerebral perfusion abnormality in adults as a function of body mass index (BMI) defined weight categories, including overweight or obese status.MethodsA large psychiatric cohort of 35,442 brain scans across 17,721 adults (mean age 40.8±16.2 years, range 18-94 years) were imaged with SPECT during baseline and concentration scans, the latter done after each participant completed the Connors Continuous Performance Test II. ANOVA was done to identify patterns of perfusion abnormality in this cohort across BMI designations of underweight (BMI

ImportanceCerebral amyloid-β aggregation is an early event in Alzheimer disease (AD). Understanding the association between amyloid aggregation and cognitive manifestation in persons without dementia is important for a better understanding of the course of AD and for the design of prevention trials.ObjectiveTo investigate whether amyloid-β aggregation is associated with cognitive functioning in persons without dementia.Design, setting, and participantsThis cross-sectional study included 2908 participants with normal cognition and 4133 with mild cognitive impairment (MCI) from 53 studies in the multicenter Amyloid Biomarker Study. Normal cognition was defined as having no cognitive concerns for which medical help was sought and scores within the normal range on cognitive tests. Mild cognitive impairment was diagnosed according to published criteria. Study inclusion began in 2013 and is ongoing. Data analysis was performed in January 2017.Main outcomes and measuresGlobal cognitive performance as assessed by the Mini-Mental State Examination (MMSE) and episodic memory performance as assessed by a verbal word learning test. Amyloid aggregation was measured with positron emission tomography or cerebrospinal fluid biomarkers and dichotomized as negative (normal) or positive (abnormal) according to study-specific cutoffs. Generalized estimating equations were used to examine the association between amyloid aggregation and low cognitive scores (MMSE score ≤27 or memory z score≤-1.28) and to assess whether this association was moderated by age, sex, educational level, or apolipoprotein E genotype.ResultsAmong 2908 persons with normal cognition (mean [SD] age, 67.4 [12.8] years), amyloid positivity was associated with low memory scores after age 70 years (mean difference in amyloid positive vs negative, 4% [95% CI, 0%-7%] at 72 years and 21% [95% CI, 10%-33%] at 90 years) but was not associated with low MMSE scores (mean difference, 3% [95% CI, -1% to 6%], P = .16). Among 4133 patients with MCI (mean [SD] age, 70.2 [8.5] years), amyloid positivity was associated with low memory (mean difference, 16% [95% CI, 12%-20%], P

Prior work suggests that differences in brain morphology and task-evoked neural activity may underlie extraordinary creative achievement. Here, we extend these findings by focusing on resting blood oxygen level–dependent (rsBOLD) functional connectivity differences between eminent creators from diverse fields of expertise and a "smart" comparison group of age- and education-matched non-eminent thinkers. Participants underwent rsBOLD imaging, along with a high-resolution structural brain scan, and completed a series of demographic and behavioral measures. The results revealed significant differences in rsBOLD connectivity between the eminent and noneminent thinkers. Eminent thinkers showed increased connectivity between (a) the right central operculum and the bilateral parietal operculum, right supramarginal gyrus, and left precentral gyrus; (b) the right precentral gyrus and the right postcentral gyrus; (c) the left parietal operculum and the right central operculum and the right sensorimotor cortex; and (d) the posterior cingulate gyrus and the right precentral gyrus. In contrast, they showed decreased connectivity between (a) the posterior cingulate gyrus and the left supracalcarine cortex and (b) between the left occipital fusiform gyrus and the left frontal operculum. These results suggest that extraordinary creativity may be associated with measurable differences in functional connectivity, particularly in areas that support creative functions. This study examined functional connectivity as measured by resting blood oxygen level–dependent MRI in individuals with exceptionally high creativity. Eminent creators from diverse fields were compared to an age- and education-matched control group. Eminence was assessed based on their Creative Achievement Questionnaire scores. Extraordinarily creative individuals showed increased functional connectivity between the left and right hemispheres and between frontoparietal and sensorimotor regions. These findings help elucidate the neurophysiological mechanisms of exceptionally high creativity. [ABSTRACT FROM AUTHOR]