The Semantic Memory Imaging In Late Life Pilot Study

Introduction: Several functional magnetic resonance imaging (fMRI) studies have analyzed the famous name discrimination task (FNDT), an uncontrolled semantic memory probe requiring discrimination between famous and unfamiliar individuals. Completion of this simple task recruits a semantic memory network that has shown utility in determining risk for Alzheimer\u27s disease (AD). Specific semantic memory probes using biographical information associated with famous individuals may build on previous findings and yield superior information regarding risk for AD. Method: Sixteen cognitively intact elders completed the FNDT and two novel tasks during fMRI: Categories (matching famous individuals to occupational categories) and Attributes (matching famous individuals to specific bodies of work or life events). Five participants were carriers of the Apolipoprotein E (APOE) ε4 allele. Results: Relative to their respective control tasks, participants recruited brain regions for all three tasks consistent with previous research, including left temporal lobe, left angular gyrus, precuneus, posterior cingulate, and anterior cingulate. The FNDT generated significantly more activity than the other tasks in anterior cingulate and several posterior regions. Categories had significantly lesser activity than other tasks in inferior parietal lobe, precuneus, and posterior cingulate. Attributes, the most specific semantic probe, demonstrated the strongest left lateralization with significantly greater activity in left inferior frontal gyrus and anterior temporal lobe. APOE ε4 carriers had regions with greater activity across all three tasks, with the greatest number of regions for Attributes, including in left anterior temporal lobe. Discussion: This pilot study identified neural correlates of different levels of semantic processing. The FNDT, an unconstrained semantic knowledge probe, demonstrated greater activity across most regions. The Attributes task, a specific semantic probe, had focused left-lateralized activity, including anterior temporal lobe and inferior frontal gyrus. APOE ε4 carriers demonstrated significantly greater activity in left anterior temporal lobe during Attributes only, demonstrating this task\u27s potential utility for determination of AD risk

Model Municipal Ordinance Project Designed to Facilitate Wind and Solar Projects and Green Buildings

Soaring oil prices and the reality of climate change have underscored the heed to reduce U.S. fossil fuel dependence by improving energy efficiency and by developing and expanding renewable sources of energy. The International Energy Agency declared in 2010 that [i]ncreasing energy efficiency, much of which can be achieved through low-cost options, offers the greatest potential for reducing CO2 emissions over the period to 2050. Furthermore, increasing our reliance on renewable resources such as wind and solar energy is not only a prudent measure in helping America to improve its energy security, but is a necessary component of a basket of measures that must be employed in order to limit atmospheric CO2 to a concentration that would avert the most damaging climate change. Presently, wind and solar energy account for only around one percent of the U.S. electricity supply. Yet the Department of Energy projects that as much as twenty percent of America\u27s electric power could be generated from wind energy alone by the year 2030

The Contribution of Blood Serum Biomarkers to the Prediction of Cognitive Decline by fMRI and Apolipoprotein-E in Healthy Older Adults

Biomarkers are a promising approach to the prediction and early intervention of Alzheimer\u27s disease. We demonstrated that cortical functional MRI (fMRI) activation during a semantic memory task and apolipoprotein-E ?4 allele inheritance (APOE?4) effectively predicted cognitive decline after 18-months in healthy, asymptomatic elders. Hippocampal volume added modest prediction, while AD family history and demographics were ineffective. Previous studies have linked plasma homocysteine (tHcy), vitamin B12 and creatinine values to cognitive funcitoning, cortical atrophy, hippocampal atrophy and neuropathology, and vascular integrity. Here we incorporated total plasma homocysteine (tHcy), B12 creatinine values into our previous predictive models. Of 78 healthy elders, 27 (34.6%) exhibited significant cognitive decline after 18-months. tHcy, but not B12 or creatinine, was marginally positively correlated with cortical semantic memory fMRI activation, particularly in stable participants. Logistic regression showed that tHcy, when added to APOE?4 and cortical fMRI, was a significant predictor of outcome and strengthed the already significant model (p = .007; C = .80 and R2 = .37). However, control for B12 and creatinine covariates diminished tHcy as a predictor (p = .084), though the model was still stronger than without this factor (C = .78 and R = 31). tHcy did not significantly interact with APOE?4, as has previously been reported. Neither B12 nor creatinine was similarly effective as a predictor. These results suggest that commonly investigated blood serum biomarkers are at best weakly associated with predicting age- and dementia-related cognitive decline in healthy, asymptomatic elders. fMRI and APOE?4 presently provided the best predictive model

The Contribution of Blood Serum Biomarkers to the Prediction of Cognitive Decline by fMRI and Apolipoprotein-E in Healthy Older Adults

Biomarkers are a promising approach to the prediction and early intervention of Alzheimer\u27s disease. We demonstrated that cortical functional MRI (fMRI) activation during a semantic memory task and apolipoprotein-E ?4 allele inheritance (APOE?4) effectively predicted cognitive decline after 18-months in healthy, asymptomatic elders. Hippocampal volume added modest prediction, while AD family history and demographics were ineffective. Previous studies have linked plasma homocysteine (tHcy), vitamin B12 and creatinine values to cognitive funcitoning, cortical atrophy, hippocampal atrophy and neuropathology, and vascular integrity. Here we incorporated total plasma homocysteine (tHcy), B12 creatinine values into our previous predictive models. Of 78 healthy elders, 27 (34.6%) exhibited significant cognitive decline after 18-months. tHcy, but not B12 or creatinine, was marginally positively correlated with cortical semantic memory fMRI activation, particularly in stable participants. Logistic regression showed that tHcy, when added to APOE?4 and cortical fMRI, was a significant predictor of outcome and strengthed the already significant model (p = .007; C = .80 and R2 = .37). However, control for B12 and creatinine covariates diminished tHcy as a predictor (p = .084), though the model was still stronger than without this factor (C = .78 and R = 31). tHcy did not significantly interact with APOE?4, as has previously been reported. Neither B12 nor creatinine was similarly effective as a predictor. These results suggest that commonly investigated blood serum biomarkers are at best weakly associated with predicting age- and dementia-related cognitive decline in healthy, asymptomatic elders. fMRI and APOE?4 presently provided the best predictive model

Functional Magnetic Resonance Imaging of Semantic Memory as a Presymptomatic Biomarker of Alzheimer’s Disease Risk

Extensive research efforts have been directed toward strategies for predicting risk of developing Alzheimer\u27s disease (AD) prior to the appearance of observable symptoms. Existing approaches for early detection of AD vary in terms of their efficacy, invasiveness, and ease of implementation. Several non-invasive magnetic resonance imaging strategies have been developed for predicting decline in cognitively healthy older adults. This review will survey a number of studies, beginning with the development of a famous name discrimination task used to identify neural regions that participate in semantic memory retrieval and to test predictions of several key theories of the role of the hippocampus in memory. This task has revealed medial temporal and neocortical contributions to recent and remote memory retrieval, and it has been used to demonstrate compensatory neural recruitment in older adults, apolipoprotein E ε4 carriers, and amnestic mild cognitive impairment patients. Recently, we have also found that the famous name discrimination task provides predictive value for forecasting episodic memory decline among asymptomatic older adults. Other studies investigating the predictive value of semantic memory tasks will also be presented. We suggest several advantages associated with the use of semantic processing tasks, particularly those based on person identification, in comparison to episodic memory tasks to study AD risk. Future directions for research and potential clinical uses of semantic memory paradigms are also discussed. This article is part of a Special Issue entitled: Imaging Brain Aging and Neurodegenerative disease

Weak Social Support as an Indicator for Worse Trauma Related Symptoms

This study investigated the relationship between social support and trauma related symptoms in trauma exposed participants. Using the SCID and CAPS, weak family support factors were found to be associated with a greater number and severity of trauma related symptoms; suggesting that family support is important for trauma exposed people

Functional Correlates Of Verbal Working Memory In Healthy Aging And Early Alzheimer\u27s Disease

Deficits in the working memory system are common in patients diagnosed with Alzheimer\u27s disease (AD). However, little is known regarding the neurobiological basis of this impairment. The current study examined the neurobiological functional correlates of the working memory system in early AD patients and cognitively intact control participants using a word list repetition task performed during positron emission tomography (PET). Compared to a reading control task, both the AD and control groups utilized a network of parietal, frontal, and cerebellar regions while completing the word rehearsal task. However, control participants displayed greater activation in all regions, especially in the parietal lobes. In the frontal lobes, AD patients displayed right-lateralized recruitment compared to bilateral frontal recruitment in the control group. Comparison of 10-word list rehearsal to 5-word indicated a shift from parietal activity to more prominent frontal and cerebellar activity in the control group with increased load demands. This type of shift in activity was not observed in the patient group. Additionally, parietal activity was inversely correlated with working memory performance in the control group only. Left cerebellar activity was correlated with behavioral performance in both groups. Overall, it appears that the working memory deficits observed in AD patients may be related to dysfunction in parietal contributions to the working memory network, and compensatory activity may occur in the frontal lobes

Performance Variability During a Multitrial List-Learning Task as a Predictor of Future Cognitive Decline in Healthy Elders

Introduction: In clinical settings, neuropsychological test performance is traditionally evaluated with total summary scores (TSS). However, recent studies demonstrated that indices of intraindividual variability (IIV) yielded unique information complementing TSS. This 18-month longitudinal study sought to determine whether IIV indices derived from a multitrial list-learning test (the Rey Auditory Verbal Learning Test) provided incremental utility in predicting cognitive decline in older adults compared to TSS. Method: Ninety-nine cognitively intact older adults (aged 65 to 89 years) underwent neuropsychological testing (including the Rey Auditory Verbal Learning Test) at baseline and 18-month follow-up. Participants were classified as cognitively stable (n = 65) or declining (n = 34) based on changes in their neuropsychological test performance. Logistic regression modeling tested the ability of baseline TSS indices (sum of Trials 1–5, immediate recall, and delayed recall) and IIV indices (lost access and gained access) to discriminate between stable and declining individuals. Results: Higher values of both lost access and gained access at baseline were associated with an increased risk for decline at 18-month follow-up. Further, the IIV indices provided predictive utility above and beyond the TSS indices. Conclusion: These results highlight the value of analyzing IIV in addition to TSS during neuropsychological evaluation in older adults. High levels of IIV may reflect impairment in anterograde memory systems and/or executive dysfunction that may serve as a prognostic indicator of cognitive decline