Nelson Butters

Bio: Nelson Butters is an academic researcher from University of California, San Diego. The author has contributed to research in topics: Dementia & Recall. The author has an hindex of 92, co-authored 228 publications receiving 32060 citations. Previous affiliations of Nelson Butters include National Institutes of Health & United States Department of Veterans Affairs.

Physical basis of cognitive alterations in Alzheimer's disease: synapse loss is the major correlate of cognitive impairment.

Abstract: We present here both linear regressions and multivariate analyses correlating three global neuropsychological tests with a number of structural and neurochemical measurements performed on a prospective series of 15 patients with Alzheimer's disease and 9 neuropathologically normal subjects. The statistical data show only weak correlations between psychometric indices and plaques and tangles, but the density of neocortical synapses measured by a new immunocytochemical/densitometric technique reveals very powerful correlations with all three psychological assays. Multivariate analysis by stepwise regression produced a model including midfrontal and inferior parietal synapse density, plus inferior parietal plaque counts with a correlation coefficient of 0.96 for Mattis's Dementia Rating Scale. Plaque density contributed only 26% of that strength.

Neuropsychology of memory

Abstract: Part I: Studies of Normal and Abnormal Memory in Humans. Broadbent, Clark, Zola, Squire, The Medial Temporal Lobe and Memory. Mayes, Exploring the Neural Bases of Complex Memory. Verfaellie, Keane, Impaired and Preserved Memory Processes in Amnesia. Kopelman, Stanhope, Anterograde and Retrograde Amnesia Following Frontal, Temporal Lobe, or Diencephalic Lesions. Shimamura, Relational Binding Theory and the Role of Consolidation in Memory Recall. Paller, Cross-Cortical Consolidation as the Core Defect in Amnesia: Prospects for Hypothesis Testing with Neuropsychology and Neuroimaging. Baddeley, Developmental Amnesia: A Challenge to Current Models? Disterhoft, Carrillo, Fortier, Gabrieli, Knuttinen, McGlinchey-Berroth, Preston, Weiss, Impact of Temporal Lobe Amnesia, Aging, and Awareness on Human Eyeblink Conditioning. Schacter, Verfaellie, Koutstaal, Memory Illusions in Amnesic Patients: Findings and Implications. Rapcsak, Nielsen, Glisky, Kaszniak, The Neuropsychology of False Facial Recognition. Knowlton, The Role of the Basal Ganglia in Learning and Memory. Rugg, Herron, Morcom, Electrophysiological Studies of Retrieval Processing. McDermott, Buckner, Functional Neuroimaging Studies of Memory Retrieval. Wagner, Cognitive Control and Episodic Memory: Contributions from Prefrontal Cortex. Nyberg, Where Encoding and Retrieval Meet the Brain. Dolan, Strange, Hippocampal Novelty Responses Studied with Functional Neuroimaging. D'Esposito, Postle, The Neural Basis of Working Memory Storage, Rehearsal, and Control Processes: Evidence from Patient and Functional Magnetic Resonance Imaging Studies. Doyon, Ungerleider, Functional Anatomy of Motor Skill Learning. Martin, van Turennout, Searching for the Neural Correlates of Object Priming. Albert, Moss, Neuropsychological Approaches to Preclinical Identification of Alzheimer's Disease. Wilson, Memory Rehabilitation. Winocur, Hasher, Circadian Rhythms and Memory in Aged Humans and Animals. Part II: Studies of Memory in Nonhuman Primates. Suzuki, Cortical Memory Systems in the Nonhuman Primate: An Anatomical and Physiological Perspective. Takahashi, Miyashita, Neuronal Representation of Visual Long-Term Memory and Its Top-Down Executive Processing. Buffalo, Desimone, Multiple Neuronal Mechanisms for Memory in the Anterior Inferior Temporal Cortex of Monkeys. Bachevalier, Nemanic, Alvarado, The Medial Temporal Lobe Structures and Object Recognition Memory in Nonhuman Primates. Murray, Brasted, Wise, Arbitrary Sensorimotor Mapping and the Life of Primates. Part III: Studies of Memory in Rodents and Birds. Eichenbaum, Declarative Memory: Cognitive Mechanisms and Neural Codes. Moser, Hollup, Moser, Representation of Spatial Information by Dynamic Neuronal Circuits in the Hippocampus. Aggleton, Brown, Integrating Systems for Event Memory: Testing the Contribution of the Fornix. Kesner, Gilbert, Lee, Subregional Analysis of Hippocampal Function in the Rat. Kilgard, How Sensory Experience Shapes Cortical Representations. Baxter, Murg, The Basal Forebrain Cholinergic System and Memory: Beware of Dogma. McGaugh, The Amygdala Regulates Memory Consolidation. Gold, Memory Modulation: Regulating Interactions between Multiple Memory Systems. Schoenbaum, Setlow, Gallagher, Orbitofrontal Cortex: Modeling Prefrontal Function in Rats. Mayfield, Korzus, Genetics of Memory in the Mouse. Clayton, Griffiths, Testing Episodic-Like Memory in Animals.

The Lewy body variant of Alzheimer's disease A clinical and pathologic entity

Abstract: Thirty-six clinically diagnosed and pathologically confirmed Alzheimer9s disease (AD) patients included 13 with cortical and subcortical Lewy bodies (LBs). The patients with LBs appeared to constitute a distinct neuropathologic and clinical subset of AD, the Lewy body variant (LBV). The LBV group showed gross pallor of the substantia nigra, greater neuron loss in the locus ceruleus, substantia nigra, and substantia innominata, lower neocortical ChAT levels, and fewer midfrontal tangles than did the pure AD group, along with a high incidence of medial temporal lobe spongiform vacuolization. Analysis of neuropsychological tests from 9 LBV subjects and 9 AD patients matched for age and degree of dementia revealed greater deficits in attention, fluency, and visuospatial processing in the LBV group. Similar comparisons of neurologic examinations showed a significant increase in masked facies; in addition there was an increase in essential tremor, bradykinesia, mild neck rigidity, and slowing of rapid alternating movements in the LBV group. Extremity rigidity, flexed posture, resting tremor, or other classic parkinsonian features were not characteristic of the LBV patient. In some cases, it may be possible to diagnose LBV premortem on the basis of the clinical and neuropsychological features.

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD). Part V. A normative study of the neuropsychological battery

Abstract: The neuropsychological tests developed for the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) are currently used to measure cognitive impairments of Alzheimer's disease (AD) in clinical investigations of this disorder. This report presents the normative information for the CERAD battery, obtained in a large sample (n = 413) of control subjects (ages 50 to 89) who were enrolled in 23 university medical centers in the United States participating in the CERAD study from 1987 to 1992. We compared separately the performance of subjects with high (> or = 12) and low (< 12) years of formal education. For many of the individual cognitive measures in the highly educated group, we observed significant age and gender effects. Only the praxis measure showed a significant age effect in the low-education group. Delayed recall, when adjusted for amount of material acquired (savings), was relatively unaffected by age, gender, and level of education. Our findings suggest that the savings scores, in particular, may be useful in distinguishing between AD and normal aging.

Detection of Abnormal Memory Decline in Mild Cases of Alzheimer's Disease Using CERAD Neuropsychological Measures

Abstract: • The present study was designed to determine which of the memory tasks included in the CERAD ( C onsortium to E stablish a R egistry for A lzheimer's D isease) neuropsychological battery best differentiate patients with early Alzheimer's disease from cognitively normal elderly control subjects and also best distinguish between the various levels of severity of the dementia process. A sample of CERAD patients with Alzheimer's disease was stratified by disease severity into those with mild, moderate, or severe dementia and matched with control subjects for sex, age, and education. Using multivariate procedures and cutting scores, the efficacy of each memory measure in distinguishing between these groups and control subjects was determined. The test for delayed recall was found to be the best overall discriminatory measure. The other tests of memory, ie, immediate recall, intrusion errors, and recognition memory, had poor overall discriminability. None of the CERAD memory measures were found to be particularly powerful in staging the severity of dementia. These findings suggest that tests for delayed recall may be particularly useful in the early detection of Alzheimer's disease and should be considered in screening batteries for dementia in community surveys.

Clinical diagnosis of Alzheimer's disease : report of the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer's Disease

Abstract: Clinical criteria for the diagnosis of Alzheimer's disease include insidious onset and progressive impairment of memory and other cognitive functions. There are no motor, sensory, or coordination deficits early in the disease. The diagnosis cannot be determined by laboratory tests. These tests are important primarily in identifying other possible causes of dementia that must be excluded before the diagnosis of Alzheimer's disease may be made with confidence. Neuropsychological tests provide confirmatory evidence of the diagnosis of dementia and help to assess the course and response to therapy. The criteria proposed are intended to serve as a guide for the diagnosis of probable, possible, and definite Alzheimer's disease; these criteria will be revised as more definitive information become available.

An integrative theory of prefrontal cortex function

Abstract: ▪ Abstract The prefrontal cortex has long been suspected to play an important role in cognitive control, in the ability to orchestrate thought and action in accordance with internal goals. Its neural basis, however, has remained a mystery. Here, we propose that cognitive control stems from the active maintenance of patterns of activity in the prefrontal cortex that represent goals and the means to achieve them. They provide bias signals to other brain structures whose net effect is to guide the flow of activity along neural pathways that establish the proper mappings between inputs, internal states, and outputs needed to perform a given task. We review neurophysiological, neurobiological, neuroimaging, and computational studies that support this theory and discuss its implications as well as further issues to be addressed

Chapter 11 Working memory

Abstract: Publisher Summary This chapter focuses on the modern notion of short-term memory, called working memory. Working memory refers to the temporary maintenance of information that was just experienced or just retrieved from long-term memory but no longer exists in the external environment. These internal representations are short-lived, but can be maintained for longer periods of time through active rehearsal strategies, and can be subjected to various operations that manipulate the information in such a way that makes it useful for goal-directed behavior. Working memory is a system that is critically important in cognition and seems necessary in the course of performing many other cognitive functions, such as reasoning, language comprehension, planning, and spatial processing. This chapter demonstrates the functional importance of dopamine to working memory function in several ways. Elucidation of the cognitive and neural mechanisms underlying human working memory is an important focus of cognitive neuroscience and neurology for much of the past decade. One conclusion that arises from research is that working memory, a faculty that enables temporary storage and manipulation of information in the service of behavioral goals, can be viewed as neither a unitary, nor a dedicated system. Data from numerous neuropsychological and neurophysiological studies in animals and humans demonstrates that a network of brain regions, including the prefrontal cortex, is critical for the active maintenance of internal representations.

Sources of Method Bias in Social Science Research and Recommendations on How to Control It

Abstract: Despite the concern that has been expressed about potential method biases, and the pervasiveness of research settings with the potential to produce them, there is disagreement about whether they really are a problem for researchers in the behavioral sciences. Therefore, the purpose of this review is to explore the current state of knowledge about method biases. First, we explore the meaning of the terms “method” and “method bias” and then we examine whether method biases influence all measures equally. Next, we review the evidence of the effects that method biases have on individual measures and on the covariation between different constructs. Following this, we evaluate the procedural and statistical remedies that have been used to control method biases and provide recommendations for minimizing method bias.

Mild Cognitive Impairment: Clinical Characterization and Outcome

Abstract: Background Subjects with a mild cognitive impairment (MCI) have a memory impairment beyond that expected for age and education yet are not demented. These subjects are becoming the focus of many prediction studies and early intervention trials. Objective To characterize clinically subjects with MCI cross-sectionally and longitudinally. Design A prospective, longitudinal inception cohort. Setting General community clinic. Participants A sample of 76 consecutively evaluated subjects with MCI were compared with 234 healthy control subjects and 106 patients with mild Alzheimer disease (AD), all from a community setting as part of the Mayo Clinic Alzheimer's Disease Center/Alzheimer's Disease Patient Registry, Rochester, Minn. Main Outcome Measures The 3 groups of individuals were compared on demographic factors and measures of cognitive function including the Mini-Mental State Examination, Wechsler Adult Intelligence Scale–Revised, Wechsler Memory Scale–Revised, Dementia Rating Scale, Free and Cued Selective Reminding Test, and Auditory Verbal Learning Test. Clinical classifications of dementia and AD were determined according to the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition and the National Institute of Neurological and Communicative Disorders and Stroke–Alzheimer's Disease and Related Disorders Association criteria, respectively. Results The primary distinction between control subjects and subjects with MCI was in the area of memory, while other cognitive functions were comparable. However, when the subjects with MCI were compared with the patients with very mild AD, memory performance was similar, but patients with AD were more impaired in other cognitive domains as well. Longitudinal performance demonstrated that the subjects with MCI declined at a rate greater than that of the controls but less rapidly than the patients with mild AD. Conclusions Patients who meet the criteria for MCI can be differentiated from healthy control subjects and those with very mild AD. They appear to constitute a clinical entity that can be characterized for treatment interventions.