152 research outputs found

    Method and apparatus for predicting the direction of movement in machine vision

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    A computer-simulated cortical network is presented. The network is capable of computing the visibility of shifts in the direction of movement. Additionally, the network can compute the following: (1) the magnitude of the position difference between the test and background patterns; (2) localized contrast differences at different spatial scales analyzed by computing temporal gradients of the difference and sum of the outputs of paired even- and odd-symmetric bandpass filters convolved with the input pattern; and (3) the direction of a test pattern moved relative to a textured background. The direction of movement of an object in the field of view of a robotic vision system is detected in accordance with nonlinear Gabor function algorithms. The movement of objects relative to their background is used to infer the 3-dimensional structure and motion of object surfaces

    Case report: Neural timing deficits prevalent in developmental disorders, aging, and concussions remediated rapidly by movement discrimination exercises

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    BackgroundThe substantial evidence that neural timing deficits are prevalent in developmental disorders, aging, and concussions resulting from a Traumatic Brain Injury (TBI) is presented.ObjectiveWhen these timing deficits are remediated using low-level movement-discrimination training, then high-level cognitive skills, including reading, attention, processing speed, problem solving, and working memory improve rapidly and effectively.MethodsIn addition to the substantial evidence published previously, new evidence based on a neural correlate, MagnetoEncephalography physiological recordings, on an adult dyslexic, and neuropsychological tests on this dyslexic subject and an older adult were measured before and after 8-weeks of contrast sensitivity-based left–right movement-discrimination exercises were completed.ResultsThe neuropsychological tests found large improvements in reading, selective and sustained attention, processing speed, working memory, and problem-solving skills, never before found after such a short period of training. Moreover, these improvements were found 4 years later for older adult. Substantial MEG signal increases in visual Motion, Attention, and Memory/Executive Control Networks were observed following training on contrast sensitivity-based left–right movement-discrimination. Improving the function of magnocells using figure/ground movement-discrimination at both low and high levels in dorsal stream: (1) improved both feedforward and feedback pathways to modulate attention by enhancing coupled theta/gamma and alpha/gamma oscillations, (2) is adaptive, and (3) incorporated cycles of feedback and reward at multiple levels.ConclusionWhat emerges from multiple studies is the essential role of timing deficits in the dorsal stream that are prevalent in developmental disorders like dyslexia, in aging, and following a TBI. Training visual dorsal stream function at low levels significantly improved high-level cognitive functions, including processing speed, selective and sustained attention, both auditory and visual working memory, problem solving, and reading fluency. A paradigm shift for treating cognitive impairments in developmental disorders, aging, and concussions is crucial. Remediating the neural timing deficits of low-level dorsal pathways, thereby improving both feedforward and feedback pathways, before cognitive exercises to improve specific cognitive skills provides the most rapid and effective methods to improve cognitive skills. Moreover, this adaptive training with substantial feedback shows cognitive transfer to tasks not trained on, significantly improving a person’s quality of life rapidly and effectively

    Quality of Life in Patients with Alzheimer's Disease as Reported by Patient Proxies

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    OBJECTIVE: To measure behaviors indicative of quality of life (QOL) in patients with Alzheimer's disease and to examine correlates of patient QOL. DESIGN: Cross-sectional investigation. SETTING: Multi-center study. PARTICIPANTS: Sample of 130 diagnosed patients. PRINCIPAL OUTCOME MEASURES: Proxy ratings of (1) the frequency, opportunity, and enjoyment of 15 non-ADL activities potentially within the capacity of a demented person, and (2) the frequency of a series of positive and negative affects, evident in clearly demarcated facial and bodily expressions. RESULTS: QOL ratings were reliably elicited. Family and institutional caregivers differed only in reports of opportunity for patient activity. Frequency of activities declined with increasing severity of dementia. The frequency of negative affects increased and positive affects declined with increasing severity of dementia, but correlations were weak. High QOL, defined by frequent activity and positive affect, was evident in a quarter of the sample. In multivariate models, functional and cognitive status independently predicted QOL among community-resident older adults; only absence of antipsychotics was related to QOL among older people in nursing homes. Patient education, a marker of premorbid state, independently predicted some activity patterns. CONCLUSIONS: Although the subjective world of the demented patient is not directly accessible, readily observable behaviors offer a basis for assessing QOL

    Systematic review: Effective Home Support in Dementia Care, components and impacts – Stage 2, effectiveness of home support interventions.

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    Aim: To explicate the outcomes of home support interventions for older people with dementia and/or their carers to inform clinical practice, policy and research. Background: Most people with dementia receive support at home. However, components and effectiveness of home support interventions have been little explored. Design: Systematic review with narrative summary. Data sources: Electronic searches of published studies in English using PubMed, Cochrane Central Register of Controlled Trials, PsychINFO, CINAHL, Applied Social Science Index and CSA Social Services Abstracts. Databases and sources were searched from inception to April 2014 with no date restrictions to locate studies. Review methods: The PRISMA statement was followed and established systematic review methods used. Using 14 components of care for people with dementia and their carers, identified previously, data across studies were synthesized. Interventions were grouped and described and effectiveness ratings applied. Qualitative studies were synthesized using key themes. Results: Seventy studies (four qualitative) were included. Most were directed to carers and of high quality. Seven interventions for carers and two for people with dementia were identified, covering 81% of studies. Those relating to daily living, cognitive training and physical activity for people with dementia were absent. Measures of effectiveness were influenced mainly by the intensity (duration and frequency) of interventions. Those containing education, social support and behaviour management appeared most effective. Conclusion: These interventions reflect emergent patterns of home support. Research is required to identify effective interventions linked to the stage of dementia, which can be applied as part of routine clinical care

    Exercise, cognition and Alzheimer’s disease: More is not necessarily better

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    Regional hypoperfusion, associated with a reduction in cerebral metabolism, is a hallmark of Alzheimer’s disease (AD) and contributes to cognitive decline. Cerebral perfusion and hence cognition can be enhanced by exercise. The present review describes first how the effects of exercise on cerebral perfusion in AD are mediated by nitric oxide (NO) and tissue-type plasminogen activator, the release of which is regulated by NO. A conclusion of clinical relevance is that exercise may not be beneficial for the cognitive functioning of all people with dementia if cardiovascular risk factors are present. The extent to which cardiovascular risk factors play a role in the selection of older people with dementia in clinical studies will be addressed in the second part of the review in which the effects of exercise on cognition are presented. Only eight relevant studies were found in the literature, emphasizing the paucity of studies in this field. Positive effects of exercise on cognition were reported in seven studies, including two that excluded and two that included patients with cardiovascular risk factors. These findings suggest that cardiovascular risk factors do not necessarily undo the beneficial effects of exercise on cognition in cognitively impaired people. Further research is called for, in view of the limitations of the clinical studies reviewed here.

    Life-Span Perspective of Personality in Dementia

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    To propose an alternative view of personality change in dementia by presenting existing evidence for the continuity of personality. Significance : As the population continues to age, dementing illnesses will account for a greater proportion of morbidity and mortality; the care of these people will have a significant effect on the health care system. Organizing Framework : Life-span perspective of personality continuity. Scope, Method : Review of current literature on personality in dementia using Medline, 1980–1994; CINAHL, 1990–1994; and Psych Lit, 1980–1994. Findings : Although there are systematic shifts in personality with dementia, individuals tend to maintain their unique pattern of premorbid personality traits. Conclusions : The personalities of dementia patients seem to reflect adaptive patterns that served them in the past. Implications : Use of a life-span perspective can enhance individualized care for demented patients and advance theory development.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73653/1/j.1547-5069.1996.tb00380.x.pd

    Overview of systematic reviews. Effective home support in dementia care: Components and impacts, Stage 1, psychosocial interventions for dementia.

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    Aim: To synthesise evidence to identify the components of effective psychosocial interventions in dementia care to inform clinical practice, policy and research. Background: With population ageing dementia represents a significant care challenge with 60% of people with dementia living at home. Design: Overview of systematic reviews with narrative summary. Data sources: Electronic searches of published systematic reviews in English using Cochrane Database of Systematic Reviews, DARE, EPPI-Centre, between September 2013 - April 2014. Review methods: Systematic reviews were appraised against Cochrane Collaboration levels of effectiveness. Components of psychosocial interventions were identified with their theoretical rationale. Findings were explored with a Patient, Public and Carer Involvement group. Results: 36 systematic reviews were included. From interventions, 14 components were identified, nine for people with dementia and five for carers, mostly undertaken in nursing/care homes. For people with dementia, there was evidence of effectiveness for cognitive stimulation and cognitive training; but less evidence for sensory stimulation, reminiscence, staff education, behavioural therapy and ADL training. For carers, there was evidence of effectiveness for education and training, psychotherapy and counselling. Conclusion: There was a lack of definitive evidence of effectiveness for most psychosocial interventions. Further studies with stronger methodology or replication of existing studies would strengthen the evidence base. Few interventions were undertaken with people with dementia and their carers living at home. Further work will investigate the extent to which components identified here are present in models of home support for people with dementia and carers and their effectiveness

    The fitness for the Ageing Brain Study II (FABS II): protocol for a randomized controlled clinical trial evaluating the effect of physical activity on cognitive function in patients with Alzheimer's disease

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    Background: Observational studies have documented a potential protective effect of physical exercise in older adults who are at risk for developing Alzheimer's disease. The Fitness for the Ageing Brain II (FABS II) study is a multicentre randomized controlled clinical trial (RCT) aiming to determine whether physical activity reduces the rate of cognitive decline among individuals with Alzheimer's disease. This paper describes the background, objectives of the study, and an overview of the protocol including design, organization and data collection methods
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