Preserved metamemorial ability in patients with mild Alzheimer's disease: shifting response bias

Patients with mild Alzheimer's disease (AD) display a greater tendency to endorse unstudied items as "old" on memory tests than healthy older adults. This liberal response bias may result in mistaken beliefs about the completion of common tasks. This research attempted to determine whether it was possible to shift the response bias of mild AD patients to be more conservative on a recognition memory test through behavioral intervention. Patients with mild AD and matched controls were evaluated with two almost identical paradigms, separated by about one week. For each session, 30 words were studied and 60 words (half studied, half novel) were shown at test. During one session participants were told that 30% of words were old, and at the other session that 70% were old. We found that both groups were able to shift their response bias between the two conditions. That patients with mild AD were able to successfully shift their response bias demonstrates that--despite their overall liberal response bias and poor memory relative to controls--one component of metamemorial ability is preserved in patients with mild AD.     

"I know what I like": stability of aesthetic preference in Alzheimer's patients

Two studies explored the stability of art preference in patients with Alzheimer's disease and age-matched control participants. Preferences for three different styles of paintings, displayed on art postcards, were examined over two sessions. Preference for specific paintings differed among individuals but AD and non-AD groups maintained about the same stability in terms of preference judgments across two weeks, even though the AD patients did not have explicit memory for the paintings. We conclude that aesthetic responses can be preserved in the face of cognitive decline. This should encourage caregivers and family to engage in arts appreciation activities with patients, and reinforces the validity of a preference response as a dependent measure in testing paradigms.     

Neural substrates of cognitive skill learning in Parkinson's disease

While cognitive skill learning is normally acquired implicitly through frontostriatal circuitry in healthy individuals, neuroimaging studies suggest that patients with Parkinson's disease (PD) do so by activating alternate, intact brain areas associated with explicit memory processing. To further test this hypothesis, 10 patients with PD and 12 healthy controls were tested on a modified, learning version of the Tower of London task while undergoing positron emission tomography at four different time points over the course of learning. Despite having less accurate problem solving abilities than controls, PD patients were able to acquire the skill learning task. However, as compared to controls, they maintained higher levels of cerebral blood flow activity in the dorsolateral prefrontal cortex and hippocampus and showed an increase in activity in the frontopolar cortex and posterior cingulate over the course of learning. These findings reflect a shift to the explicit memory system in PD patients, enabling them to learn this cognitive skill, which is normally acquired by control subjects using implicit learning strategies and frontostriatal circuitry.     

Motor asymmetry and substantia nigra volume are related to spatial delayed response performance in Parkinson disease

Studies suggest motor deficit asymmetry may help predict the pattern of cognitive impairment in individuals with Parkinson disease (PD). We tested this hypothesis using a highly validated and sensitive spatial memory task, spatial delayed response (SDR), and clinical and neuroimaging measures of PD asymmetry. We predicted SDR performance would be more impaired by PD-related changes in the right side of the brain than in the left. PD (n = 35) and control (n = 28) participants performed the SDR task. PD participants either had worse motor deficits on the right (RPD) or left (LPD) side of the body. Some participants also had magnetic resonance imaging for measurement of their substantia nigra (SN) volumes. The LPD group performed worse on the SDR task than the RPD and control groups. Right SN volume accounted for a unique and significant portion of the variance in SDR error, with smaller volume predicting poorer performance. In conclusion, left motor dysfunction and smaller right SN volume are associated with poorer spatial memory.     

Clock drawing performance and brain morphology in mild cognitive impairment and Alzheimer's disease

The Clock Drawing Test (CDT) is a widely used instrument in the neuropsychological assessment of Alzheimer's disease (AD). As CDT performance necessitates several cognitive functions (e.g., visuospatial and constructional abilities, executive functioning), an interaction of multiple brain regions is likely. Fifty-one subjects with mild cognitive impairment, 23 with AD and 15 healthy controls underwent high-resolution magnetic resonance imaging. Optimized voxel-based morphometry (VBM) was performed to investigate the putative association between CDT performance and gray matter (GM) density throughout the entire brain. In the first step of analysis (p<.001, uncorrected), VBM revealed a reduced GM density in numerous cortical (temporal lobe, frontal lobe, parietal lobe, cerebellum) and subcortical (thalamus, basal ganglia) brain regions to be associated with poorer CDT performance. When corrected for multiple comparisons (p<.01), the associations remained significant predominantly in the left temporal and--less pronounced--the right temporal lobe. VBM demonstrated CDT performance to depend on the integrity of widely distributed cortical and subcortical areas in both brain hemispheres with accentuation in the left-sided temporal lobe region.     

The Swedish National Adult Reading Test (NART-SWE): a test of premorbid IQ

The purpose of this study was to construct a Swedish version of the National Adult Reading Test (NART-SWE), a test for assessment of premorbid IQ, and to investigate its validity and reliability on healthy controls and patients with mild Alzheimer's disease. As Swedish pronunciation rules are fixed, NART-SWE was constructed using loan words. NART-SWE has satisfactory psychometric properties: Inter-rater and retest reliability as well as internal consistency are very high. The NART-SWE demonstrates face validity. In addition, high correlation with IQ was obtained. A significant model emerged when using NART-SWE to predict IQ. Furthermore, no significant differences were observed when comparing performance for healthy controls' with that of patients with Alzheimer's disease on NART-SWE. It does appear that reading of irregular words is intact in mild Alzheimer's disease.     

人格分化的智力假设

人格与智力是个体差异中相互关联的两个重要方面,人格随智力水平的提高而不断分化,智力影响了特定人格维度之间的相关。尽管人格分化的智力假设尚未获得一致性的证据,但它却暗示了智力对人格结构的潜在影响。由于人格测量工具的信度和效度可能因受测者的能力水平而异,因此未来的研究应在使用统一测量工具的基础上,尽量扩大被试的能力范围,采用多重评估或集合评定的方法,使人格测量真正独立于受测者的认知能力。     

揭开“看牙难、看牙贵”的面纱

患者对现有分科看牙模式的失望和对牙科医疗机构的商业化模式的疑问,产生了“看牙难、看牙贵”的感叹。通过14年的全科牙医诊疗体系的实践,从结构影响结果的哲学角度提出全科牙医教育培训体系的建立和牙科产业链调整的设想。通过对历史上全科牙医的回顾,推测全科牙医和专科牙医的互补形式,将成为中国牙科医疗体系的“新式样”。通过对牙科医疗机构运行机制的分析提出了改善的建议。     

论医院实行单病种限价的伦理学价值

从单病种限价在医院内部管理机制等方面的作用出发,探讨了实施单病种限价的伦理价值基础和伦理学意义。认为单病种限价政策能促使医院形成“以人为本”的管理理念,切实维护患者利益,培养医务人员的医德素质,促使医院重视德源资产和品牌形象的建设,强化医务人员精益求精的科学精神,取信于民并帮助医院树立诚信的道德形象,是医院可持续发展的可取途径。     

框架效应及其认知机制的研究进展

框架效应违背了不变性原则,是描述性决策理论违背规范性理论的经典异像。以亚洲疾病问题为代表的经典框架效应又称作风险选择框架效应,此外还包括特征框架效应等不同类别。框架效应受损益值类型和大小等社会线索影响。除展望理论可以解释其认知机制外,模糊痕迹理论和概率心理模型等也对此加以解释。框架效应的脑机制在大脑右半球和杏仁核等区域。文章最后对全文做了总结及展望。