Mouse Hippocampus and Memory
About the research study represented by the cover:
News about our knowledge of the brain and behavior
from Anthony Risser, Ph.D.
About the research study represented by the cover:
Embryonic stem cells could help restore sight to blind
Photoreceptors grown from embryonic stem cells have been successfully implanted in the retinas of blind mice
Alok Jha, Science Correspondent
Sunday 21 July 2013 18.00 BST
When Aggression Follows Dementia
By PAULA SPAN
July 12, 2013, 4:38 pm
OBJECTIVES: Physical activity may reduce the risk of cognitive decline in the elderly, but its effects among the oldest-old (i.e., those aged 85 years and older) are not well known. Our study assessed the association between very late-life physical activity and 5-year risk of mild cognitive impairment (MCI) or dementia and neuropsychological test performance among oldest-old women.
METHODS: This prospective study was conducted at three sites. Participants included 1,249 women (mean [standard deviation] age: 83.3 [2.8] years). Baseline physical activity was measured by self-reported blocks walked per week and analyzed according to tertile. Five years later, surviving participants who were 85 years and older (oldest-old) completed neuropsychological testing and underwent adjudication of clinical cognitive status (normal, MCI, or dementia). All analyses were adjusted for baseline age, education, cognition, depression, body mass index, hypertension, smoking, and coronary artery disease.
RESULTS: Compared with women in the lowest tertile, women in the highest tertile were less likely to develop dementia (13.0% versus 23.2%; multivariate adjusted odds ratio: 0.54 [95% confidence interval: 0.36-0.82]). However, risk of MCI was not associated with physical activity. Physical activity was also associated with higher performance 5 years later on tests of global cognition, category fluency, and executive function but not phonemic fluency, memory, or attention.
CONCLUSIONS: Higher level of very late-life physical activity was associated with a lower risk of subsequent dementia in oldest-old women. These findings support future studies for late-life physical activity interventions for the prevention of dementia among oldest-old women.
PMID: 23831179 [PubMed - as supplied by publisher]
OBJECTIVE: Screening for cognitive impairment in the clinical or community setting is often hampered by the lack of a suitable assessment that is not overburdened with complex administration and scoring methods. We have developed non-verbal cognitive screening instrument: the Weigl Token Test (WTT) from two existing instruments, the Weigl's Colour-Form Sorting Test (WCFST) and the Token Test. The aim of this investigation is to compare the modified WTT with a battery of 'Gold Standard' cognitive assessments, to determine its utility, sensitivity and specificity as a brief cognitive screen in a cohort of Parkinson's disease (PD) patients.
METHODS: A total of 50 PD patients consented to participate in this investigation. All participants were assessed with a battery of cognitive screening instruments including the WCFST, Mini Mental Status Examination, Addenbrooke's Cognitive Examination-Revised and Delis Kaplan Executive Function Systems. The sensitivity and specificity of the WTT to detect cognitive impairment were based upon psychiatric interview, neuropsychological assessment and application of DSM-IV criteria.
RESULTS: The optimal cut-point of the WTT was 116/120, and its sensitivity and specificity to detect cognitive impairment were 88% and 89%, respectively. The diagnostic accuracy of the WTT as calculated by the area under the receiver operating curve was 0.83 (95% CI 0.76-0.95), suggesting that this instrument has acceptable psychometric properties to discriminate between case and non-cases of cognitive impairment.
CONCLUSIONS: The WTT demonstrated excellent concurrent validity with existing 'Gold Standard' assessments of cognitive impairment. We believe that this instrument will prove to be a valuable additional screening assessment in epidemiological, primary care, specialist mental health or clinical investigations. Copyright © 2013 John Wiley & Sons, Ltd.
PMID: 23824787 [PubMed - as supplied by publisher]
Background: Some studies report a low suicide risk in general dementia and in Alzheimer's disease (AD).Objective:To evaluate suicidal behavior among patients with semantic dementia (SD), a disorder that impairs semantic knowledge. Methods: We reviewed the presence of active suicidal behavior and related factors among 25 patients with SD compared to 111 age-matched patients with early-onset AD. Results: In all, 5 (20%) patients with SD had suicidal behavior (2 successfully killed themselves) compared to 1 (0.9%) with AD (P < .001). There was significantly more depression and greater premorbid history of suicidal behavior among the patients with SD compared to those with AD. Among the patients with SD, those with suicidal behavior, compared to those without, had more depression and greater insight into their deficits. Conclusions: Patients with SD are at special risk of committing suicide, particularly if they have depression and preserved insight. Possible mechanisms include an impaired sense of semantic competence with increased impulsivity.
PMID: 23821774 [PubMed - as supplied by publisher]
Altered protein shapes may explain differences in some brain diseases
Wednesday, July 3, 2013, Noon EDT
NIH-funded study finds that various strains of alpha-synuclein have diverse effects in neurons
OBJECTIVE: This study compared the relationship between computer experience and performance on computerized cognitive tests and a traditional paper-and-pencil cognitive test in a sample of older adults (N = 634).
METHOD: Participants completed computer experience and computer attitudes questionnaires, three computerized cognitive tests (Useful Field of View (UFOV) Test, Road Sign Test, and Stroop task) and a paper-and-pencil cognitive measure (Trail Making Test). Multivariate analysis of covariance was used to examine differences in cognitive performance across the four measures between those with and without computer experience after adjusting for confounding variables.
RESULTS: Although computer experience had a significant main effect across all cognitive measures, the effect sizes were similar. After controlling for computer attitudes, the relationship between computer experience and UFOV was fully attenuated.
DISCUSSION: Findings suggest that computer experience is not uniquely related to performance on computerized cognitive measures compared with paper-and-pencil measures. Because the relationship between computer experience and UFOV was fully attenuated by computer attitudes, this may imply that motivational factors are more influential to UFOV performance than computer experience. Our findings support the hypothesis that computer use is related to cognitive performance, and this relationship is not stronger for computerized cognitive measures. Implications and directions for future research are provided.
PMID: 22929395 [PubMed - indexed for MEDLINE]
Watching The Lights Go Out
A Memoir from Inside Alzheimer's Disease
TransTech readies Alzheimer's disease treatment for late-stage clinical trials
Posted Jul. 1, 2013 at 12:34 p.m.
"The U.S. government is set to decide this month whether federal health insurance should cover the cost of a $3,000 test..."
Permanent Present Tense: The man with no memory, and what he taught the world by Suzanne Corkin – review
This fine and moving book reveals as much about the limitations of neuropsychology as about the scope of human memory
A review by Jonathan Rée
The Guardian, Thursday 27 June 2013 08.00 BST
Researchers discover two-step mechanism of inner ear tip link regrowth
Tuesday, June 11, 2013, 5 p.m. (EDT)
Run, don't walk, to enroll should a second offering of the course be announced over the next year!