scholarly journals Conceptually plausible Bayesian inference in interval timing

2021 ◽  
Vol 8 (8) ◽  
pp. 201844
Author(s):  
Sarah C. Maaß ◽  
Joost de Jong ◽  
Leendert van Maanen ◽  
Hedderik van Rijn
Keyword(s):  
Cognitive Impairment ◽  
Interval Timing ◽  
Clinical Population ◽  
Statistical Distributions ◽  
Central Tendency ◽  
Lognormal Distributions ◽  
Behavioural Responses ◽  
Empirical Distributions ◽  
Timing Data ◽  
The Mean

In a world that is uncertain and noisy, perception makes use of optimization procedures that rely on the statistical properties of previous experiences. A well-known example of this phenomenon is the central tendency effect observed in many psychophysical modalities. For example, in interval timing tasks, previous experiences influence the current percept, pulling behavioural responses towards the mean. In Bayesian observer models, these previous experiences are typically modelled by unimodal statistical distributions, referred to as the prior. Here, we critically assess the validity of the assumptions underlying these models and propose a model that allows for more flexible, yet conceptually more plausible, modelling of empirical distributions. By representing previous experiences as a mixture of lognormal distributions, this model can be parametrized to mimic different unimodal distributions and thus extends previous instantiations of Bayesian observer models. We fit the mixture lognormal model to published interval timing data of healthy young adults and a clinical population of aged mild cognitive impairment patients and age-matched controls, and demonstrate that this model better explains behavioural data and provides new insights into the mechanisms that underlie the behaviour of a memory-affected clinical population.

The Ten Point Clock Test: A Quick Screen and Grading Method for Cognitive Impairment in Medical and Surgical Patients

1994 ◽  
Vol 24 (3) ◽  
pp. 229-244 ◽  
Author(s):  
Peter J. Manos ◽  
Rae Wu
Keyword(s):  
Cognitive Impairment ◽  
Cognitive Deficits ◽  
Neuropsychological Tests ◽  
Medical Center ◽  
Neuropsychological Test ◽  
Hospitalized Patients ◽  
Surgical Patients ◽  
Tertiary Referral Center ◽  
The Mean ◽  
State Examination

Objective: The objective of this study was to evaluate the clinical utility of the ten point clock test in screening for and grading cognitive deficits in medical and surgical patients. Method: The setting was the hospital and clinics of Virginia Mason Medical Center, a tertiary referral center. Consecutive samples of hospitalized patients, and clinic outpatients—with and without a dementia—were administered the ten point clock test as well as a number of other neuropsychological tests and measures of cognitive impairment. Results: Clock scores correlated with neuropsychological test scores and with the mini-mental state examination. They were stable from rater to rater, and from day to day in stable patients. The mean clock score of elderly outpatient controls was 8.5, significantly different from the mean of 5.5 scored by patients with a dementia. A cut off score of seven identified 76 percent of outpatients with dementia and 78 percent of elderly controls. Clock scores correlated well with nurses' ratings of their inpatients' cognitive deficits (Spearman's rs = −0.61). The test was easy to administer, even to hospitalized patients. Conclusions: The ten point clock test is reliable, valid, and useful as a quick screen and grading method for cognitive deficits in medical and surgical patients.

scholarly journals Reliability and validity of a Mediterranean diet and culinary index (MediCul) tool in an older population with mild cognitive impairment

2018 ◽  
Vol 120 (10) ◽  
pp. 1189-1200 ◽  
Author(s):  
Sue Radd-Vagenas ◽  
Maria A. Fiatarone Singh ◽  
Michael Inskip ◽  
Yorgi Mavros ◽  
Nicola Gates ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Mediterranean Diet ◽  
Reliability And Validity ◽  
Community Dwelling ◽  
Systematic Bias ◽  
Older Individuals ◽  
Retest Reliability ◽  
The Mean ◽  
Test Retest Reliability

AbstractDementia is a leading cause of morbidity and mortality without pharmacologic prevention or cure. Mounting evidence suggests that adherence to a Mediterranean dietary pattern may slow cognitive decline, and is important to characterise in at-risk cohorts. Thus, we determined the reliability and validity of the Mediterranean Diet and Culinary Index (MediCul), a new tool, among community-dwelling individuals with mild cognitive impairment (MCI). A total of sixty-eight participants (66 % female) aged 75·9 (sd 6·6) years, from the Study of Mental and Resistance Training study MCI cohort, completed the fifty-item MediCul at two time points, followed by a 3-d food record (FR). MediCul test–retest reliability was assessed using intra-class correlation coefficients (ICC), Bland–Altman plots and κ agreement within seventeen dietary element categories. Validity was assessed against the FR using the Bland–Altman method and nutrient trends across MediCul score tertiles. The mean MediCul score was 54·6/100·0, with few participants reaching thresholds for key Mediterranean foods. MediCul had very good test–retest reliability (ICC=0·93, 95 % CI 0·884, 0·954, P<0·0001) with fair-to-almost-perfect agreement for classifying elements within the same category. Validity was moderate with no systematic bias between methods of measurement, according to the regression coefficient (y=−2·30+0·17x) (95 % CI −0·027, 0·358; P=0·091). MediCul over-estimated the mean FR score by 6 %, with limits of agreement being under- and over-estimated by 11 and 23 %, respectively. Nutrient trends were significantly associated with increased MediCul scoring, consistent with a Mediterranean pattern. MediCul provides reliable and moderately valid information about Mediterranean diet adherence among older individuals with MCI, with potential application in future studies assessing relationships between diet and cognitive function.

scholarly journals Short Report: Prevalence of Cognitive Impairment in Newly Diagnosed Relapsing-Remitting Multiple Sclerosis

2018 ◽  
Vol 20 (4) ◽  
pp. 153-157 ◽  
Author(s):  
Giulia DiGiuseppe ◽  
Mervin Blair ◽  
Sarah A. Morrow
Keyword(s):  
Multiple Sclerosis ◽  
Cognitive Impairment ◽  
Processing Speed ◽  
Clinical Population ◽  
Clinical Event ◽  
Routine Practice ◽  
Short Report ◽  
Newly Diagnosed ◽  
Mood Symptoms ◽  
Relapsing Remitting

Abstract Background: Cognitive impairment is common in multiple sclerosis (MS) and can manifest early in the disease process, sometimes as early as the first demyelinating event. However, the frequency of cognitive impairment in a newly diagnosed MS population has not been evaluated comprehensively in a clinical population. We sought to examine the prevalence of cognitive impairment in relapsing-remitting MS (RRMS) within a year of diagnosis in a clinic where cognitive testing at diagnosis is part of routine practice. Methods: A retrospective medical record review of persons with RRMS assessed in a cognitive MS clinic identified 107 patients assessed by the Minimal Assessment of Cognitive Function in Multiple Sclerosis battery within 1 year of a confirmed RRMS diagnosis. Results: The cohort was predominantly female (n = 82 [76.6%]) and white (n = 93 [86.9%]). Only 36 patients (33.6%) were diagnosed as having RRMS based on a second clinical event. Processing speed was the most frequently impaired domain (n = 38 [35.5%]). Only 37 patients (34.6%) were within normal limits on all cognitive domains. Regarding mood symptoms, 25 patients (23.4%) were positive for depressive symptoms; 59 (55.1%), for anxiety. Severe fatigue was correlated with a lower score on the Symbol Digit Modalities Test (SDMT) (r = −0.380, P &lt; .001), and higher depressive scores were correlated with lower performance on the SDMT (r = −0.397, P &lt; .001) and the Paced Auditory Serial Addition Test (r = −0.254, P = .009). Conclusions: Cognitive impairment, specifically processing speed, and mood symptoms are frequently present in persons with newly diagnosed RRMS.

scholarly journals Congenital malformations in neonates: analysis of morbidity and associated factors

10.3823/2465 ◽  
2017 ◽  
Vol 10 ◽  
Author(s):  
Rosana Alves de Melo ◽  
Flávia Emília Cavalcante Valença Fernandes ◽  
Ana Kariny Costa Araújo ◽  
Nadja Maria dos Santos ◽  
Maria Elda Alves de Lacerda Campos ◽  
...  
Keyword(s):  
Congenital Malformations ◽  
Neonatal Morbidity ◽  
Normal Weight ◽  
Central Tendency ◽  
Chi Square ◽  
Level Of Education ◽  
The Mean ◽  
Upper Level ◽  
The City ◽  
Prenatal Visits

Objective: To evaluate the neonatal morbidity due to congenital malformations in the city of Petrolina-PE, from 2008 to 2013. Methods: A descriptive study with data from the Information System on Live Births (Sinasc). The analyzes were carried out through frequency distribution and measures of central tendency and dispersion. The associations were tested by the Pearson and Kruskal Wallis chi-square tests. Significance was set at 5% and 95% confidence. Results: 436 cases of congenital malformations were recorded in the study period, with 2011 being the highest occurrence year. The mothers of the newborns were young (25.2 years old), single, upper level of education and household. In general multiparous, with single gestation, vaginal delivery and performed up to six prenatal visits. The newborns were males, at 39 weeks or more of gestation and with normal weight (> = 2500g). The malformations of the musculoskeletal system were the most frequent followed by the genitourinary system. Congenital malformations were especially associated with neonatal characteristics such as gender and weight. In all causes the mean weight was greater than 2500g (p <0.05). The causes of malformation of greater occurrence in both sexes were osteomuscular (p <0.05). The aspects of the mother did not present significant differences in the present study (p> 0.05). Conclusion: The present study evidenced relevant aspects in the occurrence of morbidities due to congenital malformations, directing to a greater attention the occurrence of these diseases especially in relation to the newborn.

scholarly journals COGNITIVE IMPAIRMENT, THEIR DYNAMICS AND STRUCTURE IN THE ACUTE AND RECOVERY PERIODS OF STROKE, DEPENDING ON ARTERIAL HYPERTENSION SEVERITY AND DURATION

2018 ◽  
Vol 13 (3-4) ◽  
pp. 22-27
Author(s):  
T.M. Cherenko ◽  
Yu.L. Heletyuk
Keyword(s):  
Blood Pressure ◽  
Cognitive Impairment ◽  
Arterial Hypertension ◽  
Blood Pressure Monitoring ◽  
Cognitive Status ◽  
Neurological Deficits ◽  
Stroke Patients ◽  
Mean Values ◽  
Post Stroke ◽  
The Mean

Relevance. Cognitive impairment is common in the post-stroke period. Different characteristics of arterial hypertension (AH), namely its severity, duration and variability of blood pressure, can affect the development of cognitive impairment in stroke patients. Objective: to investigate cognitive impairment, their dynamics and structure in acute and recovering stroke periods, depending on the arterial hypertension severity and duration. Materials and methods. 150 patients with a primary ischemic stroke and history of hypertension: 74 (49,3 %) women and 76 (50,7 %) men, the mean age (67,4±0,7) years have been examined. Neurological deficits was evaluated by the NIHSS scale. The cognitive status was evaluated by the MMSE scale at the end of an acute period of 21 days and 1 year. Diagnosis of hypertension was based on the clinical and instrumental examination results and medical documents. Daily blood pressure monitoring was using on admission and every 4 hours during 6 days of acute stroke stage. Mean SBP, mean DBP, maximum SBP and DBP, standard deviation (SD) of SBP and DBP were studied. Results. By the mean score on the MMSE scale, there are differences in patients during acute post-stroke period, depending on the severity of hypertension: 27,2±0,6 points in the case of hypertension stage 1, 24,3±0,6 in the case of hypertension stage 2 and 20,7±0,8 in case of AH stage 3, (p=0.001). By this indicator, patients with different AH duration were different: 26,4±0,9 points; 25,1±0,5 points; 20,5±0,7 points, respectively. The significance of these differences by the mean values of MMSE score was obtained in patients with a duration of AH less than 5 years and more than 10 years, as well as when comparing the group of "6-10 years" and "over 10 years" (p=0,001). Significant differences in the structure of cognitive deficits severity, depending on the hypertension stage and its duration, were observed only in patients with moderate and severe stroke (p=0,006). Cognitive deterioration a year after a stroke was observed in 40 (31,5 %) patients. They have significantly higher mean values SD 1-3, SD 1-6, SBP on the first day after a stroke, and duration of hypertension. Conclusions. The relationship between the degree of intellectual decline and the duration of hypertension (r=0,592, p=0,001), severity of hypertension (r=0,459, p=0,001) was found. The severity of the neurological deficiency affects the structure of cognitive impairment at discharge in patients with different severity and duration of hypertension, and higher mean values of the variability of blood pressure from 1 to 6 days, SBP on the first day after stroke and higher duration of hypertension in the history is associated with a negative dynamics of cognitive impairment in stroke patients in a year after stroke.

scholarly journals Land snails as experimental animals: a study of the variability and distribution of individual weights in Helix aspersa snails born from the same clutch

1990 ◽  
Vol 24 (1) ◽  
pp. 1-4 ◽  
Author(s):  
R. Sanz Sampelayo ◽  
J. Fonolla ◽  
F. Gil Extremera
Keyword(s):  
Normal Distribution ◽  
Growth Curve ◽  
Original Data ◽  
Helix Aspersa ◽  
Land Snails ◽  
Central Tendency ◽  
Experimental Conditions ◽  
Experimental Animals ◽  
Coefficients Of Variation ◽  
The Mean

A study was carried out to examine the distribution of individual weights in Helix aspersa snails, the aims being to establish the best estimate of the ponderal growth and also to obtain a model growth curve. Four groups of 20 snails from the same clutch were analysed and kept under experimental conditions from birth up to 6 months. The variability of their individual weights within groups was studied by calculating the coefficients of variation every 15 days. At the same time, the assumed normal distribution of those weights was being tested. The coefficients of variation increased with age and the assumed normal distribution of individual weights had to be rejected. By means of a log transformation of the original data, a model growth curve was constructed, and was used to assess the possibility of estimating age from weight. We finally reached the conclusion that median weight, rather than the mean, would be a better measure of central tendency to use until it is possible to obtain selected populations. The difficulty of estimating age from weight is emphasized.

A pilot study examining the profile of older people on clozapine

2018 ◽  
Vol 26 (6) ◽  
pp. 619-623
Author(s):  
Jen Benbow ◽  
Anne PF Wand ◽  
Brett Simpson
Keyword(s):  
Cognitive Impairment ◽  
Side Effects ◽  
Older People ◽  
Social History ◽  
Geriatric Medicine ◽  
Executive Dysfunction ◽  
Screening Tools ◽  
The Mean ◽  
Considerable Morbidity ◽  
And Function

Objective: The primary aim was to comprehensively describe the characteristics of a cohort of older people taking clozapine. Method: Participants aged ⩾ 60 had a geriatric assessment including full medical, medication and social history. Standardized screening tools for cognition, function, comorbidity and antipsychotic side effects were administered and descriptive statistics utilized. Results: Thirteen patients were eligible to participate and 10 were assessed. The mean age was 69 years. The mean clozapine dose was 309 mg/day and mean duration of use was 10 years. All participants had executive dysfunction, and half had cognitive impairment. The mean number of co-morbid conditions was five. Seven people met the criteria for polypharmacy. Eight people experienced moderate–severe antipsychotic-related side-effects. The majority demonstrated impaired physical functioning. Conclusions: This cohort of older people taking clozapine experienced considerable morbidity, functional and cognitive impairment. We suggest routine screening of cognition and function in clozapine patients aged ⩾ 60 years. Those screening positive should be considered for further assessment by Older Person’s Mental Health Services and/or a Geriatric Medicine service.

Abstract 220: Comparison of 3 Cognitive Exams in Cardiac Arrest Survivors

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Allison Koller ◽  
Jon Rittenberger ◽  
Patrick Morgan ◽  
Melissa Repine ◽  
Jeffrey Kristan ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Cognitive Impairment ◽  
Cognitive Deficits ◽  
Cognitive Testing ◽  
Percentile Score ◽  
Pairwise Correlations ◽  
The Mean ◽  
Highly Correlated ◽  
Alpha Error

Background: Cognitive deficits may detract from quality of life after cardiac arrest (CA). The pattern and prevalence of these deficits are not well documented. We used the Computer Assessment of Mild Cognitive Impairment (CAMCI), the Montreal Cognitive Assessment (MOCA) and the 41 Cent Test to assess cognitive impairment in survivors of CA. We hypothesized that CAMCI subscales and other scores that were highly correlated could identify specific domains of impairment in CA survivors. Methods: Four researchers administered the CAMCI, MOCA, and/or the 41 Cent Test to CA survivors after discharge from the intensive care unit between 2010 and 2014. Physicians screened patients with the Mini-Mental State Exam to determine when this cognitive testing was feasible. We compared the distribution of scores between patients who presented with coma and those who awoke immediately after CA. Pairwise correlations between the different subscales and tests were considered significant with alpha error of 0.05. Results: Ninety-two participants completed the CAMCI, of which 18 participants completed the CAMCI, MOCA and 41 Cent Test. The mean (SD) percentile score for CAMCI was 32.2 (20.3) out of possible 100, for the MOCA was 20.3 (5.2) out of a possible 30 points and the 41 Cent Test was 5.4 (1.1) out of a possible 7 points. MOCA correlated strongly with the overall CAMCI score (r = 0.82) and with the executive accuracy subscale of the CAMCI (r = 0.75). The executive accuracy subscale and overall CAMCI score correlated with one another (r = 0.81) when all 92 CAMCI exams were considered. The MOCA and 41 Cent Test were correlated with each other (r = 0.63). Conclusion: The CAMCI detects cognitive impairment after CA; the MOCA correlates strongly with the overall CAMCI and the executive function subscale of the CAMCI. The 41 Cent Test may not be as effective as the MOCA in detecting cognitive deficits.

15. Quantitative Analysis: Description and Inference

2020 ◽  
pp. 393-421
Author(s):  
Sandra Halperin ◽  
Oliver Heath
Keyword(s):  
Quantitative Analysis ◽  
Standard Deviation ◽  
Confidence Intervals ◽  
Quantitative Research ◽  
Building Blocks ◽  
Descriptive Statistics ◽  
Central Tendency ◽  
Margin Of Error ◽  
Univariate Statistics ◽  
The Mean

This chapter deals with quantitative analysis, and especially description and inference. It introduces the reader to the principles of quantitative research and offers a step-by-step guide on how to use and interpret a range of commonly used techniques. The first part of the chapter considers the building blocks of quantitative analysis, with particular emphasis on different ways of summarizing data, both graphically and with tables, and ways of describing the distribution of one variable using univariate statistics. Two important measures are discussed: the mean and the standard deviation. After elaborating on descriptive statistics, the chapter explores inferential statistics and explains how to make generalizations. It also presents the concept of confidence intervals, more commonly known as the margin of error, and measures of central tendency.

Treatment of Cognitive Impairment and the Role of Demographic Factors in Disease Progression: The Final Results of the Russian Observational Program “DIAMANT”

2020 ◽  
pp. 1-11
Author(s):  
Vladimir Anatolyevich Parfenov ◽  
Sergey Anatolyevich Zhivolupov ◽  
Irina Evgenyevna Poverennova ◽  
Marina Valentinovna Nesterova ◽  
Svetlana Evgenyevna Ushakova ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Socioeconomic Factors ◽  
Age Groups ◽  
Post Treatment ◽  
Wilcoxon Test ◽  
Cognitive Improvement ◽  
Number Of Patients ◽  
The Mean ◽  
Moca Score

<b><i>Background:</i></b> Chronic cerebral ischemia (CCI) is a form of cerebrovascular disease manifested as a vascular cognitive impairment (VCI). The management of the patients with CCI is determined by a healthy lifestyle and early therapy aimed at correcting and preventing this disease. Divaza is a drug with endothelial protective and nootropic effects. We present the final efficacy and safety analysis of all-Russian, open-label, prospective, observational, multicenter study of Divaza and emphasize the role of demographic and socioeconomic factors in cognitive disorder (CD) progression. <b><i>Methods:</i></b> CCI patients (<i>n</i> = 2,583) with or without CD were enrolled. Patients received Divaza (2 tablets 3 times per day for 12 weeks). Montreal Cognitive Assessment (MoCA) testing was required. The change in the mean MoCA score post-treatment was used as the primary endpoint. As the secondary endpoints, the number of patients with a MoCA &#x3c;26 and ≤17 (dementia); the percentage of patients with a MoCA score improvement in different age groups; the dynamics of mean MoCA score in age groups; and the relationship between CD and sex or regional social/economic factors were assessed. <b><i>Results:</i></b> Divaza therapy led to a significant improvement: the mean MoCA score was up to 20% higher post-treatment (Wilcoxon test, <i>p</i> &#x3c; 0.0001 vs. baseline). The number of participants with MoCA ≥26 increased by 33.6%. The number of patients with dementia was 4.1 times less after therapy (<i>p</i> &#x3c; 0.00001 vs. baseline). Divaza improved cognitive functions of patients in each age group. Findings demonstrate that regional socioeconomic factors contribute to CD development and severity. The observed divergence between sexes was a result of a larger number of women enrolled. The study confirmed the safety of Divaza. <b><i>Conclusions:</i></b> In the study, we observed the efficacy of Divaza for the treatment of CD: a therapy contributed to an increase in the mean MoCA score and the positive dynamics in the number of patients with cognitive improvement.

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