Kendrick Object Learning Test Research Articles

Pilot Study of Reticular Activating System (RAS) in Mild Dementia

AbstractBackgroundClinically, the common early symptoms of dementia include memory problems, reduced concentration, behaviour changes, apathy and withdrawal, loss of ability to do everyday tasks. These cognitive functions are mediated by the reticular activating system (RAS) that is a collection of interconnected brain nuclei that regulates wakefulness, alertness and modulate behaviors. The RAS degenerates early during Alzheimer’s disease progression in association with abnormal tau build‐up.MethodThis study aimed to explore the relationship between the RAS functioning and older people with mild grade dementia. The Kendrick Object Learning Test (KOLT) is a test of recall of everyday objects after viewing for a brief period, an immediate recall of briefly perceived visual data. The Kendrick Digit Copying Test (KDCT) is a test of speed in processing and recording information. These tests suggested cortical excitation mediated by both the RAS and the hypothalamic limbic network which deteriorate in older people with mild grade dementia.ResultIn this pilot study, 25 demented patients with mild grade dementia and 20 participants with known depression were recruited. They are matched in age (mean age 72 with sd 4.89) and shared similar demographic background. The participants were tested with the Kendrick Object Learning Test (KOLT) and the Kendrick Digit Copying Test (KDCT). To observe the short term longitudinal change of their RAS functioning, these tests were administered again 4 weeks following baseline. With regular day activity treatment, the depressive group showed improvement in KOLT (p < 0.1), but not on KDCT (p = .82). However, in the dementia group, there were no significant difference noted in both KOLT and KDCT (p < 0.5).ConclusionThe present findings echo some findings of RAS does not function properly as in the older people with dementia. The reticular system is not compromised in group of depressive participants, there would be improvement in object learning, but no significant difference on speed in processing and recording information as measured by speed‐performance tests (KDCT). Proper and targeted rehabilitation trainings and care giving techniques could be arranged in meeting the specific patients’ needs.

The kynurenine pathway and cognitive performance in community-dwelling older adults. The Hordaland Health Study

IntroductionTryptophan, its downstream metabolites in the kynurenine pathway and neopterin have been associated with inflammation and dementia. We aimed to study the associations between plasma levels of these metabolites and cognitive function in community-dwelling, older adults. MethodsThis cross-sectional study included 2174 participants aged 70–72 years of the community-based Hordaland Health Study. Tryptophan, kynurenine, neopterin and eight downstream kynurenines were measured in plasma. Kendrick Object Learning Test (KOLT), Digit Symbol Test (DST) and the Controlled Oral Word Association Test (COWAT) were all outcomes in standardized Zellner’s regression. The Wald test of a composite linear hypothesis of an association with each metabolite was adjusted by the Bonferroni method. Age, body mass index, C-reactive protein, depressive symptoms, diabetes, education, glomerular filtration rate, hypertension, previous myocardial infarction, prior stroke, pyridoxal 5′phosphate, sex and smoking were considered as potential confounders. ResultsHigher levels of the kynurenine-to-tryptophan ratio (KTR) and neopterin were significantly associated with poorer, overall cognitive performance (p < 0.002). Specifically, KTR was negatively associated with KOLT (β −0.08, p = 0.001) and COWAT (β −0.08, p = 0.001), but not with DST (β −0.03, p = 0.160). This pattern was also seen for neopterin (KOLT: β −0.07; p = 0.001; COWAT: β −0.06, p = 0.010; DST: β −0.01, p = 0.800). The associations were not confounded by the examined variables. No significant associations were found between the eight downstream kynurenines and cognition. ConclusionHigher KTR and neopterin levels, biomarkers of cellular immune activation, were associated with reduced cognitive performance, implying an association between the innate immune system, memory, and language.

The impact of early life factors on cognitive function in old age: The Hordaland Health Study (HUSK).

BackgroundPrevious studies have shown that adverse conditions during fetal and early life are associated with lower performance on neurocognitive tests in childhood, adolescence and adult life. There is, however, a paucity in studies investigating these associations into old age. The aim was to investigate the impact of early life factors on cognitive function in old age by taking advantage of the potential for a linkage between a community survey and historical birth records.MethodsA historical cohort study employing a linkage between a community survey of people aged 72–74 years with the participants’ birth records (n=346). Early life factors included anthropometric measures taken at birth, birth complications, parental socioeconomic status, and maternal health status. The main outcome was a z-scored composite cognitive score, based on test scores from Kendrick Object Learning Test, Trail Making Test A, a modified version of the Digit Symbol Test, Block Design, a modified version of Mini-Mental State Examination and an abridged version of the Controlled Oral Word Association Test (COWAT). The separate cognitive tests were also individually analysed in relation to measures identified at birth.ResultsHigher parental socioeconomic status (SES; based on father’s occupation) was associated with a higher value on the composite cognitive score (by 0.25 SD, p=0.0146) and higher Digit Symbol and Trail Making Test A performance. Higher head circumference at birth was associated with higher COWAT and Trail Making Test A performance. Both higher parental SES and head circumference at birth predicted cognitive function in old age independently of each other. There were no other consistent associations.ConclusionsIn general we found little evidence for a substantial role of early life factors on late-life cognitive function. However, there was some evidence for an association with parental SES status and head circumference on certain cognitive domains.

Plasma free choline, betaine and cognitive performance: the Hordaland Health Study

Choline and betaine are nutrients involved in one-carbon metabolism. Choline is essential for neurodevelopment and brain function. We studied the associations between cognitive function and plasma concentrations of free choline and betaine. In a cross-sectional study, 2195 subjects (55 % women), aged 70-74 years, underwent extensive cognitive testing including the Kendrick Object Learning Test (KOLT), Trail Making Test (part A, TMT-A), modified versions of the Digit Symbol Test (m-DST), Block Design (m-BD), Mini-Mental State Examination (m-MMSE) and Controlled Oral Word Association Test (COWAT). Compared with low concentrations, high choline (>8·4 μmol/l) was associated with better test scores in the TMT-A (56·0 v. 61·5, P=0·004), m-DST (10·5 v. 9·8, P=0·005) and m-MMSE (11·5 v. 11·4, P=0·01). A generalised additive regression model showed a positive dose-response relationship between the m-MMSE and choline (P=0·012 from a corresponding linear regression model). Betaine was associated with the KOLT, TMT-A and COWAT, but after adjustments for potential confounders, the associations lost significance. Risk ratios (RR) for poor test performance roughly tripled when low choline was combined with either low plasma vitamin B₁₂ (≤257 pmol/l) concentrations (RR(KOLT)=2·6, 95 % CI 1·1, 6·1; RR(m-MMSE)=2·7, 95 % CI 1·1, 6·6; RR(COWAT)=3·1, 95 % CI 1·4, 7·2) or high methylmalonic acid (MMA) (≥3·95 μmol/l) concentrations (RR(m-BD)=2·8, 95 % CI 1·3, 6·1). Low betaine (≤31·1 μmol/l) combined with high MMA was associated with elevated RR on KOLT (RR(KOLT)=2·5, 95 % CI 1·0, 6·2). Low plasma free choline concentrations are associated with poor cognitive performance. There were significant interactions between low choline or betaine and low vitamin B₁₂ or high MMA on cognitive performance.

Cognitive performance among the elderly in relation to the intake of plant foods. The Hordaland Health Study

Fruits and vegetables are among the most nutritious and healthy of foods, and are related to the prevention of many chronic diseases. The aim of the study was to examine the relationship between intake of different plant foods and cognitive performance in elderly individuals in a cross-sectional study. Two thousand and thirty-one elderly subjects (aged 70-74 years; 55% women) recruited from the general population in Western Norway underwent extensive cognitive testing and completed a comprehensive FFQ. The cognitive test battery covered several domains (Kendrick Object Learning Test, Trail Making Test--part A, modified versions of the Digit Symbol Test, Block Design, Mini-Mental State Examination and Controlled Oral Word Association Test). A validated and self-reported FFQ was used to assess habitual food intake. Subjects with intakes of >10th percentile of fruits, vegetables, grain products and mushrooms performed significantly better in cognitive tests than those with very low or no intake. The associations were strongest between cognition and the combined intake of fruits and vegetables, with a marked dose-dependent relationship up to about 500 g/d. The dose-related increase of intakes of grain products and potatoes reached a plateau at about 100-150 g/d, levelling off or decreasing thereafter, whereas the associations were linear for mushrooms. For individual plant foods, the positive cognitive associations of carrots, cruciferous vegetables, citrus fruits and high-fibre bread were most pronounced. The only negative cognitive association was with increased intake of white bread. In the elderly, a diet rich in plant foods is associated with better performance in several cognitive abilities in a dose-dependent manner.

Intake of Flavonoid-Rich Wine, Tea, and Chocolate by Elderly Men and Women Is Associated with Better Cognitive Test Performance1–3

In a cross-sectional study, we examined the relation between intake of 3 common foodstuffs that contain flavonoids (chocolate, wine, and tea) and cognitive performance. 2031 participants (70–74 y, 55% women) recruited from the population-based Hordaland Health Study in Norway underwent cognitive testing. A cognitive test battery included the Kendrick Object Learning Test, Trail Making Test, part A (TMT-A), modified versions of the Digit Symbol Test, Block Design, Mini-Mental State Examination, and Controlled Oral Word Association Test. Poor cognitive performance was defined as a score in the highest decile for the TMT-A and in the lowest decile for all other tests. A self-reported FFQ was used to assess habitual food intake. Participants who consumed chocolate, wine, or tea had significantly better mean test scores and lower prevalence of poor cognitive performance than those who did not. Participants who consumed all 3 studied items had the best test scores and the lowest risks for poor test performance. The associations between intake of these foodstuffs and cognition were dose dependent, with maximum effect at intakes of ∼10 g/d for chocolate and ∼75–100 mL/d for wine, but approximately linear for tea. Most cognitive functions tested were influenced by intake of these 3 foodstuffs. The effect was most pronounced for wine and modestly weaker for chocolate intake. Thus, in the elderly, a diet high in some flavonoid-rich foods is associated with better performance in several cognitive abilities in a dose-dependent manner.

Cognitive performance among the elderly and dietary fish intake: the Hordaland Health Study

Background: Increasing evidence suggests that cognitive impairment and dementia in older subjects might be influenced by a diet including seafood.Objective: The objective was to examine the cross-sectional relation between intake of different amounts of various seafood (fish and fish products) and cognitive performance.Design: The subjects (n = 2031 subjects; 55% women), aged 70–74 y, were recruited from the general population in Western Norway and underwent cognitive testing. A cognitive test battery included the Kendrick Object Learning Test, Trail Making Test (part A), modified versions of the Digit Symbol Test, Block Design, Mini-Mental State Examination, and Controlled Oral Word Association Test. Poor cognitive performance was defined as a score in the highest decile for the Trail Making Test and in the lowest decile for all other tests.Results: Subjects whose mean daily intake of fish and fish products was ≥10 g/d (n = 1951) had significantly better mean test scores and a lower prevalence of poor cognitive performance than did those whose intake was <10 g/d (n = 80). The associations between total intake of seafood and cognition were strongly dose-dependent; the maximum effect was observed at an intake of ≈75 g/d. Most cognitive functions were influenced by fish intake. The effect was more pronounced for nonprocessed lean fish and fatty fish.Conclusions: In the elderly, a diet high in fish and fish products is associated with better cognitive performance in a dose-dependent manner.

Apolipoprotein E ε4 and impaired episodic memory in community-dwelling elderly people: a marked sex difference. The Hordaland Health Study

Background: Among elderly people without dementia, the apolipoprotein E ε4 allele (APOE4) has been associated with cognitive deficit, particularly in episodic memory, but few reports are available on whether this...

Plasma total homocysteine and memory in the elderly: The Hordaland Homocysteine study

We examined the relation between plasma total homocysteine (tHcy), folate, vitamin B12, and episodic memory in elderly community-dwelling subjects. A population-based study was conducted in 1992 and 1993, and subjects were re-investigated after 6 years. Plasma analytes were determined on both occasions. At follow-up, memory performance, using the Kendrick Object Learning Test, was investigated in 2,189 subjects (age, 65-67 years at baseline). Subjects with memory deficit (test score, < 25) had higher tHcy and lower folate at follow-up compared with those without memory deficit: 12.6 (95% confidence interval [CI], 12.1, 13.1) versus 11.5 (95% CI, 11.3, 11.6) micromol/L (p < 0.001) for tHcy, and 6.7 (95% CI, 6.2, 7.1) versus 7.6 (95% CI, 7.5, 7.8) nmol/L (p < 0.001) for folate. The risk of memory deficit increased according to quintiles of tHcy both at baseline and at follow-up. A decline in tHcy, or an increase in folate, over a 6-year period was associated with a higher memory test score; and vice versa. These findings indicate that increased plasma tHcy is an independent risk factor for memory deficit both cross-sectionally and prospectively, and that a "favorable" change in folate or tHcy concentrations over time is associated with better memory performance.

The association between depression, anxiety, and cognitive function in the elderly general population—the Hordaland Health Study

To examine the association between depression and/or anxiety and cognitive function in the elderly general population. Non-demented participants from the general population (n = 1,930) aged 72-74 years. Symptoms and caseness of depression and anxiety disorder were assessed using the Hospital Anxiety and Depression Scale (HADS). Cognitive function was assessed by the Digit Symbol Test (modified version), the Kendrick Object Learning Test, and the 'S'-task from the Controlled Oral Word Association Test. There was a significant association between depression and reduced cognitive function. The inverse association between anxiety and reduced cognitive performance was explained by adjustment for co-morbid depression. The inverse association between depressive symptoms and cognitive function was found to be close to linear, and was also present in the sub-clinical symptom range. Males were more affected cognitively by depressive symptoms than females. The inverse association between depression and cognitive function is not only a finding restricted to severely ill patient samples, but it can also be found in the elderly general population.

Do psychological measures predict the ability of lower limb amputees to learn to use a prosthesis?

Can psychological tests predict whether, on admission to a rehabilitation ward post amputation, a lower limb amputee will learn to use a prosthesis during the ensuing inpatient rehabilitation programme? A one-sample design in which psychological variables, and transfemoral/transtibial amputation site were tested as predictors of outcome. An inpatient rehabilitation unit in the UK offering prosthetic provision. Forty-three consecutive patients with peripheral vascular disease (mean age 66.35 years, standard deviation 14.99) who had received an amputation on average 19 days previously on a surgical ward and were transferred to the unit for rehabilitation including assessment for prosthetic provision. Whether the patient learnt to use a prosthesis independently during the stay on the rehabilitation unit. During their stay in the rehabilitation unit (mean length of stay = 42 days), 31 patients learnt to use a prosthesis and 12 did not. A forward stepwise logistic regression revealed that the Kendrick Object Learning Test score on admission correctly predicted outcome in 70% of cases. The predictive power rose to 81% correct when the amputation site (transfemoral or transtibial) was included amongst the predictors. Anxiety, depression and recovery locus of control scores were not significant predictors of functional prosthetic use in this study. A simple test of learning ability and the amputation site can help to predict the patient's ability to learn to use a prosthesis following amputation and is recommended as part of the assessment process.

Specific patterns of cognitive impairment in patients with idiopathic normal pressure hydrocephalus and Alzheimer's disease: a pilot study

OBJECTIVESEleven patients with idiopathic normal pressure hydrocephalus (NPH) were selected from an initial cohort of 43 patients. The patients with NPH fell into two distinctive subgroups: preshunt, group 1 (n=5)...

Relation between cognitive dysfunction and pseudobulbar palsy in amyotrophic lateral sclerosis.

OBJECTIVES: To examine the relation between cognitive dysfunction and pseudobulbar features in patients with amyotrophic lateral sclerosis (ALS). METHODS: The performance of two patient groups, ALS with pseudobulbar palsy (n...

Neuropsychological Function in Older Subjects with Non‐insulin‐dependent Diabetes Mellitus

Neuropsychological function was compared in three well-matched groups of subjects: Group 1, 20 diabetic patients with hypertension, mean age 69.1 +/- 4.8 years, 14 males and 6 females; Group 2, 20 normotensive diabetic patients, mean age 69.0 +/- 6.2 years, 14 males and 6 females; Group 3, 20 healthy community controls, mean age 68.1 +/- 4.5 years, 13 males and 7 females. There were no significant differences between the groups in education or estimated IQ using the NART (National Adult Reading Test). Groups 1 and 2 did not differ significantly in duration of diabetes (mean 10.6 and 9.5 years, respectively), or mean glycosylated haemoglobin, HbA1 (mean 9.8 and 10.6%, respectively), or mean blood glucose before and after testing. On a battery neuropsychological tests, sensitive to cognitive impairment in older subjects, analysis of covariance using estimated IQ as the covariate showed no significant differences between the groups on tests of recall, with (Brown-Peterson Test) and without (Kendrick Object Learning Test) interference, forward and backward digit span, concentration (serial subtraction), verbal fluency, immediate and delayed prose recall, digit symbol substitution or psychomotor speed (Kendrick Digit Copying Test). These results provide no support for an association between cognitive deficits and Type 2 diabetes mellitus in older subjects or for the view that such deficits may also be mediated by hypertension.

Comparison of executive and visuospatial memory function in Huntington's disease and dementia of Alzheimer type matched for degree of dementia.

Groups of patients with Hungington's disease and probable dementia of Alzheimer type (DAT) matched for level of dementia on the basis of mini mental state examination scores were compared in several tests of visual memory and tests sensitive to frontal lobe dysfunction. Whereas recall of patients with DAT tended to be worse on the Kendrick object learning test, the two groups were equivalent on tests of sensorimotor ability and delayed matching to sample performance. By contrast, the patients with Huntington's disease were significantly worse on tests of pattern and spatial recognition, simultaneous matching to sample, visuospatial paired associates, and on three tests sensitive to frontal lobe dysfunction--namely, the Tower of London test of planning, spatial working memory, and a visual discrimination learning and reversal paradigm. The impairments in these tests, however, did not always qualitatively resemble those seen in patients with frontal lobe damage and may be more characteristic of primary neostriatal deficit. In the visual discrimination paradigm the patients with Hungtington's disease were significantly worse than the patients with DAT at the simple reversal stage, where they displayed significant preservation to the previously rewarded alternative. The results are consistent with the hypothesis that patients with Huntington's disease exhibit deficits in tests sensitive to frontostriatal dysfunction and that this form of intellectual deterioration is qualitatively distinct from that seen in Alzheimer's disease.

Intrusion errors in Alzheimer's disease.

The Kendrick Object Learning Test (OLT) was used to study the incidence of intrusion errors in patients with Alzheimer's disease (AD). Although such errors constituted a higher proportion of the responses made by patients than by controls, suggestions in the literature that patients with AD show a propensity for prior-list intrusion errors were not supported.