[Analysis of intrusion errors in free recall]. / Intrusiefouten bij geheugenonderzoek.

Extra-list intrusion errors during five trials of the eight-word list-learning task of the Amsterdam Dementia Screening Test (ADST) were investigated in 823 consecutive psychogeriatric patients (87.1% suffering from major neurocognitive disorder). Almost half of the participants (45.9%) produced one or more intrusion errors on the verbal recall test. Correct responses were lower when subjects made intrusion errors, but learning slopes did not differ between subjects who committed intrusion errors and those who did not so. Bivariate regression analyses revealed that participants who committed intrusion errors were more deficient on measures of eight-word recognition memory, delayed visual recognition and tests of executive control (the Behavioral Dyscontrol Scale and the ADST-Graphical Sequences as measures of response inhibition). Using hierarchical multiple regression, only free recall and delayed visual recognition retained an independent effect in the association with intrusion errors, such that deficient scores on tests of episodic memory were sufficient to explain the occurrence of intrusion errors. Measures of inhibitory control did not add significantly to the explanation of intrusion errors in free recall, which makes insufficient strength of memory traces rather than a primary deficit in inhibition the preferred account for intrusion errors in free recall.

[INDICATORS OF EMOTIONAL WELL-BEING IN PSYCHOGERIATRIC CARE]. / Indicatoren van emotioneel welbevinden in de psychogeriatrische praktijk.

Responses of 1,442 consecutive participants in psychogeriatric day care (mean age 78.8; SD 6.5) to 15 items of a mood questionnaire were analyzed by Mokken scale analysis which is based on nonparametric item response theory models. As from 2002, 825 participants also answered eight self-esteem questions. For the purpose of an exploratory and confirmatory study the sample was split into random halves. The sample represented a broad range of cognitive impairment, from moderately severe to mild dementia. An automated item selection procedure available in the R package mokken revealed a scale for emotional well-being consisting of nine items fitting the monotone homogeneity model of unidimensionality and adequate person separation (Loevingers H=0.37; SE=0.02; Cronbach's coefficient alpha=0.79; SE=0.02). A confirmatory analysis in the second random half of the sample confirmed these results. The scale for emotional well-being consists of the items feeling 'contented', 'healthy', 'tired', 'lonely', 'down', 'in good spirits', 'helpless', 'weak' and 'having faith in the future'. Mokken scale analysis of the eight self-worth items confirmed the unidimensionality and discriminatory power of the self-esteem scale (H=0.41; SE=0.03; Cronbach's alpha=0.80; SE=0.02). Emotional well-being was positively associated with self-worth (Spearman correlation=0.56; 95%-confidence interval [0.49;0.62]). The two scales allow the objective ordering of persons on the latent variables of emotional well-being and self-worth by their test scores. Three case vignettes illustrate application of the indicators in clinical psychogeriatric practice.

[A behavioural rating scale of activity engagement in psychogeriatric day care]. / Een gedragsobservatieschaal voor participatie in psychogeriatrische dagbehandeling.

The Participation Scale was developed as an observational measure of activity engagement (as rated by group facilitators) of adult day care clients with mild to moderate dementia. In a consecutive sample of 448 subjects Mokken scaling procedure was conducted to assess the latent structure of 27 questionnaire items. The study included an exploratory and a confirmatory approach. For that purpose the sample was randomly divided into two halves. Exploratory analysis revealed three dimensions of participation that adequately captured the item structure: motivation (10 items; Loevinger's H = 0.48), competence (7 items; H = 0.56) and self-confidence (4 items; H = 0.57). The structure was validated in a confirmatory analysis. In a stepwise multiple regression model 49% of the variance in motivation was explained by independent behavioural measures of apathy and affect. Apathy and cognitive impairment were significant predictors of competence in participation (R(2) = 31.2%). Negative affect was the main predictor of reduced self-confidence (R(2) = 37.9%). Cross-validation of these exploratory regression models on the confirmatory sample explained 39.6%, 29.2% and 23.1% of the variance in motivation, competence and self-confidence, respectively. Test-retest intraclass correlation coefficients (ICC2(A,1)) as determined in a random subsample of 56 participants, were 0.77 (motivation), 0.85 (competence) and 0.76 (self-confidence). The three measures allow the differentiation and ordering of individual participants on separate dimensions of activity engagement in psychogeriatric day care.

[Interpreting change scores of the Behavioural Rating Scale for Geriatric Inpatients (GIP)]. / Wat is een reëel verschil bij herhaalde metingen met de Gedragsobservatieschaal voor de Intramurale Psychogeriatrie (GIP)? : Onderzoek bij deelnemers aan psychogeriatrische dagbehandeling.

The Behavioural Rating Scale for Geriatric Inpatients (GIP) consists of fourteen, Rasch modelled subscales, each measuring different aspects of behavioural, cognitive and affective disturbances in elderly patients. Four additional measures are derived from the GIP: care dependency, apathy, cognition and affect. The objective of the study was to determine the reproducibility of the 18 measures. A convenience sample of 56 patients in psychogeriatric day care was assessed twice by the same observer (a professional caregiver). The median time interval between rating occasions was 45 days (interquartile range 34-58 days). Reproducibility was determined by calculating intraclass correlation coefficients (ICC agreement) for test-retest reliability. The minimal detectable difference (MDD) was calculated based on the standard error of measurement (SEM agreement). Test-retest reliability expressed by the ICCs varied from 0.57 (incoherent behaviour) to 0.93 (anxious behaviour). Standard errors of measurement varied from 0.28 (anxious behaviour) to 1.63 (care dependency). The results show how the GIP can be applied when interpreting individual change in psychogeriatric day care participants.

[The Balloons Test for the assessment of visual inattention in psychogeriatric patients]. / Aandacht voor visuele inattentie. De balloons Test in de psychogeriatrie.

The Balloons Test is a paper-and-pencil target cancellation task designed to detect visual inattention. The test consists of two subtests: subtest A for parallel, automatic processing and detection of twenty circles with an adjoining vertical line ('balloons') among a much larger number of circles as distractors. Subtest B asks for serial and effortful search of twenty circles among balloons. Among 191 consecutive participants of a psychogeriatric day care program (mean age 78 yr) 28.2% scored below 17 on subtest B, which is indicative of generalized visual inattention. Bivariate analyses showed that visual inattention was associated with deficiencies on tasks of visuospatial, constructional and executive mental control functions. Using multivariate logistic regression analysis, two tests of visuospatial perception (clock reading and picture description) retained an independent effect in the association with visual inattention. Only three participants (1.6%) were unable to take the Balloons Test. The results of this clinical study are in favour of the Balloons Test as a useful addition to inattention measurement in psychogeriatric patients.

[When shape-invariant recognition ('A' = 'a') fails. A case study of pure alexia and kinesthetic facilitation]. / Als 'A' niet meer als 'a' wordt herkend. Een analyse van verworven woordblindheid.

A right-handed patient, aged 72, manifested alexia without agraphia, a right homonymous hemianopia and an impaired ability to identify visually presented objects. He was completely unable to read words aloud and severely deficient in naming visually presented letters. He responded to orthographic familiarity in the lexical decision tasks of the Psycholinguistic Assessments of Language Processing in Aphasia (PALPA) rather than to the lexicality of the letter strings. He was impaired at deciding whether two letters of different case (e.g., A, a) are the same, though he could detect real letters from made-up ones or from their mirror image. Consequently, his core deficit in reading was posited at the level of the abstract letter identifiers. When asked to trace a letter with his right index finger, kinesthetic facilitation enabled him to read letters and words aloud. Though he could use intact motor representations of letters in order to facilitate recognition and reading, the slow, sequential and error-prone process of reading letter by letter made him abandon further training.

[The phonological variant of primary progressive aphasia, a single case study]. / De fonologische variant van primaire progressieve afasie, een gevalsstudie.

Primary progressive aphasia (PPA) is a neurodegenerative syndrome characterized by an insidious onset and gradual progression of deficits that can involve any aspect of language, including word finding, object naming, fluency, syntax, phonology and word comprehension. The initial symptoms occur in the absence of major deficits in other cognitive domains, including episodic memory, visuospatial abilities and visuoconstruction. According to recent diagnostic guidelines, PPA is typically divided into three variants: nonfluent variant PPA (also termed progressive nonfluent aphasia), semantic variant PPA (also termed semantic dementia) and logopenic/phonological variant PPA (also termed logopenic progressive aphasia). The paper describes a 79-yr old man, who presented with normal motor speech and production rate, impaired single word retrieval and phonemic errors in spontaneous speech and confrontational naming. Confrontation naming was strongly affected by lexical frequency. He was impaired on repetition of sentences and phrases. Reading was intact for regularly spelled words but not for irregular words (surface dyslexia). Comprehension was spared at the single word level, but impaired for complex sentences. He performed within the normal range on the Dutch equivalent of the Pyramids and Palm Trees (PPT) Pictures Test, indicating that semantic processing was preserved. There was, however, a slight deficiency on the PPT Words Test, which appeals to semantic knowledge of verbal associations. His core deficit was interpreted as an inability to retrieve stored lexical-phonological information for spoken word production in spontaneous speech, confrontation naming, repetition and reading aloud.

[Associative visual agnosia. The less visible consequences of a cerebral infarction]. / Associatieve visuele agnosie. De minder zichtbare gevolgen van een herseninfarct.

After a cerebral infarction, some patients acutely demonstrate contralateral hemiplegia, or aphasia. Those are the obvious symptoms of a cerebral infarction. However, less visible but burdensome consequences may go unnoticed without closer investigation. The importance of a thorough clinical examination is exemplified by a single case study of a 72-year-old, right-handed male. Two years before he had suffered from an ischemic stroke in the territory of the left posterior cerebral artery, with right homonymous hemianopia and global alexia (i.e., impairment in letter recognition and profound impairment of reading) without agraphia. Naming was impaired on visual presentation (20%-39% correct), but improved significantly after tactile presentation (87% correct) or verbal definition (89%). Pre-semantic visual processing was normal (correct matching of different views of the same object), as was his access to structural knowledge from vision (he reliably distinguished real objects from non-objects). On a colour decision task he reliably indicated which of two items was coloured correctly. Though he was unable to mime how visually presented objects were used, he more reliably matched pictures of objects with pictures of a mime artist gesturing the use of the object. He obtained normal scores on word definition (WAIS-III), synonym judgment and word-picture matching tasks with perceptual and semantic distractors. He however failed when he had to match physically dissimilar specimens of the same object or when he had to decide which two of five objects were related associatively (Pyramids and Palm Trees Test). The patient thus showed a striking contrast in his intact ability to access knowledge of object shape or colour from vision and impaired functional and associative knowledge. As a result, he could not access a complete semantic representation, required for activating phonological representations to name visually presented objects. The pattern of impairments and preserved abilities is considered to be a specific difficulty to access a full semantic representation from an intact structural representation of visually presented objects, i.e., a form of visual object agnosia.

[Category fluency (animals, professions) in normal cognitive ageing and dementia]. / Klinische bruikbaarheid van categoriegebonden woordproductie voor het onderscheiden van dementie en normale cognitieve veroudering.

Regression-based normative data for commonly used semantic verbal fluency test (VFT) scores were derived from data of the Maastricht Aging Study (N=1,825; age range 24-81). Animal naming, profession naming, and the summed score (animal + profession naming) were shown to be profoundly affected by demographical variables, especially age and educational level. The clinical utility of the newly established regression-based VFT norms was evaluated in a large sample of psychogeriatric patients (N=1,063, of which n=890 met the criteria for Alzheimer's or vascular dementia). Results showed that the animal naming VFT score was the most sensitive measure to distinguish normal aging from dementia (when the specificities of the various VFT measures were equated). Fifty patients were found to commit stuck-in-set perseverations, i.e. they generated animal names during test administration of the profession naming VFT. The prevalence of stuck-in-set perseveration was 11.3% in Parkinson dementia and frontal variant frontotemporal dementia, versus 4.6% and 5.3% in dementia of the Alzheimer type and vascular dementia, respectively. Bivariate analyses revealed that people who committed stuck-in-set perseverations were more deficient on a measure of free recall and on several tests of executive control, such as the Expanded Mental Control Test, the Behavioral Dyscontrol Scale and the Alternating Graphical Sequences Test as a measure of response inhibition. Using multivariate logistic regression analysis, only the Alternating Graphical Sequences Test retained an independent effect in the association with stuck-in-set perseveration.

Visuographic tests of set shifting and inhibitory control. The contribution of constructional impairments.

Luria's graphical or alternating sequences test (the 'rampart' design) is a well-known procedure to examine attentional processes such as set shifting and inhibition of competing responses. Although the test requires attentional control over inappropriate responses, it also relies on constructional abilities that may hamper the specificity of the test. In order to control for the influence of constructional abilities, the structural equation modelling (path analysis) was used to examine the correlations between the performance on alternating sequences and an independent criterion measure of executive functioning (the Behavioural Dyscontrol Scale), corrected for the influence of visuoconstructional ability as reflected by performance on a task of design copying. The tests were administered to 950 elderly participants in a psychogeriatric day-care programme. Performance on the Behavioural Dyscontrol Scale (BDS) and the copying tasks jointly predicted performance on the alternating sequences test (AST) (multiple R(2)=.41). Though the effect of BDS on AST was 38.9% mediated by constructional ability, BDS scores predicted performance on graphical sequences above and beyond the influence of drawing ability. In a non-parametric classification tree analysis, the performance on the AST was reliably predicted by drawing ability. When BDS performance was added to the analysis, the classification accuracy increased for participants with poor drawing, but remained unchanged for those who performed in the normal range on the copying tasks. As a task that relies on shifting and inhibitory control, the alternating sequences test is a feasible measure of executive functioning that is relatively independent of the influence of the component drawing skills.

Klinische bruikbaarheid van categoriegebonden woordproductie voor het onderscheiden van dementie en normale cognitieve veroudering.

CATEGORY FLUENCY (ANIMALS, PROFESSIONS) IN NORMAL COGNITIVE AGEING AND DEMENTIA: Regression-based normative data for commonly used semantic verbal fluency test (VFT) scores were derived from data of the Maastricht Aging Study (N=1,825; age range 24-81). Animal naming, profession naming, and the summed score (animal + profession naming) were shown to be profoundly affected by demographical variables, especially age and educational level. The clinical utility of the newly established regression-based VFT norms was evaluated in a large sample of psychogeriatric patients (N=1,063, of which n=890 met the criteria for Alzheimer's or vascular dementia). Results showed that the animal naming VFT score was the most sensitive measure to distinguish normal aging from dementia (when the specificities of the various VFT measures were equated). Fifty patients were found to commit stuck-in-set perseverations, i.e. they generated animal names during test administration of the profession naming VFT. The prevalence of stuck-in-set perseveration was 11.3% in Parkinson dementia and frontal variant frontotemporal dementia, versus 4.6% and 5.3% in dementia of the Alzheimer type and vascular dementia, respectively. Bivariate analyses revealed that people who committed stuck-in-set perseverations were more deficient on a measure of free recall and on several tests of executive control, such as the Expanded Mental Control Test, the Behavioral Dyscontrol Scale and the Alternating Graphical Sequences Test as a measure of response inhibition. Using multivariate logistic regression analysis, only the Alternating Graphical Sequences Test retained an independent effect in the association with stuck-in-set perseveration.

[Mokken scaling of the Cognitive Screening Test]. / De Cognitieve Screening Test (CST) getoetst aan het schaalmodel van Mokken.

The Cognitive Screening Test (CST) is a twenty-item orientation questionnaire in Dutch, that is commonly used to evaluate cognitive impairment. This study applied Mokken Scale Analysis, a non-parametric set of techniques derived from item response theory (IRT), to CST-data of 466 consecutive participants in psychogeriatric day care. The full item set and the standard short version of fourteen items both met the assumptions of the monotone homogeneity model, with scalability coefficient H = 0.39, which is considered weak. In order to select items that would fulfil the assumption of invariant item ordering or the double monotonicity model, the subjects were randomly partitioned into a training set (50% of the sample) and a test set (the remaining half). By means of an automated item selection eleven items were found to measure one latent trait, with H = 0.67 and item H coefficients larger than 0.51. Cross-validation of the item analysis in the remaining half of the subjects gave comparable values (H = 0.66; item H coefficients larger than 0.56). The selected items involve year, place of residence, birth date, the monarch's and prime minister's names, and their predecessors. Applying optimal discriminant analysis (ODA) it was found that the full set of twenty CST items performed best in distinguishing two predefined groups of patients of lower or higher cognitive ability, as established by an independent criterion derived from the Amsterdam Dementia Screening Test. The chance corrected predictive value or prognostic utility was 47.5% for the full item set, 45.2% for the fourteen items of the standard short version of the CST, and 46.1% for the homogeneous, unidimensional set of selected eleven items. The results of the item analysis support the application of the CST in cognitive assessment, and revealed a more reliable 'short' version of the CST than the standard short version (CST14).