Valentina Ladera

Scoring neuropsychological tests using the Rasch model: an illustrative example with the Rey-Osterrieth Complex Figure.

Parametric statistical methods are typically used for analyzing test scores, even though they are ordinal at best. The Meyers and Meyers’ Rey-Osterrieth Complex Figure four-category scoring system has been evaluated with the Rasch Rating Scale Model, and disordered thresholds have been found. However, Rasch-modeling dichotomized data led to good fit for both normal (n = 219) and Traumatic Brain Injury (n = 54) samples and generalized validity for these groups, as well as for male and female groups. The logarithmic transformation of the item and person data performed by the model converts the ordinal data to yield interval scaled data. This is desirable not only from a scientific perspective, but also from the point of view of interpretability and communicability.

Funcionamiento diferencial de los ítems del test Mini-mental en función de la patología

INTRODUCTION Comparing the height of males and females would be impossible if the measuring device did not have the same properties for both populations. In a similar way, the cognitive level of diverse groups of patients should not be compared if the test has different measurement properties for these groups. Lack of Differential Item Functioning (DIF) is a condition for measurement invariance between populations. MATERIAL AND METHODS The most internationally used screening test for dementia, the MMSE (or Mini-mental State Examination), has been analysed using an advanced psychometric technique, the Rasch Model. The objective was to determine the invariance of mini-mental measurements from diverse groups: Parkinsons disease patients, Alzheimers type dementia and normal subjects. The hypothesis was that the scores would not show DIF against any of these groups. The total sample was composed of 400 subjects. RESULTS Significant differences between groups were found. However, the quantitative comparison only makes sense if no evidence against measurement invariance was found: given the kind of items showing DIF against Parkinsons disease patients, the MMSE seems to underestimate the cognitive level of these patients. CONCLUSIONS Despite the extended use of this test, 11 items out of 30 show DIF and consequently score comparisons between groups are not justified.

The roles of word concreteness and cognitive load on interhemispheric processes of recognition.

Previous studies on hemispheric specialisation suggest that the cerebral hemispheres differ in the way verbal information is processed. There is also evidence that functional asymmetries are attributable to differences in stimulus properties and/or task complexity. To study these asymmetries in the domain of explicit recognition, concrete and abstract nouns were presented either in the right or left visual fields and recognised with foveal vision at different retention levels. We propose that different hemispheric mechanisms underlie the encoding of abstract and concrete information, which can be modulated by cognitive or mental load. To accomplish this goal, 92 right-handed undergraduate Portuguese students with normal or corrected-to-normal vision were randomly sampled from a university campus. The results showed that concrete words were discriminated better than abstract words when previously encoded in the right hemisphere for the longest retention interval between encoding and retrieval. These data suggest that there are different neural mechanisms for the semantic encoding of concrete and abstract concepts. The practical implications are discussed.

Verbal Functions in Psychopathy

The aim of this study was to compare the verbal functions and language skills of male psychopathic individuals (in prison and outside) with non-psychopaths. The purpose was therefore to analyze phonological processing, reading and writing skills, the meaning of words and images, and the understanding of sentences. Ninety individuals with an average age of 38.19 (SD = 7.67) voluntarily participated in this study. The data were collected in different settings: prisons, a private charitable organization, and private clinics and health centers. All participants completed the Psychopathy Checklist Revised and the Psycholinguistic Assessment of Language Processing in Aphasia, to assess psychopathy traits and language skills, respectively. Participants were allocated into four different groups: incarcerated psychopathic offenders (n = 13), non-incarcerated psychopathic non-offenders living in the community (n = 13), incarcerated non-psychopathic offenders (n = 25), and non-psychopathic non-offenders living in the community (n = 39). The results showed that the verbal functions and language skills between psychopaths and non-psychopaths are very similar, showing a common profile. The data presented indicate the need for more specific work opportunities for both groups within the correctional setting, with the use of appropriate language and individualized programs as necessary.

Language disorders in victims of domestic violence in children's homes

Studies that deal with child maltreatment have become relevant during these past years. One important aspect to consider is the impact of maltreatment on the cognitive functioning and more precisely on language. Our objective is to analyze the different components in the comprehension and production of language in children victims of domestic abuse in Childreńs Homes. PARTICIPANTS The sample consists of 104 participants divided in two groups. A group of children who have just been institutionalized due to domestic abuse (VG) (Age: 8 years 2 months with a standard deviation of 1, 5 years) without previous treatment; a group of comparison (CG) made up by children who have not been victim of domestic violence (Age: 8 years 6 months with a standard deviation of 2 years and a month), with similar characteristics of gender, age and schooling. MATERIAL The Child Neuropsychological Assessment by Matute, Rosselli, Ardila and Ostrosky (2007) was applied. This test includes metalinguistic, oral and written comprehension and expression skills. RESULTS The VG group showed low scores in all components of the analyzed language with exception to the discourse, syllable and non-word dictation compared to the CG children. CONCLUSIONS The alterations of the language observed in these children semantic suggest a lack of consolidation of phonological coding and a low use of code. From our findings an early language evaluation in these children can be of especial interest to apply timely intervention programs with the aim of diminishing the impact caused by domestic violence on school failure which is a frequent trait in these children.

Measurement properties of a screening questionnaire of obstructive sleep apnea risk: Little information, great prediction?☆

Introduction Previous research had shown the suitability of several questionnaires predicting the obstructive sleep apnea syndrome. Measurement properties of an online screening questionnaire were studied. Methods The sample consisted of 184 Portuguese adults (89 men and 95 women); 46 of them were polysomnographically diagnosed with the untreated obstructive sleep apnea syndrome. The participants were assessed with an online questionnaire of sleep apnea risk, from University of Maryland. Results A principal component factor analysis was performed, revealing a single factor (49.24% of the total variance). Internal consistency was minimally adequate (α=0.74). The mean of inter-item correlation was of 0.35 (0.120.61), whereas the item-total correlations were considered good (0.520.81). The total score for patients was significantly higher than for healthy participants (p<0.000), but no significant statistical differences between severity groups of patients were found (p>0.05). Furthermore, the ability of the measure in discriminating between healthy subjects and OSA subjects was good. Overall data from the Rasch analysis was consistent with the guidelines of Linacre, scores show good model fit and psychometric adequacy. Conclusions The measure showed an adequate structural, internal and criterion validity, suggesting this as a useful and effective screening for sleep apnea risk in Portuguese adults.