RESUMEN
En el presente trabajo se detallan los análisis realizados con el fin de estudiar las propiedades psicométricas la Prueba Argentina Psicolingüística de Denominación de Imágenes (PAPDI). La misma cuenta con dos cualidades que representan un valor agregado frente a las pruebas actualmente disponibles en nuestro país: a) los estímulos fueron seleccionados controlando las variables que afectan las etapas de análisis visual y de representación conceptual de la imagen del objeto y se manipularon las variables que afectan la selección y recuperación de la etiqueta léxica, en base a valores normativos de población argentina; y b) las claves semánticas se elaboraron de acuerdo con normas de producción de atributos semánticos también recolectadas en nuestro país. En este trabajo se analizaron las propiedades psicométricas mediante el estudio de pacientes con demencia tipo Alzheimer, con lesiones cerebrales focales y participantes sin patología neurológica. Se buscaron evidencias de validez de criterio mediante el análisis de grupos contrastados y la correlación con el test de Boston. A su vez, se estudió la confiabilidad de las puntuaciones por dos métodos: consistencia interna y test-retest. También se analizó la capacidad de discriminación entre pacientes con y sin anomia mediante curvas ROC. Se estudiaron además los efectos de las variables manipuladas, se realizó un análisis cualitativo de los errores y se examinó el desempeño en función del uso de las claves. Los resultados de los análisis aportan evidencia de que presenta cualidades psicométricas sumamente aceptables para su uso en nuestra población.
In the current paper we present the psychometric analysis of the Argentinean Psycholinguistic Image Naming Test (PAPDI). This test has two characteristics that makes it different from those currently available in our country: a) the stimuli has been chosen and ordered controlling certain psycholinguistic variables proven to have influence on this task, such as Visual Complexity, Image Agreement, Image Variability, Familiarity, Name Agreement, Age of Acquisition and Frequency of Use, following Argentinean normative data base; and b) semantic cues were elaborated according to semantic feature production norms also from Argentina. We present here the psychometric analysis of its properties. There were analyzed through the study of patients with Alzheimer Disease (n = 25) and focal brain lesions (n = 27) and healthy partici-pants (n = 125). On the first place, in order to study criteria validity a group comparison analysis was carried out. On the one hand Alzheimer Disease patients were compared with healthy participants. On the other hand, two focal brain damaged patients were compared: with and without aphasia. Convergent validity was also studied through the correlation with Boston naming test. In the third place, scores reliability was studied through two methods: internal consistency analysis, for Alzheimer, focal and healthy groups, and test-retest for focal brain damage group. Forth, it was analyzed the capacity to discriminate between patient with and without aphasia through ROC curves analysis. The respective sensitivity and specificity values to detect anomia were established. Fifth, the demographic variables´ influence was analyzed through a regression analysis. Moreover, there were analyzed the effects of two psycholinguistic variables that were taken into account to order the images but were not normalized: Lexical Frequency and Age of Acquisition. Finally, type of errors and response to cues were studied for focal brain damaged patients. The results indicated that the PAPDI presents acceptable psychometric properties to be used as a tool in neuropsychological assessment. It showed evidence of internal and external validity and it was observed scores reliability through internal consistency and test-retest. A suggested cutting point was established to detect anomia. Furthermore a main influence of educational level was reported. There were also detected effects of Lexical Frequency and Age of Acquisition which were observed for Alzheimer and aphasic patients groups. Moreover it was illustrated the response profile analysis for aphasic and nonaphasic focal brain damaged patients regarding a proposed taxonomy of error types. It was also studied the response to semantic and phonological cues and it was observed that both contributed to improve patients´ performance.
RESUMEN
En la primera parte de este trabajo se presenta la construcción y el desarrollo de la Prueba Argentina Psicolingüística de Denominación de Imágenes (PAPDI). La misma tiene dos características que la diferencian de las pruebas actualmente disponibles en nuestro medio: (a) Los estímulos fueron seleccionados controlando las variables que afectan las etapas de análisis visual y reconocimiento de la imagen (Complejidad visual y Concordancia con la imagen) y el conocimiento conceptual (Variabilidad de la Imagen y Familiaridad) del dibujo del objeto también se manipularon las variables (Frecuencia léxica y Edad de adquisición) que afectan la etapa que busca evaluar la prueba: activación, selección y recuperación de la etiqueta léxica. Los índices que operacionalizan a las variables son dependientes de la cultura y de la lengua de dónde se obtengan, por ello se tomaron sus valores de normas argentinas. (b) Las claves semánticas han sido elaboradas cuidadosamente, siguiendo las normas de producción de atributos semánticos también recolectadas en nuestro país, ya que el uso de las mismas permite generar hipótesis más precisas acerca de la localización del déficit. Por lo tanto, se presenta el proceso de construcción y desarrollo de la prueba mostrando cómo se tuvieron en cuenta estas particularidades, cuáles variables han sido controladas y cuáles manipuladas, y su justificación. Por último, los resultados de la prueba piloto permitieron seleccionar 30 ítems y la constitución de la versión final de la prueba, que es lo suficientemente breve para su uso en la clínica y de libre acceso.
In the current paper, first part, we present the design and development of the Argentinean Psycholinguistic Image Naming Test (PAPDI). This test has two characteristics that make it different from those currently available in our country: (a) the stimuli have been selected by controlling the variables that affect the stages of visual analysis and image recognition (Visual Complexity and Image Agreement) and conceptual knowledge (Image Variability and Familiarity) of the drawing of the object; and the variables (Frequency of Use and Age of Acquisition) that affect the stage that seeks to evaluate the test were manipulated: activation, selection and retrieval of the lexical label (phonological form of the name), to generate a gradient of difficulty in the items of the test. However, the variable Naming Agreement, that also affects this stage, was controlled to selected pictures with only one predominating name. The quantification of these factors by means of specific variables is influenced by the cultural and linguistic context from which they were obtained, consequently we took their values from Argentinean normative data base and (b) semantic cues were elaborated according to semantic feature production norms also from Argentina. The phonological cues corresponded to the first syllable of the object's name. Their use allows to generate more precise hypotheses about the location of the deficit and allows to infer relevant information about the cognitive profile. Therefore, the process of construction and development of the test is presented, showing how these particularities were taken into consideration, which variables were controlled and which were manipulated, and their justification. For the design of the test 62, black and white pictures were originally selected from the 400 pictures taken from Cycowicz's set (of frequent use in Experimental Psychology and Neuropsychology). They correspond to concrete concepts from different semantic categories belonging to both living andnon living domains. The criteria used to include those images were that they were moderately complex (in quantity of lines and details), moderately familiar and that they had a mean image variability value. They had to have a medium to high concordance degree between the mental image and its corresponding representation. Besides, these images had to have a naming agreement superior to 80%. To conform the first version of the test, the 62 images selected were ordered according to the variable Age of Acquisition and each image was assigned its corresponding semantic and phonological cues. The former were extracted from the Argentinean norms considering the most relevant features. The second consisted on the word´s first syllable. A pilot study with healthy population (n = 50), of different ages, both sexes and three educational levels, was carried out through which 30 images were selected that constituted the test´s final version. The deleted items were: figures that did not evokea univocal response, that is, they were easily confused with other objects; figures that had more than one acceptable answer although not all were correct; and items that presented a ceiling effect where the scores accumulated in high scores and did not allow to discriminate the participants' ability to select, retrieve and produce a word (only 25 and 30% of the items were retained). In the test´s final version, the items were reordered according to the Age of Acquisition and Frequency values and their difficulty in naming (following the percentage of successes in the spontaneous response). And images that were contain in another naming tests were deleted. The test is short enough for use in the clinic and freely accessible. The second part of the paper presents the psychometric studies that provide evidence of their relevance and validity.
