Testing Differential Item Functioning in Small Samples.

Differential item functioning (DIF) is a pernicious statistical issue that can mask true group differences on a target latent construct. A considerable amount of research has focused on evaluating methods for testing DIF, such as using likelihood ratio tests in item response theory (IRT). Most of this research has focused on the asymptotic properties of DIF testing, in part because many latent variable methods require large samples to obtain stable parameter estimates. Much less research has evaluated these methods in small sample sizes despite the fact that many social and behavioral scientists frequently encounter small samples in practice. In this article, we examine the extent to which model complexity-the number of model parameters estimated simultaneously-affects the recovery of DIF in small samples. We compare three models that vary in complexity: logistic regression with sum scores, the 1-parameter logistic IRT model, and the 2-parameter logistic IRT model. We expected that logistic regression with sum scores and the 1-parameter logistic IRT model would more accurately estimate DIF because these models yielded more stable estimates despite being misspecified. Indeed, a simulation study and empirical example of adolescent substance use show that, even when data are generated from / assumed to be a 2-parameter logistic IRT, using parsimonious models in small samples leads to more powerful tests of DIF while adequately controlling for Type I error. We also provide evidence for minimum sample sizes needed to detect DIF, and we evaluate whether applying corrections for multiple testing is advisable. Finally, we provide recommendations for applied researchers who conduct DIF analyses in small samples.

Has the "M" word been framed? Marijuana, cannabis, and public opinion.

Over the past two decades, a growing cadre of US states has legalized the drug commonly known as "marijuana." But even as more states legalize the drug, proponents of reform have begun to shun the term "marijuana" in favor of the term "cannabis." Arguing that the "M" word has been tainted and may thus dampen public support for legalization, policy advocates have championed "cannabis" as an alternative and more neutral name for the drug. Importantly, however, no one has tested whether calling the drug "cannabis" as opposed to "marijuana" actually has any effect on public opinion. Using an original survey experiment, we examine whether framing the drug as "marijuana" as opposed to "cannabis" shapes public attitudes across a range of related topics: support for legalization of the drug, moral acceptance of its use, tolerance of activities involving the drug, perceptions of the drug's harms, and stereotypes of its users. Throughout each of our tests, we find no evidence to suggest that the public distinguishes between the terms "marijuana" and "cannabis." We conclude with implications of our findings for debates over marijuana/cannabis policy and for framing in policy discourse more generally.

Analyzing Two Automatic Latent Semantic Analysis (LSA) Assessment Methods (Inbuilt Rubric vs. Golden Summary) in Summaries Extracted from Expository Texts / Análisis de dos métodos de evaluación automática de análisis semántico latente (LSA): un nuevo método LSA (Inbuilt Rubric) y un método LSA tradicional (Golden Sum)

The purpose of this study was to compare two automatic assessment methods using Latent Semantic Analysis (LSA): a novel LSA assessment method (Inbuilt Rubric) and a traditional LSA method (Golden Summary). Two conditions were d using the Inbuilt Rubric method: the number of lexical descriptors needed to better accommodate an expert rubric (few vs. many) and a weighting to penalize off-topic contents d in the student summaries (weighted vs. non-weighted). One hundred and sixty-six students divided in two different samples (81 undergraduates and 85 High School students) took part in this study. Students summarized two expository texts that differed in complexity (complex/ easy) and length (1,300/500 words). Results showed that the Inbuilt Rubric method simulates human assessment better than Golden summaries in all cases. The similarity with human assessment was higher for Inbuilt Rubric (r = .78 and r = .79) than for Golden Summary (r = .67 and r = .47) in both texts. Moreover, to accommodate an expert rubric into the Inbuilt Rubric method was better using few descriptors and the weighted

El objetivo de este estudio es comparar dos métodos de evaluación automática del análisis semántico latente (LSA): Un nuevo método LSA (Inbuilt Rubric) y un método LSA tradicional (Golden Summary). Se analizaron dos condiciones del método Inbuilt Rubric: el número de descriptores léxicos que se utilizan para generar la rúbrica (pocos vs. muchos) y una corrección que penaliza el contenido irrelevante incluido en los resúmenes de los estudiantes (corregido vs. no corregido). Ciento sesenta y seis estudiantes divididos en dos muestras (81 estudiantes universitarios y 85 estudiantes de instituto) participaron en este estudio. Los estudiantes resumieron dos textos expositivos que tenían distinta complejidad (difícil/fácil) y longitud (1,300/500 palabras). Los resultados mostraron que el método Inbuilt Rubric imita las evaluaciones humanas mejor que Golden Summary en todos los casos. La similitud con las evaluaciones humanas fue más alta con Inbuilt Rubric (r = .78 and r = .79) que con Golden Summary (r = .67 and r = .47) en ambos textos. Además, la versión de Inbuilt Rubric con menor número de descriptores y con corrección es la que obtuvo mejores resultados

Statistical Analysis for Subjective and Objective Evaluations of Dental Drill Sounds.

The sound produced by a dental air turbine handpiece (dental drill) can markedly influence the sound environment in a dental clinic. Indeed, many patients report that the sound of a dental drill elicits an unpleasant feeling. Although several manufacturers have attempted to reduce the sound pressure levels produced by dental drills during idling based on ISO 14457, the sound emitted by such drills under active drilling conditions may negatively influence the dental clinic sound environment. The physical metrics related to the unpleasant impressions associated with dental drill sounds have not been determined. In the present study, psychological measurements of dental drill sounds were conducted with the aim of facilitating improvement of the sound environment at dental clinics. Specifically, we examined the impressions elicited by the sounds of 12 types of dental drills in idling and drilling conditions using a semantic differential. The analysis revealed that the impressions of dental drill sounds varied considerably between idling and drilling conditions and among the examined drills. This finding suggests that measuring the sound of a dental drill in idling conditions alone may be insufficient for evaluating the effects of the sound. We related the results of the psychological evaluations to those of measurements of the physical metrics of equivalent continuous A-weighted sound pressure levels (LAeq) and sharpness. Factor analysis indicated that impressions of the dental drill sounds consisted of two factors: "metallic and unpleasant" and "powerful". LAeq had a strong relationship with "powerful impression", calculated sharpness was positively related to "metallic impression", and "unpleasant impression" was predicted by the combination of both LAeq and calculated sharpness. The present analyses indicate that, in addition to a reduction in sound pressure level, refining the frequency components of dental drill sounds is important for creating a comfortable sound environment in dental clinics.

Fluidez verbal-semántica en adultos mayores mexicanos: valores normativos / Semantic verbal fluency in elderly mexican adults: Refer

Introducción: La prueba de fluidez verbal semántica (FVS) es sensible para detectar deterioro cognoscitivo, es rápida y fácil de utilizar en cualquier contexto cultural, por ello se incluye en la mayoría de los protocolos de evaluación neuropsicológica. El objetivo fue estimar valores normativos de la prueba FVS (animales), en una población de adultos mayores de 65 años. Material y método: Se evaluó a 1233 sujetos sanos, cognitivamente conservados, residentes de 2 áreas (rural y urbana) de México. Se aplicó una batería de exploración neurológica y neuropsicológica, incluyendo la FVS. Resultados: El promedio de edad de la muestra fue de 73 + 6 y escolaridad de 4,0 + 3,9 años, el 59% fueron mujeres. El promedio de palabras generadas en la prueba FVS fue de 14 + 5 y se encontró una correlación de 0,16 de estas puntuaciones con edad, escolaridad y género (p < 0,001), permitiendo con ello el cálculo de los percentiles de acuerdo con estas variables. Por ello, el aporte más importante de este estudio es que el análisis de los datos permitió obtener valores normativos para una población mexicana de adultos mayores de 65 años. Además, confirmamos, al igual que otros estudios de evaluación neuropsicológica, que la prueba FVS está influida por variables sociodemográficas, como edad y escolaridad, aspectos que en el momento de construir el baremo se deben tomar en cuenta. Por último, destacamos que debido al bajo nivel educativo de nuestra población de estudio, la media de las puntuaciones obtenidas para FVS resultó inferior a otros valores normativos publicados

Introduction: The semantic verbal fluency test (SVF) is sensitive to detecting cognitive decline. It is fast and easy to use in any cultural context; therefore, it is included in most of the neuropsychological assessment protocols.Objective: To estimate normative values for the SVF test (animals), in an elderly population aged 65 years and over. Material and method: 1233 subjects who were healthy, cognitively preserved, residents of two areas (rural and urban) of Mexico were assessed. A neurological and neuropsychological exploration battery was applied, including SVF. Results: The age average was 73 + 6 and schooling was 4.0 + 3.9 years, with 59% women. The average of the words generated in the SVF test was 14 + 5, and a correlation of 0.16 of these scores with age, education, and gender was found (p<.001), this allowed the estimation of the percentiles in accordance with these variables. Conclusions: The most important contribution provided by this study was that the data analysis enabled normative values to be obtained for an elderly Mexican population aged 65 years and over. It was also confirmed, as other neuropsychological assessment studies have done, that the SVF test is influenced by socio-demographic variables, such as age and education, aspects to be considered at the time of obtaining normative values. Finally, it was noted that the average scores obtained were lower than other published reference values, due to the low educational level of our sample

A pilot study measuring changes in student impressions before and after clinical training using a questionnaire based on the semantic differential technique.

Students with a positive impression of their studies can become more motivated. This study measured the learning impact of clinical training by comparing student impressions before and after clinical training. The study included 32 students of radiological technology in their final year with the Division of Radiological Science and Technology, Department of Health Sciences, School of Medicine, Hokkaido University. To measure student impressions of x-ray examination training, we developed a questionnaire using the semantic differential technique. The resulting factor analysis identified 2 factors that accounted for 44.9% of the 10 bipolar adjective scales. Factor 1 represented a "resistance" impression of x-ray examination training, and factor 2 represented a "responsibility" impression. The differences in factor scores before and after the clinical training suggest that student impressions are affected by clinical training.

Why don't girls choose technological studies? Adolescents' stereotypes and attitudes towards studies related to medicine or engineering.

Gender differences in choice of studies emerge already in adolescence. Two studies with adolescents are presented, the goal of which is to explore the influence of gender by assessing males and females who choose studies related to Medicine or Engineering. Study 1, correlational (N = 330, mean age 15.9, 56.7% girls), shows that girls who choose technology are more poorly appraised than girls who choose other studies. Study 2 (N = 130; mean age 16.77, 56.2% girls), experimental, measures implicit attitudes (using the IAT) towards males and females from Medicine and Engineering. Implicit attitudes are more favorable towards women if they are studying Medicine and towards men if they study Engineering. The results are analyzed with relation to the percentages of boys and girls in the different fields of study.

The interplay between semantic and referential aspects of anaphoric noun phrase resolution: Evidence from ERPs.

In this event-related brain potential (ERP) study, we examined how semantic and referential aspects of anaphoric noun phrase resolution interact during discourse comprehension. We used a full factorial design that crossed referential ambiguity with semantic incoherence. Ambiguous anaphors elicited a sustained negative shift (Nref effect), and incoherent anaphors elicited an N400 effect. Simultaneously ambiguous and incoherent anaphors elicited an ERP pattern resembling that of the incoherent anaphors. These results suggest that semantic incoherence can preclude readers from engaging in anaphoric inferencing. Furthermore, approximately half of our participants unexpectedly showed common late positive effects to the three types of problematic anaphors. We relate the latter finding to recent accounts of what the P600 might reflect, and to the role of individual differences therein.

Negative semantic priming from consciously vs. unconsciously perceived single words

El presente estudio investiga si la obtención depriming semántico negativo ante una única palabra ignorada depende delnivel de conciencia de dicha palabra. En cada ensayo aparecía brevementeuna palabra previa seguida inmediatamente o tras un intervalo de demora,por una máscara de patrón. A continuación aparecía una palabra objetivoante la que los participantes debían realizar una tarea de categorizaciónsemántica o una tarea de identificación de elección forzada. Se instruyó alos sujetos a que atendieran la palabra objetivo e ignoraran la palabra previa,considerándola como un distractor. Las palabras previa y objetivopertenecían a la misma categoría semántica en la mitad de los ensayos, y adistintas categorías en los ensayos restantes. Los resultados mostraron unpatrón diferencial de efectos de priming semántico en función del tipo deenmascaramiento: Priming negativo con la máscara demorada, y facilitacióncon la máscara inmediata. Estos resultados demuestran que el tipo deenmascaramiento, que supuestamente afecta a la percepción consciente vs.no consciente de la palabra previa, constituiría una variable crítica paraobtener priming semántico negativo ante una única palabra. También sonconsistentes con la idea de que la percepción con y sin conciencia produceconsecuencias comportamentales cualitativamente diferentes, que reflejan lacontribución de procesos controlados y automáticos, respectivamente(AU)

The present research explores whether obtaining semantic negative primingfrom a single ignored word depends on whether that word is eitherconsciously or unconsciously perceived. On each trial a prime word wasbriefly displayed and followed either immediately or after a delay by apattern mask. The mask offset was followed by a probe display containing asingle target word that participants were required to either categorize oridentify. Participants were instructed to attend to the target while ignoringthe prime word. On half of trials the prime-target pairs were highlyassociated words belonging to the same semantic category, whereas on theremaining half they belonged to different semantic categories. A differentialpriming pattern as a function of the masking condition was found: Semanticnegative priming when the mask presentation was delayed, and positivepriming when the prime word was immediately masked, thus preventing itsconscious identification. These results suggest that masking type, whichsupposedly affects prime awareness, would be a critical factor to obtainnegative semantic priming from single words. They also provide evidencethat perceiving a stimulus with or without awareness can lead toqualitatively different behavioral consequences, which reflect thecontribution of controlled and automatic components, respectively(AU)

Parents' representations of their children: an exploratory study using the Osgood Semantic Differential Scales.

The results of an exploratory national study carried out in Italy using Osgood's Semantic Differential Scales (Osgood, Suci, & Tannenbaum, 1957) with parents of 100 normal 6- to 11-yr.-old children in mainstream classrooms are reported. The aim was to devise a simple tool to be used to explore parents' perceptions of their children in this age group. Parents were asked to rate "my child" using some of Osgood's Semantic Differential Scales especially adapted for this study. Participants were 97 fathers and 100 mothers. Fathers were 32 to 57 years of age (M = 43.2, SD = 5.4), mothers were 29 to 49 years of age (M = 39.7, SD =4.4). In factor analysis four factors were identified: Activity, Evaluation, Emotions evoked by the child, Personality/Physical contact. Average factor scores were significantly different. There were no significant differences between fathers and mothers on the four factor scores. Children were more positively evaluated the younger they were.

Contrast of frequency of positive and negative feeling state changes associated with standard and reduced cardiovascular exercise.

A field investigation was conducted to assess whether cardiovascular exercise assigned at a level to maximize improvements in fitness, i.e., a standard exercise amount or 30 min. at approximately 80% maximal heart rate, differed significantly in frequency of positive exercise-induced feeling changes when contrasted with exercise that was reduced to 20 min. at approximately 65% maximal heart rate. A significantly more frequent occurrence of positive changes in feelings just after exercise (chi1(2), = 4.95, p < .05, phi(c) = .26) was noted for adults initiating programs at the reduced (n = 36; 86% positive change) vs the standard (n = 36; 64% positive change) amount of exercise. After replication, implications for adjusting exercise to increase adherence were discussed.

Entropy and environmental mystery.

Two studies are reported regarding the effects of entropy, lighting, and occlusion on impressions of mystery in physical environments. The theoretical context of this study was the "informational theory" of environmental preference, which, among other claims, holds that mystery can be measured by the extent to which people perceive a promise of more information if they move deeper into an environment. Entropy, in the context of this article, is visual diversity as measured using information theory. Mystery was measured by a semantic differential scale. The definition of mystery was left up to each individual participant. Entropy of occluded objects was used to obtain an objective, experimentally manipulatable and operational definition of "promise of more information." Exp. 1 had 12 stimuli and 15 participants. Exp. 2 had 12 stimuli and 16 participants. Entropy of occluded objects ranged from 0 to 6 bits. Entropy of occluded objects was used to measure the promise that there would be more information if one moved deeper into an environment. Overall, amount of light had the strongest effect on responses of mystery (r = -.63, darker was more mysterious), followed by occlusion (r = .26, occluding objects made a scene seem more mysterious), and by the promise of more information if one moved about in the scene (r = .13), the more entropy in occluded objects, the greater the impression of mystery). The theoretical contribution of this work is that a relationship between subjective impressions of mystery and an objective measure of "promise of more information" was found.

Significado de la obesidad para los adolescentes de Temuco-Chile / The meaning of obesity for adolescents of Temuco-Chile

RESUMEN: La obesidad en la población adolescente ha tenido un alarmante aumento, siendo la dieta uno de los factores que más ha influido en estos cambios. La dieta se caracteriza por una alta ingesta de grasas, azúcares, alimentos procesados, todo esto estimulado por atractivos mensajes publicitarios que aumentan su consumo.Con el propósito de analizar el significado que tiene la obesidad para los adolescente de los colegios de Temuco, Chile, realizamos este trabajo, utilizando la técnica de redes semánticas naturales. Entrevistamos a 372 adolescentes, alumnos de primero y segundo de Enseñanza Media de colegios de la ciudad deTemuco, Chile. Para los adolescentes, las palabras que estaban presentes con alto valor semántico del concepto "obesidad" fueron: gordura, grasa, sobrepeso, discriminación, depresión, enfermedad, ansiedad, problemas, baja autoestima, chatarra y sedentarismo, entre otras. Esta representación demuestra que los alumnos manejan información de las alteraciones que conlleva la obesidad, que se debe estimular la actividad física, la buena alimentación de los adolescentes y que debe haber un manejo integrado de este problema, como también la mantención del peso corporal o provocar la pérdida de peso, dependiendo de la situación de cada uno de ellos.

Revisión del modelo de alerta e intervención psicolingüística en el trastorno por déficit de atención e hiperactividad / A review of the alert and psycholinguistic intervention model in attention deficit hyperactivity disorder

Introducción. En nuestros colegios, el profesorado seenfrenta a uno o dos niños con trastorno por déficit de atención ehiperactividad (TDAH) por aula, una alteración neurobiológicacon tres ejes clínicos principales: falta de atención, hiperactividade impulsividad. En general, estos niños desarrollan peoreshabilidades psicolingüísticas, aunque más del 50% de esos problemasno son detectados, enmascarados por la conducta. La mayoríade los niños sufrirá algún tipo de impacto académico, principalmenteen las áreas de la lectoescritura. Desarrollo. Las alteracionesdel lenguaje del TDAH están principalmente relacionadascon las áreas semántica y pragmática y, en menor medida,con las áreas fonético-fonológicas. Son demostrables desde losprimeros meses de vida, durante la etapa preverbal, tiempo en elque se modela el temperamento infantil, que puede catalogarse dedifícil o inflexible y explosivo en el 56,5% de los niños diagnosticados de TDAH según nuestra experiencia. Sabemos, por otro lado,que muchos niños con este trastorno manifiestan dificultadespara el desarrollo del juego, y el 30% de ellos, retraso del lenguaje.Un porcentaje no bien definido puede tener una problemáticasimilar a la de los niños con trastorno del espectro autista, lo quedificulta aún más el diagnóstico diferencial. Conclusiones. El modelomixto de intervención en el TDAH incluye el trabajo del lenguajeen el contexto de los programas cognitivo-conductuales y eldesarrollo de las habilidades narrativas y de las competenciassociales a través de un taller de creatividad literaria. Se realizauna revisión de la problemática psicolingüística que afecta a loschicos con TDAH a la luz de nuestra experiencia y otras evidenciasclínicas

Introduction. In every class in our schools, teachers are faced with one or two children with attention deficithyperactivity disorder (ADHD), a neurobiological disorder with three main clinical axes: lack of attention, hyperactivity andimpulsiveness. Generally speaking, these children develop poorer psycholinguistic skills, although over 50% of these problemsremain undetected because they are concealed by the child’s behaviour. Most of the children will see some kind of adverseeffect on their academic performance, chiefly in areas concerning reading and writing. Development. The language disordersin ADHD are mainly related to the areas of semantics and pragmatics and, to a lesser extent, to phonetic-phonologicalaspects. They are discernible from the earliest months of life, during the preverbal stage, which is the time when the infant’scharacter is being shaped. In this case, our experience shows that the character can be classed as difficult or inflexible andexplosive in 56.5% of children diagnosed with ADHD. Moreover, we know that many children with this disorder find it difficultto engage in play, and 30% of them have retarded language development. A rather undefined percentage of children can havesimilar problems to those of children with autism spectrum disorders, which makes the differential diagnosis even morecomplicated. Conclusions. The mixed model of intervention in ADHD includes language work within the context of cognitivebehaviouralprogrammes and the development of narrative skills and social competencies through a literary creativityworkshop. This study offers a review of the psycholinguistic problems affecting children with ADHD in the light of our ownexperience, together with other clinical evidence

Deterioro de la información conceptual en la enfermedad de Alzheimer / Conceptual decline in Alzheimer’s disease

Introducción. Es bien sabido que en la enfermedad de Alzheimer se produce una pérdida gradual y progresiva de la información semántica. Una pregunta de gran interés tanto teórico como práctico es qué conceptos son los primeros que se pierden y cuáles son los más resistentes al deterioro. Algunas teorías sostienen que en el inicio de la enfermedad las pérdidas afectan más a los estímulos pertenecientes a determinadas categorías conceptuales. Método. Un grupo de 22 pacientes con enfermedad de Alzheimer fue contrastado con otro grupo de 22 personas sanas de similares características en cuanto a edad, sexo y escolaridad en la denominación de dibujos de objetos pertenecientes a ocho categorías semánticas, cuatro del dominio de los seres vivos y cuatro del de los objetos inanimados. En cada grupo había 16 mujeres y 6 hombres y en ambos grupos la edad media era de 74 años. Análisis estadístico. Con el fin de comprobar si las diferencias entre pacientes con enfermedad de Alzheimer y sujetos control son mayores en determinadas categorías se realizaron ANOVA tomando como factores el grupo (pacientes/ controles) y la categoría de estímulo. Resultados. Los pacientes con enfermedad de Alzheimer puntúan significativamente menos que los controles en todas las categorías de estímulos, pero las diferencias dependen de las características de cada estímulo (familiaridad, frecuencia, edad de adquisición, etc.) más que de la categoría semántica a la que pertenece. Discusión. Más importante que la pertenencia a una determinada categoría, lo que determina la pérdida conceptual son las características específicas de cada estímulo, fundamentalmente la frecuencia de uso del nombre y la edad en la que se aprende

Introduction. In Alzheimer’s disease a gradual and progressive loss of semantic information takes place. A question of great importance on both the theoretical and practical levels is which concepts are the first to be lost and which are the most resistant to deterioration. Some theories maintain that the beginning of the disease stimuli belonging to certain conceptual categories are most affected by loss. Method. A group of twenty-two patients with mild to moderate Alzheimer’s disease was compared with a group of healthy people of similar age, gender, and educational level, in naming pictures of objects from eight semantic categories: four in the domain of living things and four in the domain of inanimate objects. In each group 16 were women and 6 men. The mean age was 74 in both groups. Statistical analysis. In order to know if differences between Alzheimer patients and control subjects are determined by the semantic categories, ANOVAS were performed taking the group (patients vs control) and the type of stimulus as factors. Results. The scores of the Alzheimer patients are statistically lower than those of the control subjects, but differences are determined by the features of each stimulus (familiarity, frequency, age of acquisition) more than, belonging to a specific category. Discussion. The results indicate that the specific characteristics of each stimulus contribute more to concept loss than does belonging to a certain category, especially the frequency of use and the age of acquisition

School children's responses on a semantic differential over a 10-year span.

A semantic differential scale was administered to 208 school children when they were in the second, fourth, sixth, eighth, tenth, and twelfth grades. Their perceptions towards two concepts were measured, Education (going to school) and Work (having a job). Each semantic differential scale had 15 adjective pairs and reflected the three underlying factors of Evaluative, Potency, and Activity. Because the study was conducted for 10 years (ages seven to 18), the changing cognitive developmental stages of the children were expected to influence factor analytic and reliability results. Confirmatory factor analysis, which forced the data into three factors, did not clearly identify the expected three factors, although more items loaded on the three factors with age. An exploratory factor analysis identified a trend across grades from six to four factors over time. Reliability also improved across age groups. Caution should be exercised when using the semantic differential with young children in investigations of abstract concepts.

Analyzing the aesthetic impressions of alexithymic Japanese students.

We investigated the association between alexithymic tendencies as measured by the 20-item Toronto Alexithymia Scale and the characteristics of aesthetic impressions for words and drawings. Impressions were measured using the semantic differential technique in three groups of Japanese students (High scores n = 31, Moderate scores n = 40, and a Control group n = 182) who were presented only words (Word condition), only drawings (Drawing condition), or pairs comprising one word plus one drawing that represented the same emotional categories (Drawing/Word condition). In a factor analysis on the data from participants, three factors (Evaluation, Activity, and Potency) were extracted. Based on the factor scores, the distances among the three conditions were calculated for each of the groups. For Potency, significant group differences were found between the Drawing/Word and other conditions. In the High-scoring alexithymia group, in particular, the Potency impressions based on tactile sensation, e.g., soft-hard, blunt-sharp, were amplified regardless of stimulus condition. These results are discussed in the context of somatosensory amplification associated with alexithymia and the difficulty of distinguishing between emotion and somatic sensations.

Distributed neuronal networks for encoding category-specific semantic information: the mismatch negativity to action words.

Mismatch negativity (MMN), an index of experience-dependent memory traces, was used to investigate the processing of action-related words in the human brain. Responses to auditorily presented movement-related English words were recorded in a non-attend odd-ball protocol using a high-density electroencephalographic (EEG) set-up. MMN was calculated using responses to the same words presented as standard and deviant stimuli in different sessions to avoid contamination from phonetic-acoustic differences. The topography of the mismatch negativity to action words revealed an unusual centro-posterior distribution of the responses, suggesting that activity was at least in part generated posterior to usually observed frontal MMNs. Moreover, responses to hand-related word stimulus (pick) had a more widespread lateral distribution, whereas leg-related stimulus (kick) elicited a more focal dorsal negativity. These differences, remarkably reminiscent of sensorimotor cortex topography, were further assessed using distributed source analysis of the EEG signal (L2 minimum-norm current estimates). The source analysis also confirmed differentially distributed activation for the two stimuli. We suggest that these results indicate activation of distributed neuronal assemblies that function as category-specific memory traces for words and may involve sensorimotor cortical structures for encoding action words.

Differences between noun and verb processing in a minimal phrase context: a semantic priming study using event-related brain potentials.

The aim of the present study was to enforce the priming of either nouns or verbs in order to evoke word-category-specific N400 effects. In two experiments two primes which were either a verb-noun or a noun-noun pair were followed by a semantically related or unrelated target which was a noun or verb, respectively. This target always completed the word sequence to a minimal phrase comprising verb, subject, and object (VNN or NNV triplets). In experiment I subjects judged the semantic relatedness of the target to the two primes, in experiment II subjects first generated an appropriate target of the required word category and then judged the semantic relatedness between self-generated word and target. ERPs were recorded from 124 scalp electrodes. In both experiments verbs and nouns as such evoked reliably distinct ERP topographies between 300 and 800 ms. With verbs in relation to nouns the amplitudes were most often found to be more positive over central to frontal or parietal areas and more negative over occipital and temporo-parietal areas. In contrast, N400 effects proved as topographically invariant for noun and verb targets in both experiments. The results suggest that access to noun and verb representations involves topographically distinct cell assemblies while the N400 effect seems to reflect semantic evaluation and integration processes which are more abstract and independent from a particular word category.

Matching faces for semantic information and names: an event-related brain potentials study.

In face identification, it has been controversial whether or not access to biographical information and to a person's name are mediated by qualitatively different loci. We recorded ERPs while participants saw two successive faces and performed a matching task that either required retrieval of semantic information ("same or different profession?"), or retrieval of the person's name ("same or different number of forename syllables?"). For both tasks, slow ERP activity between the first and the second face was characterized by a prominent right posterior negativity, with the asymmetry being larger for the name than the semantic matching task. ERPs to the second face showed a difference between congruent (matching) and incongruent (mismatching) trials, with more negative ERPs for incongruent trials. In the semantic matching task, these differences were significant between 450 and 550 ms, and resembled an N400, with a maximum negativity over the vertex. In the name matching task, the topography of this congruency effect was qualitatively different from that seen in semantic matching. These findings suggest that different brain substrates mediate the access to semantic and name information.