Review of brain mechanism of abnormal semantic processing in major depression disorder / 上海交通大学学报（医学版）

Major depression disorder (MDD) is a serious mental illness with high disability rate and high recurrence rate, accompanied by cognitive impairment including language processing. This article reviews neurophysiological evidences of abnormal semantic processing in MDD patients in recent years. Electrophysiological data indicates that abnormal semantic processing in the patients begins in the early stages of perceptual processing and persists in subsequent cognitive processing stages with hemispheric lateralization. Brain imaging studies show that the patients have abnormal activation levels in the medial prefrontal cortex and inferior frontal gyrus. The current research paradigms cannot separate semantic processing from other cognitive processes, and more research is needed.

Abnormal semantic and syntactic processing in patients with schizophrenia: an event-related potential study / 上海交通大学学报（医学版）

Objective • To explore the differences of event-related potential components (N400 and P600) in response to language processing between schizophrenia (SZ) patients with formal thought disorder (FTD), SZ patients without FTD, genetic high-risk subjects and healthy controls (HC). Methods • Thirty SZ patients with FTD (SZ-FTD group) and 29 SZ patients without FTD (SZ-nFTD group), who were hospitalized in Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 22 subjects at genetic high risk who were first degree relatives of SZ patients, and 31 healthy controls (HC) were recruited. Four different types of sentences (syntactically and semantically correct, syntactically correct but semantically incorrect, syntactically incorrect but semantically correct, and syntactically and semantically incorrect) were presented to the four groups respectively with electroencephalogram recording. Repeated measurement analysis of variance was used to compare the response accuracy of the four groups and to analyze the differences in the amplitude and latency of N400 and P600 components in response to each kind of sentence among the four groups. Results • SZFTD group showed a lower accuracy rate compared with the HC group (P=0.000). Compared with the HC group, N400 amplitude in SZ-FTD group was lower in statistically significance (P=0.003), while SZ-FTD group did not show a prominent N400 component. P600 component was well evoked in four groups, and there was an interaction between semantics, syntax and group (P=0.022). By further analysis, neither SZ-FTD nor SZ-nFTD group showed significant differences in P600 amplitudes evoked by syntactically correct and syntactically incorrect sentences. There was no significant difference in P600 amplitudes evoked by semantically correct and incorrect sentences in SZ-FTD group, whereas P600 amplitudes evoked by semantically correct sentences were greater than those evoked by semantically incorrect ones in the other three groups. Conclusion • Neural activity is impaired during semantic processing in SZ. In particular, SZ-FTD patients have impairments in both semantic and syntactic processing.

Priming semántico directo y mediado ortofonológicamente en pacientes con enfermedad de Parkinson: un estudio de tiempos de reacción / Direct and orthophonologically mediated semantic priming in patients with Parkinson's disease: evidence from reaction times

El presente estudio aborda el impacto de la enfermedad de Parkinson en el procesamiento de información semántica durante una tarea de reconocimiento visual de palabras. Para ello, se comparó el rendimiento de un grupo de pacientes con Parkinson con el rendimiento de sujetos sin daño neurológico en dos experimentos. Se evaluaron los efectos de tiempo de presentación de un prime semántico directo (Experimento 1) y un prime semántico mediado orto-fonológicamente (Experimento 2). Además, se evaluó la influencia de la frecuencia léxica tanto del prime como la palabra target, sobre el acceso léxico. Los participantes estaban divididos en tres grupos (grupo clínico, grupo de control etario, y grupo de adultos jóvenes). Los tres grupos completaron una tarea de decisión léxica de tiempo de reacción en la modalidad go-no-go. Los participantes debían responder presionando una tecla del computador si el estímulo presentado en la pantalla era una palabra. En el caso contrario cuando era una pseudo palabra, los participantes no debían presionar ninguna tecla. Los resultados en base al número de respuestas correctas y los tiempos de reacción muestran dificultades de procesamiento semántico en el grupo clínico. Sin embargo, este grupo mostró ser sensible a la frecuencia de las palabras y los tiempos de presentación de estas. En su conjunto, los resultados son coherentes con la literatura existente, y contribuyen a comprender de mejor manera el déficit lingüístico presente en la enfermedad de Parkinson.

The present study addresses the incidence of Parkinson's disease in the processing of semantic information during visual word recognition tasks. In order to do so, the performance of a group of patients with Parkinson's was compared with the performance of subjects without neurological impairment in two experiments. We evaluate the effects of presentation time of a semantic prime (Experiment 1) and anortho-phonologically mediated semantic prime (Experiment 2), and the impact of the lexical frequency of both the prime and the target words. Participants divided into three groups (a clinical group, an age control group and a group of young adults), completed a reaction time lexical decision task in the go-no-go modality. They had to respond by pressing a computer key if the stimulus presented on the screen was a word. Otherwise, the participants should not press any key. The results, based on response accuracy and reaction times, show a semantic deficit in the clinical group, while this group was, nevertheless, sensitive to the frequency of the words and their presentation time. As a whole, the results are consistent with the existing literature, and contribute to a better understanding of the linguistic deficit present in Parkinson's disease.

El papel de estructura argumental en el procesamiento de los compuestos verbo-nombre del español: Evidencias experimentales / The role of semantic argument structure in spanish verb-noun compound words: Experimental evidence

Los compuestos verbo-nombre del español presentan la particularidad de carecer de un núcleo que aporte los rasgos morfológicos, de categoría o semántico-referenciales. El acceso al significado depende entonces de la relación que mantienen los constituyentes entre sí y no a partir de la identificación de un elemento nuclear, como ocurre en compuestos que poseen un lexema referencial (telaraña, bocacalle). Dentro del compuesto verbo-nombre, la relación semántica que se establece entre los constituyentes no es única. Si bien la estructura semántica prototípica responde al patrón agente-paciente (cortacésped), existen otras posibilidades argumentales, como las relaciones locativas (pasacalle). El estudio realizado tuvo como objetivo determinar hasta qué punto la estructura argumental proyectada por el verbo tiene una influencia en el procesamiento cognitivo de estas unidades. Primeramente, se llevó a cabo un juicio de aceptabilidad para asegurar que los estímulos se correspondieran con la realidad lingüística de los participantes del estudio experimental. A continuación, se administró una prueba de decisión léxica con compuestos que poseían distintos tipos de estructura argumental: (1) agente / paciente (algo que V a N, abrelatas), (2) agente / paciente menos prototípica (procesos metafóricos, chupasangre) y (3) locativos (lugar donde x hace V a N, guardamuebles). Los resultados muestran que los tiempos de decisión (respuesta) ante compuestos locativos fueron significativamente mayores que ante los prototípicos. Este resultado no puede ser explicado por diferencias en longitud o frecuencia de los compuestos o sus constituyentes, por lo que parecen apoyar la hipótesis de que la estructura argumental juega un rol central en el procesamiento de estas palabras.

Research on the processing of compound words offers important insights on how the mental lexicon is organized. It is a current topic in psycholinguistics if compound words are represented and processed as unitary lexical units (full-listing models) or only as individual constituents analyzed via acombinatorial mechanism (full-parsing models). There is enough experimental evidence that both mechanisms are involved (dual-route models). Several characteristics of the stimuli, like length, morphological family size, frequency of compounds and their constituents are important factors to determine how they are processed. Compound words are meaningful units that contain smaller meaningful units. Therefore, in the domain of compounds' studies, several hypotheses have been proposed to explain how only one interpretation is achieved from two independent meanings. Models that describe the construction of lexical semantic features in compound words, like APPLE - Automatic Progressive Parsing and Lexical Excitation (Libben 1994,1998) or CARIN - Competition Among Relations in Nominals (Gagné, 2000), are based on the notion of a morphological head. According to these theories the recognition of the head would trigger an interpretation of the whole word. In noun-noun compounds (pez espada, 'swordfish', telaraña 'spiderweb'), in which the head has the referential features, the identification of this head and the posterior clarification of the relationship with the non-head lexeme is the way to interpret the whole compound (pez 'fish' and tela 'web', respectively). However, not every compound has a head with the referential attributes inside. Verb-noun compounding is an extremely productive word-formation process in Romance languages. Spanish verb-noun compounds have the particularity of being exocentric: these constructions do not present a categorical, morphological or semantic head. Therefore, access to the meaning depends on the relationship between both of their constituent lexemes. For these units, the traditional distinction between semantically transparent and semantically opaque compounds is not suitable, because it doesn't take under consideration the projection of the argument structure by the verbal constituent. The semantic relationship established between the lexemes within a compound is not unique. While the prototypical semantic structure responds to the agent-patient pattern (cortacésped), there are other semantic possibilities, such as locative relationships (pasacalle). The present study addresses the issue of the comprehension of Spanish verb-noun compounds in order to provide evidence about the role of the argument structure projected by the first lexeme in the whole-word meaning. It is proposed that the argument structure of the verbal constituent has a cognitive influence on the processing and comprehension of these units. Firstly, an acceptability judgment test was administrated in order to identify a group of verb-noun compounds that were adequate for the Argentinean Spanish lexicon. Secondly, a lexical decision task was conducted with the stimuli selected as acceptable. Thirty native speakers (20 females), ranged in age from 19 to 34 years old, with at least 12 years of schooling, participated in the experiment. The lexical decision task included three types of compounds according to their argument structure: (1) Agent / patient (abrelatas), (2) Agent / patient with less prototypical features or metaphorical processes (chupasangre), and (3) locatives (guardamuebles). Stimuli were matched according to the whole-word and constituent frequency and length. For the statistical analysis, ANOVAs were calculated for error rates and response times (RTs) for each condition. Results show that reaction times (answers) to locative compounds were significantly higher than to agent-patient compounds. This contrast cannot be explained by differences in frequency or length, of the compounds or their constituents. Consequently, the present results seem to support the hypothesis that argument structure plays a central role in the processing of these words.

Chinese character semantic and behavioral problems in 7-8 years old children with attention deficit hyperactivity disorder:an ERP study / 中华行为医学与脑科学杂志

Objective To explore Chinese character semantic processing feature and the relationship with behavioral problems in early childhood with ADHD.Methods Twenty ADHD children and twenty normal children (7-8 years old) performed a Chinese character semantic judgment task through event related potential (ERP),meanwhile Conners parent rating scale (PSQ) was completed by parents to analyze behavior problems in children.The relationship between behavioral problems and ERPs was analyzed.Results (1) ADHD group showed smaller amplitudes of P200 compared to the normal group (related (6.6±4.8) μV vs (11.6±6.4) μV;unrelated (6.7±3.7) μN vs (10.8±5.0) μV),and longer latency (related(240±30) ms vs (198±17)ms;the unrelated (232±26)ms vs (194±16)ms;psudoword (233±26)ms vs (197±15)ms),all P＜0.05).The amplitudes of N400 wave only showed a decreasing trend in ADHD group(P＞0.05),while the latency of N400 was significantly longer than that in normal children in three conditions(P＜0.05).(2) Four subscale scores of CPSQ(conduct problem,learning problem,hyperactivity-impulsion and hyperactivity index) were significantly higher in ADHD children compared with normal group.(3)The amplitudes of P200 in related condition had negative correlation with the scores of CPSQ subscale (conduct problem,psychoso matic disorder,hyperactivity-impulsion and hyperactivity index) (r=-0.51,-0.47,-0.45,-0.46,all P＜0.05.The latency of P200 in related condition had positive correlation with psychosomatic disorder scores (r =0.54,P=0.01).Conclusion Early semantic recognition disorder exists in 7～ 8 years old ADHD children.P200 can be used as an objective index to evaluate early childhood ADHD's language cognition,and P200 is related to behavior problems (such as conduct problem,impulsions).

A semantic processing development study in 7-11 years old children with attention deficit hyperactivity disorder and normal children:an ERP study of N400 / 中华行为医学与脑科学杂志

Objective To explore the developmental characteristics of semantic processing of chil-dren with attention deficit hyperactivity disorder( ADHD) by comparing the event related potential in normal children and ADHD children ( ages 7-11 years old) .Methods 83 ADHD children and 93 normal children ranging from 7 to 11-year were divided into 5 groups to analyze the difference of the amplitude and latency of ERP N400 in three conditions:the related,unrelated and pesudoword after the Chinese character word visual stimulus task.Results (1) The related condition:the amplitude of the 7 years old normal children group was higher than 11 years old((-10.67±4.39)μV,(-4.62±3.55)μV;P=0.005);and the amplitude was highest in 8 years old group in children with ADHD( (-10.77±6.66) ms, F=2.54, P=0.046) .The latency in normal children was shorter at 8 years old((311.7±33.1) ms, P<0.05),but was shorter at 9 years old in ADHD group.( 2) The unrelated condition:the amplitude of normal children aged 10 years was higher than that of other age groups.( 3) The pesudoword condition:the amplitude of 9 years old normal children was higher than other age groups.The amplitude of ADHD in children aged 9 years was higher than that in other age groups( (-16.08±7.14)μV, P<0.05) .Conclusion In the semantic related conditions,the amplitude of the N400 in ADHD children at the age of 8 and the latency at the age of 9 are significantly developed,and in the false words conditions,it is at the age of 11.This suggests that the ability of 7-11 years old ADHD chil-dren's orthographic semantic processing and cognitive development are slower than normal.N400 can better reflect the children's early language cognitive ability,and it is valuable for the early diagnosis of children with ADHD.

Procesamiento semántico de palabras epistémicas y metafísicas en niños y adolescentes con trastorno de espectro autista (TEA) y con desarrollo típico (DT) / Semantic processing of epistemic and metaphysical words in children and adolescents with autism spectrum disorder (ASD) and typically developing (TD)

La capacidad para entender palabras abstractas se relaciona con la inteligencia y procesos de orden superior. Sin embargo, un creciente número de investigaciones sugiere que las palabras abstractas, aun cuando tienen bajos niveles de concreción e imaginabilidad, son procesadas de una manera diferente. Este artículo proporciona evidencia experimental, donde el procesamiento de palabras abstractas-epistémicas (v.g. imaginación, certeza) es diferente al procesamiento de palabras abstractas-metafísicas (v.g. libertad, criterio). Se llevó a cabo un experimento en el que 16 niños y adolescentes con Trastorno del Espectro Autista (ASD) y un grupo pareado con Desarrollo Típico (DT) completaron nueve sentencias incompletas graduadas por dificultad. Los sujetos con TEA fueron menos precisos y lentos con palabras epistémicas-abstractas, y lentos con palabras abstractas-metafísicas que los sujetos con DT. Los resultados se discuten en términos de los procesos cognitivos y sociales para detectar y entender los estados mentales, una habilidad llamada teoría de la mente (ToM).

The ability to understand abstract words is related to intelligence and higher order processes. However, a growing corpus of research suggests that abstracts words, while having lower level of concreteness and imaginability, are processed in different manners. This article provides experimental evidence that the processing of epistemic-abstract words (eg. Imagination, certainty) is different from the processing of metaphysical-abstract words (eg. Freedom, criteria). We carried out an experiment in which 16 children and adolescents with Autism Spectrum Disorder (ASD) and a typically developing matched group (TD) completed nine sentences graded by difficulty. Subjects with ASD were less accurate and slower with abstract-epistemic words; and slower with abstract-metaphysical words, than subjects with TD. The findings are discussed in terms of the social and cognitive processes to detect and understand the mental states, an ability named theory of mind (ToM).

Processamento léxico-semântico explícito e priming semântico em lesão cerebral de hemisfério direito / Explicit lexical-semantic processing and semantic priming on right brain damage

É fundamental a melhor compreensão de alterações neuropsicológicas decorrentes de lesão de hemisfério cerebral direito (LHD). O objetivo deste estudo foi comparar os efeitos de priming semântico (EPS) e o desempenho em tarefas de processamento léxico-semântico explícito entre pacientes com LHD (n=11) e controles saudáveis (n=11). Investigaram-se também subgrupos de pacientes com LHD com relação a associações e dissociações entre o desempenho em tarefas de processamento léxicosemântico explícito (evocação lexical com critério semântico e julgamento semântico) e de priming semântico através de um estudo de série de casos. O priming semântico foi avaliado por uma tarefa de decisão lexical com estímulos monossêmicos com forte relação semântica e um Stimulus Onset Asynchrony de 500ms. Ambos os grupos apresentaram EPS e não diferiram significativamente nas tarefas de processamento léxico-semântico explícito. Contudo, no estudo de série de casos houve uma heterogeneidade no perfil de desempenho na amostra de pacientes em tarefas de processamento léxico-semântico explícito e de priming semântico. Os resultados indicam a importância de estudos de série de casos para o melhor entendimento de alterações no processamento léxico-semântico em LHD

It is essential a better understanding of neuropsychological deficits resulting from right hemisphere brain damage (RHD). This study aimed to compare semantic priming effects (SPE) and performance on explicit lexicalsemantic processing tasks between RHD patients (n=11) and healthy controls (n=11). It were also investigated subgroups of patients with RHD regarding associations and dissociations between performance on explicit lexical-semantic processing (lexical retrieval based on semantic criteria and semantic judgment) and semantic priming tasks through a case series investigation. Semantic priming was evaluated through a lexical decision task with monosemic stimuli with strong semantic relationship and 500ms Stimulus Onset Asynchrony. Both groups showed SPE and did not differ significantly on explicit lexicalsemantic processing tasks. However, there was heterogeneity in the performance of the patients sample on explicit lexical-semantic processing and priming tasks on the case series investigation. Results indicate the importance of case series investigations to a better understanding of deficits on lexical-semantc processing after RHD

O papel do processamento léxico-semântico em modelos de leitura / The role of lexical-semantic processing in reading models / El papel del procesamiento léxico-semántico en modelos de lectura

O objetivo deste estudo é apresentar uma revisão crítica dos principais modelos de leitura de palavras e de texto utilizados atualmente, enfocando o papel do processamento léxico-semântico nesses modelos. Os modelos de dupla rota e conexionistas de leitura de palavras são apresentados, discutindo-se a necessidade, em cada modelo, do processamento léxico-semântico para o reconhecimento de palavras. Em seguida, são apresentados os principais modelos de compreensão de leitura: o Modelo de Construção-Integração, a Hipótese da Qualidade Lexical e alguns modelos conexionistas. Para cada modelo, é avaliada a contribuição do processamento léxico-semântico para a compreensão. Ao final, sugerem-se temas de estudo para a investigação da relação entre leitura e processamento léxico-semântico...

The aim of this study was to examine the role of lexical-semantic processing in models of visual word recognition and in reading comprehension. Dual-route and connectionist models of word reading are presented, and it is discussed how necessary lexical-semantic processing is for word recognition. Afterwards, the main reading comprehension frameworks are reviewed: The Construction-Integration model, the Lexical Quality Hypothesis and some connectionist models. For each model, the contribution of lexical-semantic processing for reading comprehension is evaluated. Finally, some themes for study are suggested for the investigation of the relationship between reading and lexical-semantic-processing...

El objetivo de este estudio es presentar una revisión de los principales modelos de lectura de textos y palabras que se usan hoy en día, centrándose en el papel del léxico semántico en estos modelos de procesamiento.. Se presentan los modelos de doble ruta y conexionistas de lectura de palabras, discutiéndose la necesidad, en cada modelo, del procesamiento léxico-semántico para el reconocimiento de palabras. A continuación se presentan los principales modelos de comprensión lectora: el modelo de Construcción-Integración, la Hipótesis de la Calidad Léxica y algunos modelos conexionistas. Para cada modelo, se evalúa la contribución del procesamiento léxico-semántico para la comprensión. Por último, se sugieren temas de estudio para investigar la relación entre la lectura y el procesamiento léxico-semántico...

Perfil de errores en la prosucción de palabras en etapas iniciales de la enfermedad alzheimer / Words production profile errors in early stages of Alzheimer's disease

Las tareas de Denominación por confrontación visual (DCV) y fluidez verbal (FV) son amplia-mente utilizadas para evaluar el funcionamiento cognitivo de personas con diagnóstico de enfer-medad de Alzheimer (EA), un desempeño más bajo con respecto a controles, ha sido asociado a un deterioro la memoria semántica. El objetivo de este estudio fue comparar el desempeño de pacientes con EA leve con un grupo control en tareas de fluidez verbal y denominación por confrontación visual; analizando los errores cometidos por los participantes a fin de comprobar si las fallas en estas tareas tienen origen en el déficit de la memoria semántica. Los resultados muestran una gran heterogeneidad en los procesos cognitivos vinculados a la producción oral de palabras en personas con EA. Estos resultados sugieren la necesidad de evaluar a cada paciente de forma individual por medio del análisis cuantitativo y sobre todo cualitativo e interpretar los signos y síntomas independientemente de la patología

The tasks of visual confrontation naming (DCV) and verbal fluency (VF) are widely used to assess cognitive functioning in persons diagnosed with Alzheimer's disease (AD), lower perfor-mance relative to controls, has been associated with a semantic memory impairment. The goal of this study was to compare the performance of patients with mild AD with a control group on tasks of verbal fluency and visual confrontation naming; analyzing the errors made by the par-ticipants in order to ascertain whether the failure in these tasks are rooted in semantic memory deficits. The results show a great heterogeneity in production-related words in persons with AD cognitive processes. These results suggest the need to evaluate each patient individually and es-pecially by means of qualitative and quantitative analysis to interpret the signs and symptoms regardless of pathology

Pruebas de fluidez verbal categoriales, fonológicas y gramaticales en la infancia: factores ejecutivos y semánticos / Categorical, phonological and grammatical verbal fluency tasks in children: executive and semantic factors

En el presente trabajo se aplicaron las Pruebas de Fluidez Verbal (PFV), correspondientes al Explorador Neuropsicológico en Fluidez Verbal (ENFV), a una población de niños argentinos. El objetivo principal fue conocer su estructura factorial en niños y divulgar valores normativos. Se obtuvieron dos factores principales: uno ejecutivo y el otro semántico. Esto avala gran parte de la literatura especializada, que discute sobre el rol de las capacidades atencionales y otras habilidades en PFV. Respecto del rol de la edad, se encontró una elevada incidencia en todas las pruebas, excepto la categorial de supermercado. La influencia fue mayor para las pruebas fonológicas y de verbos, lo que fue relacionado con su mayor compromiso frontal y la tardía maduración de estas estructuras. Se sugiere, por último, la continuidad de estos trabajos desde una perspectiva interactiva entre nodos ejecutivos y semánticos. Esto conlleva la utilización de equipos de neuroimágenes para obtener imágenes por Tensor de Difusiones, cuyo dato principal es la conectividad entre regiones cerebrales distantes.

In this work we applied Verbal Fluency Tasks (VFT) belonging to the Verbal Fluency Neuropsychological Explorer (VFNE) to a popu-lation of Argentinean childrens. The main objective was to determine the factor structure in children and disseminate normative values. We obtained two main factors: one executive and one semantic. This supports much of the literature, which discusses the role of attentional capacities and other skills in VFT. On the role of Age, there was a high incidence in all tests except the categorical supermarket. The influence was greater for the phonological tests and verbs, which was associated with greater commitment and delayed frontal maturation of these structures. It suggests, finally, the continuity of this work from an interactive perspective be-tween executive and semantic nodes. This involves the use of neuroimaging equipment to obtain diffusion tensor images, which shows connectivity data between distant brain regions.

Efeitos de priming semântico em tarefa de decisão lexical em crianças de 3ª série / Semantic priming effects during lexical decision task with 3rd grade children

No paradigma de priming semântico, mede-se a acurácia e velocidade de resposta ao estímulo-alvo, precedido por palavra semanticamente relacionada ou não relacionada (primes). Este trabalho apresenta um estudo pré-experimental de normas de associação semântica de palavras em 156 crianças e um estudo experimental, que avalia o efeito de priming semântico em 24 crianças em uma tarefa de decisão lexical. O experimento mostrou que as decisões lexicais para alvos reais foram significativamente mais lentas e menos precisas na condição prime não relacionado comparado à condição prime relacionado. Conclui-se que houve efeitos de priming semântico no reconhecimento visual de palavras em crianças, ou seja, o contexto semântico pré-ativou a representação da palavra alvo, facilitando a decisão lexical na condição de relação semântica.

In the semantic priming paradigm, accuracy and reaction time to a target-stimulus that is preceded by a prime (semantic related or unrelated to the target) are measured. This paper presents a pre-experimental study on word semantic association norms with 156 children and an experimental study that evaluated the effect of semantic priming in 24 children during a lexical decision task. Results showed that the lexical decisions for real targets were significantly slower and less accurate in the unrelated prime condition than in the related one. It means that there were semantic priming effects in children during visual recognition of words, that is, the semantic context pre-activated the target word representation, facilitating the lexical decision in the semantic related condition.

Voluntary modulations of attention in a semantic auditory-visual matching Task: an ERP study

The present study explores the neural correlates of voluntary modulations of attention in an auditory-visual matching task. Visual stimuli (a female or a male face) were preceded in close temporal proximity by auditory stimuli consisting of the Spanish word for "man" and "woman" ("hombre" or "mujer"). In 80 percent of the trials the gender of the two stimuli coincided. Participants were asked to mentally count the specific instances in which a female face appeared after hearing the word "man" (10 percent of the trials). Our results show attention-related amplitude modulation of the early visual ERP components NI and anterior P2, but also amplitude modulations of (i) the N270 potential usually associated with conflict detection, (ii) a P300 wave related to infrequency, and (iii) an N400 potential related to semantic incongruence. The elicitation of these latter components varied according to task manipulations, evidencing the role of voluntary allocation of attention in fine-tuning cognitive processing, which includes basic processes like detection of infrequency or semantic incongruity often considered to be volition-independent.

Characteristics of Brain Activation during Semantic Processing in Schizophrenia / 신경정신의학

OBJECTIVES: Investigators reported that schizophrenies have deficits in semantic processing. However, it is unclear which brain area is associated with semantic processing dysfunction in schizophrenia. This study was designed to explore the activated brain areas associated with semantic processing in schizophrenic patients compared with controls. METHODS: Twelve patients with schizophrenia and twelve healthy controls were studied under two different visual task conditions. Subjects were required to respond to a specific semantic category in a specific figure among word-figure stimuli during the first task, and to respond to a specific figure among figure-only stimuli during the second task. Brain activation during each task was measured using [15O]H2O PET. Activated brain areas were analyzed by subtraction methods using SPM99 in each group. RESULTS: In healthy control group, the left superior temporal gyrus, left premotor area and left cerebellum were activated during semantic processing along with activation of the left inferior temporal gyrus which is a main semantic processing area. But activation of the main semantic processing area in patient group was more posteriorly than controls. In contrast with control group, lateralized activation pattern to the left and cerebellar activation were not observed in patient group. CONCLUSION: Our results suggest that patient's deficit in elaboration due to early semantic processing, decreased efficacy due to the loss of lateralization and decreased modulatory ability due to the loss of cerebellar activation may be involved in the characteristics of brain activation patterns in schizophrenia. This distorted semantic processing in schizophrenia may play a role as one of the basic determinants in thought disorder.