A survey of domestic wells and pit latrines in rural settlements of Mali: Implications of on-site sanitation on the quality of water supplies.

On-site sanitation is generally advocated as a means to eradicate the health hazards associated with open defecation. While this has provided a welcome upgrade to the livelihoods of millions of people in low-income countries, improved sanitation facilities are increasingly becoming a threat to domestic groundwater-based supplies. Within this context, a survey of pit latrines, domestic wells and improved water sources was carried out in a large rural village of southern Mali. All households were surveyed for water, sanitation and hygiene habits. Domestic wells and improved water sources were georeferenced and sampled for water quality (pH, electric conductivity, temperature, turbidity, total dissolved solids, thermotolerant coliforms, chloride and nitrate) and groundwater level, while all latrines were inspected and georeferenced. A GIS database was then used to evaluate the proportion of water points within the influence area of latrines, as well as to underpin multiple regression models to establish the determinants for fecal contamination in drinking supplies. Moreover, an appraisal of domestic water treatment practices was carried out. This revealed that nearly two-thirds of the population uses bleach to purify drinking supplies, but also that domestic-scale treatment as currently implemented by the population is far from effective. It is thus concluded that existing habits could be enhanced as a means to make water supplies safer. Furthermore, population, well and latrine density were all identified as statistically significant predictors for fecal pollution at different spatial scales. These findings are policy-relevant in the context of groundwater-dependent human settlements, since many countries in the developing world currently pursue the objective of eliminating open defecation.

Cortical surface area and cortical thickness in the precuneus of adult humans.

The precuneus has received considerable attention in the last decade, because of its cognitive functions, its role as a central node of the brain networks, and its involvement in neurodegenerative processes. Paleoneurological studies suggested that form changes in the deep parietal areas represent a major character associated with the origin of the modern human brain morphology. A recent neuroanatomical survey based on shape analysis suggests that the proportions of the precuneus are also a determinant source of overall brain geometrical differences among adult individuals, influencing the brain spatial organization. Here, we evaluate the variation of cortical thickness and cortical surface area of the precuneus in a sample of adult humans, and their relation with geometry and cognition. Precuneal thickness and surface area are not correlated. There is a marked individual variation. The right precuneus is thinner and larger than the left one, but there are relevant fluctuating asymmetries, with only a modest correlation between the hemispheres. Males have a thicker cortex but differences in cortical area are not significant between sexes. The surface area of the precuneus shows a positive allometry with the brain surface area, although the correlation is modest. The dilation/contraction of the precuneus, described as a major factor of variability within adult humans, is associated with absolute increase/decrease of its surface, but not with variation in thickness. Precuneal thickness, precuneal surface area and precuneal morphology are not correlated with psychological factors such as intelligence, working memory, attention control, and processing speed, stressing further possible roles of this area in supporting default mode functions. Beyond gross morphology, the processes underlying the large phenotypic variation of the precuneus must be further investigated through specific cellular analyses, aimed at considering differences in cellular size, density, composition, and structural covariance compared to other brain areas.

Beauty and ugliness in the bodies and faces of others: an fMRI study of person esthetic judgement.

Whether beauty and ugliness represent two independent judgement categories or, instead, opposite extremes of a single dimension is a matter of debate. In the present 3T-functional Magnetic Resonance Imaging (fMRI) study, 20 participants were scanned while judging faces and nude bodies of people classified as extremely ugly, extremely beautiful, or indifferent. Certain areas, such as the caudate/nucleus accumbens (NAcc) and the anterior cingulate cortex (ACC), exhibited a linear relationship across esthetic judgments supporting ugliness as the lowest extreme of a beauty continuum. Other regions, such as basal occipital areas, displayed an inverse pattern, with the highest activations for ugly and the lowest for beautiful ones. Further, several areas were involved alike by both the very beautiful and the very ugly stimuli. Among these, the medial orbitofrontal cortex (mOFC), as well as the posterior and medial portions of the cingulate gyrus. This is interpreted as the activation of neural circuits related to self- vs. other-assessment. Beauty and ugliness in the brain, at least in relation to natural and biologically and socially relevant stimuli (faces and bodies), appear tightly related and non-independent. Finally, neutral stimuli elicited strong and wide activations of the somatosensory and somatomotor systems together with longer reaction times and higher error rates, probably reflecting the difficulty of the human brain to classify someone as indifferent.

Spatial distribution and cognitive correlates of gamma noise power in schizophrenia.

BACKGROUND: Brain activity is less organized in patients with schizophrenia than in healthy controls (HC). Noise power (scalp-recorded electroencephalographic activity unlocked to stimuli) may be of use for studying this disorganization. Method Fifty-four patients with schizophrenia (29 minimally treated and 25 stable treated), 23 first-degree relatives and 27 HC underwent clinical and cognitive assessments and an electroencephalographic recording during an oddball P300 paradigm to calculate noise power magnitude in the gamma band. We used a principal component analysis (PCA) to determine the factor structure of gamma noise power values across electrodes and the clinical and cognitive correlates of the resulting factors. RESULTS: The PCA revealed three noise power factors, roughly corresponding to the default mode network (DMN), frontal and occipital regions respectively. Patients showed higher gamma noise power loadings in the first factor when compared to HC and first-degree relatives. In the patients, frontal gamma noise factor scores related significantly and inversely to working memory and problem-solving performance. There were no associations with symptoms. CONCLUSIONS: There is an elevated gamma activity unrelated to task processing over regions coherent with the DMN topography in patients with schizophrenia. The same type of gamma activity over frontal regions is inversely related to performance in tasks with high involvement in these frontal areas. The idea of gamma noise as a possible biological marker for schizophrenia seems promising. Gamma noise might be of use in the study of underlying neurophysiological mechanisms involved in this disease.

[The evolution of the brain in the genus Homo: the neurobiology that makes us different]. / La evolución del cerebro en el género Homo: la neurobiología que nos hace diferentes.

INTRODUCTION: For the most part, what makes us different from other animal species is comprised within our brain. However, there is no single factor, no singular reason accounting for the difference between our brain and others; rather, differences appear multiple. DEVELOPMENT AND CONCLUSIONS: Here we perform an up-to-date review of the main divergences between ours and other species' brains, which might be explaining the singularities of our behavior. When brain volume is on focus, it can be appreciated that our brain is certainly large both in relative and absolute terms, being also the case that some subdivisions of the prefrontal regions, as much as the parietal or temporal lobes appear notably increased in size relative to other brain areas. Also at variance with other species, our brain is consistently more asymmetric. But differences also involve the cellular level. In this regard, they have been reported different and peculiar proportions of neurons both within and between cortical columns, as much as certain types of neurons (like fusiform and mirror neurons) that, even if they are not exclusively human, they display in our species peculiar quantitative and functional features. Finally, neuronal receptor systems seem to exhibit exclusively human traits that might be crucial to understanding some of the singularities of the evolution of our brain.

La evolución del cerebro en el género Homo: la neurobiología que nos hace diferentes / The evolution of the brain int he genus homo: the neurobiology that makes us different

Introducción. Gran parte de lo que nos hace diferentes de otras especies animales está en el cerebro. Sin embargo, no hay un único factor, una única razón por la que nuestro cerebro sea distinto, sino que las diferencias son múltiples. Desarrollo y conclusiones. En este trabajo se revisan las principales disparidades que se conocen hoy en día entre nuestro cerebro y el de otras especies y que podrían explicar las singularidades de nuestro comportamiento. Cuando se revisa el volumen cerebral y el de sus distintas subdivisiones, se observa que es realmente grande en nuestra especie, tanto en términos relativos como absolutos, y algunas partes de nuestro cerebro, como ciertas regiones prefrontales, los lóbulos parietales o los temporales, parecen haber aumentado de tamaño notablemente más que otras. También se constata que, a diferencia de otras especies, nuestro cerebro es más sistemáticamente asimétrico. Pero las diferencias entre nuestro cerebro y el de otras especies se aprecian también a escala celular, donde podemos encontrar diferentes y peculiares proporciones de neuronas dentro y entre las columnas corticales, así como determinados tipos de neuronas (como las células en huso o las neuronas espejo) que, si bien no son exclusivas de nuestra especie, en ésta presentan ciertas particularidades en cuanto a número y función. Por último, los sistemas de receptores de las neuronas también parecen tener características propias de nuestra especie que podrían ser la clave para entender algunas de las singularidades de la evolución de nuestro cerebro (Au)

Introduction. For the most part, what makes us different from other animal species is comprised within our brain. However, there is no single factor, no singular reason accounting for the difference between our brain and others; rather, differences appear multiple. Development and conclusions. Here we perform an up-to-date review of the main divergences between ours and other species’ brains, which might be explaining the singularities of our behavior. When brain volume is on focus, it can be appreciated that our brain is certainly large both in relative and absolute terms, being also the case that some subdivisions of the prefrontal regions, as much as the parietal or temporal lobes appear notably increased in size relative to other brain areas. Also at variance with other species, our brain is consistently more asymmetric. But differences also involve the cellular level. In this regard, they have been reported different and peculiar proportions of neurons both within and between cortical columns, as much as certain types of neurons (like fusiform and mirror neurons) that, even if they are not exclusively human, they display in our species peculiar quantitative and functional features. Finally, neuronal receptor systems seem to exhibit exclusively human traits that might be crucial to understanding some of the singularities of the evolution of our brain (AU)

Differential clinical, structural and P300 parameters in schizophrenia patients resistant to conventional neuroleptics.

Schizophrenia is a heterogeneous clinical condition that may reflect a variety of biological processes. In particular, treatment-resistant (TR) schizophrenia may have a distinct neurobiological substrate. Within the context of clinical data, a simultaneous study with different imaging techniques could help to elucidate differences in cerebral substrates among schizophrenia patients with different responses to treatment. In the present work we used a set of biological data (basal and longitudinal volumetry, and P300 event-related potential measurements) to compare TR and treatment-responsive chronic schizophrenia patients with healthy controls. The TR patients showed higher baseline clinical scores, a more severe basal profile of brain alterations, as well as a different outcome as regards to volume deficits. These data support the notion that biological substrates vary among groups of different psychotic patients, even when they have the same diagnosis, and that those substrates may be related to the response to treatment.

A comparative analysis of the modification of sexual desire of users of oral hormonal contraceptives and intrauterine contraceptive devices.

OBJECTIVE: To compare the influence of oral hormonal contraceptives (OCs) and the use of intrauterine contraceptive devices (IUDs) on the modification of sexual desire. MATERIALS AND METHODS: A prospective observational study of 1073 women using OCs or an IUD at the Family Planning Center 'Marina Alta' in Alicante, Spain. In order to evaluate the relative risk regarding the decrease in libido attributed to each contraceptive method, a logistic regression analysis was undertaken which considered the factors of age adjustment, level of studies, family planning information, relationship with partner, age when sexual relationships were initiated, parity, contraceptive method previously used and the duration of use of the contraceptive method. RESULTS: No differences in the decrease of sexual desire were observed between the use of the OC and IUD (odds ratio (OR) 1.32; 95% confidence interval (CI) 0.70-2.49), yet differences were noted, however, in relation to age (OR 1.05; 95% CI 1.01-1.10). Although these differences were not statistically significant, a high level of awareness regarding family planning was shown to increase sexual desire when compared to a lower level of information on this subject (OR 0.64; 95% CI 0.41-1.01). Sexual desire was seen to decrease if the quality of the relationship with the partner was average (OR 2.24; 95% CI 1.36-3.69) or poor (OR 4.69; 95% CI 1.93-11.4). Nulliparous women showed a greater decrease in sexual desire in relation to women who had already given birth (OR 1.57; 95% CI 1.00-2.47). Sexual desire was greater if the contraceptive method had already been in use for 6-12 months (OR 0.41; 95% CI 0.17-0.98). CONCLUSIONS: Sexual desire does not vary in relation to the use of OCs or IUDs, yet it does decrease with age, in nulliparous women and in those with an average or poor relationship with their partner. Furthermore, sexual desire shows an increase between the first 6 and 12 months of contraceptive treatment.

Uterine sarcoma associated with tamoxifen use: case report.

A case of müllerian adenosarcoma with sarcomatous overgrowth in a postmenopausal 66-year-old female patient after adjuvant tamoxifen treatment for breast carcinoma is described. The patient was asymptomatic and the neoplasm was detected by pelvic sonography. The diagnosis was based on the histological findings after curettage and complementary total hysterectomy with bilateral salpingo-oophorectomy. The association of tamoxifen use and development of mesenchymal neoplasms is discussed.

Análisis epidemiológico de los resultados perinatales obtenidos en las gestantes adolescentes de la Comunidad Valenciana / Epidemiological analysis of the perinatal results obtained in teenage pregnant girls in the Autonomous Community of Valencia (Spain)

Objetivo: Estudiar los resultados perinatales en las gestantes adolescentes de la Comunidad Valenciana. Material y métodos: Estudio epidemiológico descriptivo de los 104 embarazos en 98 gestantes adolescentes que ocurrieron en un período de 5 años (entre junio de 1995 y mayo de 2000) en la comarca de la Marina Alta, en la provincia de Alicante, de la Comunidad Valenciana. Estudiamos la vía del parto, la edad gestacional, el sexo, el peso, la talla, el perímetro cefálico, el índice de Apgar y el tipo de lactancia utilizada. Resultados: Se produjeron 89 partos por vía vaginal (85,57 por ciento) y se practicaron 15 cesáreas (14,42 por ciento). La edad gestacional media fue de 39,8 ñ 1,8 semanas. Un total de 50 partos fueron varones (48,07 por ciento) y 54 mujeres (51,93 por ciento). El peso medio fue de 3.210,4 ñ 438,6 g; la talla media fue de 49,1 ñ 2 cm, y el perímetro encefálico medio fue de 34,3 ñ 1,4 cm. La valoración del test de Apgar en el primer minuto fue de 8-10 puntos y a los 5 min de 10. El tipo de lactancia utilizado fue en 85 pacientes (81,73 por ciento) materna y en 19 (18,27 por ciento) artificial. Conclusiones: La cesárea se practica en casos excepcionales y en menor proporción a los estudios revisados. El porcentaje de recién nacidos de bajo peso es muy inferior, y la vitalidad de los recién nacidos de nuestra comunidad es mayor a la referenciada en otras poblaciones. La lactancia materna es utilizada por las gestantes adolescentes en un porcentaje similar a la población general (AU)

Principales complicaciones del embarazo en las gestantes adolescentes de la Comunidad Valenciana / Main complications in the pregnancy of the adolescent pregnancies in the Valencian Community

Objetivo: estudiar las complicaciones más importantes en cuanto a repercusión en la salud del embarazo en las adolescentes gestantes de la Comunidad Valenciana. Material y métodos: estudio epidemiológico descriptivo de los 104 embarazos en 98 gestantes adolescentes que ocurrieron en un período de cinco años (entre junio de 1995 y mayo de 2000) en la Comarca de la Marina Alta en la Provincia de Alicante de la Comunidad Valenciana. Estudiamos la anemia, la isoinmunización Rh, el embarazo múltiple, la preeclampsia-eclampsia, la placenta previa, el hidramnios, la amenaza de aborto y el parto pretérmino como complicaciones principales. Resultados: sólo encontramos 3 pacientes anémicas (2,88 por ciento). Durante uno de los embarazos (0,96 por ciento) con madre Rh negativa, se detectó un Coombs directo positivo. No hubo ningún caso de embarazo múltiple, placenta previa o polihidramnios. Se objetivó una paciente con preeclampsia (0,96 por ciento), 3 casos de amenaza de aborto (2,88 por ciento) y 4 casos más de parto pretérmino (3,84 por ciento).Conclusiones: el número de adolescentes gestantes que padecen anemia o preeclampsia durante la gestación es menor a otras adolescentes pertenecientes a los estudios revisados. Las gestantes adolescentes padecen amenaza de aborto y parto pretérmino en porcentajes similares a los referenciados en algunos estudios (AU)

Principales factores de riesgo asociados a las gestantes adolescentes de la Comunidad Valenciana / Main risk factors associated with adolescent pregnancy in the Valencian Community

Objetivo: Estudiar los principales factores de riesgo asociados al embarazo en la adolescencia en la Comunidad Valenciana. Material y métodos: Estudio epidemiológico descriptivo de los 104 embarazos en 98 gestantes adolescentes que ocurrieron en un período de 5 años (entre junio de 1995 y mayo de 2000) en la comarca de la Marina Alta en la provincia de Alicante de la Comunidad Valenciana. Para conocer los factores de riesgo asociados al embarazo en la adolescencia, se estudia el consumo de tabaco y alcohol, la obesidad, la hipertensión arterial, la diabetes mellitus y otras enfermedades como el asma, la epilepsia y las enfermedades de transmisión sexual. Resultados: Se encontró a 15 pacientes (14,42%) fumadoras; 7 pacientes más (6,73%) fumaban oca-sionalmente y 82 de ellas (78,84%) eran no fumadoras. Hasta 25 pacientes (24,03%) afirmaron haber consumido alcohol muy ocasionalmente y 79 pacientes (75,96%) no eran consumidoras de alcohol. No se encontró ningún caso de obesidad, hipertensión arterial o diabetes mellitus entre las pacientes adolescentes. Dos pacientes padecían enfermedad asmática (1,92%) y otra epilepsia (0,96%). Se encontraron dos pacientes (1,92%) con los marcadores de la hepatitis B positivos, de las cuales una de ellas era VIH positiva y a una paciente se le extirparon condilomas vulvares. Conclusiones: El porcentaje de adolescentes fumadoras es inferior y el porcentaje de mujeres que afirmó haber consumido alcohol durante la gestación es equiparable al hallado en otras muestras de adolescentes embarazadas (AU)

Does FIGO clinical stage influence the survival of patients with early stages of uterine cervix carcinoma. International Federation of Gynaecology and Obstetrics.

We studied the influence of the FIGO clinical stage on the prognosis of 114 patients with early stages of uterine cervix carcinoma who had been treated with radical surgery in the "La Fe" Maternity Hospital in Valencia between 1971 and 1989. The prognosis became worse with each clinical stage, in line with the fact that the more advanced clinical stages are more likely to have certain types of spread, larger tumours and a greater stromal invasion depth. However, the Cox regression adjustment of the variables predicting disease-free and survival intervals, including the clinical stage and preoperative and postoperative treatment, did not reveal a significant link between clinical stage and the prognostic indices studied, while postoperative treatment variables showed a great predictive capacity, possibly due to the fact that the postoperative treatment used in more advanced stages is more aggressive.

Studying semantics in the brain: the rapid stream stimulation paradigm.

Event-related potentials (ERPs) provide information about the temporal course of cognitive processes in the brain. They have proved to be a valuable tool in order to explore semantic aspects of word processing. However, to date, research in this field has been mostly concerned with the study of post-lexical features by means of the N400-paradigm. We introduce here the rapid stream stimulation paradigm, in which stimuli reflecting different levels of linguistic information are presented to subjects at a high rate of stimulation. The present protocol shows in detail how this paradigm can be applied. The application of the rapid stream stimulation paradigm evokes the recognition potential (RP), an ERP component that peaks at around 260 ms after stimuli onset and seems to be reflecting lexical selection processes. Results of studies that revealed the sensibility of the RP to visual-semantic aspects and the location of its neural generators within basal extrastriate areas are reported. Although some research has been conducted with the rapid stream stimulation paradigm much remains still to be done. Some of the possibilities that this paradigm offers are further discussed.

Electrophysiological evidence of a semantic system commonly accessed by animals and tools categories.

Some theoretical perspectives propose a semantic system in which categories are represented in different brain regions. Others assume that distinctions are based rather on differences in the demands placed by different categories on shared processing systems. In this study semantic categorization processes were investigated using the recognition potential (RP), an event-related brain response that reflects semantic processing, peaks at around 250 ms after stimulus onset and originates in areas subserving perceptual-semantic analyses. Results indicate that the RP shows some degree of sensitivity to categorization processes, but that categories assumed to differ markedly in their processing demands share, to a large extent, a common neural generator. This provides support for the non-categorical view on the organization of the semantic system, though introducing subtle variations, and suggesting the existence of a semantic subsystem specializing in the processing of perceptual-semantic features regardless of the semantic category involved.

Functional differences in the semantic processing of concrete and abstract words.

There is considerable debate as to whether the semantic system is a unitary one in which meanings are available in a peculiar, perceptual-free format, or whether it is functionally segregated into anatomically discrete, modality-specific but semantic regions. In the former case, concrete and abstract words should not differ in the amount of activation of semantic areas. Neuroimaging studies in this field are, however, far from conclusive, and one reason for this may be that the degree of imageability of the stimuli - probably a crucial variable - has not been considered. Recognition Potential (RP) reflects semantic processing and appears to originate in basal extrastriate regions involved in semantic processing. In this study, we compared the RP of concrete and abstract words that actually differ in their degree of imageability. Results indicate that the semantic processing areas in which the RP originates display a higher activation for concrete (more imageable) material, but that abstract material also evokes a notably larger RP component compared with pseudowords or unpronounceable letter strings. Accordingly, the study appears to suggest that there is no full functional segregation of the semantic systems. Rather, our data support the existence of a semantic system that is specialised in concrete, imageable material, and that is also activated, though to a lower extent, by abstract material.

Semantic processing of open- and closed-class words: an event-related potentials study.

Previous research on open- and closed-class words has revealed the existence of several differences in the processing of these types of vocabulary. In this paper the processing of open- and closed-class words was compared by means of an early electrical brain response, recognition potential (RP), which indexes semantic processing and originates from basal extrastriate areas. The effects of word frequency on closed-class words were also investigated. For these purposes, open- and closed-class words, among other stimuli, were presented by means of the rapid stream stimulation procedure. Results showed that there were no significant differences when comparing the RP evoked by open- and closed-class words in the left hemisphere. However, in the right hemisphere this situation changed: the RP evoked by open- and closed-class words did differ. Moreover, there were no differences between the RP evoked by closed-class words and pseudowords. These patterns of results suggest that the semantic processing of closed-class words shares some aspects with the processing of open-class words, despite the existence of some differences. Thus, whereas the semantic processing of open-class words recruits brain areas of both hemispheres, the semantic processing of closed-class words is left-lateralized. A second purpose of this work is to study word-frequency effects on closed-class words. Our results show the insensitivity of closed-class words to word-frequency effects.

P300 amplitude as a possible correlate of frontal degeneration in schizophrenia.

The existence of neurodegeneration is a debated issue in schizophrenia research. The P300 component of event-related electrical potentials (ERP) has been related to the different degree of damage to gray and white matter. This study explores the possible relationship between P300 amplitude and/or latency and the existence of degenerative processes in schizophrenia, by assessing its correlation with volume of sulcal CSF and duration of illness, as transversal indicators of neurodegeneration. Nineteen patients (14 males, 5 females) and 13 controls (6 males, 7 females) were studied with MRI and electrophysiological records (P300). The possible influence of sex and age at the time of the exploration was statistically controlled in both groups. The results show a significant negative correlation between P300 amplitude and prefrontal CSF volume in the patient group. A lower though still significant correlation was also found between P300 amplitude and duration of illness, whereas no correlation was found in the control group. These results support the hypothesis that P300 amplitude may be interpreted as a marker of neurodegeneration in schizophrenia.

[Localization of the epileptogenic zone by analysis of electroencephalographic dipole]. / Localización de la zona epileptógena mediante el análisis de dipolos electroencefalográficos.

INTRODUCTION: In partial epilepsy with seizures which are resistant to drug treatment, better results may be obtained with surgery. This follows thorough assessment to identify the area of the brain responsible for the origin of the seizures, or the epileptogenic zone (EZ), and show that surgical operation will not cause neurological or cognitive damage which might handicap the patient. OBJECTIVE: This study analyses the value in diagnosis of electroencephalographic dipoles in delimitation of the EZ in patients with refractory partial epilepsy who are candidates for surgical treatment. PATIENTS AND METHODS: In 43 patients we made EEG recordings whilst at rest with their eyes shut during 15 minutes. The signal was analysed by digital EEG apparatus and a map drawn of cerebral electrical activity based on the maximum average amplitude of the epileptic spikes. The electric dipole equivalent to epileptiform activity between seizures was obtained using the programme for analysis of electroencephalographic sources BESA. The localization of the EZ by means of the dipole was compared with the results of EEG, MR, SPECT and seizure video-EEG using intracranial electrodes. RESULTS: The results of this study show that the dipole model used is highly sensitive for localization of EZ, and in cases in which the dipole and MR coincided, its sensitivity is similar to that of video-EEG during seizures. CONCLUSIONS: The model of dipole used in this study is of great help when indicating surgery for patients with drug-resistant epilepsy.

An early electrophysiological sign of semantic processing in basal extrastriate areas.

Recognition potential (RP), a recently discovered electrophysiological response of the brain, is sensitive to semantic aspects of stimuli. Given its peak values (about 250 ms), RP may be a good candidate for the study of semantic processing during its occurrence. However, its topography and neural generators are largely unknown. To improve this state of affairs, high-resolution electroencephalography and brain electrical source analysis were carried out. Results suggest a possible origin of RP in the lingual gyrus, hence reflecting the activity of the basal extrastriate areas. RP therefore appears to be a highly valuable tool in the study of those regions considered to be the "third language areas" (in addition to Broca's and Wernicke's areas), whose precise role in language processing is still largely unknown. Another important finding was that RP amplitude in the left hemisphere differed as a function of the semantic category of the stimuli, providing evidence for the sensitivity of this component to semantic categorization. A tentative proposal is made with regard to the role of the basal extrastriate areas.