Comparing intensities and modalities within the sensory attenuation paradigm: Preliminary evidence

It is well-documented that the intensity of a self-generated somatosensory stimulus is perceived to be attenuated in respect to an identical stimulus generated by others. At present, it is not clear whether such a phenomenon, known as somatosensory attenuation, is based not only on feedforward motor signals but also on re-afferences towards the body. To answer this question, in the present pilot investigation on twelve healthy subjects, three types of stimulations (sensory non-nociceptive electrical – ES, nociceptive electrical – NES, and vibrotactile – VTS) and intensities (1 = sensory threshold ∗ 2.5 + 2 mA, 2 = sensory threshold ∗ 2.5 + 3 mA, 3 = sensory threshold ∗ 2.5 + 4 mA for ES and NES; 1 = sensory threshold ∗ 2 Hz, 2 = sensory threshold ∗ 3 Hz, 3 = sensory threshold ∗ 4 Hz for VTS) have been directly compared in a somatosensory attenuation paradigm. The results show that the attenuation effect emerged only with electrical stimuli and that it increased with higher intensities. These pilot findings suggest that, depending on the type and the intensity of stimulation, re-afferences can have a role in somatosensory attenuation. Additionally, it is possible to speculate the effect is present only with electrical stimuli because those stimuli are prospectively judged as potentially dangerous. This, in turn, would optimize planning successful reactions to incoming threatening stimuli

Investigating the link between drug-naive first episode psychoses (FEPs), weight gain abnormalities and brain structural damages: Relevance and implications for therapy

Evidence suggests that obesity and overweight may be associated with severe brain structural abnormalities and poor cognitive and functional outcomes in the general population. Despite these observations and the high prevalence of weight gain abnormalities in patients with psychosis spectrum disorders (PSDs), no studies have investigated the impact that these metabolic disturbances may have on brain structures and development in the earliest stages of PSDs. In the present review we shed light on the association between weight gain and brain structural abnormalities that may affect the course of illness in drug-naïve FEPs. Given the lack of studies directly investigating this issue, we firstly identified and critically evaluated the literature assessing weight gain abnormalities and gray or white matter (GM, WM) volumes (either globally or in specific regions of interest) in otherwise healthy obese/overweight adolescents and young adults. We then compared the results of this systematic review with those of two recent meta-analysis investigating GM and WM abnormalities in drug-naïve FEPs. Weight gain in otherwise healthy subjects was consistently associated with frontal and temporal GM atrophy and with reduced integrity of WM in the corpus callosum. Of relevance, all these brain regions are affected in drug-naïve FEPs, and their integrity is associated with clinical, cognitive and functional outcomes. The underlying mechanisms that may explain the association between weight gain, adiposity, and brain damage in both healthy subjects and drug-naïve FEPs are widely discussed. On the basis of this knowledge, we tried: a) to deduce an integrative model for the development of obesity in psychosis spectrum disorders; b) to identify the key vulnerability factors underlying the association between weight gain and psychosis; c) to provide information on new potential targets of intervention

Endogenous orientation of visual attention in auditory space

Visuospatial attention is asymmetrically distributed with a leftward bias (i.e. pseudoneglect), while evidence for asymmetries in auditory spatial attention is still controversial. In the present study, we investigated putative asymmetries in the distribution of auditory spatial attention and the influence that visual information might have on its deployment. A modified version of the Posner task (i.e. the visuo-audio spatial task [VAST]) was used to investigate spatial processing of auditory targets when endogenous orientation of spatial attention was mediated by visual cues in healthy adults. A line bisection task (LBT) was also administered to assess the presence of a leftward bias in deployment of visuospatial attention. Overall, participants showed rightward and leftward biases in the VAST and the LBT, respectively. In the VAST, sound localization was enhanced by visual cues. Altogether, these findings support the existence of a facilitation effect for auditory targets originating from the right side of space and provide new evidence for crossmodal links in endogenous spatial attention between vision and audition

Everything is (still) illuminated: dual right cathodal-left anodal tDCS of PPC prevents fatigue on a visual detection task

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Embodied simulation and ambiguous stimuli: The role of the mirror neuron system

According to the "embodied simulation theory," exposure to certain visual stimuli would automatically trigger action simulation in the mind of the observer, thereby originating a "feeling of movement" modulated by the mirror neuron system (MNS). Grounded on this conceptualization, some of us recently suggested that when exposed to the Rorschach inkblots, in order to see a human movement (e.g., "a person running") in those ambiguous stimuli, the observer would need to experience a "feeling of movement" via embodied simulation. The current study used repetitive transcranial magnetic stimulation (rTMS) to further test this hypothesis. Specifically, we investigated whether temporarily interfering with the activity of the left inferior frontal gyrus (LIFG; a putative MNS area) using rTMS would decrease the propensity to see human movement (M) in the Rorschach inkblots. Thirty-six participants were exposed to the Rorschach stimuli twice, i.e., during a baseline (without rTMS) and soon after inhibitory rTMS. As for the rTMS condition, half of the sample was stimulated over the LIFG (experimental group) and the other half over the Vertex (control group). In line with our hypothesis, the application of rTMS over LIFG, but not over Vertex, yielded a statistically significant reduction in the attribution of M to the ambiguous stimuli, with large effect size. These findings may be interpreted as being consistent with the hypothesis that there is a link between the MNS and the "feeling of movement" people may experience, when observing ambiguous stimuli such as the Rorschach cards

Water quality in the area irrigated by the Mandoza river (Argentina)

El río Mendoza conforma el oasis norte que es el más importante de la provincia. El crecimiento urbano ha avanzado sobre áreas originalmente agrícolas, rodeando la red de canales y desagües, que también recibe los desagües pluviales urbanos, producto de tormentas convectivas. La actividad antropogénica utiliza el recurso para bebida, saneamiento, riego, recreación, etc., y vuelca sus excedentes a la red, contaminándola. Para conocer la calidad del agua de esta cuenca se seleccionaron, estratégicamente, 15 sitios de muestreo: 3 a lo largo del río y a partir del dique derivador Cipolletti (R_I a R_III), 5 en la red de canales (C_I a C_V) y 7 ubicados en los colectores de drenaje (D_I a D_VII). Se realizaron los siguientes análisis físico-químicos y microbiológicos; en el río y en la red de canales: conductividad eléctrica, temperatura, pH, aniones y cationes (cálculo de RAS), oxígeno disuelto (OD), sólidos sedimentables, demanda química de oxígeno (DQO), bacterias aerobias mesófilas (BAM), coliformes totales y fecales y metales pesados. En la red de drenaje sólo se realizaron los cuatro primeros. Los resultados de los análisis, se incorporaron a una base de datos y se sometieron a un análisis estadístico descriptivo e inferencial. Este último consistió en la aplicación de diversas pruebas en busca de posibles diferencias entre los sitios de muestreo, para cada variable respuesta, a un α = 0.05. Se realizó el análisis de la varianza de efectos fijos y de efectos aleatorios y se probaron los supuestos de homocedasticidad y de normalidad de los errores. En el caso de violación de los supuestos, se utilizó la prueba de Kruskal- Wallis. Se compararon los siguientes sitios de muestreo entre sí: ríos, R_I-canales y drenajes. Se concluyó que hay un aumento significativo de la salinidad y la sodicidad en R_II, que los cambios de calidad ocurridos entre R_II y R_III podrían deberse al aporte de otras aguas. Con respecto a la comparación de los parámetros entre la cabeza del sistema (R_I) y la red de canales se puede decir que los aportes realizados por los escurrimientos urbanos ubicados hacia el oeste del canal Cacique Guaymallén, sumados a los vuelcos de Campo Espejo (detectados en C_II), incrementan significativamente la salinidad (+55 %) y sodicidad del agua (+95 %) respecto del punto R_I, aunque el valor de sodicidad sigue siendo bajo. También se han encontrado incrementos de salinidad (+80 %), de DQO (+1159 %) y BAM (+2873 %) con lógica disminución de OD (-58 %) en el punto C_V (canal Auxiliar Tulumaya) respecto del punto R_I, ocasionados por aportes urbanos (Gran Mendoza) sumados a la carga contaminante del canal Pescara. Los metales pesados no presentan grandes diferencias entre sitios de muestreo.The Mendoza River oasis is the most important of the province. Urban growth has encroached upon areas that were formerly agricultural, surrounding the drainage canals that contain urban storm runoff from convective storms. Man uses water for drinking, sanitation, irrigation, recreation and other purposes, and discharges polluting effluents into the irrigation and drainage system. In order to analyze water quality in the oasis, three sampling points (R_I to R_III) along the river where the Cipolletti diversion dam is located, five points along the canal network (C_I to C_V), and seven along the drainage collectors (D_I to D_VII) were strategically selected. The points along the river and the canal network were tested for the following physico-chemical and microbiological parameters: electrical conductivity, temperature, pH, anions and cations (SAR calculation), dissolved oxygen (DO), settleable solids, chemical oxygen demand (COD), mesophilic aerobic bacteria (MAB), total and fecal coliforms, and heavy metals. The points along the drainage network were only tested for the first four parameters. Analytical results were stored in a data base and were used for a descriptive statistical and inferential analysis that consisted in applying different tests to detect possible differences to each response variable at α = 0.05. Fixed and random effects models of analyses of variance were applied and homocedasticity and normality assumptions were tested. When assumptions were violated, the Kruskal-Wallis test was used. A comparison was made between the following sampling points; rivers; RI and canals; and drains. It is concluded that there are significant differences in mean salinity and sodicity values in R_II, and that quality changes in R_II and R_III may be due to the inflow of additional water. A comparison of parameters between the head of the system (R_I) and the canal network shows that discharges from Greater Mendoza urban centers located to the west of the «Cacique Guaymallén» canal and discharges from the «Campo Espejo» treatment plant (detected at point C_II) significantly increase water salinity (+55 %) and sodicity (+95 %) with respect to point R_I (though the sodicity value is still low). Salinity (+80 %), COD (+1159 %), and MAB (+2873 %) also increased with the ensuing decrease in DO (-58 %) due to discharges from the Greater Mendoza area and the high industrial pollution load from the «Pescara» Canal (C_V, «Tulumaya» secondary canal) with respect to point R_I. There were no significant differences in heavy metals among sampling points.Fil: Morábito, José. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Salatino, Santa. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Medina, Rosa. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Zimmermann, Mónica. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Filippini, María Flavia. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Bermejillo, Adriana. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Nacif, Norma. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Campos, Susana. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Dediol, Cora. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Pizzuolo, Pablo Humberto. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Genovese, Dora. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Mastrantonio, Leandro. Universidad Nacional de Cuyo. Facultad de Ciencias Agraria