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Search Results: 1 - 10 of 19168 matches for " Ricardo; Kamenetzky "
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DISCRIMINACIóN DE SABORES EN PROCEDIMIENTOS DE CAMBIOS SORPRESIVOS DEL REFORZADOR DURANTE LA TEMPRANA ONTOGENIA DE LA RATA
Suárez,Andrea; Mustaca,Alba; Pautassi,Ricardo; Kamenetzky,Giselle;
Suma Psicológica , 2012,
Abstract: this study evaluated consummatory responses in infant rats exposed to different magnitude of reward, and after the devaluation (i.e., consummatory successive negative contrast) or omission (i.e., extinction) of reward. in experiment 1, 8-10 post-natal days (pnd) pups were intraorally infused with 12%, 10%, 5% or 2% sucrose (preshift phase, 2 daily trials). subsequently, all groups received 2% sucrose (postshift phase). in experiment 2, 10-14 day-old pups received 12% or 2% sucrose in 4 daily trials in the preshift phase, followed by 2% in a postshift trial. both experiments indicated that during preshift, animals exposed to 12% sucrose exhibited higher sucrose consumption than those receiving lower concentration solutions. this phenomenon, indicative of a magnitude of reinforcement effect was not accompanied by evidence of successive negative contrast. in experiment 3 we evaluated the magnitude of reinforcement extinction effect in 7-12 pnd rats. animals received 12% sucrose or water in preshift phase and both groups received a neutral solution (i.e., water) in the second phase. a magnitude of reinforcement acquisition effect was again observed, yet there were no differences between groups in extinction phase. in experiment 4 we used an anticipatory contrast procedure in 10-16 pnd pups. a magnitude of reinforcement, but not an anticipatory contrast effect was observed. overall the results indicate that: (a) rats from - at least- 8 pnd discriminate between different concentrations of sucrose, and (b) until the second week of life the response to rewards is mainly regulated by their absolute value and not by their relative value. results are discussed terms of the ontogeny of paradoxical effects of reward and its relationship to amsel's theory.
TASTE DISCRIMINATION DURING THE EARLY ONTOGENY OF TASTE DISCRIMINATION DURING THE EARLY ONTOGENY OF THE RAT IN PROCEDURES INVOLVING SURPRISING CHANGES IN REINFORCEMENT
Andrea Suárez,Alba Mustaca,Ricardo Pautassi,Giselle Kamenetzky
Suma Psicológica , 2012,
Abstract: This study evaluated consummatory responses in infant rats exposed to different magnitude of reward, and after the devaluation (i.e., consummatory successive negative contrast) or omission (i.e., extinction) of reward. In Experiment 1, 8-10 post-natal days (PND) pups were intraorally infused with 12%, 10%, 5% or 2% sucrose (preshift phase, 2 daily trials). Subsequently, all groups received 2% sucrose (postshift phase). In Experiment 2, 10-14 day-old pups received 12% or 2% sucrose in 4 daily trials in the preshift phase, followed by 2% in a postshift trial. Both experiments indicated that during preshift, animals exposed to 12% sucrose exhibited higher sucrose consumption than those receiving lower concentration solutions. This phenomenon, indicative of a magnitude of reinforcement effect was not accompanied by evidence of successive negative contrast. In Experiment 3 we evaluated the magnitude of reinforcement extinction effect in 7-12 PND rats. Animals received 12% sucrose or water in preshift phase and both groups received a neutral solution (i.e., water) in the second phase. A magnitude of reinforcement acquisition effect was again observed, yet there were no differences between groups in extinction phase. In Experiment 4 we used an anticipatory contrast procedure in 10-16 PND pups. A magnitude of reinforcement, but not an anticipatory contrast effect was observed. Overall the results indicate that: (a) rats from - at least- 8 PND discriminate between different concentrations of sucrose, and (b) until the second week of life the response to rewards is mainly regulated by their absolute value and not by their relative value. Results are discussed terms of the ontogeny of paradoxical effects of reward and its relationship to Amsel’s theory.
Modelos Animales para el Estudio del Alcoholismo
Giselle V. Kamenetzky,Alba E. Mustaca
Terapia Psicológica , 2005,
Abstract: El abuso y la dependencia al alcohol constituyen una de las causas más importantes de problemas de salud. Se han desarrollado modelos animales para el estudio de esta patología; los mismos ofrecen ventajas en la investigación sobre alcoholismo, aunque los resultados no pueden generalizarse sin tener en cuenta la multicausalidad de los comportamientos humanos. Se desarrollaron modelos de autoadministración de alcohol (caja-hogar y condicionamiento operante) y de administración forzada (condicionamiento de lugar y de sabor), para estudiar diversos estadios del consumo, la fuerza apetitiva del etanol, procedimientos para facilitar el inicio del consumo, comportamientos de compulsión y recaídas y efectos de distintos eventos externos y del estado del animal que facilitan o inhiben el consumo. Se describen los procedimientos más frecuentes, ejemplos de investigaciones recientes y sus implicancias para terapias psicológicas de esta patología.
Efecto de la edad y el entrenamiento sobre la memoria
Angel M. Elgier,Yanina Aruanno,Giselle Kamenetzky
Revista Psiencia , 2010,
Abstract: Numerosos antecedentes muestran que el envejecimiento está asociado con el deterioro de algunas capacidades cognitivas, entre ellas la memoria. Hay evidencias que indican que las deficiencias de memoria asociadas con la edad pueden mejorarse con entrenamiento, tanto en adultos jóvenes como maduros. El objetivo de la investigación fue evaluar el efecto de la edad y el entrenamiento sobre una tarea de recuerdo de palabras, comparando un grupo de adultos jóvenes con un grupo de adultos mayores, que recibían o no entrenamiento. Los adultos jóvenes recordaron más palabras que los maduros. Asimismo, el entrenamiento produjo un incremento en la cantidad de palabras recordadas en ambos grupos etareos. Los grupos Jóvenes sin entrenamiento y Maduros con entrenamiento obtuvieron un rendimiento similar. Se discuten las implicancias clínicas del efecto del entrenamiento en adultos jóvenes y maduros.
Psicofísica comparada: Efectos de la pérdida de incentivos en ratas normales e inyectadas con etanol
Pellegrini,Santiago; Cuenya,Lucas; Mustaca,Alba Elisabeth; Kamenetzky,Giselle Vanesa;
Interdisciplinaria , 2009,
Abstract: a psychophysical problem that might be of particular interest in current research on conditioning phenomena, and that exceeds the area of sensation and perception, concerns the reinforcing properties of stimuli and their relationships to the physical measures of the stimuli. stimuli acting as reinforcers are operationally defined as those which have the property of changing the probability of response output of an organism if they are presented in an ordered fashion in relation to other stimuli or responses. from a biopsychological point of view the scale in which this property is measured is referred to as the stimulus incentive value. papini and pellegrini (2006) observed that the level of consummatory responses in rats exposed to surprising reductions in sucrose concentrations is similar if the shift ratio of the solutions (preshift / postshift concentration) is the same. for example, a 32 to 4% downshift and a 16 to 2% downshift produced similar levels of consummatory responding. pellegrini and papini (2007) and pellegrini, lopez seal, and papini (2008) extended this observations to measures of anticipatory behaviours of rats in studies implementing runway, autoshaping, solid food and within subjects design. these results are in agreement with the weber′s law. the incentive downshift situations as observed in spaced-trials conditions are interesting in psychological terms because they might imply the development of emotional processes (amsel, 1992; flaherty, 1996; papini, 2002, 2003). therefore, the aforementioned proportionality in incentive downshift situations might also imply proportional emotional responses. the evidence favoring an emotional interpretation of behavioral regulation during incentive downshifts arise mostly from studies which used drugs with anxiolitic-like effects (for example, clordiazepoxide and ethanol). for example, in similar experimental conditions it has been shown that the administration of ethanol before the second postshift trial r
An analysis of the anxiolytic effects of ethanol on consummatory successive negative contrast
Kamenetzky,Giselle V.; Mustaca,Alba E.; Papini,Mauricio R.;
Avances en Psicología Latinoamericana , 2008,
Abstract: the anxiolytic properties of ethanol (1 g/kg, 15% dose, i.p.) were studied in two experiments with rats involving incentive downshifts from a 32% to a 4% sucrose solution. in experiment 1, alcohol administration before a downshift from 32% to 4% sucrose prevented the development of consummatory suppression (consummatory successive negative contrast, csnc). in experiment 2, ethanol prevented the attenuating effects of partial reinforcement (random sequence of 32% sucrose and nothing) on csnc, causing a retardation of recovery from contrast. these effects of ethanol on csnc are analogous to those described for the benzodiazepine anxiolytic chlordiazepoxide, suggesting that at least some of its anxiolytic effects are mediated by the same mechanisms.
Efectos del aislamiento en la adultez sobre el dolor y la frustración
Lucas Cuenya,Sandro Fosacheca,Alba Mustaca,Giselle Kamenetzky
Psicológica , 2011,
Abstract: Los animales que viven aislados en la adultez presentan indicadores conductuales de estrés crónico, ansiedad e hipoalgesia. Si bien existe una amplia gama de tratamientos que evidencian las relaciones entre la frustración, el dolor y la ansiedad, pocos trabajos estudiaron el efecto que podría tener el aislamiento en la adultez sobre las respuestas de los animales ante la devaluación de incentivos. Se evaluaron ratas aisladas (Aislados) y agrupadas (Agrupados) a partir de los 60 días de edad en la sensibilidad al dolor con la prueba de la placa térmica (PT) y en el efecto de reforzamiento parcial sobre el contraste sucesivo negativo consumatorio (ERP-CSNc). En el ERP-CSNc dos grupos de animales (Aislados y Agrupados) recibieron una fase de precambio con ensayos bajo un Programa de reforzamiento continuo (RC, consumo de 32% de solución azucarada) y otros dos grupos (Aislados y Agrupados) en uno de reforzamiento parcial (RP, 50% reforzados con 32% de solución azucarada y 50% no reforzados). En la fase de postcambio los cuatro grupos recibieron soluciones de sacarosa al 4%. Se midió el tiempo que el animal permanecía en contacto con el bebedero (TB). Las ratas aisladas mostraron hipoalgesia en la PT. En el ERP-CSNc, tanto las ratas aisladas como las agrupadas entrenadas en RP mostraron el mismo grado de mayor persistencia de TB durante la fase de postcambio, respecto de los entrenados bajo RC. Estos resultados se discuten en función de trabajos previos y de los posibles mecanismos implicados.
PSICOFíSICA COMPARADA: EFECTOS DE LA PéRDIDA DE INCENTIVOS EN RATAS NORMALES E INYECTADAS CON ETANOL
SANTIAGO PELLEGRINI,LUCAS CUENYA,ALBA ELISABETH MUSTACA,GISELLE VANESA KAMENETZKY
Interdisciplinaria , 2009,
Abstract: Un problema de la Psicofísica particularmente relevante para el estudio de procesos de condicionamiento es el de la re lación entre las propiedades de refuerzo y físicas de los es tímulos. Papi ni y Pellegrini (2006) observaron que el nivel de res puestas de consumo en ratas expuestas a una disminución sor presiva en la con centración de soluciones azucaradas resulta si milar, si la razón de cambio de las soluciones (concentración post-cambio / pre-cambio) es la misma. Por ejemplo, una dismi nución de 32 a 4% y una de 16 a 2% produjeron niveles de consumo similares. Estos resultados son acordes a la Ley de Weber y podrían implicar el desarrollo de procesos emocionales; algo que se ha establecido mediante el estudio de drogas ansiolíticas. En situaciones experimentales análogas en las que se estudió el efecto de contraste negativo de incentivo (con una dis minución de 32 a 4%) se demostró que la administración de etanol en el segundo ensayo post-cambio produce una recuperación más rápida de las respuestas deprimidas debido a una disminución del refuerzo (Becker & Flaherty, 1982), en com paración con controles que recibieron salina. En el presente trabajo se informa un experimento que involucró ocho grupos de ratas y que buscó replicar ambos fenómenos así como estudiar sus posibles interacciones. Se hallaron resultados compatibles con los datos previos, pero no se pudo concluir si el etanol afecta de manera determinante los niveles de respuesta proporcionales observados durante disminuciones de incentivo. Los resultados se discuten en términos de su implicancia para el estudio de la Psicofísica Comparada.
An analysis of the anxiolytic effects of ethanol on consummatory successive negative contrast
Giselle V. Kamenetzky,Alba E. Mustaca,Mauricio R. Papini
Avances en Psicología Latinoamericana , 2008,
Abstract: The anxiolytic properties of ethanol (1 g/kg, 15% dose, i.p.) were studied in two experiments with rats involving incentive downshifts from a 32% to a 4% sucrose solution. In Experiment 1, alcohol administration before a downshift from 32% to 4% sucrose prevented the development of consummatory suppression (consummatory successive negative contrast, cSNC). In Experiment 2, ethanol prevented the attenuating effects of partial reinforcement (random sequence of 32% sucrose and nothing) on cSNC, causing a retardation of recovery from contrast. These effects of ethanol on cSNC are analogous to those described for the benzodiazepine anxiolytic chlordiazepoxide, suggesting that at least some of its anxiolytic effects are mediated by the same mechanisms
NGC 1266: Characterization of the Nuclear Molecular Gas in an Unusual SB0 Galaxy
Jason Glenn,Naseem Rangwala,Philip R. Maloney,Julia R. Kamenetzky
Physics , 2015, DOI: 10.1088/0004-637X/800/2/105
Abstract: With a substantial nuclear molecular gas reservoir and broad, high-velocity CO molecular line wings previously interpreted as an outflow, NGC 1266 is a rare SB$0$ galaxy. Previous analyses of interferometry, spectrally resolved low-$J$ CO emission lines, and unresolved high-$J$ emission lines have established basic properties of the molecular gas and the likely presence of an AGN. Here, new spectrally resolved CO $J = 5 - 4$ to $J = 8 - 7$ lines from {\it Herschel Space Observatory} HIFI observations are combined with ground-based observations and high-$J$ {\it Herschel} SPIRE observations to decompose the nuclear and putative outflow velocity components and to model the molecular gas to quantify its properties. Details of the modeling and results are described, with comparisons to previous results and exploration of the implications for the gas excitation mechanisms. Among the findings, like for other galaxies, the nuclear and putative outflow molecular gas are well represented by components that are cool ($T_{nuclear} = 6^{+10}_{-2}$ K and $T_{outflow} \sim 30$ K), comprising bulk of the mass (Log $M_{nuclear}/M_{\odot} = 8.3^{+0.5}_{-0.4}$ and Log $M_{outflow}/M_{\odot} = 7.6^{+0.3}_{-0.3}$), and the minority of the luminosity (Log $L_{nuclear}/L_{\odot} = 5.44^{+0.22}_{-0.18}$ and Log $L_{outflow}/L_{\odot} \sim 6.5$) and warm ($T_{nuclear} = 74^{+130}_{-26}$ K and $T_{outflow} > 100$ K), comprising a minority of the mass (Log $M_{nuclear}/M_{\odot} = 7.3^{+0.5}_{-0.5}$ and Log $M_{outflow}/M_{\odot} \sim 6.3$) but the majority of the luminosity (Log $L_{nuclear}/L_{\odot} = 6.90^{+0.16}_{-0.16}$ and Log $L_{outflow}/L_{\odot} \sim 7.2$). The outflow has an anomalously high $L_\mathrm{CO}/L_\mathrm{FIR}$ of $1.7 \times 10^{-3}$ and is almost certainly shock excited.
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