出版社：Centro Interamericano de Investigaciones Psicológicas y Ciencias Afines
摘要：Se presenta un experimento donde se estudia el efecto de contraste sucesivo negativo consumatorio (CSNC) en un paradigma de economía cerrada. En estos diseños los animales no están privados de alimento, viven en las cajas de condicionamiento o en sus jaulas-vivienda y son expuestos al tratamiento experimental durante días. Un grupo de ratones recibió en sus jaulas vivienda agua azucarada al 32% las 24 horas durante trece días (fase precambio) y al 4% dos días (fase post-cambio, G 32-4). El grupo control recibió siempre la solución al 4% (G 4-4). Como variable dependiente se registró el consumo (en mi) diario. Para analizar los resultados se usó Análisis de Variancia (dos grupos independientes con medidas repetidas). Los animales del G 32-4 mostraron un descenso en su consumo cuando se devaluó la sustancia a 4% en comparación con un grupo que siempre recibió 4%. Este efecto se expresó a las 4 horas del cambio del reforzador y se mantuvo al menos hasta 6 horas posteriores al cambio. Este resultado indica que el efecto se presenta aún en presencia del agua y la comida, con animales saciados y en sus jaulas vivienda. Apoya el predominio de las asociaciones entre la representación interna del reforzador y el que se presenta y se minimiza el efecto de asociaciones entre el contexto y el reforzador. Por otra parte estos resultados su- gieren la potencia del fenómeno estudiado y aumenta su validez ecológica.
其他摘要：When rats are given a 5 mino access penod to 32% sucrose each day and the, on the next day, the solution is changed to 4% sucrose, intake falls to a level substantially bellow that of rats who have been given 4% each day. This consummatory successive negative contrast effect is a pervasive phenomenon, having been demonstrated in a wide variety of paradigms and species. Consummatory successive negative contrast has been suggested to be partially the result of negative emotional response, perhaps analogous to frustration or disappointment, due to violation of expectancies. The involvement of stress in consummatory successive negative contrast is supported by behavioral, pharmacological and endocrinological evidence. We were previous demonstrated this phenomenon in rnice with 3 he access situation, 1 he access situation and in both male and female mice. The effect was eliminated by the adrninistration of diazepam, tranquilizer drug, during the postshift day. That result were consistent with the view that the mechanisms underlying consummatory successive negative contrast are the same in rats and mice. The purpose of the present studies is to explore a consummatory successive negative contrast in a design of a closed economy in mice, a paradigms never studied. Ten male, experimentally naive mice (Balb-C strain), 3-month old at the start of the experiment were used. Individually satiated rnice were exposed in their home-cages with water and foods presents, to 32% sugar solution during thirteen daily sessions later (preshift phase), and two sessions of 4% sugar solution (postshift phase; Group 32-4). A control group have been received a 4% solution (Group 4-4). At 16:00 hr each day, the tube with sucrose solution was measured and refilled. The amount of solution consumed during the previous 24 hs was the dependent measure. In addition, fluid intake was measured once every hour, between 17:00 and 22:00 hr (a total of6 measurements) in day 13 (the last preshift day) and 14 (the postshift day). Three of these 6 measures were taken before the room light went off, and three after the light wen off. Total daily intake of the 32% sucrose solution raised from a mean of 3.84 mI in day 1 a 6.7 mI in day 13; the same values for the 4% solution were 2.24 and 5.5 mI This group difference was significant. The average total consumption during day 14 (the postshift day) were nonsignificant. Sucrose intake on an hourly basis for the initial 6 hours after bottle refillin day 13was higher for Group 32-4 than for 4-4. This difference reversed immediately after the shift, indicating the presence of negative contrast effect. These result demonstrate the presence of consummatory successivenegative contrast in closed economy mice during the initial 6 hours after the shift. The consummatory successive negative contrast disappeared when the overall daily intake was analyzed. This is not entirely surprising if one considers that in both rats and opossums, recovery from negative contrast is complete after four 5 mino long sessions. This result support the theory that in consummatory successive negative contrast predominately stimulus unconditional-stimulus unconditional associations than stimulus conditional-stimulus unconditional associations.
