Effect of proactive interference of novelty on consummatory Successive Negative Contrast

JUSTEL N; PAUTASSI RM; MUSTACA A

LEARNING & BEHAVIOR

PSYCHONOMIC SOC INC

Año: 2014 vol. 42 p. 58 - 68

1543-4494

Reactivity to a reinforcer is affected by prior experience with the different reward values of that reinforcer, a phenomenon known as incentive relativity, which can be studied using the consummatory Succesive Negative Contrast (cSNC) paradigm, in which the performance of animals that receive a 4% sucrose solution after trials in which they were exposed to 32% sucrose is compared with subjects that always receive the 4% sucrose solution. The exploration of a novel open field can enhance or block the acquisition of associative and non-associative memories. The effect of open field on cSNC has not yet been explored. The main result of the present study was that open field exposure significantly modified the expression of cSNC. Exposure to an open field 1 hour but not immediately before the downshift interfered with the expression of cSNC. These animals drank more of the devalued reinforcer than controls that were not exposed to the apparatus; and this behavior persisted for up to three recovery trials. This phenomenon was observed even when the animals were given a more protracted Pre-shift phase and when the discrepancy between the pre- and shift incentive values of sucrose was increased. Open field also interfered with incentive downshift when open field exposure occurred 6 hours before the downshift, and repeated exposure to the apparatus did not deteriorate this effect. The present study adds to a growing body of literature that indicates that open field exploration can interfere with memory formation.