Contextual modulation of simultaneous associations

Abstract

Subjects. Twenty-four male and 24 female adult Sprague-Dawley descended naive rats served as subjects. Body weights were 240-395 g for males and 195-280 g for females. The animals were singly housed in a vivarium maintained on a 16:8-h light:dark cycle, with experimental manipulations occurring near the middle of the light phase. The 1988, 26 (4), [371][372][373][374] Bulletin of the Psychonomic Society Contextual modulation of simultaneous associations LOUIS D. MATZEL, JUAN CASTILLO, and RALPH R. MILLER State University of New York at Binghamton, Binghamton, New YorkIn four experiments with water-deprived rats, we examined the possibility that simultaneous associations between a conditioned stimulus (CS)and an unconditioned stimulus (US) were modulated or masked by context-US associations. In Experiment 1 we determined that simultaneous CS-US pairings administered in multiple contexts enhanced responding to the CS relative to training in a single context. A forward CS-US arrangement produced no such enhancement. In subsequent experiments, animals were trained in a single context. In Experiment 2, the number ofCS-US pairings was varied and no inverse relationship between the response directly elicited by the training context and the response elicited by the CS was found. In Experiments 3 and 4, we detected no effect on the response to the CS of extensive exposure to the training context before or after simultaneous CS-US pairings, although such latent inhibition or extinction treatment reduced the response elicited by the context. In total, these results indicate that the response to a simultaneously trained CS may be modulated by its training context, but that the response to the CS does not simply vary inversely with the response potential of that context. When a conditioned stimulus (CS) and an unconditioned animals had free access to food, whereas water availability outside the stimulus (US) are paired simultaneously , the CS typically experimental sessions was limited to 10 min/day. elicits a weaker conditioned response than is elicited by Apparatus. Four typesof contexts(sixof each)were used. Eachchamber was individually housed in an environmental chest. Context A was the same CS when trained with a forward relationship to a clear Plexiglas box (22.75 x 8.25 X 13 em) with a floor of 0.48-emthe US (e.g. , Burkhardt & Ayres, 1978;Pavlov, 1927). diameter steel rods. On a narrow wall, there was a water-filledlick tube Although this simultaneous conditioning deficit typically connectedto a lickometer. Context B in verticalprofilewas a truncated V is thought to represent a learning failure due to the poor (30 em long, 28 ern high, and 21 ern wide at the top, 5.25 em wide information value of the CS (e.g., Cantor, 1981), studies at the bottom), with black Plexiglas end walls. The floor and side walls were constructed of sheet metal with a 1.25-em gap centered lengthof CS information value in classical conditioning that com-wise in the floor. A lick tube, attachedto a lickometer, protrudedthrough pare simultaneou...

Acquisition of conditioned associations in Hermissenda: Additive effects of contiguity and the forward interstimulus interval.

“…Although photokinesis was significantly reduced in Group F(2) compared with Group UP(2), which received the CS and UCS unpaired, it is somewhat surprising that Group F(2) did not differ from animals trained with the simultaneous CS–UCS arrangement, Group S(2). This stimulus arrangement is commonly used in vertebrate preparations and typically produces stronger conditioned responding than does simultaneous conditioning (e.g., Matzel, Castillo, & Miller, 1988; Matzel, Held, & Miller, 1988). It seems likely that the more contiguous occurrence of the CS and UCS in the forward condition, in which the CS overlapped the UCS, enhanced either the strength of the association or the expression of the conditioned response and that Hermissenda is more likely to benefit from this arrangement than are higher organisms.…”

“…This reliance on long stimulus durations may have contributed to one curious dissimilarity between associative processes in Hermissenda and vertebrates. Grover and Farley (1987) presented data that suggested that simultaneous pairings of a CS and UCS resulted in stronger conditioned responding in Hermissenda than did forward CS-UCS pairings, a somewhat anomalous result in the conditioning literature (e.g., Burkhardt & Ayres, 1978;Heth, 1976;Matzel, Castillo, & Miller, 1988;Schneiderman & Gormezano, 1964). However, Grover and Farley compared the simultaneous presentation of a 30-s light CS with 30 s of rotation to the analogous forward presentation of those stimuli; that is, the onset of the CS preceded the onset of the UCS by 30 s. Unfortunately, the temporal parameters of the interstimulus-interval (ISI) function for this particular conditioning preparation have not yet been determined, and in many preparations, a 30-s forward ISI is outside the range that will support conditioning.…”

Control Contextual Del Escape Discriminado Con Presentación Sucesiva Y Simultánea De Estímulos

“…Sin embargo, en otros estudios el cambio de contexto posterior a una discriminación sucesiva, ha producido la reaparición de la respuesta entrenada durante la primera discriminación con la disminución de la respuesta aprendida durante la segunda discriminación (Vila, Romero, & Rosas, 2002). Mientras que un cambio de contexto después de la adquisición de una discriminación con un ED compuesto por dos elementos presentados de manera simultánea produce un decremento de la respuesta sólo para el componente del ED que produce una menor respuesta por separado (Matzel, Castillo, & Miller, 1988). Estos estudios sugieren que el cambio de contexto, provocará la reaparición de la respuesta de discriminación adquirida con menor fuerza, más que un decremento por generalización.…”