Type of feature affects transfer in operant serial feature-positive discriminations

Saliency determines the integration of contextual information into stimulus-response episodes

When humans perform a task, it has been shown that elements of this task, like stimulus (e.g., target and distractor) and response, are bound together into a common episodic representation called stimulus–response episode (or event file). Recently, the context, a completely task-irrelevant stimulus, was found to be integrated into an episode as well. However, instead of being bound directly with the response in a binary fashion, the context modulates the binary binding between the distractor and response. This finding raises the questions of whether the context can also enter into a binary binding with the response, and if so, what determines the way of its integration. In order to resolve these questions, saliency of the context was manipulated in three experiments by changing the loudness (Experiment 1) and emotional valence (Experiment 2A and 2B) of the context. All experiments implemented the four-alternative auditory negative priming paradigm introduced by Mayr and Buchner (2006, Journal of Experimental Psychology: Human Perception and Performance, 32[4], 932–943). Results showed that the integration of context changed as a function of its saliency level. Specifically, the context of low saliency was not bound at all, the context of moderate saliency modulated the binary binding between the distractor and response, whereas the context of high saliency entered into a binary binding with the response. The current results extend a previous finding by Hommel (2004, Trends in Cognitive Sciences, 8[11], 494–500) that there is a saliency threshold which determines whether a stimulus is bound or not, by suggesting that a second threshold determines the specific structure (i.e., binary vs. configural) of the resulting binding.

Equating context conditioning in Pavlovian incubation of US signal value

The present study replicated the finding by Goddard (2013), that when a single food pellet unconditioned stimulus (US) signaled the delivery of three additional pellets, responding after the single US was significantly greater on a delayed, compared to an early, test. Importantly, the present study equated context conditioning by delivering the identical number of food pellets in both conditioning and testing and showed that responding was significantly reduced in control subjects that had received unpaired single food-triple food presentations. Implications for theories of conditioning are considered.

Operant serial feature-positive conditional discrimination with composite features and different topography responses

In a serial feature-positive conditional discrimination procedure the properties of a target stimulus A are defined by the presence or not of a feature stimulus X preceding it. In the present experiment, composite features preceded targets associated with two different topography operant responses (right and left bar pressing); matching and non-matching-to-sample arrangements were also used. Five water-deprived Wistar rats were trained in 6 different trials: X-R-->Ar and X-L-->Al, in which X and A were same modality visual stimuli and the reinforcement was contingent to pressing either the right (r) or left (l) bar that had the light on during the feature (matching-to-sample); Y-R-->Bl and Y-L-->Br, in which Y and B were same modality auditory stimuli and the reinforcement was contingent to pressing the bar that had the light off during the feature (non-matching-to-sample); A- and B- alone. After 100 training sessions, the animals were submitted to transfer tests with the targets used plus a new one (auditory click). Average percentages of stimuli with a response were measured. Acquisition occurred completely only for Y-L-->Br+; however, complex associations were established along training. Transfer was not complete during the tests since concurrent effects of extinction and response generalization also occurred. Results suggest the use of both simple conditioning and configurational strategies, favoring the most recent theories of conditional discrimination learning. The implications of the use of complex arrangements for discussing these theories are considered.

Latent inhibition of US signal value

Three experiments with rats examined the effects of preexposure to an unconditioned stimulus (US; a single food pellet) on the subsequent ability of that US to effectively signal the delivery of three food pellets during a US-US conditioning procedure. In Experiment 1, latent inhibition (LI) rats showed attenuated conditioning, compared to control (C) rats, when a single food pellet, delivered 10 minutes into a session, was followed by three additional pellets. In preexposure, one pellet had been delivered 10 minutes into each session (in group LI), or placed into the magazine at the beginning of each session (in group C). Experiment 2 showed that this effect was evident when the conditions of preexposure matched those of conditioning for group C, and Experiment 3 showed that the difference between groups LI and C was not a product of context conditioning, or latent inhibition to the noise of the feeder in group LI. Implications of these results for theories of latent inhibition are considered.

Context modulation of US signal value following explicit and nonexplicit training

Context modulation of an unconditioned stimulus (US) signal value was examined in three groups of rats. In Group A+/B-, subjects received explicit training in which a single food pellet US was followed by three additional pellets after either a short delay (in Context A) or a long delay (in Context B). Two other groups received nonexplicit training in which subjects received either the same conditions in Context A, but simple exposure to Context B (Group A+/Bo), or the same conditions in Context B, but simple exposure to Context A (Group Ao/B-). In the test, only Group A+/B- showed significantly more magazine entries shortly after the single food pellet in Context A, compared to Context B. Implications for theories of occasion setting and context modulation are considered.

Serial feature negative training to a target unconditioned stimulus

In serial feature-negative (SFN) training to a target unconditioned stimulus (US), eight rats received two types of intermingled trials: (1) trials in which a tone was followed by the delivery of a single food pellet US, and (2) trials in which the delivery of a single food pellet US was followed by three additional food pellets. Following SFN training, the tone showed little transfer to a partially reinforced light cue and the tone's negative modulation was eliminated after tone extinction. Implications for theories of occasion-setting are discussed.

The role of US signal value in contingency, drug conditioning, and learned helplessness

In Pavlovian conditioning, organisms can learn that a conditioned stimulus (CS) signals the delivery of an unconditioned stimulus (US). The present paper first reviews research showing that organisms can also learn that a stimulus, normally considered to be a US, signals the delivery of another US. Second, the paper shows how such signal value may contribute to three conditioning phenomena that are of interest to many psychologists: contingency, drug conditioning, and learned helplessness. In addition to showing how such signal value may contribute to these three phenomena, suggestions for further research, as well as current gaps in the knowledge base, are outlined.