Subscribe: Journal of Experimental Psychology: Animal Behavior Processes - Vol 35, Iss 4
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Journal of Experimental Psychology: Animal Learning and Cognition - Vol 42, Iss 3



The Journal of Experimental Psychology: Animal Learning and Cognition® publishes experimental and theoretical studies concerning all aspects of animal behavior processes. Studies of associative, nonassociative, cognitive, perceptual, and motivational pro



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Copyright: Copyright 2016 American Psychological Association
 



Incentive contrast effects regulate responding to a flavor presented in compound with a saccharin unconditioned stimulus in rats.

2016-07-04

A flavor conditioned stimulus (conditional stimulus; CS) presented in simultaneous compound with a sweet-tasting unconditioned stimulus (US) acquires a certain sweetness and/or hedonic value. The present study examined whether responding to the flavor CS is influenced by postconditioning changes in the strength of the sweet US representation. In each experiment, rats were exposed to presentations of each of 2 flavors, A and B, in simultaneous compound with a 0.4% saccharin solution, and then tested with presentations of CS A in water. Experiments 1 and 2 showed that responding to CS A depended on its pairing with saccharin and increased with the training-to-test interval. Experiment 3 showed that a progressive reduction in the saccharin concentration of the trained compounds led to an increase in responding to CS A when tested in the absence of saccharin. Experiments 4 and 5 showed that, after a 7-day training-to-test delay, responding to CS A decreased following pretest exposure to a strong saccharin solution, and increased following pretest exposure to a very weak saccharin solution. These findings are taken to imply that incentive contrast effects regulate responding to a flavor CS. Hence, responding to the flavor CS increases with the training-to-test interval as the representation of the sweet US decays; decreases following pretest exposure to very sweet solutions as these reinstate the decayed sweet US representation (negative contrast); and increases following pretest exposure to weakly sweet solutions as these are perceived as less attractive than the CS itself (positive contrast). (PsycINFO Database Record (c) 2016 APA, all rights reserved)(image)



Learning to inhibit the response during instrumental (operant) extinction.

2016-07-04

Five experiments tested implications of the idea that instrumental (operant) extinction involves learning to inhibit the learned response. All experiments used a discriminated operant procedure in which rats were reinforced for lever pressing or chain pulling in the presence of a discriminative stimulus (S), but not in its absence. In Experiment 1, extinction of the response (R) in the presence of S weakened responding in S, but equivalent nonreinforced exposure to S (without the opportunity to make R) did not. Experiment 2 replicated that result and found that extinction of R had no effect on a different R that had also been reinforced in the stimulus. In Experiments 3 and 4, rats first learned to perform several different stimulus and response combinations (S1R1, S2R1, S3R2, and S4R2). Extinction of a response in one stimulus (i.e., S1R1) transferred and weakened the same response, but not a different response, when it was tested in another stimulus (i.e., S2R1 but not S3R2). In Experiment 5, extinction still transferred between S1 and S2 when the stimuli set the occasion for R’s association with different types of food pellets. The results confirm the importance of response inhibition in instrumental extinction: Nonreinforcement of the response in S causes the most effective suppression of responding, and response suppression is specific to the response but transfers and influences performance of the same response when it is occasioned by other stimuli. Theoretical and practical implications are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved)(image)



A cumulative decision model for three-alternative choice in concurrent chains.

2016-07-04

Traditional models for choice in the concurrent-chains procedure have assumed that terminal-link stimuli acquire value as conditioned reinforcers, and that 2-alternative choice provides a measure of relative value according to the matching law. By contrast, the cumulative decision model (CDM; Christensen & Grace, 2010) explains choice as the aggregate effect of comparing delays to a criterion on initial-link responding, not conditioned reinforcement. Here we test whether the CDM can account for choice in 3-alternative concurrent-chains (3ACC) and compare it with the hyperbolic value-added model (HVA; Mazur, 2001), which assumes that choice depends on the increase in conditioned reinforcement value signaled by terminal-link stimuli and has been successful in previous 3ACC research (Mazur, 2000). In Experiment 1, 4 pigeons responded in 3ACC in which the terminal links were fixed-interval schedules, and parameter estimates from fits of CDM and HVA were used to calculate predictions for conditions with variable-interval terminal links. The predictions of CDM were more accurate than those of HVA. In Experiment 2, 7 pigeons responded in 3ACC in which the terminal links were fixed-interval schedules. Although both models described the data well, residuals from HVA fits showed a systematic pattern predicted by CDM, characterized by a third-order polynomial with a negative cubic coefficient. Finally, we conducted a residual meta-analysis (Sutton, Grace, McLean, & Baum, 2008) of data from prior 3ACC studies. HVA residuals showed the same negative cubic pattern as in Experiment 2, whereas no systematic pattern was found in the CDM residuals. Overall, results support the CDM and suggest that the same principles which describe binary choice in concurrent chains generalize without modification to 3-alternative choice. (PsycINFO Database Record (c) 2016 APA, all rights reserved)(image)



Cue salience influences the use of height cues in reorientation in pigeons (Columba livia).

2016-07-04

Although orienting ability has been examined with numerous types of cues, most research has focused only on cues from the horizontal plane. The current study investigated pigeons’ use of wall height, a vertical cue, in an open-field task and compared it with their use of horizontal cues. Pigeons were trained to locate food in 2 diagonal corners of a rectangular enclosure with 2 opposite high walls as height cues. Before each trial, pigeons were rotated to disorient them. In training, pigeons could use either the horizontal cues from the rectangular enclosure or the height information from the walls to locate the food. In testing, the apparatus was modified to provide (a) horizontal cues only, (b) height cues only, and (c) both height and horizontal cues in conflict. In Experiment 1 the lower and high walls, respectively, were 40 and 80 cm, whereas in Experiment 2 they were made more perceptually salient by shortening them to 20 and 40 cm. Pigeons accurately located the goal corners with horizontal cues alone in both experiments, but they searched accurately with height cues alone only in Experiment 2. When the height cues conflicted with horizontal cues, pigeons preferred the horizontal cues over the height cues in Experiment 1 but not in Experiment 2, suggesting that perceptual salience influences the relative weighting of cues. (PsycINFO Database Record (c) 2016 APA, all rights reserved)(image)



Perceptual learning with tactile stimuli in rats: Changes in the processing of a dimension.

2016-07-04

Four experiments with male rats investigated perceptual learning involving a tactile dimension (A, B, C, D, E), where A denotes 1 end of the continuum (e.g., a rough floor) and E the other (e.g., a smooth floor). In Experiment 1, rats given preexposure to A and E learned an appetitive discrimination between them more readily than those not given preexposure. Experiment 2a showed that rats preexposed to B and D acquired a discrimination between A and E more readily than those preexposed to A and E; and in Experiment 2b the same preexposure treatments had no effect on the acquisition of a discrimination between B and D. In Experiments 3a and 3b, rats given preexposure to C learned a discrimination between A and E more readily than those not given preexposure. Experiment 4 demonstrated that preexposure to a texture (e.g., B) that was adjacent to the to-be-discriminated textures (e.g., C and E) facilitated a discrimination between them relative to preexposure to their midpoint (D). These novel perceptual learning effects are interpreted as reflecting a redistribution of processing between the notional elements of the texture dimension. (PsycINFO Database Record (c) 2016 APA, all rights reserved)(image)



“Contexts control negative contrast and restrict the expression of flavor preference conditioning": Correction to Austen and Sanderson (2016).

2016-07-04

Reports an error in "Contexts control negative contrast and restrict the expression of flavor preference conditioning" by Joseph M. Austen and David J. Sanderson (Journal of Experimental Psychology: Animal Learning and Cognition, 2016[Jan], Vol 42[1], 95-105). In Table 2 of the article, the conditions in Experiment 3 are labeled AB and XY, but they should be AX and BY. (The following abstract of the original article appeared in record 2015-59080-002.) Consumption of a high concentration of sucrose can have either a detrimental, negative contrast effect or a facilitatory, preference conditioning effect on subsequent consumption of a low concentration of sucrose, depending on the cues that are present during consumption. The role of context and flavor cues in determining these effects were studied using analysis of the microstructure of licking in mice. Exposure to a high concentration followed by exposure to a low concentration resulted in a transient reduction in mean lick cluster size, which was context dependent (Experiment 1). However, there was no change in the total number of licks or overall consumption. When a flavor that had previously been paired with a high concentration was paired with a low concentration, there was an increase in the total number of licks, and overall consumption, but no change in the mean lick cluster size (Experiment 2). Pairing a high concentration with a flavor in a particular context before pairing the context and flavor compound with a low concentration resulted in abolishing the expression of the flavor preference conditioning effect on the total number of licks and consumption (Experiment 3). These results demonstrate that although context and flavor cues have dissociable effects on licking behavior, their interaction has an antagonistic effect on the behavioral expression of memory. (PsycINFO Database Record (c) 2016 APA, all rights reserved)(image)



Switching off perceptual learning: Anodal transcranial direct current stimulation (tDCS) at Fp3 eliminates perceptual learning in humans.

2016-07-04

Perceptual learning can be acquired as a result of experience with stimuli that would otherwise be difficult to tell apart, and is often explained in terms of the modulation of feature salience by an error signal based on how well that feature can be predicted by the others that make up the stimulus. In this article we show that anodal transcranial Direct Current Stimulation (tDCS) at Fp3 directly influences this modulation process so as to eliminate and possibly reverse perceptual learning. In 2 experiments, anodal stimulation disrupted perceptual learning (indexed by an inversion effect) compared with sham (Experiment 1) or cathodal (Experiment 2) stimulation. Our findings can be interpreted as showing that anodal tDCS severely reduced or even abolished the modulation of salience based on error, greatly increasing generalization between stimuli. This result supports accounts of perceptual learning based on variations in salience as a consequence of pre-exposure, and opens up the possibility of controlling this phenomenon. (PsycINFO Database Record (c) 2016 APA, all rights reserved)(image)