Journal of Experimental Psychology-Animal Learning and Cognition最新文献

We present a new model of transposition behavior that involves 3 predictors: (a) the disparity in generalized associative strength from the previously reinforced and nonreinforced stimuli (g) to the stimuli in the testing pair; (b) relational disparity (r), the difference in the logarithmically scaled sensory values of the testing stimuli; and (c) familiarity (f), the inverse of the Euclidean distance from the testing pair to the nearest training pair in 2-dimensional stimulus space. We evaluated the model with pigeons as subjects and with circle diameter (Experiment 1) and speed of motion (Experiment 2) as sensory dimensions. In each experiment, we presented 1, 2, or 3 training pairs as well as a wide range of testing pairs, including those comprising nonadjacent training stimuli. The control that was exerted by g did not depend on the number of training pairs and predicted behavior better than r and f after 1-pair training. In contrast, the influence of r increased dramatically with an increase in the number of training pairs. The contribution of f depended on the stimulus domain: When circle area was used (Experiment 1), the influence of f was similar to r; however, when speed of motion was used (Experiment 2), f had no discernible effect on pigeons' behavior. In sum, our results suggest that pigeons' transposition behavior is affected by both reinforcement history (g) and the relation between the experimental stimuli (r and f); our model provides a principled means for assessing the relative contribution of each predictor to choice behavior.

Rats were administered 3 versions of an object recognition task: In the spontaneous object recognition task (SOR) animals discriminated between a familiar object and a novel object; in the temporal order task they discriminated between 2 familiar objects, 1 of which had been presented more recently than the other; and, in the object-in-place task, they discriminated among 4 previously presented objects, 2 of which were presented in the same locations as in preexposure and 2 in different but familiar locations. In each task animals were tested at 2 delays (5 min and 2 hr) between the sample and test phases in the SOR and object-in-place task, and between the 2 sample phases in the temporal order task. Performance in the SOR was poorer with the longer delay, whereas in the temporal order task performance improved with delay. There was no effect of delay on object-in-place performance. In addition the performance of animals with neurotoxic lesions of the dorsal hippocampus was selectively impaired in the object-in-place task at the longer delay. These findings are interpreted within the framework of Wagner's (1981) model of memory.

Two studies of human contingency learning investigated the influence of stimulus salience on the cue competition effect of blocking. These studies demonstrated that blocking (defined as a difference in responding to blocked and control cues) was greater for target cues that had high "semantic salience" than those of lower salience. Moreover participants showed weaker responding to high salience blocked cues than low salience blocked cues, but a corresponding difference was not observed for control cues. These findings suggest that the influence of relative salience on associative learning depends on the relative validity of the cues in question. Use of eye tracking in Experiment 2 demonstrated that participants' overt attention to cues was also influenced by both relative salience and relative validity. We describe three associative learning models, based on the attentional theory proposed by Mackintosh (1975), that are able to account for our key findings.

We investigated the effect of prior investment on choice in pigeons, namely, the sunk cost effect, which is a tendency to continue an endeavor once a prior investment has been made, despite a better option being available. In a concurrent-chains procedure, pigeons chose between left and right keys in the choice phase leading to different work requirements in the outcome phase. Within each session, two components were signaled by red or green keys in the choice phase. Components were identical, except that in red components, the choice was preceded by a prior investment of 20 pecks on the left key, whereas in green components, the investment of 20 pecks was on the right key. Preference for the key with the prior investment was studied in a series of experiments in which we manipulated the absence or presence of the investment (Experiments 1a and 1b) and size of the investment (Experiments 2 and 3). We also investigated whether the bias observed was a result of carryover effects or of the sunk cost effect (Experiment 4). Overall, the results showed that choice was biased toward the alternative associated with the prior investment, consistent with the sunk cost effect, an effect that can be understood in terms of within-trial contrast and the delay-reduction hypothesis.

We investigated the sunk time effect, persistence in a nonpreferred option owing to prior investment of time in that option. Pigeons chose between two concurrently available keys-2 fixed-interval (FI) food requirements were arranged on 1 key, and an escape option, which terminated the current trial and started a new one, on a second key. One FI was longer than the other, and the shorter FI was always more probable on any given trial. In most conditions, the different FI schedules were not signaled. In this situation, the optimal behavior would be for pigeons to escape from the long FI once the duration equivalent to the short FI had elapsed without reinforcement. Several variables that could influence persistence or escape behavior were manipulated: the presence and absence of cues signaling the type of trial in effect (Experiments 1 and 2), extinction in the long interval (Experiments 3, 4, and 5), the intertrial-interval duration (Experiments 5 and 6), and the duration of the FI schedules (Experiments 1-6). Overall, the results showed that pigeons tend to persist and finish the current trial, even with extinction in the long interval, a result consistent with the sunk time effect.

This editorial explains the reasoning behind The Journal of Experimental Psychology: Animal Behavior Processes name change. This Journal started publication in 1975 as a result of a major reorganization of the American Psychological Association's basic science journals. To signal that expansion of interest, the name of the journal has been changed to Journal of Experimental Psychology: Animal Learning and Cognition. This change is not meant to discourage submission of the types of manuscripts that have most frequently appeared in the journal in recent years but to encourage submission of papers across a broader range of topics.

Pigeons prefer an alternative that provides them with a stimulus 20% of the time that predicts 10 pellets of food and a different stimulus 80% of the time that predicts 0 pellets, over an alternative that provides them with a stimulus that always predicts 3 pellets of food, even though the preferred alternative provides them with considerably less food. It appears that the stimulus that predicts 10 pellets acts as a strong conditioned reinforcer, despite the fact that the stimulus that predicts 0 pellets occurs 4 times as often. In the present research, we tested the hypothesis that early in training conditioned inhibition develops to the 0-pellet stimulus, but later in training it dissipates. We trained pigeons with a hue as the 10-pellet stimulus and a vertical line as the 0-pellet stimulus. To assess the inhibitory value of the vertical line, we compared responding to the 10-pellet hue with responding to the compound of the 10-pellet hue and the vertical line early in training and once again late in training, using both a within-subject design (Experiment 1) and a between-groups design (Experiment 2). We found that there was a significant reduction in inhibition between the early test (when pigeons chose optimally) and late test (when choice was suboptimal). Thus, the increase in suboptimal choice may result from the decline in inhibition to the 0-pellet stimulus. Implications for human gambling behavior are considered.

Planning is an important aspect of many daily activities for humans. Planning involves forming a strategy in anticipation of a future need. However, evidence that nonhuman animals can plan for future situations is limited, particularly in relation to the many other kinds of cognitive capacities that they appear to share with humans. One critical aspect of planning is the ability to remember future responses, or what is called prospective coding. Two monkey species (Macaca mulatta and Cebus apella) performed a series of computerized tasks that required encoding a future response at the outset of each trial. Monkeys of both species showed competence in all tests that were given, providing evidence that they anticipated future responses and that they appropriately engaged in those responses when the time was right for such responses. In addition, some tests demonstrated that monkeys even remembered future responses that were not as presently motivating as were other aspects of the task environment. These results indicated that monkeys could anticipate future responses and retain and implement those responses when appropriate.

When tested in rectangular arenas, the navigational behavior of the ant Gigantiops destructor can produce results similar to vertebrates. Such results are usually interpreted as supporting the ability of animals to segregate spatial geometry and features. Here, we combine a detailed analysis of ants' paths with panoramic images taken from the ant's perspective that can serve as a basis for developing view-based matching models. The corner choices observed in ants were better predicted by the use of panoramic views along with a simple matching process [rotational image difference function (rIDF)] than by models assuming segregation of geometry and features (G/F). Our view-based matching model could also explain some aspects of the ants' path (i.e., initial direction, length) resulting from the different visual conditions, suggesting that ants were using such a taxon-like strategy. Analyzed at the individual level, the results show that ants' idiosyncratic paths tend to evolve gradually from trial to trial, revealing that the ants were partially updating their route memory after each trial. This study illustrates the remarkable flexibilities that can arise from the use of taxon-like strategies and stresses the importance of considering them in vertebrates.

The role of generalization decrement in spatial overshadowing was evaluated using a landmark-based spatial search task in both a touchscreen preparation (Experiment 1a) and in an Automated Remote Environmental Navigation Apparatus (ARENA, Experiment 1b). A landmark appeared as a colored circle among a row of eight (touchscreen) or six (ARENA) potential locations. On overshadowing trials, Landmark X was located two positions away from a hidden goal, while another landmark, A, was in the position between X and the goal. On control trials, Landmark Y was positioned two locations away from the goal but without a closer landmark. All subjects were then tested with separate trials of A, X, Y, and BY. Testing revealed poor spatial control by X relative to A and Y, thereby replicating the spatial overshadowing effect. Spatial control by Y was similar when tested in compound with novel landmark (BY) and on trials of Y alone. Thus, overshadowing in a small-scale environment does not appear to be due to a process of generalization decrement between training and testing.