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Organisms are believed to attempt to maximize their net energy intake while foraging. The paradoxical choice task shows that they may instead prefer to obtain information rather than primary reward when the outcome is uncertain. That is, they prefer stimuli that consistently predict food or no food (informative option), to stimuli that inconsistently predict both food and no food in larger amounts (noninformative option). This task also seems to indicate that some species (like pigeons, Columba livia, and starlings, Sturnus vulgaris) are more prone to choose the informative option, while other species (like rats, Rattus norvegicus, and humans, Homo sapiens) tend to favor reward procurement through the noninformative option. There is empirical evidence for and against this view. However, an analysis of the literature suggests that species differences in paradoxical choice might be less pronounced than often believed. We argue that pigeons and rats are usually not tested under conditions that are motivationally equivalent for both species—in particular, the opportunities to track consistent stimulus–food pairings are less often met in the rat studies than in the pigeon studies. [ABSTRACT FROM AUTHOR]

The study of intelligence in humans has been ongoing for over 100 years, including the underlying structure, predictive validity, related cognitive measures, and source of differences. One of the key findings in intelligence research is the uniform positive correlations among cognitive tasks. This has been replicated with every cognitive test battery in humans. Nevertheless, many other aspects of intelligence research have revealed contradictory lines of evidence. Recently, cognitive test batteries have been developed for animals to examine similarities to humans in cognitive structure. The results are inconsistent, but there is evidence for some similarities. This article reviews the way intelligence and related cognitive abilities are assessed in humans and animals and suggests a different way of devising test batteries for maximizing between-species comparisons. Public Significance Statement: This review highlights the difficulty in understanding why different cognitive abilities are related to each other in human and nonhuman animals. Cognitive abilities are related in similar ways across species, but test batteries should be refined to strengthen these findings and increase translational significance. [ABSTRACT FROM AUTHOR]

To examine the mechanisms and time course of visual search behavior, we rewarded 6 experienced pigeons for locating and pecking at an odd target region randomly embedded in a larger rectangular array of contrasting distractor elements. On two-target test trials, a flanking secondary target region was briefly presented (100, 250, or 500 ms) after display onset with stimulus onset asynchrony values of 0, 50, 100, 175, 250, 375, 500, 1000, 2000, and 3000 nis. Two types of interference effects were possibly identified with target localization accuracy. One type occurred early in processing, where the secondary target appeared to interfere with search behavior, perhaps involving mechanisms similar to inhibition of return. A second type of interference was isolated that appeared to be time locked to responding and might occur at a postsearch stage of processing. Several possible connections of these effects to established mechanisms in human visual search and attention are suggested. [ABSTRACT FROM AUTHOR]

Two experiments with rats as subjects were conducted to investigate the associative structure of temporal control of conditioned inhibition through posttraining manipulation of the training excitor-unconditioned stimulus (US) temporal relationship. Experiment 1 found that following simultaneous Pavlovian inhibition training (i.e., A → US/XA-no US) in which a conditioned stimulus (CS A) was established as a delay excitor, maximal inhibition was observed on a summation test when CS X was compounded with a delay transfer CS. Furthermore, posttraining shifts in the A-US temporal relationship from delay to trace resulted in maximal inhibition of a trace transfer CS. Experiment 2 found complementary results to Experiment 1 with an A-US posttraining shift from serial to simultaneous. These results suggest that temporal control of inhibition is mediated by the training excitor-US temporal relationship. [ABSTRACT FROM AUTHOR]

The information acquired in backward conditioning (i.e., outcome → cue) was assessed in 3 Pavlovian lick-suppression experiments with water-deprived rats as subjects. Experiment 1 confirmed previous research that few outcome → cue pairings made the cue into a conditioned excitor and additionally showed that massive post-training extinction of the training context attenuated a backward-trained cue's excitatory value. Experiment 2 found that many outcome → cue pairings made the cue into a conditioned inhibitor and that the same context manipulation attenuated this inhibitory value. Experiment 3 confirmed the observations of Experiments 1 and 2 and demonstrated that these effects of context extinction were specific to backward-trained cues conditioned in the extinguished context. These results are interpreted in terms of cue → context and context → outcome associations. [ABSTRACT FROM AUTHOR]

Examines the stimulus validity effect of conditioned inhibition produced by extinction-mediated recovery in rats. Effects of stimulus validity training on conditioned response of rats; Impact of massive posttraining extinction on summation and retardation tests; Implication of conditioned stimuli for the performanced-focused extended comparator hypothesis.

Investigates the learning ability of rats through three Pavlovian conditioned lick-suppression experiments. Experiments involving an overshadowed treatment with a footshock unconditioned stimulus such that one Conditioned Stimulus (CS) overshadows another CS; Usefulness of biological significance as an intervening variable for understanding conditioned behavior.

Presents conditioned lick suppression experiments to explore the effects on overshadowing of the strength of the comparator stimulus. Attenuation of the overshadowing deficit in sensory stimulation; Investigation of the prediction of a comparator hypothesis; Dependence of the delay effect on the temporal attributes of the coding relationship.

Presents a study which used rats in three conditioned lick-suppression experiments to determine the effects of pretraining exposure to the conditioned stimulus (CS) on behavior indicative of conditioned inhibition. Indication that the rats were exposed to either Pavlovian conditioned inhibition training or explicitly unpaired inhibition training with the preexposed CS; Assessment of the inhibitory status of the CS with a retardation or a summation; Results of the study.

Investigates the possibility that latent inhibition treatment would result in the reduction of overshadowing in rats, focusing the effect of overshadowing treatment during training on latent inhibition. Examination of the hypothesis regarding the interaction of latent inhibition and overshadowing treatments; Elimination of the interaction between the latent inhibition an overshadowing treatments.

Focuses on conditioning with reference to three conditioned lick suppression experiments which explored the effects on overshadowing of the temporal relationships of two conditioned stimuli with an unconditioned stimulus. Statistical data acquired in this research; Results of these experiments.

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. [ABSTRACT FROM AUTHOR]

Gharib, Derby, and Roberts (2001) proposed that reducing reward expectation increases variation of response form. We tested this rule in a new situation and asked if it also applied to variation of response location and timing. In 2 discrete-trial experiments, pigeons pecked colored circles for food. The circles were of 6 possible colors, each associated with a different probability of reward. Reducing reward expectation did not affect peck duration (a measure of form) but did increase horizontal variation of peck location and interpeck-interval variation. The effect of reward probability on the standard deviation of interpeck intervals was clearer (larger r value) than its effect on mean interpeck interval. Two datasets from rats had similar interresponse-interval effects. [ABSTRACT FROM AUTHOR]

The authors used a touch screen-based visual-search task to investigate spatial integration in pigeons. First, pigeons were presented with a consistent spatial relationship between compound visual landmarks (LMs) A-X and B-Y, separately. Next, pigeons learned to find a hidden goal on the monitor in the presence of LMs A and B. The goal bore a consistent spatial relationship to LM A, but not to LM B. On nonreinforced probe tests, the peak and distribution of responses to LMX suggest that pigeons computed a novel X-goal spatial relationship on the basis of X-A and A-goal spatial vectors. Responses to LM Y, however, revealed no evidence of spatial integration. These results replicate and extend those of A. P. Blaisdell and R. G. Cook (2005) using an open-field task. [ABSTRACT FROM AUTHOR]

Age-related decrements in cognitive ability have been proposed to stem from deteriorating function of the hippocampus. Many birds are long lived, especially for their relatively small body mass and elevated metabolism, making them a unique model of resilience to aging. Nevertheless, little is known about avian age-related changes in cognition and hippocampal physiology. We studied spatial cognition and hippocampal expression of the age-related gene, Apolipoprotein D (ApoD), and the immediate early gene Egr-1 in zebra finches at various developmental time points. In a first experiment, middle-aged adult males outperformed middle-aged females in learning correct food locations in a four-arm maze, but all birds remembered the task equally well after a 5- or 10-day delay. In a second experiment comparing young and old birds, aged birds showed minimal evidence for deterioration in spatial cognition or motivation relative to young birds, except that aged females showed less rapid gains in accuracy during spatial learning than young females. These findings indicate that sex differences in hippocampus-dependent spatial learning and decline with age are phylogenetically conserved. With respect to hippocampal gene expression, adult females expressed Egr-1 at significantly greater levels than males after memory retrieval, perhaps reflecting a neurobiological compensation. Contrary to mammals, ApoD expression was elevated in young zebra finches compared with aged birds. This may explain the near absence of decrements in spatial memory due to age, possibly indicating an alternative mechanism of managing oxidative stress in aged birds. [ABSTRACT FROM AUTHOR]

Age-related decrements in cognitive ability have been proposed to stem from deteriorating function of the hippocampus. Many birds are long lived, especially for their relatively small body mass and elevated metabolism, making them a unique model of resilience to aging. Nevertheless, little is known about avian age-related changes in cognition and hippocampal physiology. We studied spatial cognition and hippocampal expression of the age-related gene, Apolipoprotein D (ApoD), and the immediate early gene Egr-1 in zebra finches at various developmental time points. In a first experiment, middle-aged adult males outperformed middle-aged females in learning correct food locations in a four-arm maze, but all birds remembered the task equally well after a 5- or 10-day delay. In a second experiment comparing young and old birds, aged birds showed minimal evidence for deterioration in spatial cognition or motivation relative to young birds, except that aged females showed less rapid gains in accuracy during spatial learning than young females. These findings indicate that sex differences in hippocampus-dependent spatial learning and decline with age are phylogenetically conserved. With respect to hippocampal gene expression, adult females expressed Egr-1 at significantly greater levels than males after memory retrieval, perhaps reflecting a neurobiological compensation. Contrary to mammals, ApoD expression was elevated in young zebra finches compared with aged birds. This may explain the near absence of decrements in spatial memory due to age, possibly indicating an alternative mechanism of managing oxidative stress in aged birds. [ABSTRACT FROM AUTHOR]

A. P. Blaisdell, K. Sawa, K. J. Leising, and M. R. Waldmann (2006) reported evidence for causal reasoning in rats. After learning through Pavlovian observation that Event A (a light) was a common cause of Events X (an auditory stimulus) and F (food), rats predicted F in the test phase when they observed Event X as a cue but not when they generated X by a lever press. Whereas associative accounts predict associations between X and F regardless of whether X is observed or generated by an action, causal-model theory predicts that the intervention at test should lead to discounting of A, the regular cause of X. The authors report further tests of causal-model theory. One key prediction is that full discounting should be observed only when the alternative cause is viewed as deterministic and independent of other events, 2 hallmark features of actions but not necessarily of arbitrary events. Consequently, the authors observed discounting with only interventions but not other observable events (Experiments I and 2). Moreover, rats were capable of flexibly switching between observational and interventional predictions (Experiment 3). Finally, discounting occurred on the very first test trial (Meta-Analysis). These results confirm causal-model theory but refute associative accounts. [ABSTRACT FROM AUTHOR]