Abstract: Stimuli associated with less effort or with shorter delays to reinforcement are generally preferred over those associated with greater effort or longer delays to reinforcement. However, the opposite appears to be true of stimuli that follow greater effort or longer delays. In training, a simple simultaneous discrimination followed a single peck to an initial stimulus (S+FR1 S-FR1) and a different simple simultaneous discrimination followed 20 pecks to the initial stimulus (S+FR20 S-FR20). On test trials, pigeons preferred S+FR20 over S+FR1 and S-FR20 over S-FR1. These data support the view that the state of the animal immediately prior to presentation of the discrimination affects the value of the reinforcement that follows it. This contrast effect is analogous to effects that when they occur in humans have been attributed to more complex cognitive and social factors.

Abstract: Traditional psychological approaches to animal learning and behavior have involved either the atheoretical behaviorist approach proposed by B. F. Skinner (1938), in which input-output relations are described in response to environmental manipulations, or the theoretical behaviorist approach offered by C. L Hull (1943), in which associations mediated by several hypothetical constructs and intervening variables are formed between stimuli and responses. Recently, the application of a cognitive behaviorist approach to animal learning and behavior has been found to have considerable value as a research tool. This perspective has grown out of E. C. Tolman's cognitive approach to learning in which behavior is mediated by mechanisms that are not directly observable but can be inferred from the results of critical experiments. In the present article, the author presents several examples of the successful application of the cognitive behaviorist approach. In each case, the experiments have been designed to distinguish between more traditional mechanisms and those mediated by hypothesized internal representations. These examples were selected because the evidence suggests that some form of active cognitive organization is needed to account for the behavioral results.

Abstract: In modern intensive husbandry systems there is an increasing tendency for animals to interact with technical equipment. If the animal-technology interface is well-designed this may improve animal welfare by offering challenges for cognitive adaptation. Here a system and its application is presented that acoustically calls individual pigs out of a group (n = 8) to a feeding station. In three different learning phases, the computer-controlled “call-feeding-station” (CFS) trained the animals to recognize a specific acoustic signal as a summons for food, using a combination of classical and operant conditioning techniques. The experimental group's stall contained four CFSs, at each of which one animal at a time was able to feed. When an animal had learned to discriminate and recognize its individual acoustic signal it had to localize the particular CFS that was calling and to enter inside it. Then, it received a portion of feed, the amount of which was adapted to the respective age of the animals. Each animal was called at several, unpredictable times each day and the computer programme ensured that the total feed supply was sufficient for each animal. In the last phase of the experiment the animals, in addition, had to press a button with an increasing fixed ratio for the delivery of feed. It was demonstrated that the pigs were able to adapt quickly to the CFSs. Although they were challenged over 12 h daily by requirements of attention, sensory localization and motor efforts to gain comparatively low amounts of feed, they performed well and reached fairly constant success rates between 90 and 95% and short delays between 14 and 16 s between a summons and the food release in the last phase of the experiment. The weight gain during the experiment was the same as in a conventionally fed control group (n = 8). We therefore conclude that CFSs present a positive challenge to the animals with no negative effects on performance but with a potentially beneficial role for welfare and against boredom. The system is also a suitable experimental platform for research on the effects of successful adaptation by rewarded cognitive processes in pigs.

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Abstract: Ten patients with semantic dementia resulting from bilateral anterior temporal lobe atrophy, and 10 matched controls, were tested on an object recognition task in which they were invited to choose (from a four-item array) the picture representing “the same thing” as an object picture that they had just inspected and attempted to name. The target in the response array was never physically identical to the studied picture but differed from it – in the various conditions – in size, angle of view, colour or exemplar (e.g. a different breed of dog). In one test block for each patient, the response array was presented immediately after the studied picture was removed; in another block, a 2 min filled delay was inserted between study and test. The patients performed relatively well when the studied object and target response differed only in the size of the picture on the page, but were significantly impaired as a group in the other three type-of-change conditions, even with no delay between study and test. The five patients whose structural brain imaging revealed major right-temporal atrophy were more impaired overall, and also more affected by the 2 min delay, than the five patients with an asymmetric pattern characterised by predominant left-sided atrophy. These results are interpreted in terms of a hypothesis that successful classification of an object token as an object type is not a pre-semantic ability but rather results from interaction of perceptual and conceptual processing.