Foster, T. M., Matthews, L. R., Temple, W., & Poling, A. (1997). Concurrent schedule performance in domestic goats: persistent undermatching. Behav. Process., 40(3), 231–237.
Abstract: Performance of nine domestic goats responding under concurrent variable-interval variable-interval schedules of food delivery was examined, with results analyzed in terms of the generalized matching equation. Substantial undermatching of response and time allocation ratios to obtained reinforcement ratios was evident. Post-reinforcement pause time ratios approximately matched obtained reinforcement ratios. Subtracting these times from total time allocation values yielded net time allocation ratios, which undermatched obtained reinforcement ratios to a greater degree than whole-session time allocation ratios. Slopes of regression lines relating behavioral outputs to environmental inputs characteristically were below 0.6, which is similar to previous findings in dairy cows tested under comparable conditions.
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Foster, T. M., Temple, W., Cameron, B., & Poling, A. (1997). Demand curves for food in hens: Similarity under fixed-ratio and progressive-ratio schedules. Behav. Process., 39(2), 177–185.
Abstract: Demand curves were generated for five domestic hens under progressive-ratio 5 schedules of food delivery and under fixed-ratio schedules of food delivery that began at fixed-ratio 5 and were incremented by 5 each session. All sessions ended after 10 consecutive minutes without a response. Although response rates at a given ratio were higher under the progressive-ratio schedule, all hens completed higher ratios under the fixed-ratio schedule. Similar, but not identical, demand curves were generated under progressive-ratio and fixed-ratio schedules. Under both schedules, consumption (reinforcers earned) decreased as cost (ratio size) increased. Data generally were well described by an equation in which elasticity of demand is constant, although an equation in which elasticity could vary accounted for slightly more of the variance.
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Poling, A., Temple, W., & Foster, T. M. (1996). The differential outcomes effect: A demonstration in domestic chickens responding under a titrating-delayed-matching-to-sample procedure. Behav. Process., 36(2), 109–115.
Abstract: The differential outcomes effect refers to the increase in speed of acquisition or terminal accuracy that occurs in discrimination training when each of two or more discriminative stimuli is correlated with a different outcome (e.g. type of reinforcer). The present study demonstrated this effect in domestic hens exposed to a titrating-delayed-matching-to-sample procedure, under which correct responses increased (and incorrect responses decreased) the delay between the offset of a sample stimulus and the onset of two comparison stimuli. Colors of key illumination (red, green) were used as sample and comparison stimuli and correct responses resulted in 1- or 4-s food deliveries. When 1-s food deliveries consistently followed correct responses to one key color and 4-s food deliveries followed correct responses to the other key color, the maximum delay reached by the hens and their overall accuracy was significantly higher than when 1- and 4-s food deliveries were randomly arranged following correct responses to both key colors. These data constitute the first demonstration of the differential outcomes effect in chickens, and in any species evaluated under a titrating-delayed-matching-to-sample procedure.
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Robinson, T. A., Foster, T. M., Temple, W., & Poling, A. (1995). Performance of domestic hens under progressive-ratio schedules of food delivery. Behav. Process., 34(3), 233–239.
Abstract: Domestic hens were exposed to progressive-ratio 2 and progressive-ratio 10 schedules of food delivery with different initial ratios (2, 10, 20, 30, and 40). Breaking points, defined as the largest ratios completed before responding ceased for 600 consecutive seconds, were recorded under all conditions. In general, breaking points were higher under the PR 10 schedule than under the PR 2 schedule, and the value of the initial ratio did not systematically affect the breaking point. The former finding suggests that relative satiation affected breaking points in the present study, but the latter finding suggests that the primary determinant was the `price' of the reinforcer, defined in terms of the number of responses required to produce it. Breaking points were similar under conditions where initial ratios changed from session to session and under more conventional conditions, where initial ratios remained unchanged over several sessions.
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Poling, A., Thomas, J., Hall-Johnson, E., & Picker, M. (1985). Self-control revisited: Some factors that affect autoshaped responding. Behav. Process., 10(1-2), 77–85.
Abstract: Pigeons were exposed to autoshaping procedures under which 50% of red key illuminations were followed by 9-sec food deliveries, and 50% of blue key illuminations were followed by 3-sec food deliveries. When all key illuminations were 6 sec, pigeons preferred the red stimulus. Subsequent manipulations demonstrated that preference could be shifted to the blue stimulus by either increasing the duration of the red stimulus or imposing a delay interval between the offset of that stimulus and food delivery. A final experiment demonstrated that, in two of three subjects, preference for key illuminations associated with longer, but delayed, food deliveries generally increased as the duration of all key illuminations was lengthened. These results, obtained under conditions where keypecking had no programmed consequences, are similar to those previously observed under procedures involving a positive response-food dependency.
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Duncan, I. J. H., Widowski, T. M., Malleau, A. E., Lindberg, A. C., & Petherick, J. C. (1998). External factors and causation of dustbathing in domestic hens. Behav. Process., 43(2), 219–228.
Abstract: Dustbathing is known to be motivated by complex interactions between internal factors which build up over time and external factors, such as the sight of a dusty substrate. In this study, the effects of other external factors were investigated. Environmental temperature was shown to be important; frequencies of dustbathing were greater when hens were held at 22 than at 10[degree sign]C (P<0.01). In a second experiment, a radiant heat source or a radiant heat+light source, balanced to give the same radiant heat, resulted in more dustbathing behaviour during a 1-h stimulus period than during the same period with no stimulus (P<0.05). Components of dustbathing were increased more by the heat+light stimulus than by the heat stimulus alone (P<0.03). In a third experiment, the amount of dustbathing performed by individual hens in cages with dustbaths was increased by the presence of a group of hens dustbathing in an adjoining pen with a dustbath compared with the amount occurring when the hens were absent from the pen.
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Petherick, J. C., Seawright, E., & Waddington, D. (1993). Influence of motivational state on choice of food or a dustbathing/foraging substrate by domestic hens. Behav. Process., 28(3), 209–220.
Abstract: Domestic hens were trained to run a Y-maze and make an association between differently coloured doorways and access to food pellets or sand. The hens were tested for their choice of doorway when the goals were not visible from the choice point and when they were food or sand deprived. Hens made the choice appropriate to their deprivation state (correct choice) significantly more often for food than sand and were faster at choosing and entering the goal box when food deprived. In a follow up experiment, the goals were visible from the choice point. Again the hens chose correctly significantly more often when food than sand deprived and made the choice and entered the goal box faster when food deprived. Thus, failure to choose sand in the first experiment was not due to an inability to learn the association, but appears to result from a strong motivation to feed in the Y-maze, even when not food deprived, and a weak motivation to dustbathe or forage, even when sand deprived.
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Petherick, J. C., Waddington, D., & Duncan, I. J. H. (1991). Learning to gain access to a foraging and dustbathing substrate by domestic fowl: is `out of sight out of mind'? Behav. Process., 22(3), 213–226.
Abstract: Domestic fowl were deprived of the opportunity to perform litter-related behaviour for three or four days and were tested in a Y-maze (which they had previously been trained to run) for their ability to associate a coloured cue with gaining access to peat. When the goal boxes were within sight of the choice point, most birds chose peat. However, when the birds had to rely solely on the coloured cue only one bird from 12 showed learning. However, the birds seemed to have some expectation of a reward, as they ran faster if, on the previous trial, they had chosen peat. The inability of the birds to learn the association may have been an artefact of the schedule of deprivation and testing, for when they were hungry and tested in the same way they were again unable to learn an association between the same coloured cue and food reward. The experiment with peat was repeated using “massed” trials (several trials in immediate succession) during training and testing and six from 15 birds showed learning. These results suggest that the initial failure to learn was probably due to the training and testing schedule, that access to peat appears to be rewarding and that hens can learn an association between an abstract cue and a rewarding consequence. This is consistent with the possibility that domestic fowls may have some cognitive representation of peat when it is out of sight.
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Hirata, S. (2007). A note on the responses of chimpanzees (Pan troglodytes) to live self-images on television monitors. Behav. Process., 75(1), 85–90.
Abstract: The majority of studies on self-recognition in animals have been conducted using a mirror as the test device; little is known, however, about the responses of non-human primates toward their own images in media other than mirrors. This study provides preliminary data on the reactions of 10 chimpanzees to live self-images projected on two television monitors, each connected to a different video camera. Chimpanzees could see live images of their own faces, which were approximately life-sized, on one monitor. On the other monitor, they could see live images of their whole body, which were approximately one-fifth life-size, viewed diagonally from behind. In addition, several objects were introduced into the test situation. Out of 10 chimpanzees tested, 2 individuals performed self-exploratory behaviors while watching their own images on the monitors. One of these two chimpanzees successively picked up two of the provided objects in front of a monitor, and watched the images of these objects on the monitor. The results indicate that these chimpanzees were able to immediately recognize live images of themselves or objects on the monitors, even though several features of these images differed from those of their previous experience with mirrors.
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Range, F., Bugnyar, T., Schlogl, C., & Kotrschal, K. (2006). Individual and sex differences in learning abilities of ravens. Behav. Process., 73(1), 100–106.
Abstract: Behavioral and physiological characteristics of individuals within the same species have been found to be stable across time and contexts. In this study, we investigated individual differences in learning abilities and object and social manipulation to test for consistency within individuals across different tasks. Individual ravens (Corvus corax) were tested in simple color and position discrimination tasks to establish their learning abilities. We found that males were significantly better in the acquisition of the first discrimination task and the object manipulation task, but not in any of the other tasks. Furthermore, faster learners engaged less often in manipulations of conspecifics and exploration of objects to get access to food. No relationship between object and social manipulation and reversal training were found. Our results suggest that individual differences in regard to the acquisition of new tasks may be related to personalities or at least object manipulation in ravens.
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