Our lives would not be what they are today without animals. From the food we eat, to the clothes we wear, animals provide tangible evidence of their importance every day. But more than that, animals have shaped who we are and what we believe. Often in ways we don't see. That's what inspired me to write Being Human. This work began as an examination of how humans have altered animals to better match our imaginations and ideals, and too, the way these animals have irrecoverably altered how we live and look at the world. Consider, for example, that before they became physically useful to us in providing meat or skills or companionship, animals were central figures in our stories, mythologies, and religions. All the while, of course, these animals remained both ignorant and at the mercy of whatever we imagined--or needed--them to be. And what does all of this say about us? What can we learn about ourselves from looking at animals, and more specifically, looking at the way we treat them? In a society where animal flesh comes to us freshly packed and cleanly saran-wrapped, and pets are treated as members of our families, we tend to look at animals as one thing or another. A farm pig is not a companion animal, any more than a cat is a meal-in-waiting. At least not in our culture. We generally see what's convenient or desirable and when things get messy or complicated, we tend to look away. In so doing, we miss the opportunity to clearly see who we really are, what we're capable of, and what, if anything, we might want to change as a result. I chose four specific animals that show us different sides of ourselves. These beings are both familiar and strange, part of our everyday lives but often only found on the periphery. Each animal symbolizes one of four categories: food, pest, worker and pet. And each connects to a human need: pigs with consumption, pigeons with communication, horses with control and cats with companionship. They are arranged in this order to reflect the deepening complexity of their respective human needs--from the simplest, the need to eat, to the most complex, the need for companionship. (Arguably, control can be considered the most complex, however I chose companionship as the culminating need because it inherently involves all of the other three.) I hope if I accomplish only one thing, it is this: after reading, you see these animals--and your relationship to them--a little bit differently than before.

In this scientific work the most important problems and advice under the maintenance of pigeons are described. The chapter 1 – introduction. In it it is described the past and the future pigeon breeding in the world and in Lithuania. In 2 chapter biological features of house pigeons are described. In 3 chapter cultivation and duplication of house pigeons is described. In chapter 4 it is described about care of house pigeons, preparation of their nursery and the technical equipment. There designing and a structure of a premise for pigeons, system of ventilation, the equipment is described. Also hygiene in pigeon nurseries, a temperature mode, disinfection of a dovecot and subjects of leaving. In 5 chapter it is described a mode feeding of house pigeons and the characteristic of their forage. In 6 chapter vitamins, probiotics and prebiotics are described organic and mineral substances: fibers, fats, carbohydrates, Omega-3 and Omega-6, enzymes. In 7 chapter measures the prevention of diseases of the person are described. Infectious and protozoan illnesses, helmintose, noncontagious illnesses, them etiology and preventive means are described. Parasites whom causes illnesses in house pigeons are described. Noncontagious illnesses of pigeons, their preventive maintenance are described. Also their poisoning with a forage, the illnesses connected with lack or surplus of vitamins are described. It is shortly described the first aid to a bird. In 8 chapter conclusions and are presented... [to full text]

Cognitive theories of timing and conditioned reinforcement provide two different theoretical perspectives on choice between delayed rewards. The primary objective of this research was to identify the process that generates choice in the concurrent-chains procedure and to characterize its relationship with temporal control. Experiments 1-3 investigated the relationship between the dynamics of pigeons’ preference and temporal control in concurrent chains using an arrangement in which the delays to reinforcement changed unpredictably across sessions. To obtain convergent measures of choice and timing behavior, occasional ‘no-food’ terminal links lasted longer than the schedule values and ended without reinforcement. Measures of choice (log initial-link response ratios) and timing (start and stop times from no-food terminal links) stabilized within individual sessions. Sensitivity of log response ratios to relative immediacy increased as initial-link duration decreased or absolute terminal-link delays increased, but absolute initial- and terminal-link duration did not affect temporal control. Residual covariation analyses of log response ratios with log start and stop time ratios confirmed that measures of choice and timing were interdependent. Experiments 4 and 5 used concurrent-chains procedures in which immediacy, magnitude (and probability, in Experiment 5) ratios for left and right keys were 2:1 or 1:2, determined across sessions by independent, random series. Experiment 6 was a concurrent schedule in which relative reinforcement rate and magnitude were 2:1 or 1:2, determined the same way. Multiple regression analyses showed that pigeons’ response allocation in Experiments 4-6 was sensitive to multiple dimensions of reinforcement. Levels of preference within individual sessions and initial links or interfood intervals was more extreme when all dimensions favored the same key than when at least one dimension favored each key, consistent with assumptions of the generalized matching law. Within individual sessions, changes in response allocation in all experiments tended to be abrupt, consistent with the assumptions of Rate Estimation Theory (Gallistel & Gibbon, 2000). A decision model that posits a comparison between delayed outcomes with a criterion delay (Grace & McLean, 2006) described initial-link responding in Experiments 1-3. A modified decision model in which outcome expectancy is compared to an expectancy criterion described responding in Experiments 4-6.

The quantification of choice has been a major area of research for behavioural scientists for several decades. This is, in part, due to the discovery of the matching law (Herrnstein, 1961) which stipulates that relative response rates on concurrently available alternatives “match” the available relative reinforcement rates. This theoretical construct has been developed to describe response allocation in more complex situations, such as concurrent chains, and successfully describes both human and non-human behaviour. Typically, this phenomenon becomes evident when behaviour settles at an asymptote after several sessions of training where contingencies are held constant, and is often called “steady-state” behaviour. However, a fundamental question still remains: what causes matching – that is, what are the underlying momentary process(es) that produce matching? Researchers have suggested that what is necessary to answer this question is to take a molecular approach to the analysis of choice behaviour, thereby assessing choice in transition (Grace, 2002a). Recently, a new model of choice acquisition has been developed that appears to offer promise. It combines two separate mechanisms; a “winner-takes-all” categorical discrimination, and a linear-operator acquisition process (Grace & McLean, 2006). The initial results suggest this model could provide an alternative explanation for what underlies matching – that two separate processes are cooccurring in the acquisition of choice behaviour – allowing response allocation to be either linear or non-linear. This thesis extends the Grace and McLean model to include the situation of response strength ‘carrying-over’ from session to session to describe the process of acquisition gradually accumulating with experience. Moreover, additional assumptions have been added to describe temporal phenomena 2 and presumed discounting of previous experience on current choice behaviour. A steady-state version of the extended model was derived and, when fitted to published data sets, describes choice behaviour equally well when compared to existing models of steady-state choice. As a consequence of these additions, the Extended Decision Model (EDM) predicts a unique response allocation pattern – choice behaviour follows a bitonic function when initial-link durations were increased and the terminallink delays were held constant. The results from experiments presented in this thesis support this prediction, whilst steady-state analyses found the EDM was parameter invariant – differences between parameters from two schedule types across several archival data sets were non-significant, while existing steady-state models had significant differences. These findings provide further support for the claim that the EDM and the Decision Model (DM) mechanisms provide unique and accurate descriptions of the molecular processes governing choice behaviour. Moreover, the implication from these results is that the underlying assumption of the EDM and DM – that choice is determined by the propensity to respond rather than conditioned reinforcement – appears to have further foundation. This challenges the assumptions of existing models of choice behaviour and presents the possibility that probabilistic approaches are perhaps more appropriate for describing response allocations than discrete estimates of relative value when contingencies change.

Zentall, Steirn, and Jackson-Smith (1990) found evidence for dual coding in pigeons in a radial maze analog task. Specifically, they found that pigeons used retrospective coding in which previously chosen keys were remembered when a delay was interpolated early in a trial and prospective coding in which to-be-visited keys were remembered when a delay was interpolated late in a trial. An alternative explanation, the criterion shift hypothesis proposed by Brown, Wheeler, and Riley (1989), suggests that these data are consistent with dual coding because of an artifact of the correction procedures used by Zentall et al. The criterion hypothesis suggests that retrospective coding is used and that pigeons make choices more carefully after many choices have been made on delay trials as compared to control trials, which creates the appearance of prospective coding later in a trial. The present experiments tested this hypothesis using a new testing trial procedure and new, more conservative control trials. In experiment 1, the results of Zentall et al. were replicated using a fixed delay procedure instead of their original progressive delay procedure. Experiment 2 used a forced choice procedure after the delay to make the probability of making an error 50% on each trial type. Control trials also included a forced choice procedure to eliminate the assumptions required by the corrections procedure used by Zentall et al. The results were inconsistent with the retrospective coding account predicted by the criterion shift hypothesis and with the dual coding hypothesis. Instead, the results were consistent with a prospective coding account in which to-be-visited keys were remembered. These results were replicated in Experiment 3 using the pigeons from Experiment 1. The present findings have important implications for the field of comparative cognition.

Photocopy of typescript. / Bibliography: leaves 58-62. / Microfiche. / vii, 62 leaves ill. 29 cm

The quantification of choice has been a major area of research for behavioural scientists for several decades. This is, in part, due to the discovery of the matching law (Herrnstein, 1961) which stipulates that relative response rates on concurrently available alternatives “match” the available relative reinforcement rates. This theoretical construct has been developed to describe response allocation in more complex situations, such as concurrent chains, and successfully describes both human and non-human behaviour. Typically, this phenomenon becomes evident when behaviour settles at an asymptote after several sessions of training where contingencies are held constant, and is often called “steady-state” behaviour. However, a fundamental question still remains: what causes matching – that is, what are the underlying momentary process(es) that produce matching? Researchers have suggested that what is necessary to answer this question is to take a molecular approach to the analysis of choice behaviour, thereby assessing choice in transition (Grace, 2002a). Recently, a new model of choice acquisition has been developed that appears to offer promise. It combines two separate mechanisms; a “winner-takes-all” categorical discrimination, and a linear-operator acquisition process (Grace & McLean, 2006). The initial results suggest this model could provide an alternative explanation for what underlies matching – that two separate processes are cooccurring in the acquisition of choice behaviour – allowing response allocation to be either linear or non-linear. This thesis extends the Grace and McLean model to include the situation of response strength ‘carrying-over’ from session to session to describe the process of acquisition gradually accumulating with experience. Moreover, additional assumptions have been added to describe temporal phenomena 2 and presumed discounting of previous experience on current choice behaviour. A steady-state version of the extended model was derived and, when fitted to published data sets, describes choice behaviour equally well when compared to existing models of steady-state choice. As a consequence of these additions, the Extended Decision Model (EDM) predicts a unique response allocation pattern – choice behaviour follows a bitonic function when initial-link durations were increased and the terminallink delays were held constant. The results from experiments presented in this thesis support this prediction, whilst steady-state analyses found the EDM was parameter invariant – differences between parameters from two schedule types across several archival data sets were non-significant, while existing steady-state models had significant differences. These findings provide further support for the claim that the EDM and the Decision Model (DM) mechanisms provide unique and accurate descriptions of the molecular processes governing choice behaviour. Moreover, the implication from these results is that the underlying assumption of the EDM and DM – that choice is determined by the propensity to respond rather than conditioned reinforcement – appears to have further foundation. This challenges the assumptions of existing models of choice behaviour and presents the possibility that probabilistic approaches are perhaps more appropriate for describing response allocations than discrete estimates of relative value when contingencies change.

Thesis (Ph. D.)--UCLA, 2008. / Vita. Description based on print version record. Includes bibliographical references (leaves 197-220).

Thesis (Ph.D.)--University of Alberta, 2009. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Centre for Neuroscience. Title from pdf file main screen (viewed on August 25, 2009). Includes bibliographical references.

The experiments reported in this thesis were conducted to examine the effects of executive-control and associative-learning processes on performance in conventional executive-control paradigms. For this purpose, I developed comparative task-switching and response-inhibition paradigms, which were used to assess the performance of pigeons, whose behaviour is presumably based purely on associative processes, and of humans, whose behaviour may be guided by executive control and by associative processes. Pigeons were able to perform accurately in the comparative paradigms; hence, associative-learning processes are sufficient to account for successful performance. However, some task-specific effects that can be attributed to executive-control processes, and which were found in humans applying executive control, were absent or greatly reduced in pigeons. Those effects either reflect the mental operations that are performed to ensure that a specific set of stimulus-response-contingencies is applied and any contingencies belonging to a different set are suppressed, or reflect mental preparations for the possibility that the requirement to execute a certain response suddenly changes. In particular, in Chapter 3, it is shown that the benefits of repeatedly applying the same set of stimulus-response contingencies (or, in reverse, the costs of switching from one set to another) do not apply when Pavlovian processes dominate learning, which is likely the case for pigeons. Furthermore, as shown in Chapters 4 and 5, the behavioural effects of preparing for an unpredicted change in response requirements appeared to be absent when behaviour was based purely on associative processes. Instead, associatively mediated performance was primarily influenced by the stimulus-response contingencies that were effective in each paradigm. Repeating the same response in consecutive trials facilitated the performance of pigeons and associatively learning human participants in the task-switching paradigms, and performing a particular Go response increased the pigeons' likelihood of executing that response in the following trial in two response-inhibition paradigms. In summary, any behavioural effects that can be observed at the level of abstract task requirements reflect the influence of executive-control processes, both in task-switching paradigms and in response-inhibition paradigms.