The behavior of larval zebrafish reveals stressor-mediated anorexia during early vertebrate development

The relationship between stress and food consumption has been well documented in adults but less so in developing vertebrates. Here we demonstrate that an encounter with a stressor can suppress food consumption in larval zebrafish. Furthermore, we provide indication that food intake suppression cannot be accounted for by changes in locomotion, oxygen consumption and visual responses, as they remain unaffected after exposure to a potent stressor. We also show that feeding reoccurs when basal levels of cortisol (stress hormone in humans and teleosts) are re-established. The results present evidence that the onset of stress can switch off the drive for feeding very early in vertebrate development, and add a novel endpoint for analyses of metabolic and behavioral disorders in an organism suitable for high-throughput genetics and non-invasive brain imaging

A THEORY OF BEHAVIORAL CONTRAST

abstract: The reinforcers that maintain target instrumental responses also reinforce other responses that compete with them for expression. This competition, and its imbalance at points of transition between different schedules of reinforcement, causes behavioral contrast. The imbalance is caused by differences in the rates at which different responses come under the control of component stimuli. A model for this theory of behavioral contrast is constructed by expanding the coupling coefficient of MPR (Killeen, 1994). The coupling coefficient gives the degree of association of a reinforcer with the target response (as opposed to other competing responses). Competing responses, often identified as interim or adjunctive or superstitious behavior, are intrinsic to reinforcement schedules, especially interval schedules. In addition to that base-rate of competition, additional competing responses may spill over from the prior component, causing initial contrast; and they may be modulated by conditioned reinforcement or punishment from stimuli associated with subsequent component change, causing terminal contrast. A formalization of these hypotheses employed (a) a hysteresis model of off-target responses giving rise to initial contrast, and (b) a competing traces model of the suppression or enhancement of ongoing competitive responses by signals of following-schedule transition. The theory was applied to transient contrast, the following schedule effect, and the component duration effect.This is the pre-peer reviewed version of the article, which has been published in final form at http://dx.doi.org/10.1002/jeab.10

Strategic approach to psychotherapeutic intervention with male institutionalized white adolescents to control absconding

Bibliography: pages 92-98.Using a systems theoretical orientation the objective of this study was to implement a strategic approach for psychotherapeutic intervention with six male institutionalized white adolescents at a local custodial school. It was hypothesized that a strategic approach would control absconding for the duration of the investigation. Surveys of the literature were undertaken to provide the background to psychotherapeutic intervention with adolescents in custodial institutions, strategic psychotherapy and absconding. Absconding was selected as the condition for evaluating the interventions because it was an unambiguous indicator of school-based recidivism, viz., the adolescent was either on the property or he was not. The study was structured as a design-and-demonstrate investigation. Audiotape recordings were made during the sessions. Transcriptions of characteristic procedures and sequences of the strategic approach to psychotherapeutic intervention were presented, inter alia, paradoxes, reframing, metaphors, rituals, the declaration of therapeutic impotence. Evaluation of the interventions was based on follow-up interviews with the subjects and a qualitative analysis of risk of absconding aver the course of the intervention process. At the end of the investigation there was some evidence which suggested that five out of the six subjects were not as committed to absconding as they had claimed to be at the beginning of the study. The design of the study did not allow for the conclusion that the strategic approach for controlling absconding was of greater merit than any other form of intervention or no intervention at all. It was noted, however, that twelve of the eighteen potential subjects for the study indicated that they would abscond as soon as the opportunity arose. Therefore it was recommended that the issue of absconding be given priority in therapy on the admission of each new pupil. Given a strategic approach to addressing the issue of absconding in therapy, attention was drawn to a major aim of this type of intervention, viz., to generate a sense of personal autonomy. Hence a further recommendation was that once a pupil had made a commitment not to abscond, his sense of autonomy would need to be supported by an expeditious transfer to one of the more open hostels

The Naturalisation of Intentionality and Rationality Using Systems: A Functional Explanation of Mind, Agency and Intentionality in Human Linguistic Communities

This thesis recognises two axioms of materialism. Firstly, that the human or other agent is within and is comprised of the same stuff as, a universe made up of material things, each of which is, in principle, explicable in materialist terms. Secondly, that the theorist is himself an agent, explicable within the theory of agency that he propounds. The author contends that any attempt to explain complex conscious human agency 'from the top down' faces either a potential regress of explaining the aetiology of human agency in terms of some agency of design or the view, canvassed by Colin McGinn, (1989), that the human mind is 'cognitively closed' to the concepts that would explain how human consciousness can arise from the material substance of the brain. The author has avoided this dilemma by postulating an austere characterisation of agency, from which the rich and manifold nature of human agency and intentionality has developed by the accidents of evolution. He holds that this austere agency may be explained by natural accidents of chemical combination that have led, by the accidents of evolution, to the phenomena of reproductive life, functionally characterised in this explanation by agency and autopoiesis. This austere characterisation of agency is an example of a functional system. Agency is a capacity of an entity within the physical system of an agent in the world. This capacity is enabled by functions that the author has named; 'perception', 'representation', 'cognitive process' and 'action'. Through the processes of perception, physical states of the world physically cause changes in representational states of agency; within cognitive processes, representational states combine to cause actions of agency that change states of the world, that includes the agent, in ways that maintain or tend towards those goal states of the agent in the world, that are postulated in a theory of agency. It is argued that this concept of agency is functionally isomorphic with the technological concept of regulation. Two theorems from regulation are particularly relevant. Firstly, Ashby's theorem that for successful regulation the variety of possible states in the regulator must at least match the variety of states regulated against. Secondly, the very idea of regulation stems from the epistemic contingency for the agent, of events regulated against. Life, as we know it on earth, is reproduced by reproductive behaviour that follows and reproduces the programmes encoded in DNA. The autopoietic maintenance of the structure of the living organism against the contingencies of an unpredictable world is enabled by the mechanisms of agency. The structure of the thesis and the ontological commitments of the author are set out in a first introductory chapter. In the second chapter the author summarises the history and currant range of application of the system concept and describes the philosophical implications of his notion of a physical system. The notions of physical cause, accident, function, supervenience, representation and alternative realisation that are assumed within the thesis are also described in this chapter. The third chapter is devoted to the development of the concept of agency as a capacity, characterized by goals and intentionality and enabled by the functions listed above. Examples of agency in the world are described in the fourth chapter. These range from the simple reflex agency of a governor, unicellular organism or part of a plant to the complex integrated agency of production control systems, advanced vertebrates, including us, and social groupings such as a colony of social insects or some aspects of a human corporation. Also, within this chapter, the author considers the impact of language on human social agency, the implications of social agency for the attribution of personhood and through semantic ascent, the social practices of attribution of meaning, truth and mind, and the prepositional attitudes. He concludes that, since agency necessarily involves an agent in its world and human language is about the world as it is for the human agent; language, agency and the world are explanatorily inseparable. In the fifth and sixth chapters the author applies his theory of human agency to the computational theory of mind and the apparent tension between determinism, free will and personal responsibility. The author concludes: Firstly, that the brain as an organ of representation, is not a computer since computation is an act of agency, although parts of the brain may have a combinatorial function within such acts. Secondly, if freedom is defined as an absence of physical constraint then a free agent is physically responsible for its acts. Within the social practice of attribution of personhood to the continuous ongoing agent within the community, each person is held responsible for his actions, including those that change the future agency of himself and others, for better or for worse, according to the valuation of the community. In a final chapter the author summarises some of the philosophical implications of his thesis. The notions of variety in regulation and of autopoiesis as a necessary criterion of life are used in the thesis and are explained in each of two appendices

Aprendizaje e imagen corporal : análisis experimental en psicología comparada

Fac. de PsicologíaTRUEProQuestpu

Study on cognitive abilities in the dog: discrimination of quantities and imitation learning related to the attachment

Il presente studio ha indagato e valutato alcune abilità cognitive del cane: la capacità di discriminare quantità e le capacità di apprendimento mediante imitazione; quest’ultima è poi stata messa in relazione con l’attaccamento nei confronti del proprietario. Per l’esecuzione della prima indagine sono stati messi appunto due test: il primo si è basato esclusivamente sulla presentazione di uno stimolo visivo: diversi quantitativi di cibo, differenti tra loro del 50%, sono stati presentati al cane; la scelta effettuata dai soggetti testati è stata premiata con differenti tipi di rinforzo differenziale o non differenziale. Il secondo test è stato diviso in due parti: sono stati presentati al cane diversi quantitativi di cibo sempre differenti tra loro del 50% ma nella prima parte del test l’input sensoriale per il cane è stato esclusivamente uditivo mentre nella seconda parte è stato sia uditivo che visivo. Ove è stato possibile è stato applicato ai cani un cardiofrequenzimetro al fine di eseguire una valutazione delle variazioni della frequenza cardiaca nel corso del test. Lo scopo è stato quello di valutare se i soggetti testati erano in grado di discriminare la quantità maggiore. La seconda indagine ha analizzato le capacità di apprendimento di 36 soggetti che sono stati suddivisi in cani da lavoro e pet. I soggetti protagonisti dello studio hanno eseguito il Mirror Test per la valutazione dell’apprendimento per imitazione. I soggetti presi in considerazione, sono stati sottoposti a scansione termografica all’inizio ed al termine del test ed è stata rilevata la loro frequenza respiratoria nella fase iniziale e finale del test. In 11 soggetti che hanno eseguito il precedente test è stato possibile eseguire anche il Strange Situation Test per la valutazione dell’attaccamento al proprietario; i test in questione sono stati videoregistrati ed analizzati per mezzo di un software preposto (OBSERVER XT 10).The present study investigated and evaluated some cognitive abilities of the dog: the ability to discriminate quantity and to learn through imitation; the latter kind of learning was related to the dog’s attachment to the owner. In the first analysis two tests were applied: the first is based on the presentation of a visual stimulus: different amounts of food, different from each other by 50% , were presented to the dog; the choice of the dogs was rewarded with different types of differential or non-differential reinforcement. The second test was divided into two parts: different quantities of food (different from each other by 50 %) were submitted to the dogs; in the first part of the test, the sensory input was exclusively auditory, while in the second part both auditory and visual. Where feasible, a heart rate monitor was applied to the dogs, in order to perform an assessment of the heart rate changes during the test. The aim of the test was to evaluate if the subjects were able to discriminate the larger amount of food. The second study analyzed the learning ability of 36 subjects, divided into working dogs and pets. The subjects performed the Mirror Test for the assessment of learning by imitation. In addition the subjects were subjected to thermal scanning at the beginning and at the end of the test and their respiratory rate was detected before and after the test. Finally, in 11 of these subjects the Strange Situation Test for the assessment of attachment to the owner, was performed. All tests were videotaped and then analyzed using a dedicated software (OBSERVER XT 10)