1,530 research outputs found
Naltrexone Reduces Ethanol- and/or Water-Reinforced Responding in Rhesus Monkeys: Effect Depends Upon Ethanol Concentration
The opioid antagonist naltrexone reduces responding for ethanol. If naltrexone produces this effect by blocking ethanol-induced opioid activity, then naltrexone should reduce responding for ethanol regardless of level of the ethanol responding relative to an alternatively available reinforcer. In addition, if naltrexone competitively blocks ethanol-induced opioid activity, then the naltrexone effect may be surmountable by increasing ethanol concentration and, thus, ethanol intake (g/kg). This study was conducted to determine whether naltrexone will selectively reduce ethanol-reinforced responding when the ethanol concentration is varied such that ethanol fluid deliveries are less than, greater than, or equal to the fluid deliveries of concurrently available water. Methods : Four adult male rhesus monkeys were allowed to respond for ethanol or water concurrently for 2 hr per day. Ethanol concentration was either 2%, 8%, or 32%. On various days, either saline or naltrexone (0.1 mg/kg) was given intramuscularly 30 min before the drinking session. Results : When ethanol fluid deliveries were greater than those of water (at 2% ethanol), naltrexone reduced responding for ethanol. When the ethanol and water fluid deliveries were approximately equal (at 8% ethanol), naltrexone reduced both ethanol and water fluid deliveries. When water fluid deliveries were greater than those of ethanol (at 32% ethanol), naltrexone reduced responding for water. Conclusions : Thus, naltrexone reduced responding for the preferred fluid, either ethanol or water, depending on ethanol concentration. The effect was not surmountable by increasing ethanol concentration and, therefore, ethanol intake (g/kg). Naltrexone may reduce ethanol-reinforced responding by a mechanism other than that of blocking ethanol-induced opioid activity. Naltrexone may be inducing an aversive interoceptive state.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66374/1/j.1530-0277.1999.tb04668.x.pd
Noncontingent and Response-Contingent Intravenous Ethanol Attenuates the Effect of Naltrexone on Hypothalamic-Pituitary-Adrenal Activity in Rhesus Monkeys
Background : The mechanism by which the opioid antagonist naltrexone suppresses overconsumption of ethanol is unclear. Oral ethanol consumption in humans increases hypothalamic-pituitary-adrenal (HPA) activity, and recent studies suggest that naltrexone may reduce ethanol consumption by modifying the HPA-stimulating effects of ethanol. The purpose of this study was to measure in rhesus monkeys the effects of ethanol and naltrexone, alone and in combination, on plasma levels of adrenocorticotropin hormone (ACTH). Methods : Nine adult male and female rhesus monkeys with chronic, indwelling intravenous catheters were maintained on tethers that allowed ethanol delivery and blood sampling. In one study, the monkeys received intramuscular injections of saline or 0.32 mg/kg naltrexone followed by noncontingent intravenous bolus infusions of saline or 0.3 to 1.8 g/kg ethanol. In a second study, other monkeys were given intramuscular injections of saline or 0.01 to 0.3 mg/kg naltrexone and subsequently responded on levers to receive intravenous saline or ethanol 0.03 g/kg per injection. Results : Ethanol, delivered either response contingently or noncontingently, did not produce systematic changes in ACTH plasma levels. Naltrexone alone produced increases in plasma ACTH that were attenuated by the subsequent administration of noncontingent or response-contingent ethanol. Naltrexone also produced dose-dependent reductions in intravenous ethanol self-administration. Linear regression analysis indicated that ethanol intake was negatively correlated with the plasma levels of ACTH over time. Conclusions : The route of administration may modulate ethanol's effects on HPA activity. Ethanol may attenuate naltrexone's effect on the HPA axis by impairing HPA axis sensitivity to other stimuli. The negative correlation between ethanol intake and ACTH levels supports the notion that naltrexone's effect of increasing HPA axis activity may be related to its ability to suppress ethanol consumption.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66078/1/01.ALC.0000121655.48922.C4.pd
Sport scientists in-becoming: from fulfilling one’s potential to finding our way along
It is common to encourage people to envision life as a process of fulfilling their potential. But what exactly does this mean? Traditionally, this question has been addressed by way of ‘complementarity’; dividing the human into biological and cultural components. Fulfilment is placed on the side of the cultural; an acquisition of encoded secondary information transmitted from predecessors that represents what it means ‘to know’. Potential has been defined from the biological, as a suite of innate capacities localised to the mind and body, passed on through a mechanism of genetic inheritance. Founded upon a metaphor of inter-generational transmission, this perspective leads to a conceptualisation of life as a progressive closure, ‘filling up’ the biologically innate with the culturally acquired. However, despite its prominence, this static view leads to a troubling question: with one’s potential fulfilled, where is one to go next? In this theoretical commentary, we offer an alternate, dynamical account of potential and fulfilment by leaning on Ingold’s notion of wayfaring. From this perspective, life is not a process of being ‘filled up’ with secondary information, but of responsively ‘opening up’; corresponding with varied experiences cast forward by others, as they to ours, situated within a continually unfolding field of relations. Ontologically, this view is of ‘us’, not as beings, but becomings, finding our way along generative paths inhabited alongside others. Knowledge is not transmitted inter-generationally, but is grown by primarily experiencing the coming-into-being of things we enter into correspondence with. Initiated through a prologue, these ideas are exemplified in sharing our storied journey as sport scientists in-becoming, following not objects of convention, but corresponding with things of curiosity
Sport Practitioners as Sport Ecology Designers: How Ecological Dynamics Has Progressively Changed Perceptions of Skill "Acquisition" in the Sporting Habitat
Over two decades ago, Davids et al. (1994) and Handford et al. (1997) raised theoretical concerns associated with traditional, reductionist, and mechanistic perspectives of movement coordination and skill acquisition for sport scientists interested in practical applications for training designs. These seminal papers advocated an emerging consciousness grounded in an ecological approach, signaling the need for sports practitioners to appreciate the constraints-led, deeply entangled, and non-linear reciprocity between the organism (performer), task, and environment subsystems. Over two decades later, the areas of skill acquisition, practice and training design, performance analysis and preparation, and talent development in sport science have never been so vibrant in terms of theoretical modeling, knowledge generation and innovation, and technological deployment. Viewed at an ecological level of analysis, the work of sports practitioners has progressively transitioned toward the facilitation of an evolving relationship between an organism (athlete and team) and its environment (sports competition). This commentary sets out to explore how these original ideas from Davids et al. (1994) and Handford et al. (1997) have been advanced through the theoretical lens of ecological dynamics. Concurrently, we provide case study exemplars, from applied practice in high-performance sports organizations, to illustrate how these contemporary perspectives are shaping the work of sports practitioners (sport ecology designers) in practice and in performance preparation
On ecological literacy through implicated participation
Philosopher-activist Heather Menzies advocates for an approach to ecological literacy that goes beyond knowing about the interconnected goings on of the world from afar by foregrounding the import of relating with a locale through prolonged periods of implicated participation. Here, we offer further insight to these views across three sections. First, following a brief excursus, we show how Menzies' views of implicated participation focus less on the explication of facts about the world, more as enabling us to be taught by its goings on. It is, in other words, to study with and learn from the beings and things which surround us. Second, we incorporate Menzies' views with the ecological approach to psychology, drawing specifically on the concept of affordance. This helps us take up with the practical challenge of fostering Menzies' views in places tightened by privatisation, commodification and homogenisation: factors over-constraining the ways people can engage with the affordances of a locale. Thus, section three leans on key ideas from Karen Franck and Quentin Stevens to reposition ‘leftover spaces’ as arenas for ecological literacy: thrivingly loose ecologies enriched with affordances determined over varying timescales of implicated participation. To think with these ideas, two cases are presented
On finding one's way: a comment on Bock et al. (2024).
In a recent issue of Psychological Research, Bock, O., Huang, J-Y., Onur, O. A., & Memmert, D. (2024). The structure of cognitive strategies for wayfinding decisions. Psychological Research Psychologische Forschung, 88, 476-486. https://doi.org/10.1007/s00426-023-01863-3 .) investigated cognitive strategies purported to guide wayfinding decisions at intersections. Following experimentation in a virtualised maze, it was concluded that intersectional wayfinding decisions were based on a 'generalized cognitive process', in addition to 'strategy-specific' processes. The aim of our comment is not to challenge these findings or their methodological rigour. Rather, we note how the study of human wayfinding has been undertaken from entirely different metatheoretical perspectives in psychological science. Leaning on the seminal work of James Gibson and Harry Heft, we consider wayfinding as a continuous, integrated perception-action process, distributed across the entire organism-environment system. Such a systems-oriented, ecological approach to wayfinding remediates the organismic asymmetry pervasive to extant theories of human behaviours, foregrounding the possibility for empirical investigation that takes seriously the socio-cultural contexts in which inhabitants dwell
On a Corresponsive Sport Science.
In our societally extractive age, sport science risks being swept up in the intensifying desire to commodify the experiences of those that scientists proclaim to study. Coupled with the techno-digital revolution, this stems from a vertical (onto)logic that frames the sporting landscape as a static space filled with discrete objects waiting for us to capture, analyse, re-present and sell on as knowledge. Not only does this commodification degrade primary experience in the false hope of epistemological objectivity, it reinforces the unidirectionality of extractivism by setting inquirer apart from, and above of, inquiry. Here, we advocate for a different, more sentient logic grounded in the relationality of gifting as understood in indigenous philosophies. This foregrounds an ecological orientation to scholarship that sets out neither to objectify or describe that which is of concern, but to correspond with its becoming. On this, there are three threads we cast forward. First, in a corresponsive sport science, inhabitants are not objects of analysis, but lines in-becoming, who in answering to others, form knots in a meshwork. These knots constitute communal places in which inhabitants have joined with the differentiating coming-into-being of others. Second, knowledge is not authoritatively (re)cognitive, but humbly ecological; not produced vertically through imposition, but grown longitudinally in responsively moving from place to place. Third, research does not follow a vertically extractive (onto)logic, but is a practice of participant observation. This perspective appreciates that we, sport scientists, are also lines in-becoming that form parts of the knots in which we seek to know. In coda, our thesis is not a call for more qualitative or applied research in the sport sciences. It is a call to response-ably open up to that which sparks our curiosity, answering to what is shared with care, sensitivity and sincerity
Towards a contemporary player learning in development framework for sports practitioners
As it is appreciated that learning is a non-linear process – implying that coaching methodologies in sport should be accommodative – it is reasonable to suggest that player development pathways should also account for this non-linearity. A constraints-led approach (CLA), predicated on the theory of ecological dynamics, has been suggested as a viable framework for capturing the non-linearity of learning, development and performance in sport. The CLA articulates how skills emerge through the interaction of different constraints (task-environment-performer). However, despite its well-established theoretical roots, there are challenges to implementing it in practice. Accordingly, to help practitioners navigate such challenges, this paper proposes a user-friendly framework that demonstrates the benefits of a CLA. Specifically, to conceptualize the non-linear and individualized nature of learning, and how it can inform player development, we apply Adolph’s notion of learning IN development to explain the fundamental ideas of a CLA. We then exemplify a learning IN development framework, based on a CLA, brought to life in a high-level youth football organization. We contend that this framework can provide a novel approach for presenting the key ideas of a CLA and its powerful pedagogic concepts to practitioners at all levels, informing coach education programs, player development frameworks and learning environment designs in sport
Destabilizing effects of visual environment motions simulating eye movements or head movements
In the present paper, we explore effects on the human of exposure to a visual virtual environment which has been enslaved to simulate the human user's head movements or eye movements. Specifically, we have studied the capacity of our experimental subjects to maintain stable spatial orientation in the context of moving their entire visible surroundings by using the parameters of the subjects' natural movements. Our index of the subjects' spatial orientation was the extent of involuntary sways of the body while attempting to stand still, as measured by translations and rotations of the head. We also observed, informally, their symptoms of motion sickness
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