Effects of pre-operant running and sucrose concentration on operant wheel running on a fixed interval schedule of reinforcement

Prior research proposed that temporal control over the pattern of operant wheel running on a fixed interval (FI) schedule of sucrose reinforcement is a function of automatic reinforcement generated by wheel running and the experimentally arranged sucrose reinforcement. Two experiments were conducted to assess this prediction. In the first experiment, rats ran for different durations (0, 30, 60, and 180 min) prior to a session of operant wheel running on a FI 120-s schedule. In the second experiment, the concentration of sucrose reinforcement on a FI 180-s schedule was varied across values of 0, 5, 15, and 25%. In Experiment 1, as the duration of pre-operant running increased, the postreinforcement pause before initiation of running lengthened while wheel revolutions in the latter part of the FI interval increased. In Experiment 2, wheel revolutions markedly increased then decreased to a plateau early in the FI interval. Neither manipulation increased temporal control of the pattern of wheel running. Instead, results indicate that operant wheel running is regulated by automatic reinforcement generated by wheel activity and an adjunctive pattern of running induced by the temporal presentation of sucrose. Furthermore, the findings question whether the sucrose contingency regulates wheel running as a reinforcing consequence.     

Judgments of happiness during trail running: Pleasure,engagement, and meaning

ObjectivesIt has been theorized that happiness is derived from three major, unique sets of life experience: pleasure, engagement, and meaning. The present study examined the mental processes by which individuals combined five information cues (relatedness, autonomy, competence, mental vitality and physical vitality) when judging the degree of happiness felt by a trail runner during a run.Design/methodThe participants (104 adult male athletes; M_age = 32.70; SD = 10.86) rated pleasure, engagement, and meaning in 32 scenarios built from combinations of these cues.ResultsThe results of multivariate and univariate analyses of variance indicated that all five cues had a positive effect on judgments of pleasure, engagement, and meaning. The participants used three different information integration rules, depending on the pathway to happiness being probed.ConclusionsThe information integration and the integration rules highlighted the different contributions of pleasure, engagement, and meaning in cognitive building of happiness.     

Between the Horns: A Dilemma in the Interpretation of the Running of the Bulls–Part 2: The Evasion

This second part of the essay deals with the horns of the dilemma at the conceptual level and ‘on the street’. The first part ended with that quandary where a deep understanding was precluded no matter which way one turned, whether an inadequate comprehension based on individual and partial notions, a perplexing pluralist path or a relinquishment of the hermeneutic enterprise altogether. The philosophical solution of existential overtones presently put forward deftly avoids the sharp ends of the predicament by means of a three-tiered phenomenological analysis of the event. First, death is considered via Heidegger's and Sartre's existential examination; next, risk and related concepts, such as fear, are scrutinised; and third, Nietzsche's and Ortega y Gasset's life-affirming views lead us to the liberating conclusion: facing danger and death are means to an enhanced and joyful experience of life. As in the first part, this one also presents several photographs that complement the text at different levels. Once several objections are disposed of, readers are left with a philosophical elucidation of a sense of joy predicated on the ability to face daring challenges willingly undertaken for the fun of it.     

Between the Horns: A Dilemma in the Interpretation of the Running of the Bulls – Part 1: The Confrontation

The essay, divided in two parts, examines the event of the running of the bulls (encierro in Spanish). The phenomenon of the encierro, a complex cultural activity of deep historical roots, demands to be understood: What drives people to risk injury or death at the horns of untamed bulls? How should we make sense of this, subjective and objectively? To answer these questions, I use a framework that relies on explanation and assessment of popular views on the way to arguing for a philosophical alternative. This arrangement is readily adaptable to many other sporting (and non-sporting) activities where risk and/or mass participation are key factors. Its unorthodox format – organised around an opening narrative of a paradigmatic, skilled and lucky run with the bulls, as well as hors texte (direct appeals to the reader) – brings the reader straight into the fray, philosophical and otherwise. Part I begins by presenting the history of the encierro. It also explains the dynamics of the event, often via images with pedagogical and critical side-commentaries. It proceeds to introduce and critically engage with prevalent explanations, most with ethnological tendencies, that conceive the running as tradition, rite, ritual and sport. This part ends with a dilemma whereby we either try to explain matters by resorting to particular and partial interpretations, or a ‘democratic’ conglomerate of superficial and confusing boundaries, or in the end we simply concede our inability to understand the phenomenon of the running of the bulls in toto. This philosophical impasse will be evaded in part 2 (Sport, Ethics and Philosophy 2, 1) via existentialist and phenomenological analysis.     

Quantitative studies of reinforcement relativity

Three experiments examined an application of the matching law to the area of reinforcement relativity. In Experiment I, rats ran in a wheel and drank a sucrose solution. Equations derived from the matching law made fairly accurate predictions of the amounts of time spent running and drinking when licks and wheel revolutions had to occur in fixed proportions. In Experiment II, rats were required to spend four times as much time drinking as running, but the absolute durations of the cycles of drinking and running were varied. Except for the shortest cycle size tested, durations were close to those predicted. Experiments III investigated a tendency for obtained durations of running and drinking to be slightly longer than predicted. Simply shortening the periods when these behaviors were available increased their values. It was concluded that the matching law equations provided reasonably accurate predictions in some experiments, but changes in motivation set the limits of such accuracy.     

Effects upon rats' responses on a running wheel of single alternation of large and small rewards and external cues

Thirty-two rats were trained to run on a running wheel for one or six pellets of food, in either single alternation (SA) or quasi-random sequences of reward magnitude and with external cues either informing or not informing the rats of the reward magnitude. Reward-magnitude discrimination was clearly shown when the informative cues were given, but without such cues the SA patterning of responding appeared only late in training. The reward-magnitude discrimination developed most quickly when internal (SA) cues and external informative cues were both present; the effects of these two classes of cues on discrimination were interactive rather than additive. Possible explanations are given for the superior discrimination under the condition where both the internal and external cues were present over the condition when only the external cues were present.     

Running and responding reinforced by the opportunity to run: effect of reinforcer duration.

The present study investigated the effect of reinforcer duration on running and on responding reinforced by the opportunity to run. Eleven male Wistar rats responded on levers for the opportunity to run in a running wheel. Opportunities to run were programmed to occur on a tandem fixed-ratio 1 variable-interval 30-s reinforcement schedule. Reinforcer duration varied across conditions from 30 to 120 s. As reinforcer duration increased, the rates of running and lever pressing declined, and latency to lever press increased. The increase in latency to respond was consistent with findings that unconditioned inhibitory aftereffects of reinforcement increase with reinforcer magnitude. The decrease in local lever-pressing rates, however, was inconsistent with the view that response strength increases with the duration of the reinforcer. Response rate varied inversely, not directly, with reinforcer duration. Furthermore, within-session data challenge satiation, fatigue, and response deprivation as determinants of the observed changes in running and responding. In sum, the results point to the need for further research with nonappetitive forms of reinforcement.     

The currency of procurement cost

As the number of instrtumental responses required to procure access to food is increased, animals decrease the frequency of initiating meals and increase meal size, conserving total intake while limiting the increase in the overall cost of feeding. In two studies, one using wheel turns and one using bar presses as the instrumental response, we asked whether freely feeding laboratory rats measure cost according to the energy or the time they expend. In each study we varied both the price (i.e., number of wheel turns or bar presses) and the force required to make a response (i.e., torque on the wheel or weight of the bar). Price affected both procurement time (from the first to the last procurement response) and procurement work, whereas torque and bar weight affected work without altering time in most cases. Meal patterns were altered by all manipulations of price, but changes in torque and bar weight had little effect on meal patterns, except in the conditions in which they altered procurement time. These results suggest that time is a critical currency of procurement cost in rats.     

Effects of cocaine on fixed-interval responding reinforced by the opportunity to run

Rate-dependent drug effects have been observed for operant responding maintained by food, water, heat, light onset, electrical brain stimulation, shock-stimulus termination, and shock presentation. The present study sought to determine if the effects of cocaine on lever pressing maintained by the opportunity to run could also be described as rate dependent. Seven male Wistar rats were trained to respond on levers for the opportunity to run in a wheel. The schedule of reinforcement was fixed-interval 60 s, and the reinforcing consequence was the opportunity to run for 60 s. On this schedule, overall rates of responding were low, usually below six presses per minute, and pauses frequently exceeded the 60-s interval. Despite these differences, an overall scalloped pattern of lever pressing was evident for each rat. Doses of 1, 2, 4, 8, and 16 mg/kg cocaine were administered 10 min prior to a session. Only at the 16 mg/kg dose did the responding of the majority of rats change in a manner suggestive of a rate-dependent drug effect. Specifically, lower response rates at the beginning of the intervals increased and higher rates at the end of the intervals decreased, as indicated by the fact that slopes from the regression of drug rates on control rates decreased. These data provide tentative support for the generalization of rate-dependent effects to operant responding maintained by wheel running. Differences in the baseline performance maintained by wheel running compared to those for food and water point to the need for further experimentation before this effect can be firmly established.