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- All Subjects: Behavioral psychology
- Creators: Wynne, Clive
Description
Theories of interval timing have largely focused on accounting for the aggregate properties of behavior engendered by periodic reinforcement, such as sigmoidal psychophysical functions and their scalar property. Many theories of timing also stipulate that timing and motivation are inseparable processes. Such a claim is challenged by fluctuations in and out of states of schedule control, making it unclear whether motivation directly affects states related to timing. The present paper seeks to advance our understanding of timing performance by analyzing and comparing the distribution of latencies and inter-response times (IRTs) of rats in two fixed-interval (FI) schedules of food reinforcement (FI 30-s and FI 90-s), and in two levels of food deprivation. Computational modeling revealed that each component was well described by mixture probability distributions embodying two-state Markov chains. Analysis of these models revealed that only a subset of latencies are sensitive to the periodicity of reinforcement, and pre-feeding only reduces the size of this subset. The distribution of IRTs suggests that behavior in FI schedules is organized in bouts that lengthen and ramp up in frequency with proximity to reinforcement. Pre-feeding slowed down the lengthening of bouts and increased the time between bouts. When concatenated, these models adequately reproduced sigmoidal FI response functions. These findings suggest that behavior in FI fluctuates in and out of schedule control; an account of such fluctuation suggests that timing and motivation are dissociable components of FI performance. These mixture-distribution models also provide novel insights on the motivational, associative, and timing processes expressed in FI performance, which need to be accounted for by causal theories of interval timing.
ContributorsDaniels, Carter W (Author) / Sanabria, Federico (Thesis advisor) / Brewer, Gene (Committee member) / Wynne, Clive (Committee member) / Arizona State University (Publisher)
Created2015
Description
The present series of studies examined whether a novel implementation of an
intermittent restraint (IR) chronic stress paradigm could be used to investigate hippocampal-dependent spatial ability in both sexes. In experiments 1 and 2, Sprague- Dawley male rats were used to identify the optimal IR parameters to assess spatial ability. For IR, rats were restrained for 2 or 6hrs/day (IR2, IR6, respectively) for five days and then given two days off, a process that was repeated for three weeks and compared to rats restrained for 6hrs/d for each day (DR6) and non-stressed controls (CON). Spatial memory was tested on the radial arm water maze (RAWM), object placement (OP), novel object recognition (NOR) and Y-maze. The results for the first two experiments revealed that IR6, but not IR2, was effective in impairing spatial memory in male rats and that task order impacted performance. In experiment 3, an extended IR paradigm for six weeks was implemented before spatial memory testing commenced in male and female rats (IR- M, IR-F). Unexpectedly, an extended IR paradigm failed to impair spatial memory in either males or females, suggesting that when extended, the IR paradigm may have become predictable. In experiment 4, an unpredictable IR (UIR) paradigm was implemented, in which restraint duration (30 or 60-min) combined with orbital shaking, time of day, and the days off from UIR were varied. UIR impaired spatial memory in males, but not females. Together with other reports, these findings support the interpretation that chronic stress negatively impairs hippocampal-dependent function in males, but not females, and that females appear to be resilient to spatial memory deficits in the face of chronic stress.
intermittent restraint (IR) chronic stress paradigm could be used to investigate hippocampal-dependent spatial ability in both sexes. In experiments 1 and 2, Sprague- Dawley male rats were used to identify the optimal IR parameters to assess spatial ability. For IR, rats were restrained for 2 or 6hrs/day (IR2, IR6, respectively) for five days and then given two days off, a process that was repeated for three weeks and compared to rats restrained for 6hrs/d for each day (DR6) and non-stressed controls (CON). Spatial memory was tested on the radial arm water maze (RAWM), object placement (OP), novel object recognition (NOR) and Y-maze. The results for the first two experiments revealed that IR6, but not IR2, was effective in impairing spatial memory in male rats and that task order impacted performance. In experiment 3, an extended IR paradigm for six weeks was implemented before spatial memory testing commenced in male and female rats (IR- M, IR-F). Unexpectedly, an extended IR paradigm failed to impair spatial memory in either males or females, suggesting that when extended, the IR paradigm may have become predictable. In experiment 4, an unpredictable IR (UIR) paradigm was implemented, in which restraint duration (30 or 60-min) combined with orbital shaking, time of day, and the days off from UIR were varied. UIR impaired spatial memory in males, but not females. Together with other reports, these findings support the interpretation that chronic stress negatively impairs hippocampal-dependent function in males, but not females, and that females appear to be resilient to spatial memory deficits in the face of chronic stress.
ContributorsPeay, Dylan (Author) / Conrad, Cheryl D. (Thesis advisor) / Bimonte-Nelson, Heather A. (Committee member) / Wynne, Clive (Committee member) / Arizona State University (Publisher)
Created2019
Description
Loss aversion manifests as a decision bias in which avoiding losses is preferred over acquiring rewards and can drastically alter an individual’s decision-making by overweighting potential losses relative to gains of equal magnitude. Consequently, individuals may require greater positive compensation to offset potential losses, exhibit contradictory choice preferences, or even avoid the decision entirely; and this behavior may be ascribed to an over-reliance on automatic, unconscious (intuitive) judgments rather than initiating analytic reasoning more capable of objectively evaluating outcomes.
Religion (specifically Christianity) is the topic of focus, as preliminary evidence suggests an individual’s intuitive inclinations positively correlate with and predict religious beliefs. Moreover, self-reported religious beliefs significantly differed as a function of inducing either intuitive or reflective mindsets. Therefore, the purpose of this experiment was to test the hypothesis that religious participants will display significantly greater levels of loss aversion than nonreligious participants.
This hypothesis extends from a previous study relating large-scale cultural and religious differences with loss aversion. While their results revealed religious orthodoxy strongly influenced loss aversion, the parameters elicited may be less stable as only two lottery questions were asked and religion was determined by cultural demographics. This study used the same design, but with a total of ten lotteries and a more detailed investigation into individual religious factors.
While loss aversion coefficients replicated the overall behavioral effect (Median θ = 2.6), independent sample, Mann-Whitney U tests did not yield any significant differences between Christian and Nonreligious participants (p > 0.05); nor did any of the religious factors examined account for a significant amount of variability.
This study attempted to add to current knowledge by further conflating the relationship between religiosity and adaptive decision strategies susceptible to errant and inconsistent behavior. While the hypotheses were unsupported, a null finding is still important, and future research re-testing this association or introducing causational designs may prove more fruitful in understanding these complex relationships.
Religion (specifically Christianity) is the topic of focus, as preliminary evidence suggests an individual’s intuitive inclinations positively correlate with and predict religious beliefs. Moreover, self-reported religious beliefs significantly differed as a function of inducing either intuitive or reflective mindsets. Therefore, the purpose of this experiment was to test the hypothesis that religious participants will display significantly greater levels of loss aversion than nonreligious participants.
This hypothesis extends from a previous study relating large-scale cultural and religious differences with loss aversion. While their results revealed religious orthodoxy strongly influenced loss aversion, the parameters elicited may be less stable as only two lottery questions were asked and religion was determined by cultural demographics. This study used the same design, but with a total of ten lotteries and a more detailed investigation into individual religious factors.
While loss aversion coefficients replicated the overall behavioral effect (Median θ = 2.6), independent sample, Mann-Whitney U tests did not yield any significant differences between Christian and Nonreligious participants (p > 0.05); nor did any of the religious factors examined account for a significant amount of variability.
This study attempted to add to current knowledge by further conflating the relationship between religiosity and adaptive decision strategies susceptible to errant and inconsistent behavior. While the hypotheses were unsupported, a null finding is still important, and future research re-testing this association or introducing causational designs may prove more fruitful in understanding these complex relationships.
ContributorsHowatt, Brian (Author) / Robles-Sotelo, Elias (Thesis advisor) / Vargas, Perla (Committee member) / Neal, Tess (Committee member) / Arizona State University (Publisher)
Created2017
Description
A handheld metal noisemaker known as a “clicker” is widely used to train new behaviors in dogs; however, evidence for the superior efficacy of clickers as opposed to providing solely primary reinforcement or other secondary reinforcers in the acquisition of novel behavior in dogs is almost entirely anecdotal. Three experiments were conducted to determine under what circumstances a clicker may result in acquisition of a novel behavior more rapidly or to a higher level compared to other readily available reinforcement methods. In Experiment 1, three groups of 30 dogs each were trained to emit a novel sit and stay behavior of increasing duration with either the delivery of food alone, a verbal stimulus paired with food, or a clicker with food. The group that received only a primary reinforcer reached a significantly higher criterion of training success than the group trained with a verbal secondary reinforcer. Performance of the group experiencing a clicker secondary reinforcer was intermediate between the other two groups, but not significantly different from either. In Experiment 2, three different groups of 25 dogs each were shaped to emit a nose targeting behavior and then perform that behavior at increasing distances from the experimenter using the same three methods of positive reinforcement as in Experiment 1. No statistically significant differences between the groups were found. In Experiment 3, three groups of 30 dogs each were shaped to emit a nose-targeting behavior upon an array of wooden blocks with task difficulty increasing throughout testing using the same three methods of positive reinforcement as previously. No statistically significant differences between the groups were found. Overall, the findings suggest that both clickers and other forms of positive reinforcement can be used successfully in training a dog to perform a novel behavior, but that no positive reinforcement method has significantly greater efficacy than any other.
ContributorsGilchrist, Rachel (Author) / Wynne, Clive (Thesis advisor) / Hahs, Adam (Committee member) / Anderson, Samantha (Committee member) / Arizona State University (Publisher)
Created2020