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- Genre: Masters Thesis
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
In baseball, the difference between a win and loss can come down to a single call, such as when an umpire judges force outs at first base by typically comparing competing auditory and visual inputs of the ball-mitt sound and the foot-on-base sight. Yet, because the speed of sound in air only travels about 1100 feet per second, fans observing from several hundred feet away will receive auditory cues that are delayed a significant portion of a second, and thus conceivably could systematically differ in judgments compared to the nearby umpire. The current research examines two questions. 1. How reliably and with what biases do observers judge the order of visual versus auditory events? 2. Do observers making such order judgments from far away systematically compensate for delays due to the slow speed of sound? It is hypothesized that if any temporal bias occurs it is in the direction consistent with observers not accounting for the sound delay, such that increasing viewing distance will increase the bias to assume the sound occurred later. It was found that nearby observers are relatively accurate at judging if a sound occurred before or after a simple visual event (a flash), but exhibit a systematic bias to favor visual stimuli occurring first (by about 30 msec). In contrast, distant observers did not compensate for the delay of the speed of sound such that they systematically favored the visual cue occurring earlier as a function of viewing distance. When observers judged simple visual stimuli in motion relative to the same sound burst, the distance effect occurred as a function of the visual clarity of the ball arriving. In the baseball setting, using a large screen projection of baserunner, a diminished distance effect occurred due to the additional visual cues. In summary, observers generally do not account for the delay of sound due to distance.
ContributorsKrynen, R. Chandler (Author) / McBeath, Michael (Thesis advisor) / Homa, Donald (Committee member) / Gray, Robert (Committee member) / Arizona State University (Publisher)
Created2017
Description
In a trial, jurors are asked to set aside their emotions and make judgments based solely on evidence. Research suggests jurors are not always capable of this, particularly when exposed to gruesome photographic evidence. However, previous research has not looked at the potentially moderating effect of when and for how long jurors are exposed to emotionally disturbing photographs, nor how many photographs they see. In two experiments I tested the impact of the timing of and extent of exposure to gruesome photographs on jurors’ emotions, verdicts, and punishment recommendations. In Study 1, I investigated the effect of timing and exposure duration to a single gruesome photograph of a victim in a murder case (no exposure, brief early exposure, brief late exposure, and prolonged exposure) on mock jurors’ emotions and case judgments. Prolonged exposure (relative to no or brief exposure, regardless of timing) increased disgust, which in turn was associated with harsher punishment. Contrary to previous research, the photograph manipulation did not influence verdicts. The results were mixed and inconclusive regarding brief early versus late exposure. In Study 2, I compared repeatedly viewing a single gruesome photograph to viewing a set of four similar, but unique gruesome photographs—holding the exposure time constant—to assess the impact of quantity of photos on jurors’ emotions and case judgments. Viewing multiple gruesome photos (relative to no photos) led to increase in guilty verdicts through increased disgust, replicating previous research. Viewing a single gruesome photo (relative to no photo) led to increase in guilty verdicts through disgust, differing from Study 1 findings. Viewing multiple gruesome photos and a single gruesome photo led to more disgust, compared to viewing no photo. However, differing from Study 1, gruesome photographs did not lead to an increase in punishment recommendations. There were no significant differences between exposure to a single or multiple gruesome photos on disgust, verdicts, or punishments. Overall, greater exposure to gruesome evidence led to increased disgust and punitiveness, relative to those with less exposure. However, jurors with greater exposure to the same or different photographs did not differ in reported emotions, verdicts, or punitiveness.
ContributorsBean, Samantha Rae (Author) / Salerno, Jessica M (Thesis advisor) / Schweitzer, Nicholas (Committee member) / Duran, Nicholas (Committee member) / Arizona State University (Publisher)
Created2020