A Computational Theory of Subjective Probability

In this article we demonstrate how algorithmic probability theory is applied to situations that involve uncertainty. When people are unsure of their model of reality, then the outcome they observe will cause them to update their beliefs. We argue that classical probability cannot be applied in such cases, and that subjective probability must instead be used. In Experiment 1 we show that, when judging the probability of lottery number sequences, people apply subjective rather than classical probability. In Experiment 2 we examine the conjunction fallacy and demonstrate that the materials used by Tversky and Kahneman (1983) involve model uncertainty. We then provide a formal mathematical proof that, for every uncertain model, there exists a conjunction of outcomes which is more subjectively probable than either of its constituents in isolation.Comment: Maguire, P., Moser, P. Maguire, R. & Keane, M.T. (2013) "A computational theory of subjective probability." In M. Knauff, M. Pauen, N. Sebanz, & I. Wachsmuth (Eds.), Proceedings of the 35th Annual Conference of the Cognitive Science Society (pp. 960-965). Austin, TX: Cognitive Science Societ

Evidence of Muddy Knowledge in Reaching for the Stars: Creating Novel Endings for Event Sequences

This experiment examines people’s ability to invent creative outcomes to simple event sequences. We report a study where participants are given everyday event descriptions and asked to describe either a predictable outcome (Predictable group) or a creative outcome (Creative group). Following the Creative Cognition approach (Finke, Ward & Smith, 1992), we expected that though those instructed to be creative might generate novel and interesting outcomes, they would also be bound by their knowledge of the outcomes that typically occur. The results support this prediction, in that while the Creative group manifested more inventive variability in their outcomes relative to the Predictable group, their proposed outcomes still overlapped in part with those of the Predictable group. These results show that although creativity may take people beyond their knowledge, they can never fully break free from that knowledge

Understanding Surprise: Can Less Likely Events Be Less Surprising?

Surprise is often thought of as an experience that is elicited following an unexpected event. However, it may also be the case that surprise stems from an event that is simply difficult to explain. In this paper, we investigate the latter view. Specifically, we question why the provision of an enabling factor can mitigate perceived surprise for an unexpected event despite lowering the overall probability of that event. One possibility is that surprise occurs when a person cannot rationalise an outcome event in the context of the scenario representation. A second possibility is that people can generate plausible explanations for unexpected events but that surprise is experienced when those explanations are uncertain. We explored these hypotheses in an experiment where a first group of participants rated surprise for a number of scenario outcomes and a second group rated surprise after generating a plausible explanation for those outcomes. Finally, a third group of participants rated surprise for the both the original outcomes and the reasons generated for those outcomes by the second group. Our results suggest that people can come up with plausible explanations for unexpected events but that surprise results when these explanations are uncertain

A Cognitive Model of Surprise Judgements

In this paper we outline a cognitive theory and model of surprise judgements which aims to explain how and why some events are considered to be surprising in a piece of text , while others are not. The model is based on a series of experiments carried out by Grimes-Maguire and Keane (2005a), which show that subtle changes in the predictability of a discourse can have a profound effect on a reader’s perceived surprise at certain events. Rather than defining surprise in terms of expectation, we conceive of it as a process involving Representation-Fit. We have implemented this theory in a computational model that has two stages: the Integration stage entails building a coherent representation of the scenario by means of an objective knowledge base rooted in WordNet. The Analysis stage then outputs a surprise rating for a specified event, based on the degree to which that event can be supported by the prior representation. Simulations reveal a strong correspondence between model and participant generated surprise ratings

Understanding Surprise: Can Less Likely Events Be Less Surprising?

Surprise is often thought of as an experience that is elicited following an unexpected event. However, it may also be the case that surprise stems from an event that is simply difficult to explain. In this paper, we investigate the latter view. Specifically, we question why the provision of an enabling factor can mitigate perceived surprise for an unexpected event despite lowering the overall probability of that event. One possibility is that surprise occurs when a person cannot rationalise an outcome event in the context of the scenario representation. A second possibility is that people can generate plausible explanations for unexpected events but that surprise is experienced when those explanations are uncertain. We explored these hypotheses in an experiment where a first group of participants rated surprise for a number of scenario outcomes and a second group rated surprise after generating a plausible explanation for those outcomes. Finally, a third group of participants rated surprise for the both the original outcomes and the reasons generated for those outcomes by the second group. Our results suggest that people can come up with plausible explanations for unexpected events but that surprise results when these explanations are uncertain

Tart cherry supplementation and recovery from strenuous exercise: a systematic review and meta-analysis: Tart cherry juice and recovery

The aim of this study was to determine the efficacy of tart cherry (TC) supplementation on recovery following strenuous exercise. A systematic review and meta-analysis were conducted using studies investigating TC supplementation on measures of muscle soreness, muscular strength, muscular power, creatine kinase, C-reactive protein, Interleukin-6, and tumor necrosis factor alpha. A literature search ending in July 2020 was conducted in three databases (SPORTDiscus, Web of Science, and PubMed). Data from 14 studies were extracted and pooled for analysis. Tart cherry supplementation had a small beneficial effect in reducing muscle soreness (effect size [ES] = −0.44, 95% confidence interval [CI] [−0.87, −0.02]). A moderate beneficial effect was observed for recovery of muscular strength (ES = −0.78, 95% CI [−1.11, −0.46]). A moderate effect was observed for muscular power (ES = −0.53, 95% CI [−0.77, −0.29]); a further subgroup analysis on this variable indicated a large effect of TC supplementation on recovery of jump height (ES = −0.82, 95% CI [−1.18, −0.45]) and a small significant effect of supplementation on sprint time (ES = −0.32, 95% CI [−0.60, −0.04]). A small effect was observed for both C-reactive protein (ES = −0.46, 95% CI [−0.93, −0.00]) and Interleukin-6 (ES = −0.35, 95% CI [−0.68, −0.02]. No significant effects were observed for creatine kinase and tumor necrosis factor alpha. These results indicate that the consumption of a TC supplement can aid aspects of recovery from strenuous exercise

2016 Ruby Yearbook

A digitized copy of the 2016 Ruby, the Ursinus College yearbook.https://digitalcommons.ursinus.edu/ruby/1120/thumbnail.jp

On the horns of a dilemma: Key factors informing train horn use at rail level crossings

Questions are arising as to whether train horn use at level crossings remain beneficial for all types of crossings, environments, and users. Six focus groups were undertaken with experienced train drivers (n = 19) across five rail organisations and three Australian states, with data collected using a scenario-based task. Study findings revealed that train horn utilisation was highly varied, considered beneficial in some situations, but non-beneficial in others. The results suggest that the uses of trains horns need to be carefully unpacked if more clarity in policy and direction in potential alternatives is to be further investigated

Trajectories of internalizing symptoms across childhood: The roles of biological self-regulation and maternal psychopathology

Whether internalizing symptoms increase or remain at similar levels throughout childhood is currently not well understood. Moreover, the association between vagal regulation of cardiac activity and internalizing symptoms across childhood needs to be clarified. We used a multilevel conceptual framework to examine how children's vagal regulation of cardiac activity and mothers' internalizing symptoms were jointly associated with children's developmental trajectories of internalizing symptoms from ages 4 to 10 years old. Data came from 384 children who participated in an ongoing longitudinal study. Children and their mothers came to the research laboratory at ages 4, 5, 7, and 10. Mothers reported their children's and their own internalizing symptoms. Children's vagal regulation of cardiac activity was assessed during quiet baseline tasks and also during challenge tasks. Multilevel models revealed that child internalizing symptoms increased from ages 4 to 10 years old, but only in females, and especially between ages 7 and 10. More vagal withdrawal in response to challenge was associated with more internalizing symptoms, particularly with more somatic symptoms. Associations between children's physiological regulation and internalizing symptoms differed by children's age, sex, and presence of maternal internalizing symptoms. Understanding associations between vagal regulation of cardiac activity and internalizing symptoms during childhood calls for fine-grained developmental analyses that take into account the heterogeneity of internalizing symptoms, and also developmental phase, context, and sex