Experience-Expectant Plasticity in the Mushroom Bodies of the Honeybee

Worker honeybees (Apis mellifera) were reared in social isolation in complete darkness to assess the effects of experience on growth of the neuropil of the mushroom bodies (MBs) during adult life. Comparison of the volume of the MBs of 1-day-old and 7-day-old bees showed that a significant increase in volume in the MB neuropil occurred during the first week of life in bees reared under these highly deprived conditions. All regions of the MB neuropil experienced a significant increase in volume with the exception of the basal ring. Measurement of titers of juvenile hormone (JH) in a subset of bees indicated that, as in previous studies, these rearing conditions induced in some bees the endocrine state of high JH associated with foraging, but there was no correlation between JH titer and volume of MB neuropil. Treatment of another subset of dark-reared bees with the JH analog, methoprene, also had no effect of the growth of the MB neuropil. These results demonstrate that there is a phase of MB neuropil growth early in the adult life of bees that occurs independent of light or any form of social interaction. Together with previous findings showing that an increase in MB neuropil volume begins around the time that orientation flights occur and then continues throughout the phase of life devoted to foraging, these results suggest that growth of the MB neuropil in adult bees may have both experience-expectant and experience-dependent components.     

Extending the argument from unconceived alternatives: observations,models, predictions,explanations, methods,instruments, experiments,and values

Synthese - Stanford’s argument against scientific realism focuses on theories, just as many earlier arguments from inconceivability have. However, there are possible arguments against...     

Challenges and Gifts of Teaching Luther in a Lutheran College1

This article examines what can be learned from teaching Luther to American college students. It reviews several ways in which college students benefit from studying Luther. The article suggests that identifying the “operating principles” in Luther's thought can help students more carefully discern the contemporary significance of his thought. After discussing some challenges encountered when teaching Luther to college students, the article ends with reflections on the theological significance of the college context. While Luther's discovery of a gracious God remains central, the college setting promotes a retrieval of several broader themes in Luther's thinking that have often been neglected by Lutherans: ongoing creation, wisdom, the Bible as “torah,” the suffering of God, and societal reform.     

The Insufficiency of the Dutch Book Argument

It is a common view that the axioms of probability can be derived from the following assumptions: (a) probabilities reflect (rational) degrees of belief, (b) degrees of belief can be measured as betting quotients; and (c) a rational agent must select betting quotients that are coherent. In this paper, I argue that a consideration of reasonable betting behaviour, with respect to the alleged derivation of the first axiom of probability, suggests that (b) and (c) are incorrect. In particular, I show how a rational agent might assign a ‘probability’ of zero to an event which she is sure will occur.     

Bertrand's Paradox and the Maximum Entropy Principle

An important suggestion of objective Bayesians is that the maximum entropy principle can replace a principle which is known to get into paradoxical difficulties: the principle of indifference. No one has previously determined whether the maximum entropy principle is better able to solve Bertrand's chord paradox than the principle of indifference. In this paper I show that it is not. Additionally, the course of the analysis brings to light a new paradox, a revenge paradox of the chords, that is unique to the maximum entropy principle.     

Group Level Interpretations of Probability: New Directions

In this article, I present some new group level interpretations of probability, and champion one in particular: a consensus‐based variant where group degrees of belief are construed as agreed upon betting quotients rather than shared personal degrees of belief. One notable feature of the account is that it allows us to treat consensus between experts on some matter as being on the union of their relevant background information. In the course of the discussion, I also introduce a novel distinction between intersubjective and interobjective interpretations of probability.     

Ostracism Reduces Reliance on Poor Advice from Others during Decision Making

Decision making is rarely context‐free, and often, both social information and non‐social information are weighed into one's decisions. Incorporating information into a decision can be influenced by previous experiences. Ostracism has extensive effects, including taxing cognitive resources and increasing social monitoring. In decision making situations, individuals are often faced with both objective and social information and must choose which information to include or filter out. How will ostracism affect the reliance on objective and social information during decision making? Participants (N = 245) in Experiment 1 were randomly assigned to be included or ostracized in a standardized, group task. They then performed a dynamic decision making task that involved the presentation of either non‐social (i.e. biased reward feedback) or social (i.e., poor advice from a previous participant) misleading information. In Experiment 2, participants (N = 105) completed either the ostracism non‐social condition or social misleading information condition with explicit instructions stating that the advice given was from an individual who did not partake in the group task. Ostracized individuals relied more on non‐social misleading information and performed worse than included individuals. However, ostracized individuals discounted misleading social information and outperformed included individuals. Results of Experiment 2 replicated the findings of Experiment 1. Across two experiments, ostracized individuals were more critical of advice from others, both individuals who may have ostracized them and unrelated individuals. In other words, compared with included individuals, ostracized individuals underweighted advice from another individual but overweighed non‐social information during decision making. We conclude that when deceptive objective information is present, ostracism results in disadvantageous decision making. Copyright © 2015 John Wiley & Sons, Ltd.     

Dopamine,depressive symptoms,and decision-making: the relationship between spontaneous eye blink rate and depressive symptoms predicts Iowa Gambling Task performance

Depressive symptomatology has been associated with alterations in decision-making, although conclusions have been mixed, with depressed individuals showing impairments in some contexts but advantages in others. The dopaminergic system may link depressive symptoms with decision-making performance. We assessed the role of striatal dopamine D₂ receptor density, using spontaneous eye blink rates, in moderating the relationship between depressive symptoms and decision-making performance in a large undergraduate sample that had not been screened for mental illness (N?=?104). The regression results revealed that eye blink rate moderated the relationship between depressive symptoms and advantageous decisions on the Iowa Gambling Task, in which individuals with more depressive symptomatology and high blink rates (higher striatal dopamine D₂ receptor density) performed better on the task. Our computational modeling results demonstrated that depressive symptoms alone were associated with enhanced loss-aversive behavior, whereas individuals with high blink rates and elevated depressive symptoms tended to persevere in selecting options that led to net gains (avoiding options with net losses). These findings suggest that variation in striatal dopamine D₂ receptor availability in individuals with depressive symptoms may contribute to differences in decision-making behavior.     

Writing programs on the Apple for the student psychology laboratory: Routines,subroutines, and sources of information

Writing programs for the student psychology laboratory on the Apple II series of microcomputers presents the programmer with a number of problems. Among these are increasing program execution speed, obtaining precise response and interval timing, reducing program memory requirements, obtaining efficient disk I/O, providing good error trapping, and presenting clear screen displays. Since Applesoft BASIC is not equipped with many of the desirable features of a more advanced language, ways to solve these problems are not obvious. This paper suggests a number of potential solutions and provides additional sources of information.     

A comparison of inexpensive statistical packages for apple II microcomputers

The purpose of this paper is to describe and compare some inexpensive software packages that calculate a variety of statistics on the Apple II microcomputer. For each package, hardware requirements, program capacity, limitations, constraints, accuracy, editing, error handling, and other features were studied.