Recovery Recovered

The most controversial condition that the AGM theory of rational belief change places on belief contraction is the recovery condition. The condition is controversial because of a series of putative counterexamples due (separately) to I. Levi and S. O. Hansson. In this paper we show that the conflicts that Levi and Hansson arrange between AGM contraction and our intuitions about how to give up beliefs are merely apparent. We argue that these conflicts disappear once we attend more closely to the identification of the beliefs contracted away in each counterexample case. Since, on our view, speakers" belief contraction intentions are often more complicated than they may first appear, we are led to develop apparatus for thinking about the communication and identification of those intentions. Our argument refocuses attention on the difficult question of how to apply the AGM theory to particular cases.     

Voluntary Action and Rational Sin in Anselm of Canterbury

Anselm of Canterbury (1033–1109) holds that freedom of the will is a necessary condition for moral responsibility. This condition, however, turns out to be trivially fulfilled by all rational creatures at all times. In order to clarify the necessary conditions for moral responsibility, we must look more widely at his discussion of the nature of the will and of willed action. In this paper, I examine his theory of voluntariness by clarifying his account of the sin of Satan in De casu diaboli. Anselm agrees with Augustine that the sinful act cannot be given a causal explanation in terms of a distinct preceding act of will or desire or choice. He thus rejects volitionalist accounts of Satan's sin and thus of voluntary action in general. He moves beyond his predecessor, however, in insisting on the necessity of an explanation in terms of reasons, and his theory of the dual nature of the rational will is designed to meet this demand. A comparison of Satan's case with the case of the miser of De casu diaboli 3, finally, shows that Anselm's account requires that acts of the will or ‘willings’ qualify as voluntary, a suggestion as interesting as problematic.     

Social connectedness as a source and consequence of meaning in life

Multiple studies have shown that the sense of belonging and connectedness contribute to meaning in life, but does meaning also influence social connectedness? The present research examines the reciprocal relationships between meaning and different types of connectedness: intimate, relational, and collective. Analyzing data from a nationally representative longitudinal study (Study 1) with cross-lagged panel models, we found that only collective connectedness was prospectively associated with meaning, whereas meaning was prospectively associated with all three types of connectedness, controlling for life satisfaction. The beneficial effect of meaning extended to behavioral indicators of collective and intimate connectedness (Study 2). Higher levels of meaning in life were prospectively associated with an increased likelihood of joining voluntary associations and getting married, and, for people high in marital satisfaction, with a decreased likelihood of marital separation. Together, these findings suggest that the relationship between social connectedness and meaning in life is bidirectional.     

How intention and monitoring your thoughts influence characteristics of autobiographical memories

Involuntary autobiographical memories come to mind effortlessly and unintended, but the mechanisms of their retrieval are not fully understood. We hypothesize that involuntary retrieval depends on memories that are highly accessible (e.g., intense, unusual, recent, rehearsed), while the elaborate search that characterizes voluntary retrieval also produces memories that are mundane, repeated or distant – memories with low accessibility. Previous research provides some evidence for this ‘threshold hypothesis’. However, in almost every prior study, participants have been instructed to report only memories while ignoring other thoughts. It is possible that such an instruction can modify the phenomenological characteristics of involuntary memories. This study aimed to investigate the effects of retrieval intentionality (i.e., wanting to retrieve a memory) and selective monitoring (i.e., instructions to report only memories) on the phenomenology of autobiographical memories. Participants were instructed to (1) intentionally retrieve autobiographical memories, (2) intentionally retrieve any type of thought (3) wait for an autobiographical memory to spontaneously appear, or (4) wait for any type of thought to spontaneously appear. They rated the mental content on a number of phenomenological characteristics both during retrieval and retrospectively following retrieval. The results support the prediction that highly accessible memories mostly enter awareness unintended and without selective monitoring, while memories with low accessibility rely on intention and selective monitoring. We discuss the implications of these effects.     

Stochastic matching and the voluntary nature of choice

Attempts to characterize voluntary behavior have been ongoing for thousands of years. We provide experimental evidence that judgments of volition are based upon distributions of responses in relation to obtained rewards. Participants watched as responses, said to be made by "actors," appeared on a computer screen. The participant's task was to estimate how well each actor represented the voluntary choices emitted by a real person. In actuality, all actors' responses were generated by algorithms based on Baum's (1979) generalized matching function. We systematically varied the exponent values (sensitivity parameter) of these algorithms: some actors matched response proportions to received reinforcer proportions, others overmatched (predominantly chose the highest-valued alternative), and yet others undermatched (chose relatively equally among the alternatives). In each of five experiments, we found that the matchingactor's responses were judged most closely to approximate voluntary choice. We found also that judgments of high volition depended upon stochastic (or probabilistic) generation. Thus, stochastic responses that match reinforcer proportions best represent voluntary human choice.     

Do Unilateral Right and Left Face Contractions Induce Positive and Negative Emotions? A Further Test of Schiff and Lamon's (1989) Hypothesis

Schiff and Lamon (1989) proposed that unilateral face contractions induce positive or negative changes in emotion depending on the side of contraction; support for this proposal, however, has been mixed. In a new test, 40 right-handed and 38 left-handed men performed four alternating face contractions (LRLR or RLRL) and, after each one, completed a different version of the Depression Adjective Checklist (Lubin, 1994). A repeated-measures ANCOVA failed to reveal any significant effect of side of face contraction or handedness on direction of emotion change. Instead, regardless of side of contraction, the subjects' negative emotional state increased significantly across the four contractions with the degree of change being significantly related to the subjects' reported level of difficulty in holding the contraction irrespective of whether the more difficult side was the left or the right.     

Infinitary Belief Revision

This paper extends the AGM theory of belief revision to accommodate infinitary belief change. We generalize both axiomatization and modeling of the AGM theory. We show that most properties of the AGM belief change operations are preserved by the generalized operations whereas the infinitary belief change operations have their special properties. We prove that the extended axiomatic system for the generalized belief change operators with a Limit Postulate properly specifies infinite belief change. This framework provides a basis for first-order belief revision and the theory of revising a belief state by a belief state.     

Influence of Strategy on Muscle Activity During Impact Movements

Participants (N = 10) made flexions or extensions about the elbow. Movements either were pointing (i.e., self-terminated) or terminated by impact on a barrier. The author examined how the trajectory and the electromyographic (EMG) patterns varied according to the distance moved, the instruction provided concerning speed, or the type of termination. Variations in kinematics induced by changes in the target distance or the instruction regarding speed were the same for impact and pointing movements. In comparison with a pointing movement of similar distance and speed instruction, an impact movement (a) accelerated longer and reached a higher velocity, (b) had a longer agonist EMG burst, and (c) had a low level of contraction that started slightly after the agonist burst and continued throughout the movement but had little or no antagonist burst. Because the different types of movements required different forces from the muscles, there were systematic, task-specific differences in EMG patterns that reflected task-specific differences in central control. The results of this experiment demonstrate that impact movements share some of the rules used in the control of other tasks, such as pointing and reversing movements. The sharing is not imposed by mechanical or physiological constraints but, rather, represents the imposition of internal constraints.     

动作自主性与结果性质对不同预测性条件下施动感的影响

采用时间估计法考察动作自主性水平、动作结果性质(利己、利他、中性)以及结果是否可预测对施动感的影响。结果发现, 高自主性的自由选择条件比低自主性的服从条件增强了个体的施动感, 且不受动作结果性质与结果是否可预测的影响; 在低自主性的服从条件下, 当结果可预测时利己结果比利他结果的施动感更强, 而在结果不可预测时利己和利他结果的施动感没有区别, 但均弱于中性结果。这揭示出动作的主观意愿在施动感产生过程中的重要作用, 同时在自主性较低的服从条件下, 对利己或利他道德属性的动作结果能否被预测, 对个体的施动感产生了不同的影响。研究结果说明具有利己或利他道德属性的动作对施动感会产生自上而下的调节作用, 且这种调节作用在低自主条件下较为突显。