Triviality Results for Probabilistic Modals

In recent years, a number of theorists have claimed that beliefs about probability are transparent. To believe probably p is simply to have a high credence that p. In this paper, I prove a variety of triviality results for theses like the above. I show that such claims are inconsistent with the thesis that probabilistic modal sentences have propositions or sets of worlds as their meaning. Then I consider the extent to which a dynamic semantics for probabilistic modals can capture theses connecting belief, certainty, credence, and probability. I show that although a dynamic semantics for probabilistic modals does allow one to validate such theses, it can only do so at a cost. I prove that such theses can only be valid if probabilistic modals do not satisfy the axioms of the probability calculus.     

Anticipatory responses to perturbation of co-ordination in one-handed catching.

Anticipatory responses to perturbation have rarely been studied in the co-ordination of dynamic interceptive actions. In this study, the kinematics of ball catching were examined in skilled catchers when mechanical perturbation of the catching arm was expected and unexpected. During trials where the perturbation was anticipated, participants initiated movements earlier (207 +/- 32 ms) than in randomly perturbed trials (223 +/- 34 ms). Furthermore, several individuals also tended to move their hand faster when perturbations were expected compared to baseline trials. Individual analyses revealed that three out of eight participants exhibited changes in the relative timing of the grasp phase to adapt to the specific manipulation of task constraints. Anticipatory responses were revealed in changes not only at movement initiation but also in the resulting adaptations to the co-ordination of reach and grasp phases of ball catching. When the catchers could not anticipate perturbations, movement strategies suggested the use of a continuous tracking-based mode of control rather than a prediction-based mode of control.     

Reviews: Books

SCHOPENHAUER'S PORCUPINES: INTIMACY AND ITS DILEMMAS. By Deborah Anna Luepnitz. 275 pp. New York: Basic Books, 2002. $25.00. CITY OF ONE A MEMOIR. By Francine Cournos. 253 pp. New York: Plume, 2000. $12.95. YIDDISHE KOP: CREATIVE PROBLEM SOLVING IN JEWISH LEARNING, LORE, AND HUMOR. By Rabbi Nilton Bonder. Boston: Shambhala, 1999.     

Establishing an Alcohol and Other Drug Assessment and Intervention Program Within an On‐Site Counselor Education Research and Training Clinic

The authors describe the Substance Information Program, a university alcohol and other drug (AOD) assessment and intervention program. The Substance Information Program is housed in a counseling department's on‐site training and research clinic and gives counselors‐in‐training an opportunity to gain practical addictions training.     

Generating alternatives: A key component in human reasoning?

According to mental models theory, a key aspect of deductive reasoning is the production of alternative models that can falsify provisional conclusions. In the present paper, the possibility is investigated that there are individual differences in the ability to produce alternative models. The results indicate that some people do not proceed beyond the first model when they reason with syllogisms but that others do. Furthermore, the ability to generate alternatives can be independently measured by asking participants to generate different representations of pairs of premises. These findings support the predictions of mental models theory and also indicate the potential importance of alternatives generation as a measure of individual differences in processing style.     

Plumbing semantic depths in Amsterdam

The 13th Amsterdam Colloquium was held at the Institute for Logic, Language and Linguistics at the University of Amsterdam, on 17-19 December 2001.     

Construction of preferences by constraint satisfaction

Participants were given a choice between two multiattribute alternatives (job offers). Preferences for the attributes were measured before, during, and after the choices were made. We found that over the course of decision making, the preferences shifted to cohere with the choice: The attributes of the option that was eventually chosen came to be rated more favorably than they had been rated initially, while the attributes of the rejected option received lower preference ratings than before. These coherence shifts were triggered by a single attribute that decisively favored one option (Experiment 1), and occurred spontaneously in the absence of a decisive attribute (Experiment 2). The coherence shift preceded commitment to choice. These findings favor constraint-satisfaction models of decision making.     

Bias at the racetrack: effects of individual expertise and task importance on predecision reevaluation of alternatives

These studies were designed to test cognitive dissonance theory's assertion that alternatives are not reevaluated before a choice. Participants viewed information about horses in a simulated race and rated each one's chance of winning three times before placing their bet and once after placing it. It was found that ratings of the chosen horse increased within the predecision period as well as after betting. Predecision bolstering occurred even when participants did not expect to bet, and predecision preference increased with task importance and participant expertise. The findings are attributed to maintenance of consistency throughout a cognitive system.     

Estimation and interpretation of 1/f<Superscript>α</Superscript> noise in human cognition

Recent analyses of serial correlations in cognitive tasks have provided preliminary evidence of the presence of a particular form of long-range serial dependence known as 1/fnoise. It has been argued that long-range dependence has been largely ignored in mainstream cognitive psychology even though it accounts for a substantial proportion of variability in behavior (see, e.g., Gilden, 1997, 2001). In this article, we discuss the defining characteristics of long-range dependence and argue that claims about its presence need to be evaluated by testing against the alternative hypothesis of short-range dependence. For the data from three experiments, we accomplish such tests with autoregressive fractionally integrated moving-average time series modeling. We find that long-range serial dependence in these experiments can be explained by any of several mechanisms, including mixtures of a small number of short-range processes.