On Fork Arrow Logic and its Expressive Power

We compare fork arrow logic, an extension of arrow logic, and its natural first-order counterpart (the correspondence language) and show that both have the same expressive power. Arrow logic is a modal logic for reasoning about arrow structures, its expressive power is limited to a bounded fragment of first-order logic. Fork arrow logic is obtained by adding to arrow logic the fork modality (related to parallelism and synchronization). As a result, fork arrow logic attains the expressive power of its first-order correspondence language, so both can express the same input–output behavior of processes.     

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Philosophical Studies -     

When the Solution Is on the Doorstep: Better Solving Performance,but Diminished Aha! Experience for Chess Experts on the Mutilated Checkerboard Problem

Insight problems are difficult because the initially activated knowledge hinders successful solving. The crucial information needed for a solution is often so far removed that gaining access to it through restructuring leads to the subjective experience of “Aha!”. Although this assumption is shared by most insight theories, there is little empirical evidence for the connection between the necessity of restructuring an incorrect problem representation and the Aha! experience. Here, we demonstrate a rare case where previous knowledge facilitates the solving of insight problems but reduces the accompanying Aha! experience. Chess players were more successful than non‐chess players at solving the mutilated checkerboard insight problem, which requires retrieval of chess‐related information about the color of the squares. Their success came at a price, since they reported a diminished Aha! experience compared to controls. Chess players’ problem‐solving ability was confined to that particular problem, since they struggled to a similar degree to non‐chess players to solve another insight problem (the eight‐coin problem), which does not require chess‐related information for a solution. Here, chess players and non‐chess players experienced the same degree of insight.     

The conceptualization of helplessness: II. Laboratory correlates of the phenomenological definition of helplessness

The present research was designed to investigate the correspondence between the phenomenological definition of helplessness and its laboratory analogue—the learned helplessness paradigm. In experiment 1, subjects were exposed to unsolvable, solvable, or no problems. It was found that exposure to unsolvable problems increased the report of helplessness feelings and impaired subsequent performance. In addition, experiment 1 demonstrated a negative and significant correlation between performance and the report of helplessness feelings. Experiment 2 isolated the cognitive component of helplessness by measuring the amount of expectancy changes following success and failure. The amount of expectancy changes was negatively correlated with the belief in an outcome's uncontrollability. Finally, experiment 3 showed that exposure to only one unsolvable problem was associated with the reports of coping and anger feelings, whereas exposure to four unsolvable problems was related to surrender feelings. These results demonstrated that laboratory-induced helpless situations elicit the same feelings as real-life helplessness situations.The study was conducted by the first author in partial fulfillment of the requirements for the M.A. degree at Bar Ilan University under the supervision of Prof. R. E. Lubow.     

Influence in canonical correlation analysis

The perturbation theory of the generalized eigenproblem is used to derive influence functions of each squared canonical correlation coefficient and the corresponding canonical vector pair. Three sample versions of these functions are described and some properties are noted. As particular applications, the influence function of the squared multiple correlation coefficient and influence functions of eigenvalues and eigenvectors in correspondence analysis are obtained. Three numerical examples are briefly discussed.We thank the Editor and the anonymous reviewers for their helpful comments. This research was carried out with the financial support of the Italian Ministry of the University and the National Research Council.     

The impact of cognitive interference on performance during prolonged sleep loss

Summary A study was conducted on the effects of off-task cognitions on performance during sleep deprivation. Subjects answered the Thought Occurrence Questionnaire, assessing their proneness to engage in off-task cognitions, and were deprived of sleep for 72 hours, during which they performed a variety of tasks including visual discrimination and three versions of a logical reasoning task in which cognitive load was varied systematically. In addition, every day subjects answered the Cognitive Interference Questionnaire, which taps off-task cognitions during the experiment. Results indicated that subjects who habitually engage in off-task cognitions performed worse during 72 hours of sleep loss than subjects who do not engage in such distracting activities. In addition, it was found that the engagement in off-task cognitions increased during the 72 hours of sleep loss and such an engagement was related to deficits in performance accuracy. The mechanisms of off-task cognitions and sleep loss underlying these effects are discussed.     

Speculation: Wild and sound

There is no original research without guessing or speculation. However, in science there are constraints on speculation: the latter must harmonize with the bulk of background knowledge and it must be testable in some way or other. In other words, it is false that in science “anything goes”, as epistemological anarchism claims.     

The relationship of probability of success and performance following unsolvable problems: Reactance and helplessness effects

The present study assessed the effects of amount of helplessness training and probability of success given prior to performance on motivational involvement and on subsequent task performance. Subjects were exposed to either high, low, or no helplessness training on a series of cognitive discrimination problems and were given instructions regarding the probability of success on those problems. In the low helplessness condition, subjects who received moderate probability of success exhibited higher motivation to perform, higher levels of frustration and hostility, and better performance than subjects in the no helplessness condition. In the high helplessness condition, subjects who received moderate or high probability of success exhibited higher motivational involvement and greater performance decrements in the subsequent task than did control subjects. The results are discussed within the context of Wortman and Brehm's theory of reactance and helplessness.