Update Semantics of Security Protocols

We present a model-theoretic approach for reasoning about security protocols, applying recent insights from dynamic epistemic logics. This enables us to describe exactly the subsequent epistemic states of the agents participating in the protocol, using Kripke models and transitions between these based on updates of the agents’ beliefs associated with steps in the protocol. As a case study we will consider the SRA Three Pass protocol and discuss the Wide-Mouthed Frog protocol.     

From Aristotle's Syllogistic to Stoic Conditionals: Holzwege or Detectable Paths?

This paper is chiefly aimed at individuating some deep, but as yet almost unnoticed, similarities between Aristotle's syllogistic and the Stoic doctrine of conditionals, notably between Aristotle's metasyllogistic equimodality condition (as stated at APr. I 24, 41b27–31) and truth-conditions for third type (Chrysippean) conditionals (as they can be inferred from, say, S.E. P. II 111 and 189). In fact, as is shown in §1, Aristotle's condition amounts to introducing in his (propositional) metasyllogistic a non-truthfunctional implicational arrow '', the truth-conditions of which turn out to be logically equivalent to truth-conditions of third type conditionals, according to which only the impossible (and not the possible) follows from the impossible. Moreover, Aristotle is given precisely this non-Scotian conditional logic in two so far overlooked passages of (Latin and Hebraic translations of) Themistius' Paraphrasis of De Caelo (CAG V 4, 71.8–13 and 47.8–10 Landauer). Some further consequences of Aristotle's equimodality condition on his logic, and notably on his syllogistic (no matter whether modal or not), are pointed out and discussed at length. A (possibly Chrysippean) extension of Aristotle's condition is also discussed, along with a full characterization of truth-conditions of fourth type conditionals.     

The effect of the September 11 terrorist attacks on suicide and deliberate self-harm: a time trend study

Suicide rates may be affected by world news. Our objective was to investigate the possible impact of the terrorist attacks of September 11, 2001, on suicidal behavior in the Netherlands. There was evidence of an increase in rates of suicide and deliberate self-harm in the weeks immediately following the attacks. These findings contrast with Durkheim's (1897) original suggestion that suicide rates decline in times of war and outside threat but are in line with findings of increases in suicidal behavior after media coverage of lethal violence.     

Two measures of affect and emotion in Italian children aged 6 to 11 years

The authors investigated the relation between affective and cognitive processes in fantasy play and emotional understanding of 50 Italian children (25 boys and 25 girls) enrolled in regular elementary school in Northern Italy. Children were administered a standardized play task, the Affect in Play Scale, and answered questions about their understanding of emotions. Consistent, yet modest, relationships were found between dimensions of fantasy play and emotional understanding.     

A six-factor structure of personality-descriptive adjectives: solutions from psycholexical studies in seven languages

Standard psycholexical studies of personality structure have produced a similar 6-factor solution in 7 languages (Dutch, French, German, Hungarian, Italian, Korean, Polish). The authors report the content of these personality dimensions and interpret them as follows: (a) a variant of Extraversion, defined by sociability and liveliness (though not by bravery and toughness); (b) a variant of Agreeableness, defined by gentleness, patience, and agreeableness (but also including anger and ill temper at its negative pole); (c) Conscientiousness (emphasizing organization and discipline rather than moral conscience); (d) Emotionality (containing anxiety, vulnerability, sentimentality, lack of bravery, and lack of toughness, but not anger or ill temper); (e) Honesty-Humility; (f) Intellect/Imagination/Unconventionality. A potential reorganization of the Big Five factor structure is discussed.     

The interpersonal effects of anger and happiness in negotiations

Three experiments investigated the interpersonal effects of anger and happiness in negotiations. In the course of a computer-mediated negotiation, participants received information about the emotional state (anger, happiness, or none) of their opponent. Consistent with a strategic-choice perspective, Experiment 1 showed that participants conceded more to an angry opponent than to a happy one. Experiment 2 showed that this effect was caused by tracking--participants used the emotion information to infer the other's limit, and they adjusted their demands accordingly. However, this effect was absent when the other made large concessions. Experiment 3 examined the interplay between experienced and communicated emotion and showed that angry communications (unlike happy ones) induced fear and thereby mitigated the effect of the opponent's experienced emotion. These results suggest that negotiators are especially influenced by their opponent's emotions when they are motivated and able to consider them.     

Contour-based object identification and segmentation: Stimuli,norms and data,and software tools

We summarize five studies of our large-scale research program, in which we examined aspects of contour-based object identification and segmentation, and we report on the stimuli we used, the norms and data we collected, and the software tools we developed. The stimuli were outlines derived from the standard set of line drawings of everyday objects by Snodgrass and Vanderwart (1980). We used contour curvature as a major variable in all the studies. The total number of 1,500 participants produced very solid, normative identification rates of silhouettes and contours, straight-line versions, and fragmented versions, and quite reliable benchmark data about saliency of points and object segmentation into parts. We also developed several software tools to generate stimuli and to analyze the data in nonstandard ways. Our stimuli, norms and data, and software tools have great potential for further exploration of factors influencing contour-based object identification, and are also useful for researchers in many different disciplines (including computer vision) on a wide variety of research topics (e.g., priming, agnosia, perceptual organization, and picture naming). The full set of norms, data, and stimuli may be downloaded fromwww.psychonomic.org/archive/.     

The effect of grammatical gender and semantic context on lexical access in Italian using a timed word-naming paradigm

The effects of sentence context and grammatical gender on lexical access were investigated in Italian using a timed word-naming paradigm. Large main effects of both sentence context and the gender of the article were observed; the interaction between gender and semantics was significant over subjects. Strong facilitation by both gender and semantics was observed, relative to a neutral-control baseline condition. Results are compared with (1) a prior study with the same design, using a picture-naming paradigm, except that objects described by written words were replaced by pictures (Bentrovato, Devescovi, D'Amico, & Bates, 1999); (2) a separate norming study of timed word reading in a list format, using the same stimuli (D'Amico, Devescovi, & Bates, 2001); and (3) a prior study of German comparing word and picture naming in short, semantically neutral phrases (Jacobsen, 1999). Differences in methodology and in findings between the Italian word naming and the German word naming are compared and discussed. Findings of the present study are interpreted in support of interactive-activation models in which different sources of information are combined on-line to predict, anticipate, or preactivate lexical targets.     

Repetition priming in picture naming and translation depends on shared processes and their difficulty: evidence from spanish-english bilinguals

Two experiments with highly fluent Spanish-English bilinguals examined repetition priming of picture identification and word retrieval in picture naming. In Experiment 1, between-language priming of picture naming was symmetric, but within-language priming was stronger in the nondominant language. In Experiment 2, priming between picture naming and translation was symmetric within both the dominant language and the nondominant language, but priming was stronger in the nondominant language. A mathematical model required only 3 process parameters to explain the pattern of priming across 8 conditions. These results indicate that shared processes are the basis of priming, that difficulty influences priming only at the process level, and that translation in both directions is concept mediated in fluent bilinguals.