Interactions between Knowledge,Action and Commitment within Agent Dynamic Logic

This paper considers a new class of agent dynamic logics which provide a formal means of specifying and reasoning about the agents activities and informational, motivational and practical aspects of the behaviour of the agents. We present a Hilbert-style deductive system for a basic agent dynamic logic and consider a number of extensions of this logic with axiom schemata formalising interactions between knowledge and commitment (expressing an agent s awareness of her commitments), and interactions between knowledge and actions (expressing no learning and persistence of knowledge after actions). The deductive systems are proved sound and complete with respect to a Kripke-style semantics. Each of the considered logics is shown to have the small model property and therefore decidable.Presented by Ewa Orlowska     

Selection of tool diameter by New Caledonian crows<Emphasis Type="Italic"> Corvus moneduloides</Emphasis>

One important element of complex and flexible tool use, particularly where tool manufacture is involved, is the ability to select or manufacture appropriate tools anticipating the needs of any given task—an ability that has been rarely tested in non-primates. We examine aspects of this ability in New Caledonian crows—a species known to be extraordinary tool users and manufacturers. In a 2002 study, Chappell and Kacelnik showed that these crows were able to select a tool of the appropriate length for a task among a set of different lengths, and in 2002, Weir, Chappell and Kacelnik showed that New Caledonian crows were able to shape unfamiliar materials to create a usable tool for a specific task. Here we examine their handling of tool diameter. In experiment 1, we show that when facing three loose sticks that were usable as tools, they preferred the thinnest one. When the three sticks were presented so that one was loose and the other two in a bundle, they only disassembled the bundle when their preferred tool was tied. In experiment 2, we show that they manufacture, and modify during use, a tool of a suitable diameter from a tree branch, according to the diameter of the hole through which the tool will have to be inserted. These results add to the developing picture of New Caledonian crows as sophisticated tool users and manufacturers, having an advanced level of folk physics.Electronic Supplementary Material Supplementary material is available in the online version of this article at     

Implementing communication between Windows PCs and test equipment using RS-232 and Borland C+ + Builder

Modern experiments in the behavioral sciences frequently employ several items of electronic equipment such as computers, monitoring devices, stimulus presentation equipment, and response collection systems. In many cases it would be advantageous for these items to communicate directly with each other. Such communication may facilitate greater automation of experiments (i.e., reduced experimenter influences during the experiment), more precise experiment control (i.e., superior timing and synchronization capabilities of electronic devices), and greater accuracy of data collection (i.e., reduced ambiguity of participant responses). Many electronic experiment devices already provide external interfacesthrough which communication with other devices can be implemented. The most common is based on the RS-232 protocol, which is also found in all standard PCs. Therefore, Microsoft Windows based computers can be programmed to control experiments by communicating directly with electronic experiment devices. We show how to implement this RS-232 interconnection between devices and a Windows PC using currently available software tools.     

Divine retribution: A defence

The concept of divine justice has been the subject of considerable scrutiny in recent philosophical theology, as it bears upon the notion of punishment with respect to the doctrine of eternal damnation. In this essay, I set out a version of the traditional retributive view of divine punishment and defend it against one of the most important and influential contemporary detractors from this position, Thomas Talbott. I will show that, contrary to Talbott’s argument, punishment may satisfy divine justice, and that perfect justice is commensurate with retribution, rather than, as he suggests, reconciliation and restoration.     

Task-set reconfiguration with predictable and unpredictable task switches

Participants switched frequently between high/low and odd/even classification of a digit. The interval between a task cue and the next digit varied between blocks. In Experiment 1, the task switched predictably every two, four, or eight trials. In Experiment 2, switching predictably every four trials was compared with random switching. With predictable switching, the cost was limited to the first trial of a run. Random switching produced a more gradual approach to asymptotic performance. After one performance, control processes attenuate the resulting change in task-set bias if a further switch is likely, but this strategic modulation is soon overwhelmed by task-set priming through further performances. Preparation reduced switch costs but not interference from the irrelevant attribute: Control of interference appears to be reactive, not proactive. Switch costs did not increase with run length, suggesting that retrieval of the task set last associated with the stimulus did not contribute to switch costs.     

Perceptual completion and object-based representations in short-term visual memory

Object-based representations in visual short-term memory (VSTM) were examined using a change detection memory task. A display comprising two rows of four differently colored elements was followed by a probe display in which only one of the rows reappeared. On same trials, the probed row was identical to the corresponding row in the memory display. On different trials, two of the elements in the probed row had their colors exchanged. In each memory display, a task-irrelevant visual element appeared between the two rows, with the potential to function as an occluder. Performance was enhanced when perceptual completion meant that four, rather than eight, objects were perceived in the memory display and when the probe display revealed that the occluded elements continued behind the occluder. It appears that several forms of representation can co-occur to support VSTM, one of which is object based.     

Transferring voice effects in recognition memory from remembering to knowing

In five experiments, we investigated the effects of voice congruency (same vs. different voices at study and at test) on remembering and knowing in recognition memory. With low- and medium-frequency three- or four-syllable words, a voice congruency effect occurred only in remembering. With nonwords, voice congruency effects occurred both in remembering and in knowing. With nonwords and divided attention at study, the voice congruency effect transferred almost completely from remembering to knowing. By showing a transfer of effects from remembering to knowing as encoding became more impoverished, these findings support a distinctiveness/fluency account of remembering and knowing as well as the theory that remembering and knowing indicate retrieval of events from episodic and semantic memory systems, respectively.     

Irrelevant speech,articulatory suppression,and phonological similarity: A test of the phonological loop model and the feature model

Two experiments tested competing predictions about the nature of the irrelevant speech effect that were derived from Neath's (2000) feature model and from Salamé and Baddeley's (1982) phonological loop model. The first experiment examined the combined effects of irrelevant speech and articulatory suppression when target items were presented auditorily. Contrary to the suggestions of Neath, but consistent with the phonological loop model, the effects of articulatory suppression and irrelevant speech were additive even when the irrelevant speech was presented during the retention interval The second experiment examined the combined effects of irrelevant speech and phonological similarity when target items were presented visually. Consistent with the phonological loop model, the effects of phonological similarity and irrelevant speech were additive when participants were specifically instructed to use articulatory/phonological rehearsal to remember the list items. The results therefore contradicted Neath's claim that irrelevant speech abolishes the phonological similarity effect when list items are presented visually. However, the effect of phonological similarity was abolished in the irrelevant speech conditions when no instructions were given concerning rehearsal. It is argued that the phonological similarity effect disappears in some experiments because participants sometimes employ a semantic rehearsal strategy, consistent with the views of Salamé and Baddeley (1986).     

A cross-modal interference effect in grasping objects

The aim of the present paper was to investigate how the kinematics of a hand reaching toward a visual target would be influenced by haptic and proprioceptive input from an unseen distractor actively grasped in the other, nonreaching hand. The main results were that the amplitude of maximum grip aperture was smaller and the time to maximum grip aperture was earlier when the distractor was smaller than the target. The interference effect from the distractor was similar for both hands as they reached. Furthermore, results from a vibrating-distractor condition for passive tactile input revealed that the interference effects were evident only when the distractor was actively grasped. We suggest that neural processing of proprioceptive and tactile information relevant to distractor size produced the observed interference effects. We also emphasize the importance of active manipulation of the distractor stimulus in eliciting such interference effects.