Fregean Abstraction, Referential Indeterminacy and the Logical Foundations of Arithmetic

In Die Grundlagen der Arithmetik, Frege attempted to introduce cardinalnumbers as logical objects by means of a second-order abstraction principlewhich is now widely known as ``Hume's Principle' (HP): The number of Fsis identical with the number of Gs if and only if F and G are equinumerous.The attempt miscarried, because in its role as a contextual definition HP fails tofix uniquely the reference of the cardinality operator ``the number of Fs'. Thisproblem of referential indeterminacy is usually called ``the Julius Caesar problem'.In this paper, Frege's treatment of the problem in Grundlagen is critically assessed. In particular, I try to shed new light on it by paying special attention to the framework of his logicism in which it appears embedded. I argue, among other things, that the Caesar problem, which is supposed to stem from Frege's tentative inductive definition of the natural numbers, is only spurious, not genuine; that the genuine Caesar problem deriving from HP is a purely semantic one and that the prospects of removing it by explicitly defining cardinal numbers as objects which are not classes are presumably poor for Frege. I conclude by rejecting two closely connected theses concerning Caesar put forward by Richard Heck: (i) that Frege could not abandon Axiom V because he could not solve the Julius Caesar problem without it; (ii) that (by his own lights) his logicist programme in Grundgesetze der Arithmetik failed because he could not overcome that problem.     

The Word's Eternal Silence: A Commentary on Schneider-Harpprecht's Essay

Once the post-modern account of individual and cultural identityas creative openness to change is re-construed in terms of aconstructivist rendering of the semiotic theory of culture,and once interdenominational and inter-faith hospital chaplaincyis interpreted on a model of cross-cultural communication whichagrees with this theory, chaplains can conceive of their abilityto fulfill their mission in offering understanding and helpto the client from other faith communities only by explicitlyinvoking the intervention of the Holy Spirit. The commentaryargues that Schneider-Harpprecht's all too generalized accountof that intervention leaves chaplains with no spiritual substancefor distinguishing between truely and only apparent pastoralhelpfulness.     

Emotional after‐effects on the P3 component of the event‐related brain potential

Agrowing body of literature indicates that affective states can influence cognitive processes. The core assumption of Ellis and Ashbrook's (1988) model explaining these emotional after‐effects on cognition is that the emotional state regulates the allocation of processing resources. A negative emotional state is supposed to pre‐empt capacity normally allocated to the cognitive task at hand. This is assumed to occur because the negative emotional state leads to an increase in intrusive, irrelevant thoughts, which compete with relevant cognitive activities and thus result in a lack of attention given to relevant features of the task to be performed. In the present study, the hypothesis that negative emotions lead to a reduced information‐processing capacity and that this is observable on a very basic level of information processing is tested. Therefore, 102 participants were assigned to three independent groups, each inducing one of a negative, a positive, or a neutral mood by means of a 3‐minute video‐clip. Shortly after the video‐clip, two acoustical stimuli with increasing information were presented, while the P3 component of the event‐related brain potential on these stimuli was measured as a psychophysiological indicator of cognitive resource allocation. In addition, the expenmental manipulation was checked by assessing subjective and external mood ratings as well as cortical alpha activity. Results show that the videos did in fact induce positive, neutral, or negative mood. Moreover, even when controlling for video‐related unspecific cortical arousal, a significant emotional after‐effect was found on the P3 component of the event‐related brain potential, indicating reduced information‐processing capacity, particularly in the negative mood condition. The reported data support Ellis and Ashbrook's model of emotional after‐effects on cognitive processes. As those effects were observable after an event that did not demand a high amount of cognitive resources, this suggests that even tasks that do not heavily engage central processing resources and are not likely to be influenced by cognitive strategies, seem to be affected by a negative emotional state.     

The involvement of executive functions in prospective memory performance of adults

The present study examines the relationship between prospective memory performance and executive functioning. The four phases of the prospective memory process—intention formation, intention retention, reinstantiation of the intention, and intention execution—are assumed to require different amounts of executive processing, most of which is demanded in the phases of intention formation and intention execution. At present, though, it is still unclear whether, and to what extent, prefrontal executive systems are involved in different kinds of prospective memory tasks, as some findings suggest that prospective memory might rather rely on nonstrategic processes that are unlikely to depend on prefrontal executive systems. Therefore, this study focuses on the following questions: (1) to what degree does executive functioning predict prospective memory performance in different standard prospective memory tasks and, furthermore, are certain executive measures better predictors than others; (2) are age‐related effects in different prospective memory measures due to individual differences in executive functioning; and (3) do age‐related differences in prospective memory exist that are not explained by individual differences in executive functioning. In a sample of 80 adults (20‐80 years), we applied four instruments to measure prospective memory: a traditional single‐task paradigm, two more complex tasks—one time‐based and one event‐based—and a highly complex multi‐task paradigm. We further assessed a broadly defined construct of executive functioning using several standard neuropsychological tests. Results showed that executive functioning did not predict performance in the simple single‐task paradigm. However, executive functioning, but not age, predicted performance in the two more complex standard tests of prospective remembering, and both executive functioning and age predicted performance in the most complex paradigm. In sum, the obtained data underline the assumption that frontal/ executive functions are related to prospective memory performance across a range of prospective paradigms. It also seems clear that age differences in prospective memory performance partially depend on age‐related individual differences in frontal/executive functions.     

Lexicality, morphological structure, and semantic transparency in the processing of German ver-verbs: The complementarity of on-line and off-line evidence

Two types of experiments investigate the visual on-line and off-line processing of German ver-verbs (e.g., verbittern ‘to embitter'). In Experiments 1 and 2 (morphological priming), latency patterns revealed the existence of facilitation effects for the morphological conditions (BITTER-VERBITTERN and BITTERN-VERBITTERN) as compared to the neutral conditions (SAUBER-VERBITTERN and SÄUBERN-VERBITTERN). In Experiments 3 and 4 (rating tasks) participants had to judge whether the target (VERBITTERN) “comes from,” “contains a form of,” or “contains the meaning of” the root (BITTER) or the root+en substring (BITTERN). Taken together, these studies revealed the combined influence of the three factors of lexicality (real word status), morphological structure, and semantic transparency.     

Probing the attentional control theory in social anxiety: An emotional saccade task

Volitional attentional control has been found to rely on prefrontal neuronal circuits. According to the attentional control theory of anxiety, impairment in the volitional control of attention is a prominent feature in anxiety disorders. The present study investigated this assumption in socially anxious individuals using an emotional saccade task with facial expressions (happy, angry, fearful, sad, neutral). The gaze behavior of participants was recorded during the emotional saccade task, in which participants performed either pro- or antisaccades in response to peripherally presented facial expressions. The results show that socially anxious persons have difficulties in inhibiting themselves to reflexively attend to facial expressions: They made more erratic prosaccades to all facial expressions when an antisaccade was required. Thus, these findings indicate impaired attentional control in social anxiety. Overall, the present study shows a deficit of socially anxious individuals in attentional control—for example, in inhibiting the reflexive orienting to neutral as well as to emotional facial expressions. This result may be due to a dysfunction in the prefrontal areas being involved in attentional control.     

Psychological and demographic correlates of career patterns

Recent years have witnessed a growing diversity of career patterns, resulting from the relative decline of stable employment. In the present study of 1368 employed and self-employed German adults career pattern diversity was assessed using nine pictograms. The goal was to identify psychological and demographic correlates of these patterns and to answer the question of whether they differed for participants from the former (communist) East and the capitalist West. Findings indicated that upward-pointing career patterns still connected to extrinsic criteria such as income and job security. With regard to psychological correlates, upward patterns connected to lower work-related demands imposed by social change and a higher level of personal and social resources. Only in the West, upward patterns related to male gender and high education, reflecting more traditional access to upwardly mobile career opportunities.     

Visual and tactile action effects determine bimanual coordination performance

Effect-based models of motor control assign a crucial role to anticipated perceptual feedback in action planning. Two experiments were conducted to test the validity of this proposal for discrete bimanual key press responses. The results revealed that the normally observed performance advantage for the preparation of two responses with homologous rather than non-homologous fingers becomes inverted when homologous fingers produce non-identical visual effects, and non-homologous fingers produce identical visual effects. In the second experiment the finger homology effect was strongly reduced when homologous fingers produced non-identical tactile feedback. The results show that representations of to-be-produced visual and tactile action effects both contribute to action planning, though possibly to a varying degree. Implications of these results for effect-based models of motor control are considered.     

Effect of delay on children's delay-execute prospective memory performance

To date, little work has been done investigating prospective memory in children, particularly using a delay-execute paradigm. Two experiments were conducted to investigate this issue with children aged 5–11 years. While playing a computer driving game, children's ability to carry out a delayed intention either immediately a target cue appeared or after an additional delay, was assessed. These findings supported the few previous studies in this area by showing that preschool children are able to perform event-based prospective memory tasks. The results also extended these findings by demonstrating the impact of briefly delaying the execution of a retrieved intention, and revealing that there were important improvements in prospective memory performance from early to late childhood. The suggestion is made that executive resources may be responsible for this pattern of performance.     

Constructing robust crew schedules with bicriteria optimization

Optimization‐based computer systems are used by many airlines to solve crew planning problems by constructing minimal cost tours of duty. However, today airlines do not only require cost effective solutions, but are also very interested in robust solutions. A more robust solution is understood to be one where disruptions in the schedule (due to delays) are less likely to be propagated into the future, causing delays of subsequent flights. Current scheduling systems based solely on cost do not automatically provide robust solutions. These considerations lead to a multiobjective framework, as the maximization of robustness will be in conflict with the minimization of cost. For example crew changing aircraft within a duty period is discouraged if inadequate ground time is provided. We develop a bicriteria optimization framework to generate Pareto optimal schedules for the domestic airline. A Pareto optimal schedule is one which does not allow an improvement in cost and robustness at the same time. We developed a method to solve the bicriteria problem, implemented it and tested it with actual airline data. Our results show that considerable gain in robustness can be achieved with a small increase in cost. The additional cost is mainly due to an increase in overnights, which allows for a reduction of the number of aircraft changes. Copyright © 2003 John Wiley & Sons, Ltd.