Events in Branching Time

The concept of event is one of the key notions of many theories dealing with causality or agency. In this paper we study different approaches to events that share the basic assumption that events can be analyzed fruitfully in branching-time structures. The terminological framework developed thereby may be helpful for further analyses in the fields of causality and agency and also in those fields of computational semantics, where similar concepts are considered.     

Representation facilitates reasoning: what natural frequencies are and what they are not

A good representation can be crucial for finding the solution to a problem. Gigerenzer and Hoffrage (Psychol. Rev. 102 (1995) 684; Psychol. Rev. 106 (1999) 425) have shown that representations in terms of natural frequencies, rather than conditional probabilities, facilitate the computation of a cause's probability (or frequency) given an effect--a problem that is usually referred to as Bayesian reasoning. They also have shown that normalized frequencies--which are not natural frequencies--do not lead to computational facilitation, and consequently, do not enhance people's performance. Here, we correct two misconceptions propagated in recent work (Cognition 77 (2000) 197; Cognition 78 (2001) 247; Psychol. Rev. 106 (1999) 62; Organ. Behav. Hum. Decision Process. 82 (2000) 217): normalized frequencies have been mistaken for natural frequencies and, as a consequence, "nested sets" and the "subset principle" have been proposed as new explanations. These new terms, however, are nothing more than vague labels for the basic properties of natural frequencies.     

The P600 as an indicator of syntactic ambiguity

In a study using event-related brain potentials, we show that the current characterization of the P600 component as an indicator of revision processes (reanalysis and repair) in sentence comprehension must be extended to include the recognition of syntactic ambiguity. By comparing the processing of ambiguous and unambiguous sentence constituents in German, we show that the P600 is elicited when our language processing system has syntactic alternatives at a certain item given in the input string. That the P600 is sensitive to syntactic ambiguity adds crucial evidence to current debates in psycholinguistic modelling, as the results clearly favour parallel models of syntactic processing which assume that ambiguity is recognized and costly.     

Predictive validity of an Implicit Association Test for assessing anxiety

The Implicit Association Test (IAT) was adapted to measure anxiety by assessing associations of self (vs. other) with anxiety-related (vs. calmness-related) words. Study 1 showed that the IAT-Anxiety exhibited good internal consistency and adequate stability. Study 2 revealed that the IAT-Anxiety was unaffected by a faking instruction. Study 3 examined the predictive validity of implicit and explicit measures and showed that the IAT-Anxiety was related to changes in experimenter-rated anxiety and performance decrements after failure. Study 4 found that several behavioral indicators of anxiety during a stressful speech were predicted by the IAT. Taken together, these studies show that the IAT-Anxiety is a reliable measure that is able to predict criterion variables above questionnaire measures of anxiety and social desirability.     

Social contacts and production of 50-kHz short ultrasonic calls in adult rats

The goal of the study was to provide evidence that the production of 50-kHz calls by adult rats is driven by potential or direct social contacts. The calls have been studied during daily visits to a cage by single or paired rats. Repeated exposure of rats to the cage frequently visited by other rats or direct contact between rats significantly increased the number of 50-kHz calls. The increase in production of 50-kHz calls was reduced by 78% after intrapreoptic-anterior hypothalamic injection of MK-801, an N-methyl-D-aspartate-type glutamate receptor antagonist. Calls emitted in all situations had a similar acoustic profile. It was found that 50-kHz calls were produced in anticipation of, and/or during, direct social contacts among adult rats and were predominantly initiated by olfactory stimuli. The calls seem to express an appetitive behavioral state in which the central glutamatergic mechanism is implicated.     

The invisible power and counseling

Pastoral Psychology -     

The interleaving of actions in everyday life multitasking demands

It has been argued that executive tests should capture central aspects of executive functions in everyday life such as initiating and monitoring parallel actions in low-structured environments (so-called multitasking; see Burgess, 2000). We present a cooking task in order to assess executive function impairments in brain-damaged patients, which focuses on a central feature of multitasking, the interleaving of tasks (Burgess, 2000). Behavioural performance of 21 brain-damaged patients (stroke, traumatic brain injury) and of a group of matched controls was analysed on the basis of a standardized protocol. In comparison to controls, the patients explored less, were less successful in monitoring their actions and corrected errors less efficiently. Interleaving of actions was observed less frequently in patients, with respect to both cooking itself as well as to subordinate goals (e.g., cleaning up). Interleaving proved efficient, as it was associated with less time to complete the task. Patients' scores in the cooking task correlated with performance in both the Behavioural Assessment of the Dysexecutive Syndrome (BADS) Zoo Map Test and the BADS Six Elements Test, but not with tests of attention, verbal memory, or figural fluency, thus demonstrating convergent and discriminant validity. In summary, our task demonstrates that cooking can provide a valid testing ground for assessing a central aspect of everyday multitasking demands, namely, the interleaving of actions.     

Mining event-related brain dynamics

This article provides a new, more comprehensive view of event-related brain dynamics founded on an information-based approach to modeling electroencephalographic (EEG) dynamics. Most EEG research focuses either on peaks 'evoked' in average event-related potentials (ERPs) or on changes 'induced' in the EEG power spectrum by experimental events. Although these measures are nearly complementary, they do not fully model the event-related dynamics in the data, and cannot isolate the signals of the contributing cortical areas. We propose that many ERPs and other EEG features are better viewed as time/frequency perturbations of underlying field potential processes. The new approach combines independent component analysis (ICA), time/frequency analysis, and trial-by-trial visualization that measures EEG source dynamics without requiring an explicit head model.     

Is the Motor or the Garage More Important to the Car? The Difference Between Semantic Associations in Single Word and Sentence Production

The aim of the present study was to investigate the impact of part-whole (e.g., car-motor) and functional associations (e.g., car-garage) on single word (Experiment 1) and sentence production (Experiment 2). In Experiment 1, a classical picture-word task was used. In Experiment 2, the same stimuli and distractors were embedded into a sentence. The relation between target and distractor was either part-whole, functional or unrelated. At single word level, part-whole and functional relations facilitate naming. Additionally, the facilitation effect was stronger for part-whole in comparison to functional associations. During sentence production, facilitation shifted to interference. The difference between both relations disappeared. The findings of the different effects between functional and part-whole associations depend on the length of utterances and highlight the divergent impact of associations. The differences between part-whole and functional associations in single word production might reflect a differential organization of associative links at the conceptual level. In contrast, during sentence production the syntactic processing at the lexical level seem to be more important than types of semantic associations at the conceptual level.