Effects of irrelevant spatial S-R compatibility depend on stimulus complexity

Summary Choice-reaction time is known to depend on the spatial correspondence of stimulus and response, even if the stimulus location is irrelevant to the task (Simon effect). An experiment investigated whether this effect depends on stimulus complexity — i. e., on whether properties of the stimulus render stimulus discrimination easy or difficult. It was hypothesized that high demands on discrimination slow down the processing of stimulus identity in relation to location, so that the facilitating or conflicting location code has more time to decay, thus losing impact on response selection. In fact, the results revealed an effect of irrelevant spatial S-R correspondence with easy, but not with difficult, stimulus discrimination. This finding resolves an apparent contradiction between the results of several previous experiments on the Simon effect.The other central argument rests on findings of Stoffer (1991) obtained with a single frame. These, however, have recently been challenged by Hommel (1993 b).     

The Fishbein and Ajzen Theory of Reasoned Action Applied to Contraceptive Behavior: Model Variants and Meaningfulness1

Suggested modifications of the theory of reasoned action, which conceptualize the functional operation of the attitudinal and normative components in intention formation as separate, separate but contingent, and inseparable, are discussed. The model structures are examined with regard to the underlying psychological assumptions (psychological meaningfulness) and with regard to the required scale levels for the model variables, so that the results of model tests are invariant under the admissible scale transformations (formal meaningfulness). Using a procedure that combines “optimal scaling” with hierarchical regression analysis, the model variants are tested for women's (n= 89) and men's (n= 89) intentions to use contraceptive methods (pill, intrauterine device, condom, and natural methods) that require the model variables to be measured on interval scales. The results strongly favored the theory of reasoned action above the other model variants. Only for the subjective norm model was a better model fit found for a belief-only model compared to the original product-sum model. Gender differences were found with regard to the salient belief sets and the explanatory power of the normative model component.     

Ätiologie und Pathogenese der Migräne

Migräne ist eine weltweit sehr häufige Erkrankung, die zu einer erheblichen Beeinträchtigung der Lebensqualität Betroffener führen kann. Bereits zu Beginn der Migräneattacke konnte eine Aktivierung des Hypothalamus gezeigt werden. Ein wesentlicher Aspekt ist dann die nachfolgende Aktivierung des trigeminovaskulären Systems. Hier spielt das Neuropeptid Calcitonin Gene-Related Peptide (CGRP) eine tragende Rolle. Durch die Aktivierung nozizeptiver Fasern kommt es zur Reizweiterleitung nach zentral in den Hirnstamm und über periphere und zentrale Sensibilisierung zu den typischen migräneartigen Kopfschmerzen. Durch besseres Verständnis der Pathophysiologie der Migräne ist es zuletzt gelungen, eine medikamentöse Prophylaxe zu entwickeln, die spezifisch in die komplexe Abfolge der Migränekaskade eingreift, indem das CGRP bzw. sein Rezeptor durch spezifische monoklonale Antikörper blockiert werden.     

Consciousness and control in task switching

Participants were required to switch among randomly ordered tasks, and instructional cues were used to indicate which task to execute. In Experiments 1 and 2, the participants indicated their readiness for the task switch before they received the target stimulus; thus, each trial was associated with two primary dependent measures: (1) readiness time and (2) target reaction time. Slow readiness responses and instructions emphasizing high readiness were paradoxically accompanied by slow target reaction time. Moreover, the effect of task switching on readiness time was an order of magnitude smaller then the (objectively estimated) duration required for task preparation (Experiment 3). The results strongly suggest that participants have little conscious awareness of their preparedness and challenge commonly accepted assumptions concerning the role of consciousness in cognitive control.     

Control of stimulus-response translation in dual-task performance

In contradiction to stimulus-response- (S-R-) translation bottleneck models of dual-task control, stimulus processing in a primary task is affected by its compatibility with the response in a secondary, later performed task (Hommel, 1998a)- an indication of parallel S-R translation. Here we show that this backward-compatibility effect is independent of working-memory load, whether this is induced by an extra memory task (Experiment 1) or by increasing the number of S-R alternatives in the primary task (Experiment 2). However, backward effects occur even when the secondary task is no longer carried out (Experiment 3) and they are strongly affected by the inconsistency of previously used S-R mappings (Experiment 4). These findings suggest that S-R translation is (or can be) capacity-independent and automatic even under multiple-task conditions, and that it is mediated by direct S-R associations that emerge after only little practice.     

Perception in action: multiple roles of sensory information in action control

Perceptual processes play a central role in the planning and control of human voluntary action. Indeed, planning an action is a sensorimotor process operating on sensorimotor units, a process that is based on anticipations of perceptual action effects. I discuss how the underlying sensorimotor units emerge, and how they can be employed to tailor action plans to the goals at hand. I also discuss how even a single action can induce sensorimotor binding, how intentionally implemented short-term associations between stimuli and responses become autonomous, how feature overlap between stimulus events and actions makes them compatible, and why action plans are necessarily incomplete.

Zur Problematik der Suchtgefährdung von berufstätigen Medizinern

Two samples of working physicians have been compared in a cross-sectional study – one representative sample of addicted physicians with a substance abuse problem (n=142) and one representative sample (n=275) of physicians in general; the objective was to develop preventive strategies. As a measuring instrument a specific questionnaire on quality of life of physicians (Reimer and Jurkat) has been used. Generally, quality of life is lower in the substance abuse sample in comparison to the control group. It can be concluded that the variables concerning the areas life satisfaction/-dissatisfaction and health differentiate even more between the groups than the areas work satisfaction/-dissatisfaction and choice of occupation. Whereas quality of life of female physicians was on the average somewhat higher than that of their male colleagues in the control group, this could not be confirmed in the sample of impaired physicians. Especially the ability to relax seems to be essential as a preventive measure, and apparently it is of high importance for working physicians to care for an adequate and satisfying private life to balance their stressful working life.     

A Simon effect induced by induced motion and location: Evidence for a direct linkage of cognitive and motor maps

It has been argued that two distinct maps of visual space are formed: a cognitive map that is susceptible to illusions, and a motor map that represents the physical world veridically. In the present study, subjects responded to a nonspatial attribute of a visual target stimulus by pressing a left or right key, while an illusory horizontal displacement of the target was induced. A Simon-type effect was obtained to the induced target motion or position shift—that is, responses were faster when the illusory target motion or location corresponded to the response position. Further experiments indicated that the observed effects cannot be accounted for by attentional shifts. These results suggest that the content of the cognitive map does not only influence perceptual judgments but is also responsible for the automatic activation of response codes. In other words, perception and action seem to be fed by a common, cognitively penetrable, spatial representation.     

No inhibitory deficit in older adults' episodic memory

Selectively retrieving a subset of previously studied material can cause forgetting of the unpracticed material. Such retrieval-induced forgetting is attributed to an inhibitory mechanism recruited to resolve interference among competing items. According to the inhibition-deficit hypothesis, older people experience a specific decline in inhibitory function and thus should show reduced retrieval-induced forgetting. However, the results of the two experiments reported here show the same amount of retrieval-induced forgetting in younger and older adults. These results indicate that retrieval inhibition is intact in older adults' episodic recall. The findings suggest that the common view of a general inhibitory deficit in older adults needs to be updated and that older adults show intact inhibition in some cognitive tasks and deficient inhibition in others.