The dual-stage two-phase (DSTP) model is introduced as a formal and general model of selective attention that includes both an early and a late stage of stimulus selection. Whereas at the early stage information is selected by perceptual filters whose selectivity is relatively limited, at the late stage stimuli are selected more efficiently on a categorical basis. Consequently, selectivity is first low but then abruptly increases during the course of stimulus processing. Although intended as a general model of selective attention, in the present study the DSTP model was applied to account for the distributional data of 3 flanker task experiments. The fit of the model to the data was not only rather good but also superior to those of alternative single-stage models with a continuously increasing selectivity. All together, the model provides a comprehensive account of how early and late stages of attention interact in the control of performance.

In the Eriksen flanker task as well as in the Simon task irrelevant activation produces a response conflict that has to be resolved by mental control mechanisms. Despite these similarities, however, the tasks differ with respect to their delta functions, which express how the congruency effects develop with response time. The slope of the delta function is mostly positive for the flanker task, but negative for the Simon task. Much effort has been spent to explain this difference and to investigate whether it results from task-specific control. A prominent account is that the temporal overlap between irrelevant and relevant response activation is larger in the flanker task than in the Simon task. To test this hypothesis, we increased the temporal distance in a flanker task by presenting the flankers ahead of the target. This not only produced negatively sloped delta functions but also caused reversed congruency effects. We also conducted a Simon-task experiment in which we varied the proportion of congruent stimuli. As a result, the delta function was negatively sloped only if the proportion was low. These results demonstrate that a long temporal distance is necessary but not sufficient for observing negatively sloped delta functions. Finally, we modeled the data with drift-diffusion models. Together, our results show that differently sloped delta functions can be produced with both tasks. They further indicate that activation suppression is an important control mechanism that can be adapted rather flexibly to the control demands.

Repetition effects are often helpful in revealing information about mental structures and processes. Usually, positive effects have been observed when the stimuli or responses are repeated. However, in task shift studies it has also been found that response repetitions can produce negative effects if the task shifts. Although several mechanisms have been proposed to account for this interaction between task shifting and response repetition, many details remain open. Therefore, a series of four experiments was conducted to answer two questions. First, are motor responses necessary to produce response-related repetition effects, or is response activation sufficient? Second, does the risk of an accidental re-execution of the last response affect the repetition costs? The results show that response activation alone can produce repetition effects. Furthermore, the risk of accidental response re-execution largely modulates these effects.

This article presents and tests the authors' integration hypothesis of global/local processing, which proposes that at early stages of processing, the identities of global and local units of a hierarchical stimulus are represented separately from information about their respective levels and that, therefore, identity and level information have to be integrated at later stages. It further states that the cerebral hemispheres differ in their capacities for these binding processes. Three experiments are reported in which the integration hypothesis was tested. Participants had to identify a letter at a prespecified level with the viewing duration restricted by a mask. False reporting of the letter at the nontarget level was predicted to occur more often when the integration of identity and level could fail. This was the case. Moreover, visual-field effects occurred, as expected. Finally, a multinomial model was constructed and fitted to the data.

The aesthetic appreciation of a picture largely depends on the perceptual balance of its elements. The underlying mental mechanisms of this relation, however, are still poorly understood. For investigating these mechanisms, objective measures of balance have been constructed, such as the APB (Assessment of Preference for Balance) score of Wilson and Chatterjee (2005). In the present study we examined the APB measure and compared it to an alternative measure (DCM; Deviation of the Center of ‘Mass’) that represents the center of perceptual ‘mass’ in a picture and its deviation from the geometric center. Additionally, we applied measures of homogeneity and of mirror symmetry. In a first experiment participants had to rate the balance and symmetry of simple pictures, whereas in a second experiment different participants rated their preference (liking) for these pictures. In a third experiment participants rated the balance as well as the preference of new pictures. Altogether, the results show that DCM scores accounted better for balance ratings than APB scores, whereas the opposite held with respect to preference. Detailed analyses revealed that these results were due to the fact that aesthetic preference does not only depend on balance but also on homogeneity, and that the APB measure takes this feature into account.