Location-specific attentional control is also possible in the Simon task.

Goal-directed behavior usually requires mental control that directs attention to task-relevant information and ignores irrelevant information. For investigating how flexible this mechanism is, researchers have varied the proportion of congruent trials depending on some context, such as stimulus location. The corresponding studies revealed that attentional control indeed adapts to location-specific demands. However, until now, this flexibility has only been demonstrated for the Eriksen flanker task and for the Stroop task but not for the Simon task. Therefore, a Simon-task experiment was conducted in the present study, where the proportion of congruent trials differed for stimuli appearing above or below fixation, respectively. As a result, a reliable interaction between congruency and stimulus location was found. This demonstrates, for the first time, that location-specific control also is possible in the Simon task.

Evidence for strategic suppression of irrelevant activation in the Simon task.

It is well known that the Simon effect usually decreases with an increasing response time. According to a prominent account this is due to a gradually increasing suppression of irrelevant location-induced activation. What is open, however, and what was investigated in the present study, is to what extent this selective suppression can be adjusted strategically. We hypothesized that strategic suppression should depend on the availability of information about the inhibitory demands. Therefore, in two experiments the demand was modulated by varying the delay between a spatial cue and the target. In the first experiment, where target delay was randomized, there was a negative Simon effect for the longer delays. In a second experiment, where delay was blocked, the Simon effect remained positive. However, the overall Simon effect was larger than in Experiment 1. Together, our results show that the strength of selective suppression can be adjusted strategically, but that this does not necessarily lead to a smaller Simon effect.

Development of cognitive and affective control networks and decision making.

Cognitive control and decision making are two important research areas in the realm of higher-order cognition. Control processes such as interference control and monitoring in cognitive and affective contexts have been found to influence the process of decision making. Development of control processes follows a gradual growth pattern associated with the prolonged maturation of underlying neural circuits including the lateral prefrontal cortex, anterior cingulate, and the medial prefrontal cortex. These circuits are also involved in the control of processes that influences decision making, particularly with respect to choice behavior. Developmental studies on affective control have shown distinct patterns of brain activity with adolescents showing greater activation of amygdala whereas adults showing greater activity in ventral prefrontal cortex. Conflict detection, monitoring, and adaptation involve anticipation and subsequent performance adjustments which are also critical to complex decision making. We discuss the gradual developmental patterns observed in two of our studies on conflict monitoring and adaptation in affective and nonaffective contexts. Findings of these studies indicate the need to look at the differences in the effects of the development of cognitive and affective control on decision making in children and particularly adolescents. Neuroimaging studies have shown the involvement of separable neural networks for cognitive (medial prefrontal cortex and anterior cingulate) and affective control (amygdala, ventral medial prefrontal cortex) shows that one system can affect the other also at the neural level. Hence, an understanding of the interaction and balance between the cognitive and affective brain networks may be crucial for self-regulation and decision making during the developmental period, particularly late childhood and adolescence. The chapter highlights the need for empirical investigation on the interaction between the different aspects of cognitive control and decision making from a developmental perspective.