ABSTRACTThe present study examined the effect of stimulus valence on two levels of selection in the cognitive system, selection of a task-set and selection of a response. In the first experiment, participants performed a spatial compatibility task in which stimulus-response mappings were determined by stimulus valence. There was a standard spatial stimulus-response compatibility effect for positive stimuli and a reversed SRC effect for negative stimuli, but the same data could be interpreted as showing faster responses when positive and negative stimuli (...) were assigned to compatible and incompatible mappings, respectively, than when the assignment was opposite. Experiment 2 disentangled these interpretations, showing that valence did not influence a spatial SRC effect when task-set retrieval was unnecessary. Experiments 3 and 4 replaced keypress responses with joystick deflections that afforded appr... (shrink)

The present study investigated the influence of emotional stimuli in the flanker task. In six experiments, separate influences of anticipating and reacting to valence-laden stimuli (affective pictures or facial expressions) on the flanker effect and its sequential modulation (also known as conflict adaptation) were examined. The results showed that there was little evidence that emotional stimuli influenced cognitive control when positive and negative stimuli appeared randomly during the flanker task. When positive and negative stimuli were separated between different participant groups (...) in order to exclude a possible contamination from the effect of one valence to that of another, the sequential modulation was reduced when valence-laden stimuli were anticipated or had been presented on a preceding trial, regardless of the valence of the stimuli. A similar pattern was also obtained with facial expressions but only for response accuracy and only after valence-laden stimuli were presented on a preceding trial. The influences of anticipating and reacting to emotional stimuli were only partially replicated in the final two experiments where the arousal and valence of affective pictures were manipulated orthogonally. The lack of consistent influences of emotional stimuli on the flanker effect challenges the existing theories that implicate affective contributions to cognitive control. (shrink)