No abstract

In two experiments, we examined the extent to which automatic attentional biases, as indexed by performance in the emotional Stroop task (Experiment 1) and the dot-probe task (Experiment 2), are modulated by feature-specific attention allocation. In both experiments, participants were encouraged to attend to either affective stimulus information (affective groups) or non-affective semantic stimulus information (non-affective groups). In both experiments, an attentional bias towards negative stimuli was found in the affective groups but not in the non-affective groups. In Experiment 1, we also observed an attentional bias towards non-affective semantic stimulus information in the non-affective group but not in the affective groups. We argue that these effects are due to a modulation of automatic stimulus processing by feature-specific attention allocation. Our data demonstrate that automatic attentional biases toward negative stimuli are not unconditional but instead depend on the relevance of negative information. Moreover, the results of Experiment 1 suggest that attention is automatically biased towards non-affective stimulus dimensions that are currently relevant.

Affective priming studies have shown that participants are faster to pronounce affectively polarized target words that are preceded by affectively congruent prime words than affectively polarized target words that are preceded by affectively incongruent prime words. We examined whether affective priming of naming responses depends on the valence proportion (i.e., the proportion of stimuli that are affectively polarized). In one group of participants, experimental trials were embedded in a context of filler trials that consisted of affectively polarized stimulus materials (i.e., high valence proportion condition). In a second group, the same set of experimental trials was embedded in a context of filler trials consisting of neutral stimuli (i.e., low valence proportion condition). Results showed that affective priming of naming responses was significantly stronger in the high valence proportion condition than in the low valence proportion condition. We conclude that (a) subtle aspects of the procedure can influence affective priming of naming responses, (b) finding affective priming of naming responses does not allow for the conclusion that affective stimulus processing is unconditional, and (c) affective stimulus processing depends on selective attention for affective stimulus information.

Previous behavioral studies have shown that instructions about stimulus-response (S-R) mappings can influence task performance even when these instructions are irrelevant for the current task. In the present study, we tested whether automatic effects of S-R instructions occur because the instructed stimuli automatically activate their corresponding responses. We registered the lateralized readiness potentials (LRPs) that were evoked by the instructed stimuli while participants were performing a task for which those mappings were irrelevant. Instructed S-R mappings clearly affected task performance in electrophysiological and behavioral measures. The LRP was found to deflect in the direction of the response tendency that corresponded with the instructed S-R mapping. Early activation of the instructed response was observed but occurred predominantly on slow trials. In contrast, response conflict evoked by instructed S-R mappings did not modulate the N2 amplitude. The results strongly suggest that, like experienced S-R mappings, instructed S-R mappings can lead to automatic response activation, but possibly via a different route

This study examines two contrasting explanations for early tendencies to fight and flee. According to a stimulus-driven explanation, goal-incompatible stimuli that are easy/difficult to control lead to the tendency to fight/flee. According to a goal-directed explanation, on the other hand, the tendency to fight/flee occurs when the expected utility of fighting/fleeing is the highest. Participants did a computer task in which they were confronted with goal-incompatible stimuli that were (a) easy to control and fighting had the highest expected utility, (b) easy to control and fleeing had the highest expected utility, and (c) difficult to control and fleeing and fighting had zero expected utility. After participants were trained to use one hand to fight and another hand to flee, they either had to choose a response or merely observe the stimuli. During the observation trials, single-pulse Transcranial Magnetic Stimulation (TMS) was applied to the primary motor cortex 450 ms post-stimulus onset and motor-evoked potentials (MEPs) were measured from the hand muscles. Results showed that participants chose to fight/flee when the expected utility of fighting/fleeing was the highest, and that they responded late when the expected utility of both responses was low. They also showed larger MEPs for the right/left hand when the expected utility of fighting/fleeing was the highest. This result can be interpreted as support for the goal-directed account, but only if it is assumed that we were unable to override the presumed natural mapping between hand (right/left) and response (fight/flight).