Simon effects might partly reflect stimulus-triggered response activation. According to the response-discrimination hypothesis, however, stimulus-triggered response activation shows up in Simon effects only when stimulus locations match the top-down selected spatial codes used to discriminate between alternative responses. Five experiments support this hypothesis. In Experiment 1, spatial codes of each response differed by horizontal and vertical axis position, yet one axis discriminated between alternative responses, whereas the other did not. Simon effects resulted for targets on discriminating axes only. In Experiment 2, both spatial axes discriminated between responses, and targets on both axes produced Simon effects. In Experiment 3, Simon effects resulted for a spatial choice-reaction task but not for a go/no-go task. Even in the go/no-go task, a Simon effect was restored when a two-choice reaction task preceded the go/no-go task (Experiment 4) or when participants initiated trials with responses spatially discriminated from the go response (Experiment 5).

According to the processing-fluency explanation of aesthetics, more fluently processed stimuli are preferred (R. Reber, N. Schwarz, & P. Winkielman, 2004, Processing fluency and aesthetic pleasure: Is beauty in the perceiver's processing experience? Personality and Social Psychology Review, Vol. 8, pp. 364-382.). In this view, the subjective feeling of ease of processing is considered important, but this has not been directly tested in perceptual processing. In two experiments, we therefore objectively manipulated fluency (ease of processing) with subliminal perceptual priming (Study 1) and variations in presentation durations (Study 2). We assessed the impact of objective fluency on feelings of fluency and liking, as well as their interdependence. In line with the processing-fluency account, we found that objectively more fluent images were indeed judged as more fluent and were also liked more. Moreover, differences in liking were even stronger when data were analyzed according to felt fluency. These findings demonstrate that perceptual fluency is not only explicitly felt, it can also be reported and is an important determinant of liking.

The present study investigates sequential modulations of the Simon effect. The Simon effect involves faster responses to spatially corresponding than to noncorresponding stimuli, even when stimulus position is irrelevant. Recently, the Simon effect has been shown to decrease or to disappear after noncorresponding predecessor trials. Possible explanations for these sequential modulations include (a) the gating of position-based response activation (conflict monitoring), (b) repetition or alternation effects, and (c) the interaction between feature integration (binding) processes and stimulus-response (S-R) correspondence. Three experiments tested different predictions of these models by comparing Simon effects after neutral trials with those after corresponding and noncorresponding trials, respectively, and by varying the stimulus-onset asynchrony (SOA) between and within experiments. Experiments 1 and 2 revealed large Simon effects after corresponding trials, intermediate Simon effects after neutral trials, and small (or no) Simon effects after noncorresponding trials. Moreover, some systematic effects of S-R repetitions and S-R alternations were observed. Finally, the sequential modulations were maximal at short SOAs and decreased with increasing SOA, but still occurred at an SOA of 6 seconds. The results seem to exclude repetition or alternation effects as the main cause of sequential modulations of the Simon effect, but both conflict monitoring and binding may contribute to these effects.

In 5 experiments, the authors tested whether the processing of nonconscious spatial stimulus information depends on a prior intention. This test was conducted with the metacontrast dissociation paradigm. Experiment 1 demonstrated that masked primes that could not be discriminated above chance level affected responses to the visible stimuli that masked them. Experiments 2 and 3 showed that this effect was abolished when the task instruction was changed in such a way that the primes ceased to be task relevant. Experiments 4 and 5 demonstrated that a prime's effect depended on whether it was associated with the same response as the target or with an opposite response.

According to contingent-processing accounts, peripheral cuing effects are due to the cues' inadvertent selection for processing by control settings set up for targets (e.g., C. L. Folk, R. W. Remington, & J. C. Johnston, 1992). Consequently, cues similar to targets should have stronger effects than do dissimilar cues. In the current study, this prediction is confirmed for cue-target combinations similar or dissimilar in the static features of color (Experiments 1-3) and location (Experiment 4), even when both cues and targets share the dynamic feature of abrupt onset. Perceptual priming (Experiment 2) and reallocation of attention did not account for similar-dissimilar differences (Experiments 3 and 4). The results are best explained by top-down-contingent attentional effects of the similar cues. Implications for bottom-up accounts of peripheral cuing effects are discussed. ((c) 2003 APA, all rights reserved)