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The Simon effect has most often been investigated with key-press responses and eye fixation. In the present study, we asked how the type of eye movement and the type of manual response affect response selection in a Simon task. We investigated three eye movement instructions (spontaneous, saccade, and fixation) while participants performed goal-directed (i.e., reaching) or symbolic (i.e., finger-lift) responses. Initially, no oculomotor constraints were imposed, and a Simon effect was present for both response types. Next, eye movements were constrained. Participants had to either make a saccade toward the stimulus or maintain gaze fixed in the screen centre. While a congruency effect was always observed in reaching responses, it disappeared in finger-lift responses. We suggest that the redirection of saccades from the stimulus to the correct response location in noncorresponding trials contributes to the Simon effect. Because of eye-hand coupling, this occurred in a mandatory manner with reaching responses but not with finger-lift responses. Thus, the Simon effect with key-presses disappears when participants do what they typically do-look at the stimulus.

Salient vocalizations, especially aggressive voices, are believed to attract attention due to an automatic threat detection system. However, studies assessing the temporal dynamics of auditory spatial attention to aggressive voices are missing. Using event-related potential markers of auditory spatial attention (N2ac and LPCpc), we show that attentional processing of threatening vocal signals is enhanced at two different stages of auditory processing. As early as 200 ms post-stimulus onset, attentional orienting/engagement is enhanced for threatening as compared to happy vocal signals. Subsequently, as early as 400 ms post-stimulus onset, the reorienting of auditory attention to the center of the screen (or disengagement from the target) is enhanced. This latter effect is consistent with the need to optimize perception by balancing the intake of stimulation from left and right auditory space. Our results extend the scope of theories from the visual to the auditory modality by showing that threatening stimuli also bias early spatial attention in the auditory modality. Attentional enhancement was only present in female and not in male participants. [ABSTRACT FROM AUTHOR]

The orientation-bias hypothesis states that there is a bias to attend to the right visual hemifield (RVF) when there is spatial competition between stimuli in the left and right hemifield [Pollmann, S. (1996). A pop-out induced extinction-like phenomenon in neurologically intact subjects. Neuropsychologia, 34(5), 413- 425. doi:10.1016/0028-3932(95)00125-5]. In support of this hypothesis, stronger interference was reported for RVF distractors with contralateral targets. In contrast, previous studies using rapid serial visual presentation (RSVP) found stronger interference from distractors in the left visual hemifield (LVF). We used the additional singleton paradigm to test whether this discrepancy was due to the different distractor features that were employed (colour vs. orientation). Interference from the colour distractor with contralateral targets was larger in the RVF than in the LVF. However, the asymmetrical interference disappeared when observers had to search for an inconspicuous colour target instead of the inconspicuous shape target. We suggest that the LVF orienting-bias is limited to situations where search is driven by bottom-up saliency (singleton search) instead of top-down search goals (feature search). In contrast, analysis of the literature suggests the opposite for the LVF bias in RSVP tasks. Thus, the attentional asymmetry may depend on whether the task involves temporal or spatial competition, and whether search is based on bottom-up or top-down signals. [ABSTRACT FROM AUTHOR]

Evidence for motion extrapolation at motion offset is scarce. In contrast, there is abundant evidence that subjects mentally extrapolate the future trajectory of weak motion signals at motion offset. Further, pointing movements overshoot at motion offset. We believe that mental and sensorimotor extrapolation is sufficient to solve the problem of perceptual latencies. Both present the advantage of being much more flexible than motion extrapolation.

Gaze-cueing is the automatic spatial orienting of attention in the direction of perceived gaze. Participants respond faster to targets located at positions congruent with the direction of gaze, compared to incongruent ones (gaze cueing effect, GCE). However, it still remains unclear whether its occurrence depends on intact integration of information from the entire eye region or face, rather than simply the presence of the eyes per se. To address this question, we investigated the GCE in PS, an extensively studied case of pure acquired prosopagnosia. In our gaze-cueing paradigm, we manipulated the duration at which cues were presented (70ms vs. 400ms) and the availability of facial information (full-face vs. eyes-only). For 70ms cue duration, we found a context-dependent dissociation between PS and controls: PS showed a GCE for eyes-only stimuli, whereas controls showed a GCE only for full-face stimuli. For 400ms cue duration, PS showed gaze-cueing independently of stimulus context, whereas in healthy controls a GCE again emerged only for full-face stimuli. Our findings suggest that attentional deployment based on the gaze direction of briefly presented faces requires intact processing of facial information, which affords salience to the eye region. [ABSTRACT FROM AUTHOR]

We are faster and more accurate at detecting frequently occurring objects than infrequent ones, just as we are faster and more accurate at detecting objects that have been spatially cued. Does this behavioral similarity reflect similar processes? To evaluate this question we manipulated orientation probability and exogenous spatial cuing within a single perceptual estimation task. Both increased target probability and spatial cuing led to shorter response initiation times and more precise perceptual reports, but these effects were additive. Further, target probability changed the shape of the distribution of errors while spatial cuing did not. Different routes and independent mechanisms could lead to changes in behavioral measures that look similar to each other and to 'attentional' effects. [ABSTRACT FROM AUTHOR]

Peripheral cues reduce reaction times (RTs) to targets at the cued location with short cue-target SOAs (cueing benefits) but increase RTs at long SOAs (cueing costs or inhibition of return). In detection tasks, cueing costs occur at shorter SOAs and are larger compared with identification tasks. To account for effects of task, detection cost theory claims that the integration of cue and target into an object file makes it more difficult to detect the target as a new event, which is the principal task-requirement in detection tasks. The integration of cue and target is expected to increase when cue and target are similar. We provided evidence for detection cost theory in the modified spatial cueing paradigm. Two types of cues (onset, color) were paired with two types of targets (onset, color) in separate blocks of trials. In the identification task, we found cueing benefits with matching (i.e., similar) cue-target pairs (onset-onset, color-color) and no cueing effects with nonmatching cue-target pairs (onset-color, color-onset), which replicates previous work. In the detection task, cueing effects with matching cues were reduced and even turned into cueing costs for onset cues with onset targets, suggesting that cue-target integration made it more difficult to detect targets at the cued location as new events. In contrast, the results for nonmatching cue-target pairs were not affected by task. Furthermore, the pattern of false alarms in the detection task provides a measure of similarity that may explain the size of cueing benefits and costs. [ABSTRACT FROM AUTHOR]

In visual search for a shape target, interference from salient-but-irrelevant color singletons can be resisted in feature search mode, but not in singleton detection mode. In singleton detection mode, we observed a contralateral positivity (P D ) after 260–340 ms, suggesting that the salient distractor was suppressed. Because RTs in singleton detection mode increased when a distractor was present, we conclude that active suppression of distractors takes time. In feature search mode, no increase in RTs and no P D to the distractor was observed, showing that resistance to interference was not accomplished by suppression. Rather, the smaller N2pc to the target in feature search than in singleton detection mode suggests that enhancement of target features avoided interference. Thus, the strong top-down set in feature search mode eliminated the need to suppress the early attend-to-me signal (corresponding to the Ppc, from 160 to 210 ms) that was generated by salient stimuli independently of search mode. [ABSTRACT FROM AUTHOR]