Development of dynamic attention: Time-based visual selection for objects in motion between 6-12 years of age.

By approximately 6 years of age, children can use time-based visual selection to ignore stationary stimuli, already in the visual field and prioritize the selection of newly arriving stimuli. This ability can be studied using preview search, a version of the visual search paradigm with an added temporal component, in which one set of distractors is presented (previewed) before a second set that contains the target item. Preview search is more efficient than if all items are presented simultaneously, suggesting that temporally "old" objects can be ignored (the preview benefit).

Look on the bright side: Positivity bias modulates interference effects in the simon task.

Negative faces are detected more quickly but categorized more slowly than positive faces. Using a Simon task, we examined stimulus- and response-related processes of this dissociation: If negative stimuli are both processed and responded to more quickly than positive ones, they should elicit reduced Simon effects. Conversely, if negative stimuli are processed more quickly but responded to more slowly, enlarged Simon effects should occur.

Inhibition in time-based visual selection: Strategic or by default?

The visual marking mechanism (Watson & Humphreys, 1997) allows new objects to be prioritized by applying top-down inhibition to a set of previewed distractors, increasing the efficiency of future visual search. However, if this inhibition results in little or no search facilitation, do people continue to apply it or do they strategically withhold it? Here we present 6 experiments in which we examined how participants control this inhibitory mechanism. Experiments 1 to 3 showed that in difficult search contexts, participants did not modulate the extent to which they applied inhibition based on the proportion of trials in which inhibition would have been useful.

Ignoring real faces: effects of valence, threat, and salience.

Facial stimuli have been shown to accrue a special status within visual processing, particularly when attention is prioritized to one face over another on the basis of affective content. This has been examined in relation to the ability of faces to guide or hold attention, or to resist attentional suppression. Previous work has shown that schematic faces can only be partially ignored and that the emotional valence of to-be-ignored faces has little effect.

Tagging multiple emotional stimuli: negative valence has little benefit.

Six experiments examined the influence of emotional valence on the tagging and enumeration of multiple targets. Experiments 1, 5 and 6 found that there was no difference in the efficiency of tagging/enumerating multiple negative or positive stimuli. Experiment 2 showed that, when neutral-expression face distractors were present, enumerating negative targets was faster overall, but was only more efficient for small numbers of targets.

Negative triangles: simple geometric shapes convey emotional valence.

It has been suggested that downward pointing triangles convey negative valence, perhaps because they mimic an underlying primitive feature present in negative facial expressions (Larson, Aronoff, and Stearns, 2007). Here, we test this proposition using a flanker interference paradigm in which participants indicated the valence of a central face target, presented between two adjacent distracters. Experiment 1 showed that, compared with face flankers, downward pointing triangles had little influence on responses to face targets.

Emotional triangles: a test of emotion-based attentional capture by simple geometric shapes.

Previous work has proposed that simple geometric shapes, carrying the features present within negative or threatening faces are especially effective at capturing or guiding attention. Here we test this account and provide converging evidence for a threat-based attentional advantage. Experiment 1 found that downward-pointing triangles continue to be detected more efficiently than upward-pointing triangles when: (i) both overall RT and search slope measures are obtained; and (ii) when the set size is varied and the stimuli are presented in random configurations.

Visual marking and facial affect: can an emotional face be ignored?

Previewing a set of distractors allows them to be ignored in a subsequent visual search task (Watson & Humphreys, 1997). Seven experiments investigated whether this preview benefit can be obtained with emotional faces, and whether negative and positive facial expressions differ in the extent to which they can be ignored. Experiments 1-5 examined the preview benefit with neutral, negative, and positive previewed faces.

Incidental learning of S-R contingencies in the masked prime task.

Subliminal motor priming effects in the masked prime paradigm can only be obtained when primes are part of the task set. In 2 experiments, the authors investigated whether the relevant task set feature needs to be explicitly instructed or could be extracted automatically in an incidental learning paradigm. Primes and targets were symmetrical arrows, with target color, not shape, the response-relevant feature.

No difference between conscious and nonconscious visuomotor control: evidence from perceptual learning in the masked prime task.

Negative compatibility effects (NCEs) in the masked-prime paradigm are usually obtained when primes are masked effectively. With ineffective masks-and primes above the perceptual threshold-positive compatibility effects (PCEs) occur. We investigated whether this pattern reflects a causal relationship between conscious awareness and low-level motor control, or whether it reflects the fact that both are affected in the same way by changes in physical stimulus attributes.