Search

Psychological research has extensively shown that individuals are limited in their ability to process environmental information temporally. In a rapid serial visual presentation, the ability to identify the second of two targets presented in close succession among distractors is usually impaired, a phenomenon known as attentional blink (AB). Paradoxically, when the second target immediately succeeds the first one (lag 1), such an ability is relatively spared, but individuals are more prone to misreport their correct temporal succession. Competitive mechanisms based on prior entry and perceptual integration processes have been suggested to account for the apparent loss of temporal information. We report findings from four experiments, showing that, once identified, categorical dimensions of the stimuli used as targets (here, the ordinality of numbers) may guide the perception and the resulting report of their temporal order. Specifically, at lag 1 individuals more frequently encode the two digits in ascending order. Such a biased regularization may represent another possible outcome of the failure in temporal segregation observed at lag 1, indicating that a mechanism based on prior entry is not generalizable in explaining order reversals. The kind of stimuli chosen as targets in AB paradigms can activate high-level categorical dimensions capable of influencing the performance on this task. [ABSTRACT FROM AUTHOR]

In selective attention tasks, the efficiency of processing concurrently presented target and distractor stimuli in a given display is often influenced by the relationship these stimuli have with those in the previous display. When a to-be-attended target on a current trial (the probe trial) matches the ignored, non-target distractor on a previous trial (the prime trial), a response to the target is typically delayed compared with when the two stimuli are not associated. This negative priming (NP) phenomenon has been observed in numerous studies with traditional NP tasks presenting the target and distractor simultaneously in both the prime and probe trial couplets. Here, however, in four experiments using a mixture of stimulus types (letters, digits, English number words, and logographic Chinese number words), target and distractor stimuli were temporally separated in two rapid serial visual presentation (RSVP) streams instead of concurrently presented. The findings provide a conceptual replication and substantial extension of a recent study by Wong ( Plos One, 7, e37023, 2012), and suggest that active suppression of irrelevant distracting information is a more ubiquitous form of cognitive control than previously thought. [ABSTRACT FROM AUTHOR]

Performance in rapid serial visual presentation tasks has been shown to depend on the temporal integration of target stimuli when they are presented in direct succession. Temporal target integration produces a single, combined representation of visually compatible stimuli, which is comparatively easy to identify. It is currently unknown to what extent target compatibility affects this perceptual behavior, because it has not been studied systematically to date. In the present study, the effects of compatibility on temporal integration and attention were investigated by manipulating the Gestalt properties of target features. Of particular interest were configurations in which a global illusory shape was formed when all stimulus features were present; a Kanizsa stimulus, which was expected to have a unifying effect on the perception of the successive targets. The results showed that although the presence of a Kanizsa shape can indeed enhance temporal integration, this also was observed for other good Gestalts, such as due to common fate and closure. Identification accuracy seemed to vary, possibly as a result of masking strength, but this did not seem associated with attentional processing per se. Implications for theories of Gestalt processing and temporal integration are discussed. [ABSTRACT FROM AUTHOR]

This study proposed and verified a new hypothesis on the relationship between gaze direction and visual attention: attentional bias by default gaze direction based on eye-head coordination. We conducted a target identification task in which visual stimuli appeared briefly to the left and right of a fixation cross. In Experiment 1, the direction of the participant's head (aligned with the body) was manipulated to the left, front, or right relative to a central fixation point. In Experiment 2, head direction was manipulated to the left, front, or right relative to the body direction. This manipulation was based on results showing that bias of eye position distribution was highly correlated with head direction. In both experiments, accuracy was greater when the target appeared at a position where the eyes would potentially be directed. Consequently, eye-head coordination influences visual attention. That is, attention can be automatically biased toward the location where the eyes tend to be directed. [ABSTRACT FROM AUTHOR]

Recent studies of visual search suggest that learning about valued outcomes (rewards and punishments) influences the likelihood that distractors will capture spatial attention and slow search for a target, even when those value-related distractors have never themselves been the targets of search. In the present study, we demonstrated a related effect in the context of temporal, rather than spatial, selection. Participants were presented with a temporal stream of pictures in a fixed central location and had to identify the orientation of a rotated target picture. Response accuracy was reduced if the rotated target was preceded by a 'valued' distractor picture that signaled that a correct response to the target would be rewarded (and an incorrect response punished), relative to a distractor picture that did not signal reward or punishment. This effect of signal value on response accuracy was short-lived, being most prominent with a short lag between distractor and target. Impairment caused by a valued distractor was observed if participants were explicitly instructed regarding its relation to reward/punishment (Exps. 1, 3, and 4), or if they could learn this relationship only via trial-by-trial experience (Exp. 2). These findings show that the influence of signal value on attentional capture extends to temporal selection, and also demonstrate that value-related distractors can interfere with the conscious perception of subsequent target information. [ABSTRACT FROM AUTHOR]

Attentional blink occurs when two target items, T1 and T2, are presented within brief moments of each other in a series of rapidly presented items and participants fail to report T2. The purpose of the present study was to examine the effect of characteristics of T2 on T2 reporting. Participants ( N = 67) completed 4 blocks of 40 trials. Each trial consisted of 15 images, two of which were designated as T1 and T2. T2 was manipulated in three ways: animacy (animate or inanimate), threat (threatening or nonthreatening), and lag (200 ms or 400 ms after T1). The results indicated that more T2s were reported at the longer lag and that animate objects were reported more often than inanimate objects at both lags. Threat did not have a significant effect on T2 reporting although it interacted with lag: threatening objects were reported more frequently than nonthreatening objects at lag 2 but this trend reversed at lag 4. The results were consistent with the animate monitoring hypothesis, which claims that animate objects, because of their importance in ancestral environments, attract attention more easily than inanimate objects. Animate objects appear to capture attention more easily than inanimate objects as second targets in a rapid serial visual presentation task. This result is similar to animacy advantages reported with other attention tasks and with memory tasks. [ABSTRACT FROM AUTHOR]

Rationale: The specific role of neuromodulator systems in regulating rapid fluctuations of attention is still poorly understood. Objectives: In this study, we examined the effects of clonidine and scopolamine on multiple target detection in a rapid serial visual presentation task to assess the role of the central noradrenergic and cholinergic systems in temporal attention. Method: Eighteen healthy volunteers took part in a crossover double-dummy study in which they received clonidine (150/175 μg), scopolamine (1.2 mg), and placebo by mouth in counterbalanced order. A dual-target attentional blink task was administered at 120 min after scopolamine intake and 180 min after clonidine intake. The electroencephalogram was measured during task performance. Results: Clonidine and scopolamine both impaired detection of the first target (T1). For clonidine, this impairment was accompanied by decreased amplitudes of the P2 and P3 components of the event-related potential. The drugs did not impair second-target (T2) detection, except if T2 was presented immediately after T1. The attentional blink for T2 was not affected, in line with a previous study that found no effect of clonidine on the attentional blink. Conclusions: These and other results suggest that clonidine and scopolamine may impair temporal attention through a decrease in tonic alertness and that this decrease in alertness can be temporarily compensated by a phasic alerting response to a salient stimulus. The comparable behavioral effects of clonidine and scopolamine are consistent with animal studies indicating close interactions between the noradrenergic and cholinergic neuromodulator systems. [ABSTRACT FROM AUTHOR]

Converging evidence has shown that onset capture can be completely eliminated by the demands of a concurrent task and during the attentional blink. In the present study, we investigated contingent capture during the attentional blink. We found that contingent capture was attenuated, or even completely eliminated, during the 'blink' time of the attentional blink. These results indicate that contingent capture requires limited attentional resources. [ABSTRACT FROM AUTHOR]

Previous investigations of the ability to maintain separate attentional control settings for different spatial locations have relied principally on a go/no-go spatial-cueing paradigm. The results have suggested that control of attention is accomplished only late in processing. However, the go/no-go task does not provide strong incentives to withhold attention from irrelevant color-location conjunctions. We used a modified version of the task in which failing to adopt multiple control settings would be detrimental to performance. Two RSVP streams of colored letters appeared to the left and right of fixation. Participants searched for targets that were a conjunction of color and location, so that the target color for one stream acted as a distractor when presented in the opposite stream. Distractors that did not match the target conjunctions nevertheless captured attention and interfered with performance. This was the case even when the target conjunctions were previewed early in the trial prior to the target (Exp. 2). However, distractor interference was reduced when the upcoming distractor was previewed early on in the trial (Exp. 3). Attentional selection of targets by color-location conjunctions may be effective if facilitative attentional sets are accompanied by the top-down inhibition of irrelevant items. [ABSTRACT FROM AUTHOR]

Identification of the second of two targets (T1, T2, inserted in a stream of distractors) is impaired when presented within 500 ms after the first (attentional blink, AB). Barring a T1-T2 task-switch, it is thought that T2 must be backward-masked to obtain an AB (Giesbrecht & Di Lollo, Journal of Experimental Psychology: Human Perception and Performance, 24, 1454-1466, ). We tested the hypothesis that Giesbrecht & Di Lollo's findings were vitiated by ceiling constraints arising from either response scale (experiment 1) or data limitations (experiment 2). In experiment 1, digit-distractors were replaced with pseudoletters to increase task difficulty, bringing performance below ceiling. An AB occurred without backward masking of T2. In experiment 2, a ceiling-free procedure estimated the number of noise dots needed for 80% T2 identification. An AB was revealed: fewer noise dots were required during the AB period than outside it. Both outcomes confirm that an AB can be obtained without either masking of T2 or task switching. [ABSTRACT FROM AUTHOR]

When identifying two targets presented in a rapid serial visual presentation stream, one's accuracy on the second target is reduced if it is presented shortly (within 500 msec) after the first target-an attentional blink (AB). Individuals differ greatly in the size of their AB. One way to learn about the AB is to understand what underlies these individual differences. Recent studies have suggested that when a broadened or diffused attentional state is induced, the AB deficit can be attenuated. The present study examined whether natural (dispositional) individual differences in focus and diffusion of attention as assessed by the global/local task could predict performance on the AB task. Performance that was consistent with diffusion correlated negatively with AB size, and performance that was consistent with focusing correlated positively with AB size, showing that dispositional focus and diffusion of attention can predict individual differences in the AB. These findings are consistent with the Olivers and Nieuwenhuis (2006) overinvestment hypothesis. [ABSTRACT FROM AUTHOR]