Attention, perception & psychophysics
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In contextual cuing (CC), reaction times for finding targets are faster in repeated displays than in displays that have never been seen before. This has been demonstrated using target-distractor configurations, global background colors, naturalistic scenes, and covariation of targets with distractors. The majority of CC studies have used displays in which the target is always present. ⋯ Experiment 2 showed that there is no CC when the same spatial layout can be both target present and target absent on different trials. The presence of distractors in locations that had contained targets on other trials appeared to interfere with CC, and even disrupted the expression of CC in previously learned contexts (Exps. 3-5). These results show that target-distractor associations are the important element in producing CC and that, consistent with a response selection account, changing the response type from an orientation task to a detection task removes the CC effect.
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Atten Percept Psychophys · Oct 2011
Absence of attentional capture in parallel search is possible: a failure to replicate attentional capture in a non-singleton target search task.
The notion of a singleton versus a feature search mode (Bacon & Egeth, 1994) in visual search is generally widely accepted. Yet Theeuwes (2004) claimed a different, potentially more parsimonious position. He suggested that the size of an attentional window is under top-down control and that salient distractors within this window capture attention. ⋯ Experiment 4 was similar to Experiment 1 but incorporated further details that may account for the discrepant findings. Still, no attentional capture was found. In sum, it was not possible to replicate a crucial piece of evidence for the attentional window hypothesis, and our results are more consistent with the assumption of two different search modes.
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Atten Percept Psychophys · May 2010
Attentional capture decreases when distractors remain visible during rapid serial visual presentations.
The identification of a central visual target is impaired by the onset of a peripheral distractor. This impairment is said to occur because attentional focus is diverted to the peripheral distractor. We examined whether distractor offset would enhance or reduce attentional capture by manipulating the duration of the distractor. ⋯ Identification accuracy was greater in the long-duration condition than in the short-duration condition. The same pattern of results was obtained when participants identified a target of a designated color among heterogeneous nontargets when the color of the distractor was the same as that of the target. These findings suggest that attentional capture consists of stimulus onset and offset, both of which are susceptible to top-down attentional set.
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Contextual information provides an important source for behavioral orienting. For instance, in the contextual-cuing paradigm, repetitions of the spatial layout of elements in a search display can guide attention to the target location. The present study explored how this contextual-cuing effect is influenced by the grouping of search elements. ⋯ The presence of such a square eliminated the contextual-cuing effect, despite the fact that the square's location still had a predictive value for the target location. Three follow-up experiments demonstrated that other types of grouping abolished contextual cuing in a similar way and that the mere presence of a task-irrelevant singleton had only a diminishing effect (by half) on contextual cuing. These findings suggest that a segmented, salient region can interfere with contextual cuing, reducing its predictive impact on search.
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Atten Percept Psychophys · Jul 2009
Temperature perception on the hand during static versus dynamic contact with a surface.
Innocuous cooling or heating of the forearm can evoke nociceptive sensations, such as burning, stinging, and pricking (low-threshold thermal nociception, LTN), that are inhibited by dynamic contact. In the present study, I investigated whether LTN can also be perceived on the hand, and if so, whether it is normally suppressed by active touching. Innocuous cold (28 degrees , 25 degrees , and 18 degrees C) and warm (38 degrees , 40 degrees , and 43 degrees C) temperatures were delivered to the distal metacarpal pads and intermediate and distal phalanges of the fingers via a handgrip thermode that subjects either statically held or actively grasped. ⋯ The results showed that LTN can be perceived on the hand, although less frequently and less intensely than on the forearm. Dynamic contact inhibited nociceptive and thermal sensations on the hand, although less strongly than on the forearm. These findings indicate that temperature perception on the hand is attenuated and its quality is changed when thermal stimulation is accompanied by dynamic tactile stimulation, as it is during haptic exploration.