Simultaneous attentional guidance by working-memory and selection history reveals two distinct sources of attention

Recent theories of attention have proposed that selection history is a separate, dissociable source of information that influences attention. The current study sought to investigate the simultaneous involvement of selection history and working-memory on attention during visual search. Experiments 1 and 2 used target feature probability to manipulate selection history and found significant effects of both working-memory and selection history, although working-memory dominated selection history when they cued different locations. Experiment 3 eliminated the contribution of voluntary refreshing of working-memory and replicated the main effects, although selection history became dominant. Using the same methodology, but with reduced probability cue validity, both effects were present in Experiment 4 and did not significantly differ in their contribution to attention. Effects of selection history and working-memory never interacted. These results suggest that selection history and working-memory are separate influences on attention and have little impact on each other. Theoretical implications for models of attention are discussed.     

False feedback increases detection of low-prevalence targets in visual search

Many critical search tasks, such as airport and medical screening, involve searching for targets that are rarely present. These low-prevalence targets are associated with extremely high miss rates Wolfe, Horowitz, & Kenner (Nature, 435, 439?C440, 2005). The inflated miss rates are caused by a criterion shift, likely due to observers attempting to equate the numbers of misses and false alarms. This equalizing strategy results in a neutral criterion at 50?% target prevalence, but leads to a higher proportion of misses for low-prevalence targets. In the present study, we manipulated participants?? perceived number of misses through explicit false feedback. As predicted, the participants in the false-feedback condition committed a higher number of false alarms due to a shifted criterion. Importantly, the participants in this condition were also more successful in detecting targets. These results highlight the importance of perceived prevalence in target search tasks.     

Prevalence-based decisions undermine visual search

In visual search, observers make decisions about the presence or absence of a target based on their perception of a target during search. The present study investigated whether decisions can be based on observers’ expectation rather than perception of a target. In Experiment 1, participants were allowed to make target-present responses by clicking on the target or, if the target was not perceived, a target-present button. Participants used the target-present button option more frequently in difficult search trials and when target prevalence was high. Experiment 2 and 3 employed a difficult search task that encouraged the use of prevalence-based decisions. Target presence was reported faster when target prevalence was high, indicating that decisions were, in part, cognitive, and not strictly perceptual. A similar pattern of responses were made even when no targets appeared in the search (Experiment 3). The implication of these prevalence-based decisions for visual search models is discussed.     

Intentional inferences are not more likely than unintentional ones: some evidence against the intentionality bias hypothesis

We conducted a study to test the hypothesis that inferences about intentionality are biased toward an intentional interpretation. Contrary to previous research, participants were no more likely to judge ambiguous actions as intentional in a speeded compared to an unspeeded condition. Further, participants were faster to respond and more consistent in responding to unintentional rather than intentional actions.     

Retention of a Time Pressure Heuristic in a Target Identification Task

S. Rice and D. Keller (2009) previously reported that participants who were put under time pressure tended to comply more with a diagnostic aid than participants who were not put under time pressure. The present study investigates whether or not learning the benefits of this time pressure heuristic carries over to a second session. Seventy-two New Mexico State University students performed a simulated target-detection task, assisted by a 95% reliable diagnostic aid. Participants were exposed to the following conditions, which were composed of two sessions: speeded–speeded, unspeeded–speeded, speeded–unspeeded, or unspeeded–unspeeded. Results showed that participants who completed the speeded condition for Session 1 performed just as well in the 2nd session regardless of whether or not they were put under time pressure. Participants found that complying with the aid was beneficial to overall performance and continued to comply in a 2nd session even when allowed more time to overrule the aid.     

Can priming your self lead to punishing others?

Previous research has shown that priming the individual self can increase the accessibility of individual self-cognitions. In turn, we hypothesized that blame for immoral behaviors also would increase, leading to higher assignments of punishment, but that the size of this effect would depend on whether the behaviors violated perfect or imperfect duties. To test these hypotheses, participants assigned yearly bonus penalties to employees who had performed dishonest, disloyal, unfriendly, or uncharitable acts. As expected, the individual prime increased punishments, and this effect was accentuated for violations of perfect duties relative to violations of imperfect duties.     

Prioritization within visual working memory reflects a flexible focus of attention

When motivated, people can keep nonrecent items in a list active during the presentation of new items, facilitating fast and accurate recall of the earlier items. It has been proposed that this occurs by flexibly orienting attention to a single prioritized list item, thus increasing the amount of attention-based maintenance directed toward this item at the expense of other items. This is manipulated experimentally by associating a single distinct feature with a higher reward value, such as a single red item in a list of black items. These findings may be more parsimoniously explained under a distinctiveness of encoding framework rather than a flexible attention allocation framework. The retrieval advantage for the prioritized list position may be because the incongruent feature stands out in the list perceptually and causes it to become better encoded. Across three visual working memory experiments, we contrast a flexible attention theory against a distinctiveness of encoding theory by manipulating the reward value associated with the incongruent feature. Findings from all three experiments show strong support in favor of the flexible attention theory and no support for the distinctiveness of encoding theory. We also evaluate and find no evidence that strategy use, motivation, or tiredness/fatigue associated with reward value can adequately explain flexible prioritization of attention. Flexible attentional prioritization effects may be best understood under the context of an online attentional refreshing mechanism.

     

Generalizing Kant's Distinction between Perfect and Imperfect Duties to Trust in Different Situations

Based on previous research that violations of perfect duties cause stronger correspondent inferences than violations of imperfect ones, the authors performed four experiments to generalize this effect to trust. In Experiment 1, abstract violations of perfect duties resulted in less trust than violations of imperfect ones for specific trust scenarios. In Experiments 2 and 3, the authors experimented with different levels of abstractness of the duty violations and obtained similar effects. Experiment 4 was concerned with generalizing further—from duty violations in one situation to trust in a different situation. Although mostly consistent with the findings from Experiments 1–3, the data also demonstrated partial generalization for violations of both perfect and imperfect duties.     

Task-hemispheric integrity in dual task performance

A condition of task hemispheric integrity is predicted to result in a dual task situation when the central processing and response components of each task are associated exclusively with a given cerebral hemisphere. The prediction that this condition will generate more efficient time-sharing is tested in a series of four experiments. In experiment 1 the prediction is confirmed when a spatial (tracking) and verbal (letter memory search) task are time-shared, and the hand assignment to task responses is manipulated. In experiment 2 a spatial variant of the memory search is used instead of the verbal letter search, and hand assignment effects are not obtained, since when two spatial tasks are time-shared an integrity assignment is impossible. Experiment 3 validates the hemispheric lateralization of the two single task variants of the memory search task, while experiment 4 establishes the separate “spatial’ and “verbal” resource demands of the two variants by observing their differential interference with concurrent spatial and verbal tasks.     

Flexibility within working memory and the focus of attention for sequential verbal information does not depend on active maintenance

The focus of attention seems to be a static element within working memory when verbal information is serially presented, unless additional time is available for processing or active maintenance. Experiment 1 manipulated the reward associated with early and medial list positions in a probe recognition paradigm and found evidence that these nonterminal list positions could be retrieved faster and more accurately if participants were appropriately motivated—without additional time for processing or active maintenance. Experiment 2 used articulatory suppression and demonstrated that the underlying maintenance mechanism cannot be attributed to rehearsal, leaving attentional refreshing as the more likely mechanism. These findings suggest that the focus of attention within working memory can flexibly maintain nonterminal early and medial list representations at the expense of other list representations even when there is not additional time for processing or active maintenance. Maintenance seems to be accomplished through an attentional refreshing mechanism.