Kähler, Svantje

Attention can be directed to the global or local level of a visual stimulus (i.e., Navon figure). Previous studies yielded reliable trial-to-trial level switch costs (i.e., worse performance when responding to the other level than on a previous trial), even though level cueing effects indicated anticipatory deployment of attention to the upcoming target level. To investigate the interplay of attentional preparation and persistence, we applied a probe trial method assumed to ensure a high degree of preparation for the upcoming target level and minimizing stimulus-specific proactive interference. Mirroring previous findings obtained in the domain of spatial attention, we found evidence for anticipatory attentional focusing on global/local target levels but not for persistence of the attentional set adopted on the previous trial. In a second experiment, we prevented preparation for upcoming attentional demands (in both global-local and spatial attention tasks). This resulted in the modulation of performance (in critical probe trials) by the attentional demands of the predecessor trial. Together, our findings demonstrate sensitivity of the probe trial method for attentional persistence and raise the possibility that such persistence can be completely eliminated by sufficiently strong preparation for the attentional demands of the following trial.

Public attitude toward Unmanned Aerial Vehicles (UAVs) has been extensively researched, frequently using surveys or experimental settings involving sound/noise. In this study, we present an experiment using visual stimuli, exploring not only the acceptance of UAVs as such but also of their interactions with different environments. The stimuli were pictures of quadcopters, either white or orange, with medical or commercial markings. For comparison, pictures of helicopters with the same four variations and a goose were also used. These pictures were superimposed over three types of backgrounds: urban, industrial, and rural. Twenty-four student participants took part in this study, each responding to 81 stimuli with Likert scale ratings for the acceptance and beauty of the stimuli after responding to objects that were used as a manipulation check. Reaction times for all responses were recorded. Afterward, participants completed a survey designed to identify the reasons for their judgments regarding acceptance. Our results deliver a complex view of the acceptance of UAVs. For example, the usage of the UAV had the largest impact on acceptance, with medical usage having the highest acceptance rating. Commercial usage was more accepted in industrial areas, and UAVs were more accepted than helicopters. The survey showed a heterogeneous variety and relevance of reasons for the acceptance ratings. On average, usefulness, traffic relief, reduction of privacy, and acceptance by society were indicated as the most relevant factors affecting the acceptance ratings. In general, our study suggests that the less considered visual factors of drones (salience in our study) can be expected to influence the acceptance of UAVs in addition to the noise factor. Most importantly, the physical characteristics of UAVs alone are insufficient to predict their acceptance. The purposes for which UAVs are used (that might be visually recognizable) and the environment in which they are operated play an important role in shaping public attitudes towards this new technology.

Visual attention can be adjusted to task requirements. We asked participants to switch between judging the symmetry of vertically presented three-letter strings and identifying the central stimulus (i.e., Eriksen task) to investigate anticipatory adjustment of attention. Our experiments provide evidence for anticipatory adjustment of visual attention, depending on the cued task (i.e., focusing and defocusing of attention after the Eriksen task cue and after the symmetry task cue, respectively). Although, symmetry judgments were, overall, considerably slower than the identification of the central letter, the effects of response congruency between tasks were comparable in the two tasks, which suggested strong response priming from concurrent symmetry judgment in Eriksen task trials. Symmetry judgment performance was best for homogeneous letter strings (e.g., HHH), worst for strings that were symmetrical and inhomogeneous (e.g., XHX), and intermediate for asymmetrical strings (e.g., HHX). The difficulty of categorizing symmetrical-inhomogeneous items markedly deviated from the aesthetic ratings of the stimuli, displaying a pronounced preference for symmetrical strings, but only little difference among the symmetrical items, and might be accounted by conflict with response priming based on inhomogeneity detection. Although our study provides little evidence for an effect of aesthetic appreciation in simple symmetry judgments, it demonstrates the strong role of contextual dependencies.

Evidence from behavioral and physiological studies suggests attentional weighting of stimulus information from different sources, according to task demands. We investigated the adoption of task-specific attentional sets by administering a flanker task, which required responding to a centrally presented letter while ignoring two adjacent letters, and a same-different judgment task, which required a homogenous/heterogeneous classification concerning the complete three-letter string. To assess the distribution of attentional weights across the letter locations we intermixed trials of a visual search task, in which a target stimulus occurred randomly in any of these locations. Search task reaction times displayed a stronger center-to periphery gradient, indicating focusing of visual attention on the central location, when the search task was intermixed into blocks of trials of the flanker task than into blocks of trials of the same-different task (Experiment 1) and when a cue indicated the likely occurrence of the flanker task as compared to the likely occurrence the same-different task (Experiment 2). These findings demonstrate flexible adoption of task-specific sets of visual attention that can be implemented during preparation. In addition, responses in the intermixed search task trials were faster and (marginally significantly) more error-prone after preparation for a (letter) task repetition than for a task switch, suggesting that response caution is reduced during preparation for a task repetition.