VISUAL COGNITION最新文献

Visual search is critical in many activities. Under time pressure or when targets are hard to detect, decisions about target presence might be forced with insufficient information. Then an estimation of confidence is essential for subsequent actions. We asked participants to search for a small target in two search stimuli and to choose the one they felt more confident about. Target presence and the size of one stimulus was varied. The hit rate decreased as gaze-target distance increased. At large distances, hits and false alarms were similar and correlated across participants, suggesting lucky guesses. Performance was better in chosen than in non-chosen stimuli, mainly because of higher hit rate. Confidence choices preferred smaller stimuli and target-present responses. The latter preference decreased with increasing gaze-target distance, indicating reliance on target visibility. These results indicate that confidence in visual search is influenced by target visibility and the probability that the target was overlooked.

To detect changes in our visual environments, the visual system compares pre-and post-change representations maintained in active working memory. Previous research has suggested that change detection is primarily informed by high-level semantics in naturalistic scenes. Here, across two experiments, we used meaning maps - a data driven method to measure the visual semantic information in naturalistic scenes - to investigate whether semantic features predicted visual change detection in a flicker paradigm. Experiment 1 showed that changes in highly meaningful regions were more easily detected than changes in non-meaningful regions despite controlling for low-level visual saliency. Experiment 2 found that the meaning-driven advantage was significantly reduced by scene inversion, further supporting the role of semantics in change detection. Together, these results demonstrate that the visual system relies on semantic features during change detection.

During everyday functioning, the visual world is explored by using saccadic eye movements to direct the information-rich fovea to specific locations. These eye movements are guided by visual input from outside of the fovea, where processes of perceptual organization piece together scene and object structure, including contour information. The current study investigates variation in how the typical population uses eye movements to complete a search for a closed-contour target formed by oriented gabor patches. Performance at contour integration tasks varies across a range of clinical populations, although it is unknown the degree to which performance differs within the typical population and if these differences relate to how individuals move their eyes during the task. The results show large variation in first saccade latency between individuals, with these differences correlating with first saccade accuracy and the total number of fixations needed to complete the task. Within-subject performance variation across trials mirrored these effects, although equivalent changes in first saccade latency did not influence saccadic behavior for all participants in the same way. This finding that longer first saccade latency improves eye movement guidance differently across participants is discussed in terms of the potential benefits of having additional time for recurrent processing and individual differences in ability to spatially spread attention.