Clusters of holes, such as those in a lotus seedpod, induce trypophobic discomfort. Previous research has demonstrated that high-contrast energy at midrange spatial frequencies in images causes trypophobic discomfort. The present study examined the effects on discomfort of eliminating various spatial frequency components from the images to reveal how each spatial frequency contributes to the discomfort. Experiment 1 showed that eliminating midrange spatial frequencies did not affect trypophobic discomfort, while Experiment 2 revealed that images of holes that consisted of only high-spatial frequencies evoked less discomfort than other images and that images containing only low or midrange spatial frequencies induced as much trypophobic discomfort as did the original images. Finally, Experiment 3 found that participants with a high level of the trypophobic trait experienced stronger discomfort from the original images and the images containing only low or midrange spatial frequencies than participants with a low level of the trypophobic trait. Our findings thus suggest that trypophobic discomfort can be induced by middle and low spatial frequencies.

A JavaScript framework named 'jsPsych' developed by de Leeuw (2015) is widely used for conducting Web-based experiments, and its functionality can be enhanced by using plugins. This article introduces a new jsPsych plugin which enables experimenters to set different onset times for geometric figures, images, sounds, and moving objects, and present them synchronized with the refresh of the display. Moreover, this study evaluated the stimulus onset asynchronies (SOAs) using visual and audio stimuli. The results showed that: (i) the deviations from the intended SOAs between two visual stimuli were less than 10 ms, (ii) the variability across browser-computer combinations was reduced compared with the no-plugin condition, and (iii) the variability of the SOAs between visual and audio stimuli was relatively large (about 50 ms). This study concludes that although the use of audio stimuli is somewhat limited, the new plugin provides experimenters with useful and accurate methods for conducting psychophysical experiments online. The latest version of the plugin can be downloaded freely from https://jspsychophysics.hes.kyushu-u.ac.jp under the MIT license.

Summary This study examined whether the functional field of view shrinks by the presence of a weapon or the increase of emotional arousal. In Experiment 1, participants viewed two types of pictures depicting scenes involving weapons or control objects and were asked to identify digits presented at the periphery when the pictures disappeared. The results showed that the presence of a weapon impaired identification of the peripheral digits, even when the pictures were equal with respect to emotional arousal level. In Experiment 2, participants viewed emotionally arousing pictures or neutral pictures, neither of which included weapons, and they were asked to identify digits presented at the periphery when the pictures disappeared. The results revealed that the increased emotional arousal did not impair identification of the peripheral digits. These results indicate that the functional field of view shrinks because of the presence of a weapon but not because of increased emotional arousal.Copyright © 2015 John Wiley & Sons, Ltd.

The present study aimed to investigate whether the visual system scales apparent depth from binocularly unmatched features by using absolute distance information. In Experiment 1 we examined the effect of convergence on perceived depth in phantom stereograms [Gillam, B., & Nakayama, K. (1999). Quantitative depth for a phantom surface can be based on cyclopean occlusion cues alone. Vision Research, 39, 109-112.], monocular gap stereograms [Pianta, M. J., & Gillam, B. J. (2003a). Monocular gap stereopsis: manipulation of the outer edge disparity and the shape of the gap. Vision Research, 43, 1937-1950.] and random dot stereograms. In Experiments 2 and 3 we examined the effective range of viewing distances for scaling the apparent depths in these stereograms. The results showed that: (a) the magnitudes of perceived depths increased in all stereograms as the estimate of the viewing distance increased while keeping proximal and/or distal sizes of the stimuli constant, and (b) the effective range of viewing distances was significantly shorter in monocular gap stereograms. The first result indicates that the visual system scales apparent depth from unmatched features as well as that from horizontal disparity, while the second suggests that, at far distances, the strength of the depth signal from an unmatched feature in monocular gap stereograms is relatively weaker than that from horizontal disparity.

The two Bayesian adaptive psychometric methods named QUEST (Watson & Pelli, 1983) and QUEST+ (Watson, 2017) are widely used to estimate psychometric parameters, especially the threshold, in laboratory-based psychophysical experiments. Considering the increase of online psychophysical experiments in recent years, there is a growing need to have the QUEST and QUEST+ methods available online as well. We developed JavaScript libraries for both, with this article introducing one of them: jsQuestPlus. We offer integrations with online experimental tools such as jsPsych (de Leeuw, 2015), PsychoPy/JS (Peirce et al., 2019), and lab.js (Henninger et al., 2021). We measured the computation time required by jsQuestPlus under four conditions. Our simulations on 37 browser–computer combinations showed that the mean initialization time was 461.08 ms, 95% CI [328.29, 593.87], the mean computation time required to determine the stimulus parameters for the next trial was less than 1 ms, and the mean update time was 79.39 ms, 95% CI [46.22, 112.55] even in extremely demanding conditions. Additionally, psychometric parameters were estimated as accurately as the original QUEST+ method did. We conclude that jsQuestPlus is fast and accurate enough to conduct online psychophysical experiments despite the complexity of the matrix calculations. The latest version of jsQuestPlus can be downloaded freely from https://github.com/kurokida/jsQuestPlus under the MIT license.