Japanese bilinguals retrieved autobiographical memories in response to 20 English and 20 Japanese cue words. US monolinguals were cued with 40 English words. All participants reported one earliest memory. Japanese bilinguals retrieved more memories and earlier memories when cued with Japanese words. They also retrieved more memories when the cue language matched either the language of memory encoding or the language of first thought. Although English cues elicited equivalent numbers of English and Japanese memories in the more fluent speakers of English, Japanese words elicited significantly larger numbers of Japanese memories in all Japanese-English bilinguals. The average age of cued autobiographical memories was significantly earlier for US than for Japanese students but age of the earliest memory did not differ.

Intrinsically photosensitive retinal ganglion cells (ipRGCs) contain photoreceptors that are especially sensitive to blue light. Nevertheless, how blue light and ipRGCs affect time perception remains unsolved. We used the oddball paradigm and manipulated the background light to examine whether and how blue light and ipRGCs affect perceived duration. In the oddball paradigm, participants were asked to judge the duration of the target (oddball), compared to that of the standard, with a two alternative-forced-choice procedure. When the background light was controlled to be either blue or red in Experiment 1, results showed that blue light led to longer subjective duration compared to red light. Experiment 2 further clarified the contribution of the ipRGCs. A set of multi-primary projector system that could manipulate the ipRGC stimulation were used, while the color and luminance of the background lights were kept constant throughout. Results showed that increased stimulation of ipRGCs under metameric background expanded subjective time. These results suggest that ipRGC stimulation increases arousal/attention so as to expand subjective duration.

The mutual understanding of color-normal observers (CNOs) and colordefective observers (CDOs) is now essential because personal color information display environments have been widely adopted. However, existing tools for CDOs offer only color discrimination; they fail to support color impression (ie, saturation and contrast). Therefore, we need a novel tool that offers help in distinguishing opponent colors, while preserving color saturation. We introduce two key techniques for realizing this difficult goal. The former is the repeated sequential display of the original and processed images to support the formation of unified correct percepts that provide discrimination of both red-green and yellow-blue opponent colors. One image, ie, original, exhibits correct yellowblue but distorted red-green information for CDOs while the other, ie, processed, provides synthesized distinguishable red-green but confusable yellow-blue information for CDOs; here, hue rotation (HR) is useful for advanced users whereas hue blending (HB) is suitable for general. The latter is realized by the real-time video processing available on smartphones; our algorithms support direct processing of the digital component video signal formats (eg, Y, C R , and C B ). Subjective tests suggest that the two above-mentioned algorithms will, along with embedding a lightweight real-time dichromatic simulation facility for CNOs, greatly help the mutual understanding of CNOs and CDOs.

Results of earlier multiple object tracking (MOT) studies imply that humans can track several moving targets in a 2D environment simultaneously. Recently, a study suggested that stereoscopic depth has positive effect on tracking multiple objects when the objects are presented separately on multiple planes. However, it remains unclear whether or not humans can track moving targets in a real 3D environment. In this study, we investigated this issue displaying four targets and four distractors on near and/or far depth planes separated physically by 6, 10 or 50 cm using a half-mirror and two CRT-monitors. In addition we also tested whether participants could track the targets when either a target or a distractor changed depth during tracking. Our results suggested that performance dropped if the targets were presented on both depth planes especially when the distance between the planes was 50 cm. In addition, participants could track a depth-changed target if targets were presented on both planes before the start of a motion phase regardless of whether the initial state of targets distribution randomly varied or not, whereas they failed to track the target if all targets were presented on a single plane before MOT. In conclusion, humans have the ability to set attention on a wide range for MOT in a real 3D environment, with the provision that the efficiency of the tracking is critically dependent not only on the distance in depth but also on an initial state of distribution of the targets without the predictability of the initial state.

No abstract