Although visual and auditory inputs are initially processed in separate perception systems, studies have built on the idea that to maintain spatial information these modalities share a component of working memory. The present study used working memory navigation tasks to examine functional similarities and dissimilarities in the performance of updating tasks. Participants mentally updated the spatial location of a target in a virtual array in response to sequential pictorial and sonant directional cues before identifying the target's final location. We predicted that if working memory representations are modality-specific, mixedmodality cues would demonstrate a cost of modality switching relative to unimodal cues. The results indicate that updating performance using visual unimodal cues positively correlated with that using auditory unimodal cues. Task performance using unimodal cues was comparable to that using mixed modality cues. The results of a subsequent experiment involving updating of target traces were consistent with those of the preceding experiments and support the view of modality-nonspecific memory.

Although objects with curved contours are generally preferred over those with sharp-angled contours, the strength of this preference varies according to several factors. In the present study, non-Western Japanese observers viewed and rated their preferences (e.g., liking or attractiveness) for real and meaningless objects with curved or sharp-angled contours. We varied the presentation time (90 ms vs. until a response was received) and the response measure (like/dislike vs. 1–100 rating scale). When using like/dislike ratings, a preference for curved objects was found only when images of real objects were presented briefly (90 ms), whereas this effect was reversed (i.e., increased preference for sharp-angled contours) when using the 1 to 100 scale under the until-response condition. In addition, the curvature effect was not observed for real objects when the like/dislike rating and the until-response condition were employed or when the 1 to 100 scale and 90 ms presentation time were used. The curvature effect for meaningless objects remained unstable regardless of presentation time or response measure. Similar to the preference for real objects, a preference for sharp-angled objects was observed when preference was measured using a 1 to 100 rating scale. Taken together, the present findings indicate that the preferences for curved objects were situation-dependent in Japanese observers.

Auditory perceived distance can be distorted in one’s internal representation. Thus, the present study examined whether blindfolded sighted participants could reduce the bias and preserve estimated distance for 5 to 15 s using echolocation. The participants performed a delayed reproduction task that consisted of testing sessions on 2 separate days in which the target distance was manipulated from 20 to 50 cm. Participants were blindfolded and asked to reproduce the distance of a target after a temporal delay of several seconds using click bursts produced by a loudspeaker. The testing session was preceded by a practice session that included training and feedback. The relationship between estimated and actual distances was approximated based on a power function and the over- and underestimation of the target distance on each test day. Although participants showed systematic bias in distance estimation on both days, participants changed their bias in the second session by shifting reproduced locations closer to their bodies. The accuracy and consistency of their responses improved across the 2 days. Neither accuracy nor consistency was affected by the retention intervals. These enhancements of performance might be due to improved hearing ability or calibration of internal spatial references through a practice session.

Echolocation performance differs widely among individuals. This study examined a possible factor that may explain this variation, namely, visual working memory, which is a subcomponent of spatial working memory. Sighted participants performed an object-detection task consisting of initial testing on 2 separate days (up to 8 days apart) with follow-up testing on a third day (up to 1 month after the second day of testing) while manipulating the target distance from 20 to 50 cm. Participants performed two types of visual spatial working memory tasks, one of which required them to memorize color-location combinations and the other, an imaginary pathway. The participants' performance on the object-detection task generally improved in the first 2 days, but there were substantial individual differences in detection ability. A positive correlation was observed between performance on these tasks and visual working memory capacity, except on the second day, after detection ability had improved. These findings suggest that factors contributing to echolocation skill are related to nonauditory factors in a sighted group.

A Spatial distribution of cetacean has been thought to be closely related to marine environment, such as sea surface temperature, chlorophyll-a concentration, sea floor gradient, and water depth which may affect an abundance of prey and in turn may affect spatial distribution of cetacean. In this study, from the data of sighting survey in Tsugaru Strait conducted by Hokkaido University cetacean research group, encounter rate and degree of aggregation of Pacific white-sided dolphin (PWS) were examined for every division. In addition to this, a relationship of a spatial distribution of PWS to the marine environment ware also examined by using generalized linear mixed model (GLMM). From these analysis, it was shown that PWS is aggregated on one or two divisions inside a bay area. Moreover, the division where PWS aggregated had feature low sea surface temperature and low chlorophyll-a concentration. Prevented studies show that aggregation of cetacean related with high chlorophyll-a concentration, however, the result of this study indicated the opposite tendency to these studies. Additionally the aggregation of PWS was seen regardless of the feature low sea surface temperature and low chlorophyll-a concentration. Thus it was showed that in spite of the environment the spatial distribution of PWS is determined in Tsugaru Strait.