Self-motion perception compresses time experienced in return travel

It is often anecdotally reported that time experienced in return travel (back to the start point) seems shorter than time spent in outward travel (travel to a new destination). Here, we report the first experimental results showing that return travel time is experienced as shorter than the actual time. This discrepancy is induced by the existence of self-motion perception.     

The mental number line in depth revealed by vection

To explore how numbers are represented in depth in our mental space, we asked participants to sequentially speak random numbers while they observed forward/backward vection. We found that participants tended to generate larger numbers when they perceived backward self-motion. The results suggest that numerical magnitudes were topographically mapped onto our mental space from front to rear in an ascending order.     

Attentional load inhibits vection

In this study, we examined the effects of cognitive task performance on the induction of vection. We hypothesized that, if vection requires attentional resources, performing cognitive tasks requiring attention should inhibit or weaken it. Experiment 1 tested the effects on vection of simultaneously performing a rapid serial visual presentation (RSVP) task. The results revealed that the RSVP task affected the subjective strength of vection. Experiment 2 tested the effects of a multiple-object-tracking (MOT) task on vection. Simultaneous performance of the MOT task decreased the duration and subjective strength of vection. Taken together, these findings suggest that vection induction requires attentional resources.     

Eyes pursue moving objects, not retinal motion signals

For smooth-pursuit eye movements, a moving target is necessary, but we show that it is not sufficient. Observers pursued targets that appeared to move in one direction even though they really moved in another. Changes in perceived direction did not disrupt pursuit eye movements, but motion-based failures in object parsing did.     

Inhibition of vection by red

We investigated the effects of colors on vection induction. Expanding optical flows during one’s forward self-motion were simulated by moving dots. The dots and the background were painted in equiluminant red and green. Experiments 1 and 2 showed that vection was weaker when the background was red than when the background was green. In addition, Experiment 3 showed that vection was weaker when the moving dots were red than when the dots were green. Experiment 4 demonstrated that red dots on a red background induced very weak vection, as compared with green dots on a green background. In Experiments 5 and 6, we showed that the present results could not be explained by a luminance artifact. Furthermore, Experiment 7 showed that a moving red grating induced weaker vection than did a green one. We concluded that a red visual stimulus inhibits vection.     

Locomotor experience affects self and emotion

Two studies investigated the role of locomotor experience on visual proprioception in 8-month-old infants. Visual proprioception refers to the sense of self-motion induced in a static person by patterns of optic flow. A moving room apparatus permitted displacement of an entire enclosure (except for the floor) or the side walls and ceiling. In Study 1, creeping infants and prelocomotor/walker infants showed significantly greater postural compensation and emotional responses to side wall movement than did same-age prelocomotor infants. Study 2 used true random assignment of prelocomotor infants to locomotor-training (via a powered-mobility device) and no-training conditions. Experimental infants showed powerful effects of locomotor training. These results imply that locomotor experience is playing a causal role in the ontogeny of visual proprioception.     

The effects of attributions of intent and apology on forgiveness: When saying sorry may not help the story

Despite the oft-cited positive effects of an apology on forgiveness, forgiveness does not always follow. In three studies we tested the ironic notion that, following an interpersonal transgression, an apology following an attribution of intent might further hinder, rather than benefit, the forgiveness process. The findings of three studies were systematically replicated and supported our primary prediction that, following attributions of intent, saying sorry does not always lead to forgiveness. When offenders intentionally committed a transgression, forgiveness was less likely following an apology. However, when offenses were unintentional, forgiveness was more likely following an apology. We also showed that these effects were explained by participants’ impression of the transgressor.     

Sex differences in preferences for coffee sweetness among Japanese students

The purpose of the present study was to examine sex differences in preferences for coffee sweetness. The participants were 59 Japanese undergraduate students. Men preferred sweeter coffee than women, while both men and women showed almost the same preference for acidic beverage sweetness. The sex difference in preferences for coffee sweetness may be related to coffee-drinking habits.     

Ontogeny of sex differences in defensive burying behavior in rats: effect of social isolation

The aim of the present experiments was to clarify sex differences in socio-developmental factors that affected defense behavior in rats. Sex differences in the defensive burying behavior of rats, and related social factors, were explored in three developmental stages: juvenile, puberty, and adult; 30, 50, and 80 days of age, respectively. The duration of burying, digging into bedding material, stretch-attend postures, and crouch/freezing were measured in a shock-prod test. For males, the duration of burying was longer in the juvenile and pubertal stages than in adulthood. For females, no age differences in the duration of burying were found. Males showed longer burying durations than females in both the juvenile and pubertal stages. For both sexes, the highest duration of digging was found in the juvenile stage, and females showed longer durations of digging than males. Both male and female rats isolated during the juvenile stage, from 26 to 40 days of age, showed smaller durations of burying behavior compared to pair-reared rats. This effect of juvenile isolation was maintained among both adult males and females even when they were returned to pair rearing after isolation. Isolation during adulthood, from 66 to 80 days of age, increased burying behavior in males, but decreased it in females. The durations of digging, stretch-attend postures, and crouch/freezing were not affected by isolation. The decrease in defensive burying and its increase resulting from isolation in adult male rats, suggest that the emergence of adult-like social relationships in males suppressed the duration of burying. Male and female rats isolated during the juvenile stage maintained lower levels of burying, suggesting that social experience as juveniles is important for the emergence of defensive burying behavior.     

损毁大鼠双侧内嗅皮质对束缚应激反应的影响

采用大鼠急性束缚应激动物模型,用鹅羔氨酸损毁大鼠双侧内嗅皮质来建立内嗅皮质损伤模型,观察束缚应激1小时后下丘脑室旁核快反应基因c-Fos表达情况以及应激后血浆促肾上腺皮质激素含量的动态变化,并与对照组相比较,探讨内嗅皮质与束缚应激反应的关系。结果表明,损毁内嗅皮质,明显抑制了应激诱导的下丘脑室旁核c-Fos的表达和血浆促肾上腺皮质激素含量的上升。结果提示,内嗅皮质参与调节束缚应激反应时HPA轴功能。