Time-shrinking: A discontinuity in the perception of auditory temporal patterns

Recent research at our laboratories in the field of human auditory time perception revealed that the duration of short empty time intervals (<～200 msec) is considerably underestimated if they are immediately preceded by shorter time intervals. Within a certain range, the amount of subjective time shrinking is a monotonous function of the preceding time interval: the shorter it is, the more it shrinks its successor. In the present study, the preceding interval was kept constant at 50 msec, and the following interval for which the duration had to be judged, varied from 40 to 280 msec. The results showed that at up to 100 msec, the perceived duration increased to a much lesser extent than did the objective duration. Beyond 120 msec, the perceived duration quickly increased and reached a veridical value at 160 msec. Such a sudden change of perceived duration in a temporal pattern in which the objective duration varies gradually indicates a typical example of categorical perception. We suggest that such a categorization of the time dimension might be a clue for processes of speech and music perception.     

The effects of trial repetition and individual characteristics on decision making under uncertainty

The authors examined participants' preferences between certain and uncertain outcomes in a multistage gambling task and the effects of individual difference characteristics on those preferences. In Study 1, 144 participants made choices in single-stage gambles under gain and loss conditions and replicated the certainty effect in a previous study (D. Kahneman & A. Tversky, 1979). In Study 2, 94 participants engaged in a multistage gambling task using the same decision problems as those in Study 1. They also answered a questionnaire consisting of the Japanese version (M. Kamahara, K. Higuchi, & N. Shimizu, 2001) of the Locus of Control Scale (J. B. Rotter, 1966), the Reflection-Impulsivity Scale (K. Takigiku & A. Sakamoto, 2001), and a Japanese version (M. Terasaki, K. Shiomi, Y. Kishimoto, & K. Hiraoka, 1987) of the Sensation-Seeking Scale (M. Zuckerman, 1994). The results indicated that the certainty effect (Kahneman & Tversky) disappears in multistage gambling tasks and that differences in reflection-impulsivity and in gender influence the process of decision making under gain conditions. These results are discussed in terms of the decision strategies and cognitive biases involved in the multistage gambling task.     

Involvement of IP3 receptors in LTP and LTD induction in guinea pig hippocampal CA1 neurons

The role of inositol 1, 4, 5-trisphosphate receptors (IP3Rs) in long-term potentiation (LTP) and long-term depression (LTD) was studied in CA1 neurons in guinea pig hippocampal slices. In standard solution, short tetanic stimulation consisting of 15 pulses at 100 Hz induced LTP, while three short trains of low-frequency stimulation (LFS; 200 pulses at 1 Hz) at 18-min intervals or one long train of LFS (1000 pulses at 1 Hz) induced stable LTD in both the slope of the field EPSP (S-EPSP) and the amplitude of the population spike (A-PS). Bath application of 2-aminoethoxydiphenyl borate (2-APB), an IP3R antagonist, or of alpha-methyl-4-carboxyphenylglycine (MCPG), a wide-spectrum metabotropic glutamate receptor antagonist, during weak tetanic stimulation significantly increased the magnitude of the LTP in both the S-EPSP and A-PS. Three short trains of LFS or one long train of LFS delivered in the presence of 2-APB or MCPG did not induce LTD, but elicited LTP. Based on these results, we conclude that, in hippocampal CA1 neurons, IP3Rs play an important role in synaptic plasticity by attenuating LTP and facilitating LTD.     

An N-channel stroboscopic tachistoscope for typewritten stimuli

The n-channel tachistoscope described employs the principle of “stopping” a continuously moving list of words by means of stroboscopic flashes of light. It can present as many as 50 stimuli per trial at any rate between 5 and 40 items per second. Stimulus materials can be prepared on an electric typewriter. It provides only partial control over the various time parameters.     

Justice Orientation as a Moderator of the Framing Effect on Procedural Justice Perception

Justice orientation is a justice-relevant personality trait, which is referred to as the tendency to attend to fairness issues and to internalize justice as a moral virtue. This study examined the moderating role of justice orientation in the relationship between justice perception and response to a decision problem. The authors manipulated procedural justice and the outcome valence of the decision frame within a vignette, and measured justice orientation of 174 Japanese participants. As hypothesized, the results indicated an interaction between procedural justice and framing manipulation, which was moderated by individual differences in justice orientation. In negative framing, justice effects were larger for individuals with high rather than low justice orientation. The results are explained from a social justice perspective, and the contributions and limitations of this study are also discussed with respect to our sample and framing manipulation.     

Emotion Regulation: The Interplay of Culture and Genes

Given the mounting empirical evidence to support both the cultural and biological shaping of emotional processes, there is a clear need to integrate these determinants of emotional processes. Much in the same vein as these efforts, in our research on gene‐culture interactions, we have examined how cultural and biological factors jointly influence emotion regulation. The present paper specifically aims to present research considering both cultural and genetic factors as two interacting influences that shape emotion regulation. A series of studies conducted to test the gene‐culture interaction involving OXTR rs53576 consistently show that individuals with the variant that is associated with socio‐emotional sensitivity tend to utilize culturally normative forms of emotion regulation more than those without it. These findings underscore the importance of considering the interplay between socio‐cultural and genetic factors that shape social behaviors.     

Regulatory fit in framing strategy of parental persuasive messages to young children

The present research examined regulatory fit in parental messages aimed at young children. Study 1 measured parents' chronic regulatory focus, asking them to select either positively or negatively framed messages for promotion‐ and prevention‐focused outcomes. The results showed that parents preferred positive frames for promotion‐focused messages and negative frames for prevention‐focused messages. Furthermore, parents with a chronic promotion focus favored a positively framed strategy more than parents with a prevention focus. Study 2 found that parents adopted different message strategies depending on whether they favored an active responsive or an active restrictive parenting style. Together, these findings demonstrate for the first time the applicability of regulatory focus/fit theory to explain parents' preferences for positively and negatively framed messages targeting children.     

Effects of positive and negative affect and emotional suppression on short-term life satisfaction

Relationships between emotional experiences and health and adjustment are influenced by many variables, with emotional suppression (ES) being one of the most influential factors. In the current study, we examined the effects of affect and ES on short-term life satisfaction (LS) measured over the previous week. We also considered the dimension of activation status for both positive affect (PA) and negative affect (NA). The final sample included data collected from 398 undergraduates (184 men and 214 women). Participants answered six questionnaires, two of which were used for another study. All of the tests were of Japanese versions and were answered with regard to the previous week's experiences. Results showed that LS was positively associated with PA and negatively with NA, but that the positive association was stronger for activated PA than deactivated PA, while the negative association was stronger for deactivated NA than activated NA. Furthermore, an interactive effect between deactivated NA and ES on LS was significant in men, where post hoc tests demonstrated that deactivated NA was more negatively associated with LS when ES was higher. This study suggests that activated and deactivated affect differ in their effects on LS. In addition, it is likely that the detrimental effect of deactivated NA on LS is larger when NA is more strongly suppressed. The necessity of interventional research along with the limitations of this study is discussed for future research.     

Dynamic grouping and interpolation induced by flickering stimuli

A novel grouping and interpolation effect induced by flickering stimuli is described: a matrix of flickering elements forms stick-like clusters, then the clusters gradually dissociate back into the discrete elements within a few seconds. On continuous viewing, this flicker-induced grouping and interpolation repeatedly disappeared and reappeared. The perceived strength of this phenomenon peaked when the luminance of the flickering elements was alternately darker and lighter than the background; thus, the reversal of the luminance contrast polarity was responsible for flicker-induced grouping. The temporal dynamics of flicker-induced grouping showed the stochastic nature of perceptual alternation, which depended on the global structure of the stimulus. From these results, it is concluded that flicker-induced grouping reflects multiple stages of visual processing.