Temporal characteristics of the effects of visual pattern redundancy on encoding and storage processes: evidence from rapid serial visual presentation

Pattern redundancy is a key concept for representing the amount of internal mental load (encoding efficiency) needed for pattern perception/recognition. The present study investigated how pattern redundancy influences encoding and memory processes in the visual system using a rapid serial visual presentation (RSVP) paradigm. With RSVP, it is well known that participants often fail to detect repetitions of words (repetition blindness, RB). We used this phenomenon as an index of the encoding and storage of visual patterns. In three experiments, we presented patterns with higher and lower redundancy, as defined by Garner’s equivalent set size (ESS). The results showed that RB occurred more frequently for higher redundancy patterns when the temporal distance between the targets was less than 500 ms; this tendency was reversed with longer temporal distances of over 500 ms. Our results suggest that pattern redundancy modulates both the early encoding and subsequent memory processes of a representation.     

Atomistic study of structural fluctuations during radiation-induced amorphization in the ordered intermetallic compound NiTi

We have carried out an atomistic study of electron-induced amorphization of an ordered intermetallic compound NiTi by means of in-situ high-resolution high-voltage electron microscopy observations and molecular dynamics simulations. Both theoretical and experimental results show that metastable nanometre-size atomic clusters form and disappear during irradiation, so that a spatiotemporal fluctuation under amorphization is induced. Mean-lifetime measurements of these clusters demonstrate that high-energy particle irradiation provides a useful tool to study dynamic fluctuations of the local atomic structure in the non-equilibrium open systems.     

Neuroscientific information bias in metacomprehension: The effect of brain images on metacomprehension judgment of neuroscience research

In the present study, we investigated how brain images affect metacomprehension judgments of neuroscience research. Participants made a prereading judgment of comprehension of the text topic and then read a text about neuroimaging findings. In Experiment 1, participants read text only or text accompanying brain images. In Experiment 2, participants read text accompanying bar graphs or text accompanying brain images. Then participants were asked to rate their comprehension of the text. Finally, they completed comprehension tests. The results of Experiment 1 showed that the text accompanying brain images was associated with higher metacomprehension judgments than was the text only, whereas the performance of the comprehension test did not differ between each condition. The results of Experiment 2 showed that the text accompanying brain images was associated not only with credibility of the text, but also with higher metacomprehension judgments than was the text accompanying the bar graphs, whereas the performance of the comprehension test did not differ between each condition. The findings suggest that the readers’ subjective judgments differ from actual comprehension.     

Persisting effect of prior experience of change blindness

Most cognitive scientists know that an airplane tends to lose its engine when the display is flickering. How does such prior experience influence visual search? We recorded eye movements made by vision researchers while they were actively performing a change-detection task. In selected trials, we presented Rensink's familiar 'airplane' display, but with changes occurring at locations other than the jet engine. The observers immediately noticed that there was no change in the location where the engine had changed in the previous change-blindness demonstration. Nevertheless, eye-movement analyses indicated that the observers were compelled to look at the location of the unchanged engine. These results demonstrate the powerful effect of prior experience on eye movements, even when the observers are aware of the futility of doing so.     

Spatial and nonspatial working memory and visual search

It has been indicated that visual search is interfered with in spatial working memory (WM), although not in nonspatial WM. In this study, the effects on visual search of individual differences in spatial and nonspatial WM were examined. Two visual search conditions were used: a conjunction search condition comprising two features (color and shape) and a disjunction condition comprising only one feature (color or shape). 96 participants (42 men, 54 women, M age = 20.9 yr., SD = 3.5) participated in this study. The participants were divided into high and low WM groups based on their spatial and nonspatial WM test scores. As a result, statistically significant group differences in the conjunction search rate were observed in spatial WM but not in nonspatial WM. These results suggest there is a relationship between visual search and the individual spatial WM ability, but this does not hold for nonspatial WM.     

Does test delay eliminate collaborative inhibition?

Earlier research has demonstrated that collaborative groups recall more than individuals, but less than nominal groups (pooled performance of individuals), thus exhibiting collaborative inhibition. In two experiments, all participants were first asked to recall story material on their own. Some participants were then assigned to pairs and recalled the material collaboratively. On the other hand, the participants in the individual recall condition were asked to recall the material once again on their own. In Experiment 1, the collaborative pairs recalled less than the nominal pairs in accordance with previous studies. In Experiment 2, the timing of the initial individual recall was manipulated by inserting one week between the learning and the recall. The collaborative inhibition was eliminated in this situation. Sources of the collaborative inhibition in immediate recall and its disappearance in delayed recall are discussed in terms of the effect of cross cueing in collaborative remembering.     

Colony aggression in laboratory rats: A review and some recommendations

The behavioral response of established colonies of domesticated rats to the presence of an unfamiliar intruder of the same species represents one of the most effective procedures yet developed to study aggression in the laboratory. Here, the social, experiential, and environmental variables that influence attack severity are reviewed and several important methodological issues are discussed. Brief exposures of intruders to intact colonies may produce misleading results but long-term test sessions increase the likelihood that intruders will be either killed or severely injured. We describe a simple modification of the colony-intruder procedure whereby intruders can successfully defend themselves during long sessions and thus reduce serious injury. The modified procedure appears to conform more closely to what happens during aggressive encounters in free-living populations of wild rats.     

Play fighting and the development of agonistic behavior in male and female rats

Two longitudinal studies were conducted to quantify the social behaviors exhibited by both male and female Long-Evans rats from the immediate postweaning period until young adulthood. In Experiment 1, male sibling pairs engaged in a high level of play fighting during the early juvenile period but such activity declined to a level significantly lower than that of female and mixed-sex pairs after 54 days of age. In Experiment 2, social exchanges during maturation were examined during the presence and absence of the piloerection response in an effort to distinguish play fighting from agonistic interactions. In male pairs, piloerection was rarely seen before 55–75 days of age but thereafter occurred with increasing frequency especially among dominant males. Furthermore, subordinate males retreated from their dominant partners and remained in an escape chamber for a significant amount of time only during encounters involving the exhibition of piloerection. This finding suggests that piloerection can be useful in identifying play and aggressive interactions. In female and heterosexual pairs, piloerection was observed infrequently during social encounters occurring throughout maturation. In addition, when given the opportunity to escape, females were less likely to retreat from play activity if their partner was another female than a male.     

Conscientiousness mediates the relation between perceived parental socialisation and self-rated health

The pathways between parenting behaviours, personality and physical health have all been separately studied. Prior research has paid little attention to the indirect effects of personality in the path between parenting behaviours and better health. The purpose of this study was to explore the mediational effects of conscientiousness on the relationships between parental socialisation of responsibility and self-rated health, and to examine potential age differences in this mediational pathway. In total, 736 female and 749 male members across Japan participated in this study. They were divided into three groups by age category: younger-, middle-aged and older-aged. Conscientiousness and health were concurrently rated, while parental socialisation of responsibility was retrospectively assessed. Our analyses revealed that parental socialisation of responsibility is positively associated with conscientiousness and self-rated health, that conscientiousness is positively associated with self-rated health, and that conscientiousness fully mediated the effect of parental socialisation of responsibility on self-rated health. The mediational links were consistent across younger, middle-aged and older-aged cohorts. Our findings suggest that greater parental socialisation of responsibility relates to higher conscientiousness, and consequently healthier adults. These findings imply that parental behaviours could be a plausible target for intervention to foster the development of conscientiousness and better health.