Hippocampus is required for paired associate memory with neither delay nor trial uniqueness

Cued retrieval of memory is typically examined with delay when testing hippocampal functions, as in delayed matching-to-sample tasks. Equally emphasized in the literature, on the other hand, is the hippocampal involvement in making arbitrary associations. Paired associate memory tasks are widely used for examining this function. However, the two variables (i.e., delay and paired association) were often mixed in paired associate tasks, and this makes it difficult to localize the cognitive source of deficits with hippocampal perturbation. Specifically, a few studies have recently shown that rats can learn arbitrary paired associations between certain locations and nonspatial items (e.g., object or flavor) and later can retrieve the paired location when cued by the item remotely. Such tasks involve both (1) delay between sampling the cue and retrieving the target location and (2) arbitrary association between the cueing object and its paired location. Here, we tested whether delay was necessary in a cued paired associate task by using a task in which no delay existed between object cueing and the choice of its paired associate. Moreover, fixed associative relationships between the cueing objects and their paired locations were repeatedly used, thus involving no trial-unique association. Nevertheless, inactivations of the dorsal hippocampus with muscimol severely disrupted retrieval of paired associates, whereas the same manipulations did not affect discriminating individual objects or locations. The results powerfully demonstrate that the hippocampus is inherently required for retrieving paired associations between objects and places, and that delay and trial uniqueness of the paired associates are not necessarily required.     

Dynamic properties of an ultrafine-grained Mg–Zn–Zr alloy

The effect of ultrafine-grained structure formation in Mg–Zn–Zr alloy ZK60 on its mechanical response was investigated at strain rates ranging from quasi-static to dynamic regimes. The study demonstrated that the strength characteristics of the material rise significantly with increasing strain rate, while its ductility is reduced. These effects are particularly pronounced in the dynamic loading regime, at strain rates in the (1?5)?×?10²?s^?1 range. In the ultrafine-grained alloy ZK60, the energy absorption per unit volume, W, is enhanced by grain refinement by a factor as high as eight for the highest strain rate of 5?×?10²?s^?1 investigated. The analysis is focused on the microstructure features that bring about the observed improvement of the tensile characteristics, as well as the deformation and fracture modes prevalent at different strain rates. The results obtained contribute to the exploration and understanding of dynamic behaviour of magnesium alloys.     

The Emergence of Student Creativity in Classroom Settings: A Case Study of Elementary Schools in Korea

This research explores the emergence of student creativity in classroom settings, specifically within two content areas: science and social studies. Fourteen classrooms in three elementary schools in Korea were observed, and the teachers and students were interviewed. The three types of student creativity emerging in the teaching and learning process found in this research were: (a) heuristic creativity when the students express their thoughts about a new concept based on their experience, (b) interpretive creativity when the students explain the meaning of materials based on students' knowledge, and (c) integrative creativity when students generate new solutions or make new products based on their internalized knowledge. The study results will challenge teachers to find instances of student creativity in their teaching and learning situations and to facilitate student creativity when the students interpret data or materials related to the contents of the curriculum.     

Cultural differences in the dialectical and non-dialectical emotional styles and their implications for health

Previous cross-cultural studies have repeatedly demonstrated that East Asians are more likely to show a dialectical emotional style than Americans, but do not distinguish between specific types of dialectical emotional styles. Using an age diverse sample, we found that compared to Americans, Japanese are more likely to experience both positive and negative emotions moderately frequently (i.e., moderate dialectical), but are no more likely to experience them frequently (i.e., high dialectical). Thus, dialectical emotions prevalent in East Asia may be characterised by a "middle way" rather than by emotional extremes. Furthermore, we explored whether dialectical emotion types are associated with better health profiles depending on cultural background. Our results show that the moderate dialectical type is associated with fewer physical symptoms in Japan than in the USA. Together, these findings show the cultural differences in the experience of balanced positive and negative emotions and their health correlates.     

A Speeded Item Response Model with Gradual Process Change

An item response theory model for dealing with test speededness is proposed. The model consists of two random processes, a problem solving process and a random guessing process, with the random guessing gradually taking over from the problem solving process. The involved change point and change rate are considered random parameters in order to model examinee differences in both respects. The proposed model is evaluated on simulated data and in a case study. The research reported in this paper was supported by IAP P5/24 and GOA/2005/04, both awarded to Paul De Boeck and Iven Van Mechelen, and by IAP P6/03, awarded to Iven Van Mechelen. Yuri Goegebeur’s research was supported by a grant of the Danish Natural Science Research Council.     

The intergenerational transmission of implicit and explicit attitudes toward smoking: Predicting adolescent smoking initiation

This study examined the intergenerational transmission of implicit and explicit attitudes toward smoking, as well as the role of these attitudes in adolescents’ smoking initiation. There was evidence of intergenerational transmission of implicit attitudes. Mothers who had more positive implicit attitudes had children with more positive implicit attitudes. In turn, these positive implicit attitudes of adolescents predicted their smoking initiation 18-months later. Moreover, these effects were obtained above and beyond the effects of explicit attitudes. These findings provide the first evidence that the intergenerational transmission of implicit cognition may play a role in the intergenerational transmission of an addictive behavior.     

The Traditional Explanation for Resistance Versus Attitude Accessibility

This investigation compared the traditional explanation for the way inoculation confers resistance to influence with an alternative rationale for resistance based on attitude accessibility. Four hundred forty‐three participants took part in the investigation in four phases spanning 54 days. The combined multiple regression and structural equation modeling results suggest that the traditional and alternative explanations for the way that inoculation confers resistance involve separate processes; counterarguing and accessibility appear to be distinct tracks en route to resistance, but the two explanations also are overlapping processes in which elicited threat plays an integral role.     

Vision following extended congenital blindness

Animal studies suggest that early visual deprivation can cause permanent functional blindness. However, few human data on this issue exist. Given enough time for recovery, can a person gain visual skills after several years of congenital blindness? In India, we recently had an unusual opportunity to work with an individual whose case history sheds light on this question. S.R.D. was born blind, and remained so until age 12. She then underwent surgery for the removal of dense congenital cataracts. We evaluated her performance on an extensive battery of visual tasks 20 years after surgery. We found that although S.R.D.'s acuity is compromised, she is proficient on mid- and high-level visual tasks. These results suggest that the human brain retains an impressive capacity for visual learning well into late childhood. They have implications for current conceptions of cortical plasticity and provide an argument for treating congenital blindness even in older children.