This paper claims that, contrary to the "Theory oriented" approach to cognitive development and instruction, children's informal concepts play important roles in learning, and reports two cases that support the constructivist view of learning. It is widely believed that children's knowledge about various domains is organized into coherent systems, i.e., theories. Although this approach provides a new perspective on knowledge organization, too much emphasis on the conceptual difference makes the interaction of prior knowledge and learning materials impossible. Without the interaction, learned rules remained uninterpreted. Consequently they can be applied only to a restricted set of problems. A case from mathematics revejJed that students' informal concept of concentration can be bridged to the formad one, by rewording quantitative terms in problems with quzditative terms. A case from physics showed that by combining fragmentJiry understandings, students could acquire the concept of force decomposition which is difficult to learn by formal instruction. Finally, instructional techniques are proposed that make use of informal concepts as a partial base analog to enrich students' understanding.

Subliminal information has been suggested to facilitate insight problem solving. The present study examinedwhether subliminal hints may influence not only retention of the goals but also planning of sequential steps required to solve thenine-dot problem. Using continuous flash suppression, participants were subliminally presented with either an image depictingthe entire solution of the problem, the three steps to solve the problem in a sequential order, or an image of the nine dots thatdoes not involve solution of the problem. Participants presented with the entire solution of the problem tended to show bettersolution performance and greater relaxation of constraints than those in the latter two conditions, whose performance failedto significantly differ from each other. These results indicate that subliminal information may be stored as a global and staticvisuo-spatial representation to influence solution but may not involve planning of each step to achieve insight problem solving.

This study explored the effects c: a goal and subject's knowledge in similsirity judgements. W e hypothesized that the process of computing similarity consist of two phases: the processes of explanation and feature comparison. W h e n a goal is salient and the knowledge required to achieve it is available, people compute similarity by explaining the goal in terms of a given state by using domain knowledge. Thus, in this case, rated similarity should be a function of the distance between the goal and the state. W h en the explanation fails, the judgements should instead to be based on the feature comparison. Expert, novice, and naive subjects were asked to solve the Tower of Hanoi puzzle. The subjects were required to judge the similarity between the goal and various states of the puzzle. The results showed that their judgements differed, depending on their expertise. While experts' ratings were best characterized by the number of operators necessary to transform a given state to the goal, those of naive subjects were completely based on the number of shared features. The second experiment revealed that the experts' judgements of similarity are not be due to learned contiguity through practice.

We developed a computational model of similarity judgment in problem-solving contexts. The model first attempts to transform an object to another using the knowledge of the domain, the strategy, and the goal. If the transformation succeeds, new feature about transformability is created. A similarity of an object to another is computed, based on the created features. If the model fails to create a new feature, it computes a similarity by feature comparison in the same way as the contrast model. An important prediction of the model is that the asymmetry of similarity judgments is caused by the directionadity of the problem-solving skills. W e examined the model's prediction. The materijJ was the Tower of Hanoi puzzle. Subjects were required to rate the similarities of one state to the goal as well as those of the goal to a state. In Experiment 1, we taught one group of subjects the 'move-pattern strategy' that induced learners to acquire highly directional skills, and compared their judgments with those by naive subjects. The asymmetry was observed only in the judgments by the trained subjects. The second experiment showed that the results of the experiment 1 could not be attributed to the 'prototypicality' of the goal.

Magnetic resonance image (MRI) is now widely used for imaging follow-up for post coiling brain aneurysms. However, the accuracy on the estimation of residual aneurysm, which is crucial for the retreatment planning, remains to be controversial. The purpose of this study is to evaluate a new post-processing technique that provides improved estimation of the residual aneurysm after coil embolization. One hundred aneurysms on 93 patients who underwent coil embolization for brain aneurysm were evaluated using the 1.5 Tesla time-resolved magnetic resonance angiography (TR-MRA) one year after the treatment. To minimize the inter-observer variability caused by the window level adjustment, an automatic post processing protocol using the full-width at half-maximum (FWHM) value was utilized. The result was then compared with that from the conventional cerebral angiography. Of the 97 aneurysms that underwent both TR-MRA and DSA, 23 (23.7%) showed residual neck / dome during follow-up. After window level adjustment, the size of the parent artery in the TR-MRA was consistent with that in the DSA. The reconstructed Volume Rendering images provided clear contours of the residual aneurysms and contributed to the understanding the configuration of residual aneurysm. The largest and the smallest diameter of the residual aneurysms was larger in the TR-MRA than in the DSA (8.05 vs. 7.72 mm, p = 0.0004; 4.99 vs. 4.19 mm, p = 0.007 respectively). The sensitivity, specificity, and positive and negative predictive values of TR-MRA compared to DSA were 100%, 97%, 73%, and 100%, respectively. Using the FWHM value to optimize the window level adjustment, the size of the residual component observed in the TR-MRA was larger compared to that in the DSA whereas the size of neck and the parent artery showed consistency between the two modalities. This image processing technique can be used as an effective screening tool for evaluating residual component in post-coiling brain aneurysms.

Magnetic resonance image (MRI) is now widely used for imaging follow-up for post coiling brain aneurysms. However, the accuracy on the estimation of residual aneurysm, which is crucial for the retreatment planning, remains to be controversial. The purpose of this study is to evaluate a new post-processing technique that provides improved estimation of the residual aneurysm after coil embolization. One hundred aneurysms on 93 patients who underwent coil embolization for brain aneurysm were evaluated using the 1.5 Tesla time-resolved magnetic resonance angiography (TR-MRA) one year after the treatment. To minimize the inter-observer variability caused by the window level adjustment, an automatic post processing protocol using the full-width at half-maximum (FWHM) value was utilized. The result was then compared with that from the conventional cerebral angiography. Of the 97 aneurysms that underwent both TR-MRA and DSA, 23 (23.7%) showed residual neck / dome during follow-up. After window level adjustment, the size of the parent artery in the TR-MRA was consistent with that in the DSA. The reconstructed Volume Rendering images provided clear contours of the residual aneurysms and contributed to the understanding the configuration of residual aneurysm. The largest and the smallest diameter of the residual aneurysms was larger in the TR-MRA than in the DSA (8.05 vs. 7.72 mm, p = 0.0004; 4.99 vs. 4.19 mm, p = 0.007 respectively). The sensitivity, specificity, and positive and negative predictive values of TR-MRA compared to DSA were 100%, 97%, 73%, and 100%, respectively. Using the FWHM value to optimize the window level adjustment, the size of the residual component observed in the TR-MRA was larger compared to that in the DSA whereas the size of neck and the parent artery showed consistency between the two modalities. This image processing technique can be used as an effective screening tool for evaluating residual component in post-coiling brain aneurysms.

Recently, lidocaine topical systems utilizing nonaqueous matrices have been developed and provide efficient lidocaine delivery through the skin, such that lower concentrations of drug provide equivalent or greater drug delivery than drug-in-matrix hydrogel lidocaine patches. This study characterizes drug delivery from a nonaqueous lidocaine topical system with increasing drug load both in vitro and in vivo. Topical systems formulated with either 1.8% or 5.4% lidocaine were applied to healthy volunteers' backs (n = 15) for 12 h in a single-center, open-label, four-treatment, four-period crossover pharmacokinetic study. Subjects were dosed with either three 1.8% systems or one, two, or three 5.4% systems in each period. Blood was collected for up to 48 h, and plasma lidocaine levels were measured with a validated HPLC method. In parallel, human and mouse skin models characterized the in vitro skin permeation profile. The pharmacokinetic profile was linear between one, two, and three lidocaine 5.4% applications. Application of three lidocaine 1.8% systems (108 mg lidocaine) was bioequivalent to one lidocaine 5.4% system (108 mg lidocaine). Both topical systems remained well adhered to the skin and irritation was mild. The 5.4% system had approximately threefold higher skin permeability than the 1.8% system in the mouse and human skin models. The results indicate increasing the drug load by three times results in triple the drug delivery both in vivo and in vitro. The relationship between the in vitro permeation and in vivo absorption correlates and is nonlinear.