Developmental correspondence between action prediction and motor ability in early infancy.

乳児期初期における他者理解のメカニズムを解明. 京都大学プレスリリース. 2011-06-08How do infants understand the goals of others' actions? It has been proposed that action-understanding results from a mechanism whereby an observed action is mapped onto the observer's own motor representation of that action. However, direct evidence of the matching process in early infancy is difficult to find. Here we show the developmental correspondence between action prediction and motor ability by comparing gazing and grasping responses to interesting objects in 4- to 10-month-old infants and adults. The onset of infants' ability to predict the goal of others' action was found to be synchronized with the onset of their own ability to perform that action. Moreover, there was correspondence relationship between action-prediction ability and motor ability of same action. Our findings indicate that the ability to predict others' action goals requires a corresponding motor ability, providing ontogenetic evidence for a direct matching process by a mirror neuron system

Rigid-body fitting to atomic force microscopy images for inferring probe shape and biomolecular structure

Atomic force microscopy (AFM) can visualize functional biomolecules near the physiological condition, but the observed data are limited to the surface height of specimens. Since the AFM images highly depend on the probe tip shape, for successful inference of molecular structures from the measurement, the knowledge of the probe shape is required, but is often missing. Here, we developed a method of the rigid-body fitting to AFM images, which simultaneously finds the shape of the probe tip and the placement of the molecular structure via an exhaustive search. First, we examined four similarity scores via twin-experiments for four test proteins, finding that the cosine similarity score generally worked best, whereas the pixel-RMSD and the correlation coefficient were also useful. We then applied the method to two experimental high-speed-AFM images inferring the probe shape and the molecular placement. The results suggest that the appropriate similarity score can differ between target systems. For an actin filament image, the cosine similarity apparently worked best. For an image of the flagellar protein FlhAC, we found the correlation coefficient gave better results. This difference may partly be attributed to the flexibility in the target molecule, ignored in the rigid-body fitting. The inferred tip shape and placement results can be further refined by other methods, such as the flexible fitting molecular dynamics simulations. The developed software is publicly available

A new method of inducing selective brain hypothermia with saline perfusion into the subdural space: effects on transient cerebral ischemia in cats.

In this study, we tested brain surface cooling as a new method of inducing selective brain hypothermia, and evaluated its effects on focal cerebral ischemia using a cat model of transient middle cerebral artery (MCA) occlusion. Cats underwent 1 h of MCA occlusion followed by 5 h of reperfusion. Brain surface cooling was induced for 4 h during and after MCA occlusion in the hypothermia group, but not in the normothermia group. Brain surface cooling was performed using saline perfusion into the subdural space. Rectal temperature, brain surface temperature, and deep brain temperature were monitored, and regional cerebral blood flow (rCBF) and somatosensory evoked potential (SEP) were serially measured. After 5 h of reperfusion, water content was also measured. Although the rectal temperature was maintained at about 37 degrees C, the brain surface temperature decreased rapidly to 33 degrees C and was maintained at that temperature. For 3 h following reperfusion, the rCBF was lower in the hypothermia group than in the normothermia group. At 4 and 5 h after reperfusion, the recovery of SEP amplitude was significantly more enhanced in the hypothermia group than in the normothermia group. In the gray matter, the water content was significantly more diminished in the hypothermia group than in the normothermia group. These results demonstrate that our method is useful for protecting the ischemic brain from a transient MCA occlusion. This method may be adapted for neurological surgery.</p

Implicit social associations for geometric-shape agents more strongly influenced by visual form than by explicitly identified social actions

Studies of infants' and adults' social cognition frequently use geometric-shape agents such as coloured squares and circles, but the influence of agent visual-form on social cognition has been little investigated. Here, although adults gave accurate explicit descriptions of interactions between geometric-shape aggressors and victims, implicit association tests for dominance and valence did not detect tendencies to encode the shapes’ social attributes on an implicit level. With regard to valence, the lack of any systematic implicit associations precludes conclusive interpretations. With regard to dominance, participants implicitly associated a yellow square as more dominant than a blue circle, even when the true relationship was the reverse of this and was correctly explicitly described by participants. Therefore, although explicit dominance judgements were strongly influenced by observed behaviour, implicit dominance associations were more clearly influenced by preconceived associations between visual form and social characteristics. This study represents a cautionary tale for those conducting experiments using geometric-shape agents

分散配置９軸センサロガーによる気球系の飛翔中挙動計測とダイナミクス同定法の研究

金沢大学理工研究域先端宇宙理工学研究センター / 大阪大学大型の成層圏気球は様々な科学観測に用いられている．より高精度な科学観測を行うため，ペイロード部（ゴンドラ）の高精度な姿勢制御が求められている．本研究では制御系設計に供する動力学数値モデルを得るため，飛翔中の気球系（気球本体，吊り紐，ゴンドラ）の姿勢運動を直接計測した．本研究に必要な計測器を開発し，研究期間内に2回の飛翔実験を行った．計測結果の初期解析から，気球系の構造モデルを推定した．Large stratospheric balloons have been used for various scientific missions. Some of such missions recently require more precise attitude control of the gondola　(payload part) for better quality of the science. This study aimed to develop the numerical dynamics model of the balloon flight system for the design of the attitude control system, and conducted the direct measurement of the attitude motion during the flights. For the measurement, the special measurement system was developed and was applied to two balloon flight experiments. Then, the structure models of the flight system were estimated based on the flight results.研究課題/領域番号:15K21130, 研究期間(年度):2015 - 201

Imaginary agents exist perceptually for children but not for adults

Mental imagery refers to representations and the accompanying experience of sensory information in the absence of appropriate sensory input. Little is known about children’s social imagery, imagery about an agent. It is possible that children’s social imagery may qualitatively differ from that of adults by involving more perceptual characteristics. We conducted three experiments to investigate the perceptual existence of social imagery when induced by verbal cues. Experiment 1 was a precondition for Experiments 2 and 3, and we examined whether children’s and adults’ predictive eye movements were disrupted by the presence of a real person’s face. Preschool children (n = 20) and adults (n = 20) watched a video where a woman, with/without her face shown, placed balls into a bucket. Participants’ gazes were less predictive of the woman’s actions in ‘Face’ versus ‘No-Face’ videos, indirectly indicating the perceptual presence of agents. Next, we examined whether adults’ and children’s predictive eye movements were affected by imagining a person. In Experiment 2, adult participants were presented with a video where the balls moved automatically and were asked to either watch the video (Ball condition, n = 20) or imagine that an invisible person moved the balls (Imagination condition, n = 20). Adult gazes did not differ between conditions. However, in Experiment 3, preschool children’s gazes were less predictive when imagining an invisible person’s actions (Invisible condition, n = 20) than when not imagining anything (Ball condition, n = 20) or when imagining an object (Fan condition, n = 20). The results suggest that children experience realistic social imagery induced by verbal cues

Efficient generation of highly squeezed light and second harmonic wave with periodically poled MgO:LiNbO_3

We report on effective generation of continuous-wave squeezed light and second harmonics with a periodically poled MgO:LiNbO$_{\mathrm{3}}$ (PPMgLN) crystal which enables us to utilize the large nonlinear optical coefficient $d_{\mathrm{33}}$. We achieved the squeezing level of $-7.60 \pm 0.15$dB at 860 nm by utilizing a subthreshol optical parametric oscillator with a PPMgLN crystal. We also generated 400 mW of second harmonics at 430 nm from 570 mW of fundamental waves with 70% of conversion efficiency by using a PPMgLN crystal inside an external cavity.Comment: 4 pages, 3 figure

Characterization of the lasing properties of a 5%Yb doped Lu_2SiO_5 crystal along its three principal dielectric axes

The laser performance of a 5% Yb doped Lu2SiO5 (Yb:LSO) has been investigated in quasi continuous-wave pumping regime along the three principal dielectric axes of the crystal, to obtain a complete characterization of its laser properties. The comparison among the obtained results for differently polarized lasers, in term of relative slope efficiency and absolute efficiency, allows the exploitability of different orientations of the material in order to be determined to obtain efficient laser sources. The laser slope efficiency and the energy conversion efficiency were similar for emission polarized along the three indicatrix axes, with noticeable maximum values of slope efficiency around 90% for polarization along the Y and Z axes. Tunable laser action has been obtained in the range 990 nm - 1084 nm, with sizeable differences in the shape of the tuning curve for polarization along the X, Y and Z axes. In particular, the tuning for polarization along the Z axis is relatively flat and uniform in the range 1023 nm - 1083 nm