Studies of interaction between He and elements with mass number 140 in Fe by time-differential perturbed-angular-correlation measurements

Room-temperature time-differential perturbed-angular-correlation (TDPAC) spectra of ¹⁴⁰Ce arising through ¹⁴⁰Ba-¹⁴⁰La from ¹⁴⁰Cs in He-doped Fe, unannealed and annealed in vacuum at various temperatures, were obtained in order to examine whether Ce (or rather, La and Ba) and He form complexes having a definite geometrical structure in Fe, as suggested by first-principles density-functional theory calculations. No clear signal of such complexes was observed in the TDPAC spectra. However, the TDPAC spectra indicate that Ce and He form complexes having a variety of geometrical structures. Comparison with reported TDPAC results on ¹¹¹Cd arising from ¹¹¹In in He-doped stainless steel shows that the parent atoms (La and Ba) of ¹⁴⁰Ce trap He atoms more efficiently than In atoms do, indicating stronger bonding of He to the former atoms, while different from the present case, ¹¹¹Cd (In)–He complexes form a unique geometrical structure.     

Formation of Cu precipitates and vacancy clusters in neutron-irradiated Fe–Cu alloys

Two Fe–Cu binary model alloys, Fe–0.3Cu and Fe–0.6Cu, were irradiated with fission neutrons at doses ranging from 4?×?10^?6 to 0.16 dpa (displacements per atom) at ～573 K to investigate the formation of Cu precipitates and microstructural evolution. The Cu content only affected the formation of Cu precipitates and microvoids at low doses. In Fe–0.3Cu, the formation of microvoids and Cu precipitates initiated at doses of 1.2?×?10^?4 and 4?×?10^?5 dpa, respectively. On the other hand, the formation of microvoids started at a dose of 4?×?10^?4 dpa in Fe–0.6Cu, and Cu precipitates were formed even after irradiation to 4?×?10^?6 dpa. On further irradiation, the difference in the formation of Cu precipitates and microvoids was small. Microvoids grew with increasing irradiation dose up to 3?×?10^?3 dpa in both alloys. Prominent aggregation of Cu atoms occurred upon irradiation from 3?×?10^?3 to 1.6?×?10^?2 dpa and the microvoids shrank. The Cu precipitates no longer grew, and microvoids nucleated and grew in the matrix above a dose of 1.6?×?10^?2 dpa in both alloys. The present studies clearly reveal the relationships between the formation and growth of Cu precipitates and microvoids with irradiation dose.     

Production of single quasicrystals and their electrical resistivity in the Al-Pd-Re system

Single Al-Pd-Re icosahedral quasicrystals with a maximum diameter of 5mm have been grown by a slow cooling method on the basis of a partial phase diagram determined in the present study. Laue X-ray and electron diffraction verified the highly ordered structure of the single icosahedral quasicrystals. The electrical resistivity rho of the single quasicrystals was measured to be 2000- 4000muOmegacm at 300K and 3000-6000muOmegacm at 2K, revealing a negative temperature dependence with a rho_4.2K/rho_300K value smaller than 2.     

Effects of experience on preference between forced and free choice

Preference between forced choice and free choice in concurrent-chain schedules of reinforcement was investigated in pigeons after exposure to particular combinations of terminal links. In Experiment 1, in which terminal links always ended with reinforcers, one of three pairs of terminal links was arranged as preexposure: (a) both terminal links had only one key (forced choice), (b) both terminal links had two keys (free choice), or (c) a combination of forced and free choice was arranged across sessions. In test sessions following the preexposure, pigeons' preferences rapidly shifted to the terminal links with which they had no recent experience. In Experiment 2, the same procedure was repeated except that each terminal link ended intermittently with reinforcers with a probability of .5 and there was no terminal-link arrangement with a combination of free and forced choice. Pigeons showed the same preference changes as in Experiment 1, but the preference changes did not appear immediately at the beginning of test sessions. These data suggest that recent previous experience was a more important determinant of preference than the difference between forced-choice and free-choice terminal links.     

Multistable syllables as enacted percepts: a source of an asymmetric bias in the verbal transformation effect

Perceptual changes are experienced during rapid and continuous repetition of a speech form, leading to an auditory illusion known as the verbal transformation effect. Although verbal transformations are considered to reflect mainly the perceptual organization and interpretation of speech, the present study was designed to test whether or not speech production constraints may participate in the emergence of verbal representations. With this goal in mind, we examined whether variations in the articulatory cohesion of repeated nonsense words--specifically, temporal relationships between articulatory events--could lead to perceptual asymmetries in verbal transformations. The first experiment displayed variations in timing relations between two consonantal gestures embedded in various nonsense syllables in a repetitive speech production task. In the second experiment, French participants repeatedly uttered these syllables while searching for verbal transformation. Syllable transformation frequencies followed the temporal clustering between consonantal gestures: The more synchronized the gestures, the more stable and attractive the syllable. In the third experiment, which involved a covert repetition mode, the pattern was maintained without external speech movements. However, when a purely perceptual condition was used in a fourth experiment, the previously observed perceptual asymmetries of verbal transformations disappeared. These experiments demonstrate the existence of an asymmetric bias in the verbal transformation effect linked to articulatory control constraints. The persistence of this effect from an overt to a covert repetition procedure provides evidence that articulatory stability constraints originating from the action system may be involved in auditory imagery. The absence of the asymmetric bias during a purely auditory procedure rules out perceptual mechanisms as a possible explanation of the observed asymmetries.     

Right hemispheric dominance in processing of unconscious negative emotion

Right hemispheric dominance in unconscious emotional processing has been suggested, but remains controversial. This issue was investigated using the subliminal affective priming paradigm combined with unilateral visual presentation in 40 normal subjects. In either left or right visual fields, angry facial expressions, happy facial expressions, or plain gray images were briefly presented as negative, positive, and control primes, followed by a mosaic mask. Then nonsense target ideographs were presented, and the subjects evaluated their partiality toward the targets. When the stimuli were presented in the left, but not the right, visual fields, the negative primes reduced the subjects' liking for the targets, relative to the case of the positive or control primes. These results provided behavioral evidence supporting the hypothesis that the right hemisphere is dominant for unconscious negative emotional processing.     

Illusion of sense of self-agency: discrepancy between the predicted and actual sensory consequences of actions modulates the sense of self-agency, but not the sense of self-ownership

It is proposed that knowledge of motor commands is used to distinguish self-generated sensation from externally generated sensation. In this paper, we show that the sense of self-agency, that is the sense that I am the one who is generating an action, largely depends on the degree of discrepancy resulting from comparison between the predicted and actual sensory feedback. In Experiment 1, the sense of self-agency was reduced when the presentation of the tone was unpredictable in terms of timing and its frequency, although in fact the tone was self-produced. In Experiment 2, the opposite case was found to occur. That is, participants experienced illusionary sense of self-agency when the externally generated sensations happened to match the prediction made by forward model. In Experiment 3, the sense of self-agency was reduced when there was a discrepancy between the predicted and actual sensory consequences, regardless of presence or absence of a discrepancy between the intended and actual consequences of actions. In all the experiments, a discrepancy between the predicted and actual feedback had no effects on sense of self-ownership, that is the sense that I am the one who is undergoing an experience. These results may suggest that both senses of self are mutually independent.     

Development of carefulness and quickness observed for a tray-carrying task

The purpose of this study was to investigate the developmental change in performance of groups of children instructed to behave carefully and quickly in a tray-carrying task. The subjects were 69 nonhandicapped children from a kindergarten, ages 3-4 to 6 years, and 20 adult students who volunteered. Subjects were instructed to carry as fast as they could a tray with a glass of water for 3 m without a spill. The amounts of water spilled and the times taken were measured. The amounts of water spilled were hardly different within groups of children of the same ages or between age groups. But the times were different among groups: the younger ones took longer, and the difference in time between tray-carrying and normal walking was greatest for the youngest group. Children could carry the tray as carefully as adults but could not do so quickly. The nature of the representation of the instruction in relation to the behavior of children and the difference in strategy to guarantee carefulness between children and the adults are discussed.     

Emotional empathy and associated individual differences

Emotional empathic tendency is defined as an individual’s characteristic inclination to respond with emotions similar to those of others who are present. Within a three-dimensional framework for describing temperament, more empathic persons were found to be more arousable, and secondarily, more pleasant. Greater skin conductance and heart-rate responses of more empathic persons to emotional stimuli confirmed their greater arousability. Also, more empathic individuals were more emotional, evidenced by their greater tendency to weep. Males were found consistently to be less empathic than females. Compared with parents of low-empathy subjects, those of high-empathy subjects were found to spend more time with their children, display more affection for them, and to be verbally more explicit about feelings. Also, more emphatic mothers were more tolerant of infant cries and were less prone to engage in child abuse. High-empathy, compared with low-empathy, subjects engaged more in altruistic behaviors, were less aggressive, more affiliative, rated positive social traits as more important, scored higher on measures of moral judgment, and volunteered more to help others. A modified Emotional Empathic Tendency Scale (EETS) for children correlated negatively with teacher ratings of child aggressiveness.     

Selection of effective tests of motor ability in preschool children based on pass-or-fail criteria: examination of reliability, objectivity, and rate of passing

The purpose of this study was to select effective tests of motor ability based on pass-or-fail criteria for use with preschool children. 37 items selected by examining theoretical validity and the results of preliminary tests were administered to preschool children (3 yr.: M = 3.7 yr., SD = 0.28; 4 yr.: M = 4.7 yr., SD = 0.28; 5 yr.: M = 5.7 yr., SD = 0.28). A skilled tester and each child's homeroom teacher rated whether the child's performance passed certain criteria or not. With agreement on two trials as an index of test-retest reliability, the mean agreement among the three grades ranged from 69% to 99% for Locomotion, 59% to 95% for Manipulation; and 66% to 100% for Stability. Disagreement on two trials may reflect instability in movement, practice effects, and so on. With agreement between two testers as an index of objectivity for 37 items, 33 showed interrater agreement of 80% or more for all three grades. No significant increase in pass rate with age was found on 10 items. In examining the three conditions mentioned above 27 items were selected as tests of motor ability: 14 items for Locomotion, 7 items for Manipulation, and 6 items for Stability.