Effect of applied stress on precipitation of Guinier–Preston zones in a Cu–0.9 wt.% Be single crystal

A stress-oriented formation of plate-shaped Guinier–Preston (GP) zones in single crystals of a Cu–0.9?wt.%?Be alloy aged at 200°C has been found. A compressive stress applied in the [001] direction assists the formation of the GP zones perpendicular to the [001] axis, while a tensile stress results in the preferential formation of the GP zones parallel to the stress axis. The applied stress strongly affects the nucleation of the GP zones. Free ageing at 275°C after compressive-stress ageing at 200°C produces plate-shaped γ′′ precipitates perpendicular to the stress axis, indicating a continuous change in the structure of the GP zones into that of the γ′′ phase. From length-change measurements during ageing, the misfit strains of the GP zone or γ′′ precipitate in directions parallel and perpendicular to the plate plane are estimated, respectively, as ?0.01 and ?0.10 for the GP zone and ?0.01 and ?0.11 for the γ′′ precipitate.     

Representation of plans: Activation in memory

The purpose of this study is to examine the temporal representation of plans in memory. Two experiments using a priming paradigm were conducted to investigate which plans would be activated in memory when participants processed a particular plan. The 64 undergraduates who participated in Experiment 1 were asked to memorise a 1-month schedule of plans. Results showed that when participants were presented with a particular plan as a prime, the preceding plan in the schedule was immediately activated. After the activation of the preceding plan, the plan following the prime plan in the schedule was activated. Experiment 2 was conducted to examine whether the sequential effect found in Experiment 1 might be based on day order (e.g., plans for day 1, plans for day 2, etc.) or simple ordering of plans (e.g., plan 1, plan 2, etc.). However, in the results of Experiment 2, with 48 undergraduate participants, the dynamic transition in the activation of plans along the time course, seen in Experiment 1, was not observed.     

Changes in the affect of infants before and after episodes of crying

This study examined the affect of infants just before the onset of crying and just after crying stopped. Two infants (between 7 and 14 months old) were observed longitudinally. In total, 102 crying episodes were analyzed. The infants displayed negative affect almost always just before starting to cry and soon after crying terminated. However, there were exceptions. Positive affect was observed. These were crying behaviors that the mother identified as “fake crying” or “emergence of fake crying”. These data indicate that, although normally infant affect just before and right after crying is negative, infants also can exhibit positive affect when they show fake crying. Infants who are capable of fake crying might communicate successfully with their caregivers.     

Tilted InSb nanostructures fabricated by off-normal ion beam irradiation

ABSTRACT

Using a two-step focused ion beam irradiation process, tilted InSb nanostructures have been fabricated using a off-normal angle of irradiation. In the first step, a well-focused ion beam was used to irradiate the surface of the structure to achieve top-down sputtering. In the second step, the ion beam was used to irradiate the entire surface to promote bottom-up nanostructure growth through the migration of ion-beam-induced interstitial atoms. The formation of a nanostructure with a 46° tilt and an aspect ratio of 0.5 was achieved using ion beam irradiation at an angle of 45° in both steps of the process. The 2% concentration of point defects obtained by changing the volume of the nanostructure before and after irradiation contributed to the growth of the structure. The results showed that many point defects did not recombine, and survived to contribute toward the growth of the wall structure.     

Taste avoidance caused by spontaneous wheel running: effects of duration and delay of wheel confinement

Confinement of a rat in a running wheel results in the rat's subsequent avoidance of the taste consumed before the confinement. This phenomenon has been ascribed to taste aversion conditioned by spontaneous wheel running. As a first step toward clarification of the underlying mechanism of this phenomenon, we manipulated two parameters of the taste-confinement procedure: duration of wheel confinement (Experiments 1A and 1B) and temporal intervals between the taste consumption and the wheel confinement (Experiments 2A and 2B). In general, longer confinement and shorter inter-event interval caused stronger taste avoidance. However, the results also suggested that it is possible to establish taste avoidance when wheel confinement was delayed 1-h after the taste consumption. These results correspond to those of conventional taste aversion caused by illness-inducing agents, suggesting similar mechanisms in the both preparations. Experiment 3 revealed that running in a wheel rather than wheel confinement itself is the effective factor for establishing taste avoidance.     

Attention can retrospectively distort visual space

A brief visual cue that attracts attention repels the perceived location of a subsequent visual stimulus away from the focus of attention (attentional repulsion). In the first experiment reported here, we presented a visual cue after a visual target and found that the perceived location of the target stimulus shifted toward the location of the cue (attentional attraction). The subsequent experiments ruled out nonattentional hypotheses and indicated that the mislocalization effect is attributable to the attentional shift. The results of this study suggest that preceding and succeeding contexts differentially modulate the perceived location of a briefly presented stimulus. Our findings also underscore the importance of retrospective processes in visual attention.     

Modulation of physical understanding by common marmosets (<Emphasis Type="Italic">Callithrix jacchus</Emphasis>)

The understanding of physical causality in common marmosets was tested using support problems in which a pair of sheets was presented to determine whether subjects would choose the sheet that had a food item on it (i.e., the sheet was supporting the food item). In two experiments, the conditions were manipulated in terms of the length of the sheet, the distance between the sheet and the food item, the presence of a gap separating the two sheets, and the size of the food item. In Experiment 1, the marmosets had difficulty rejecting an irretrievable food item when it was located closer to them than a retrievable item. Although their performance was strongly affected by the size of the irretrievable food item, they quickly learned to reject that alternative. In contrast, no improvement was found when one sheet was divided into two pieces such that the food item could not be retrieved when its near side was pulled. A similar response tendency was observed in Experiment 2, in which the effects of the large food item were examined in three different conditions. Thus, common marmosets were influenced by the perceptual features of the food in solving the support problems, as are other non-human primates. In addition, they consistently failed to appreciate the presence of a gap and, therefore, failed to reject the distracter alternative. However, all animals rapidly learned that the size of the food item was an irrelevant variable, and some showed an elementary conceptual understanding of support. These findings suggest that marmosets’ physical understanding may improve with experience.     

Multisensory perceptual learning reshapes both fast and slow mechanisms of crossmodal processing

Previous research has shown that sounds facilitate perception of visual patterns appearing immediately after the sound but impair perception of patterns appearing after some delay. Here we examined the spatial gradient of the fast crossmodal facilitation effect and the slow inhibition effect in order to test whether they reflect separate mechanisms. We found that crossmodal facilitation is only observed at visual field locations overlapping with the sound, whereas crossmodal inhibition affects the whole hemifield. Furthermore, we tested whether multisensory perceptual learning with misaligned audio-visual stimuli reshapes crossmodal facilitation and inhibition. We found that training shifts crossmodal facilitation towards the trained location without changing its range. By contrast, training narrows the range of inhibition without shifting its position. Our results suggest that crossmodal facilitation and inhibition reflect separate mechanisms that can both be reshaped by multisensory experience even in adult humans. Multisensory links seem to be more plastic than previously thought.     

Do bantams (Gallus gallus domesticus) amodally complete partly occluded lines? An analysis of line classification performance

Humans perceive a line touching an edge of a large rectangle longer than the reality. Kanizsa (1979) has suggested that this illusion occurs because we perceive that the line is partly "hidden" behind the rectangle and automatically completes it. We tested whether bantams (Gallus gallus domesticus) would experience this perceptual phenomenon using a line classification task on the touch monitor, which was used in our previous study with rhesus monkeys and pigeons (Fujita, 2001). We trained three bantams to classify six lengths of black target lines into two categories, "short" or "long," ignoring a gray rectangle (Experiment 1) or a gray area (i.e., a left or a right half of the monitor was filled with gray; Experiment 2) located at the same distance (8 pixels) from the target line. In the test, the gap between the line and the gray rectangle (or area) sometimes changed (0, 4, or 8 pixels; we labeled these stimuli as G0, G4, and G8 respectively). Both of the two successfully trained bantams showed an illusion for G0, but the direction of illusion was reversed; that is, they judged the line in G0 to be "shorter" than that in G4 and G8. Further analyses proved that neither the gaps between the target line and the gray rectangle nor the total widths of the stimuli could account for the bantams' responses. These results suggest that bantams do not complete the "occluded" portion even when identification of its shape is not required.     

Development of infant crying behavior: A longitudinal case study

This study documents the development of infant crying behavior during the second half of the first year (across a key developmental transition). Two female infants were observed twice a month for 6 months when the infants were between 7 and 14 months of age. The infants exhibited crying behavior that seemed to become more sophisticated with increasing age. This marked a proactive stance in communicating with the mother on the part of the infant. Interestingly, at 11–12 months, “fake crying” was observed during a naturalistic interaction with the mother. This implied that deceptive infant behavior could be seen at quite an early stage.