Towards a “virtual pigeon”: A new technique for investigating avian social perception

The purpose of the present study is to examine the applicability of a computer-generated, virtual animal to study animal cognition. Pigeons were trained to discriminate between movies of a real pigeon and a rat. Then, they were tested with movies of the computer-generated (CG) pigeon. Subjects showed generalization to the CG pigeon, however, they also responded to modified versions in which the CG pigeon was showing impossible movement, namely hopping and walking without its head bobbing. Hence, the pigeons did not attend to these particular details of the display. When they were trained to discriminate between the normal and the modified version of the CG pigeon, they were able to learn the discrimination. The results of an additional partial occlusion test suggest that the subjects used head movement as a cue for the usual vs. unusual CG pigeon discrimination.This contribution is part of the special issue ‘Animal Logics’ (Watanabe and Huber 2006)     

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.     

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.     

THE WORLDWIDE BURDEN OF INFANT MENTAL AND EMOTIONAL DISORDER: REPORT OF THE TASK FORCE OF THE WORLD ASSOCIATION FOR INFANT MENTAL HEALTH

Children worldwide experience mental and emotional disorders. Mental disorders occurring among young children, especially infants (birth –3 years), often go unrecognized. Prevalence rates are difficult to determine because of lack of awareness and difficulty assessing and diagnosing young children. Existing data, however, suggest that rates of disorders in young children are comparable to those of older children and adolescents (von Klitzing, Dohnert, Kroll, & Grube, 2015 ). The lack of widespread recognition of disorders of infancy is particularly concerning due to the unique positioning of infancy as foundational in the developmental process. Both the brain and behavior are in vulnerable states of development across the first 3 years of life, with potential for enduring deviations to occur in response to early trauma and deprivation. Intervention approaches for young children require sensitivity to their developmental needs within their families. The primacy of infancy as a time of unique foundational risks for disorder, the impact of trauma and violence on young children's development, the impact of family disruption on children's attachment, and existing literature on prevalence rates of early disorders are discussed. Finally, global priorities for addressing these disorders of infancy are highlighted to support prevention and intervention actions that may alleviate suffering among our youngest world citizens.     

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.