Global scene layout modulates contextual learning in change detection

Change in the visual scene often goes unnoticed – a phenomenon referred to as “change blindness.” This study examined whether the hierarchical structure, i.e., the global–local layout of a scene can influence performance in a one-shot change detection paradigm. To this end, natural scenes of a laid breakfast table were presented, and observers were asked to locate the onset of a new local object. Importantly, the global structure of the scene was manipulated by varying the relations among objects in the scene layouts. The very same items were either presented as global-congruent (typical) layouts or as global-incongruent (random) arrangements. Change blindness was less severe for congruent than for incongruent displays, and this congruency benefit increased with the duration of the experiment. These findings show that global layouts are learned, supporting detection of local changes with enhanced efficiency. However, performance was not affected by scene congruency in a subsequent control experiment that required observers to localize a static discontinuity (i.e., an object that was missing from the repeated layouts). Our results thus show that learning of the global layout is particularly linked to the local objects. Taken together, our results reveal an effect of “global precedence” in natural scenes. We suggest that relational properties within the hierarchy of a natural scene are governed, in particular, by global image analysis, reducing change blindness for local objects through scene learning

An annotated checklist of the jumping plant-lice (Insecta: Hemiptera: Psylloidea) from the Mercantour National Park, with seven new records for France and one new synonymy

A total of 68 psyllid species are listed from the Mercantour National Park in Southeast France, where a targeted collecting campaign was conducted between 2009 and 2012, as part of the project "ATBI+M" Mercantour. The insects were collected using Malaise traps, flight intercept traps and sweep nets to sample in the vegetation. Additional information on distribution, biology and host-plants is provided for each species. Seven species are recorded for the first time from France: Craspedolepta artemisiae (Foerster, 1848), Craspedolepta nebulosa (Zetterstedt, 1828), Cacopsylla propinqua (Schaefer, 1949), Cyamophila prohaskai (Priesner, 1927), Eryngiofaga cf. refuga (Loginova, 1966), Bactericera parastriola Conci, Ossiannilsson & Tamanini, 1988 and Trioza flixiana Burckhardt & Lauterer, 2002. Trioza (Trioza) rapisardai Conci & Tamanini, 1984 is a new subjective synonym of Trioza brachyceraea Hodkinson & White, 1979, which was previously known only from the male holotype. The abundance, distribution and introduction status of some species are discussed

Amodal completion in visual working memory

Amodal completion refers to the perceptual “filling-in” of partly occluded object fragments. Previous work has shown that object completion occurs efficiently, at early perceptual stages of processing. However, despite efficient early completion, at a later stage, the maintenance of complete-object representations in visual working memory (VWM) may be severely restricted due to limited mnemonic resources being available. To examine for such a limitation, we investigated whether the structure of to-be-remembered objects influences what is encoded and maintained in VWM using a change detection paradigm. Participants were presented with a memory display that contained either “composite” objects, that is, notched shapes abutting an occluding square, or equivalent unoccluded, “simple” objects. The results showed overall increased memory performance for simple relative to composite objects. Moreover, evidence for completion in VWM was found for composite objects that were interpreted as globally completed wholes, relative to local completions or an uncompleted mosaic (baseline) condition. This global completion advantage was obtained only when the “context” of simple objects also supported a global object interpretation. Finally, with an increase in memory set size, the global object advantage decreased substantially. These findings indicate that processes of amodal completion influence VWM performance until some overall-capacity limitation prevents completion. VWM completion processes do not operate automatically; rather, the representation format is determined top-down based on the simple object context provided. Overall, these findings support the notion of VWM as a capacity-limited resource, with storage capacity depending on the structured representation of to-be-remembered objects

Feature guidance by negative attentional templates depends on search difficulty

Prior knowledge about an upcoming target can bias attention and facilitate visual search performance. However, whether knowledge about distractors can likewise enhance search, biasing attention away from to-be-avoided items, is less clear. Here, we investigated whether the utilization of such attentional templates is affected by search difficulty. Results from two experiments revealed search efficiency to be reliably increased when positive cues provide information about the upcoming target (relative to neutral, baseline cues) irrespective of whether search was easy (low target-nontarget similarity) or difficult (high target-nontarget similarity). By contrast, negative cues that inform about a to-be-avoided distractor were found to facilitate performance only during difficult (but not easy) search, that is, when responses were relatively slow. This suggests that, contrary to positive target templates, negative distractor templates can be used effectively only when the search task is difficult, which provides sufficient time for processes of distractor inhibition to operate

Whatever after next? adaptive predictions based on short- and long-term memory in visual search

Generating predictions for task-relevant goals is a fundamental requirement of human information processing, as it ensures adaptive success in our complex natural environment. Clark (in press) proposed a model of hierarchical predictive processing, in which perception, attention, and learning are unified within a coherent framework. In this view, incoming sensory signals are constantly matched with top-down expectations or predictions, with the aim of minimizing the prediction error to generate adaptive behavior. For example, in a natural environment such as a kitchen, search for a given target object (e.g., a pan) might be guided by a variety of predictive cues generated by previously acquired knowledge, such as the target’s typical appearance (e.g., its color, size, and shape as defined by a top-down implemented search template). In addition, predictions can also be derived from contextual factors, such as the most probable location of the target (e.g., on the stove), and its typical co-occurrence with other objects (e.g., pan and kettle; see Oliva and Torralba, 2007; Wolfe et al., 2011, for reviews)

Strain sensitivity enhancement of broadband ultrasonic signals in plates using spectral phase filtering.

The focused signal obtained by the time-reversal or the cross-correlation techniques of ultrasonic guided waves in plates changes when the medium is subject to strain, which can be used to monitor the medium strain level. In this paper, the sensitivity to strain of cross-correlated signals is enhanced by a post-processing filtering procedure aiming to preserve only strain-sensitive spectrum components. Two different strategies were adopted, based on the phase of either the Fourier transform or the short-time Fourier transform. Both use prior knowledge of the system impulse response at some strain level. The technique was evaluated in an aluminum plate, effectively providing up to twice higher sensitivity to strain. The sensitivity increase depends on a phase threshold parameter used in the filtering process. Its performance was assessed based on the sensitivity gain, the loss of energy concentration capability, and the value of the foreknown strain. Signals synthesized with the time–frequency representation, through the short-time Fourier transform, provided a better tradeoff between sensitivity gain and loss of energy concentration

Secuenciación Parcial del Genoma de Xanthomonas translucens pv. undulosa Empleando Nuevas Tecnologías

La espiga negra o rayado bacteriano es una enfermedad causada por la bacteria Xanthomonas translucens pv. undulosa. Esta enfermedad se manifiesta sobre las hojas con manchas estriadas marrones, mientras que los granos y tallos adquieren un aspecto marrón oscuro de apariencia húmeda. Se manifiesta en cultivos de trigo (Triticum spp), cebada (Hordeum vulgare), centeno (Secale cereale) y avena (Avena sp), donde las epidemias son de carácter esporádico, dependiendo del manejo del cultivo, condiciones climáticas y genotipos utilizados. Eventualmente podrían representar una limitante para la producción en estos cultivos.Hasta el momento, no se ha secuenciado ningún aislamiento de esta bacteria en Argentina, limitando estudio y comprensión de su patogenicidad. Con el objetivo de conocer aspectos genómicos básicos de dicha bacteria, se purificó ADN a partir de colonias aisladas a partir de trigo con síntomas y se secuenció empleando la tecnología MinION (Oxford Nanopore), de pequeño tamaño y bajo costo. Como resultado se obtuvieron 2.9x103 lecturas contabilizando un total de 500Mb secuenciados. En el ensamblaje final se obtuvo un solo contig de aproximadamente 4.5Mb con una cobertura promedio de 70X y con una identidad a nivel de nucleótidos cercanas al 96% respecto de la secuencia referencia de Xanthomonas translucens pv. undulosa cepa ICMP11055 (CP009750). En el proceso de anotación de genes se identificaron 6 rDNA, 57 RNAt y más de 5000 CDSs (secuencias codificantes). Se continúa trabajando en la determinación del repertorio de genes que codifican para proteínas efectorasy otras regiones genómicas asociadas a la patogenicidad.Los resultados expuestos permiten valorar el empleo de las nuevas tecnologías de secuenciación para el conocimiento de diferentes genomas. Las mismas deben ser consideradas como una herramienta económicamente accesible, versátiles ya que no requieren de equipo pesado ni condiciones exigentes para su uso y rápidas, indispensables para el estudio de diferentes agentes fitopatógenos

Aphid species (Hemiptera: Aphididae) reported for the first time in Tucumán, Argentina

Aphids (Hemiptera: Aphididae) are considered among the most important pests all around the world. The total number of aphid species recorded in Argentina between 2003 and 2013 has risen from 200 to 237, which demonstrates the continuous introduction and discovery of new species in the territory. Therefore, faunistic studies should be conducted without interruption in areas of interest. The aim of this study was to establish if there were aphid species in Tucuman Province, Argentina that had not been recorded previously in the province. Aphids were collected with modified Moericke yellow water pan traps in potato crops during 2 seasons in 3 regions of Tucumán. Seventeen species, among the 47 species identified, and the genus Illinoia represent new records for the Province.Los pulgones se incluyen entre las plagas más importantes del mundo entero. El número total de especies de áfidos registrados en Argentina entre 2003 y 2013 se incrementó de 200 hasta 237, lo que demuestra la permanente introducción y hallazgo de nuevas especies en el territorio. Por lo tanto, son necesarios constantes estudios faunísticos en las áreas de interés. El objetivo de este estudio fue determinar si existían especies de áfidos en Tucumán, Argentina, que no habían sido citadas anteriormente en la provincia. Los pulgones se recolectaron con trampas amarillas de agua tipo Moericke durante dos temporadas de cultivo de papa, en tres regiones de Tucumán. Entre las 47 especies identificadas, 17 y el género Illinoia, representaron nuevas citas para la provincia.EEA MendozaFil: Avila, Ana Lucía. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; ArgentinaFil: Vera, M. Alejandro. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Ortego, Jaime. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Ploper, Leonardo Daniel. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; ArgentinaFil: Conci, Vilma Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Aphid (Hemiptera: Aphididae) Diversity in Potato Production Areas in Tucumán, Argentina

Aphids are recognized as important plant pests worldwide and they are major vectors of viruses. It is necessary to identify the aphid species in an agroecosystem in order to develop appropriate pest management strategies. The aim of this work was to determine the taxonomic diversity of aphid species present in potato crops in different agroecological regions of Tucumán, Argentina. Monitoring was done by 2 methods: modified Moericke yellow water traps were used for the alatae, while the apterae were collected directly from the plants. A total of 15,169 winged aphids were caught and 7,455 apterae colonizing the crop were collected. Fifty-six species were identified, 27 of which were present in all regions surveyed. Differences in species diversity between regions are discussed.Los pulgones se incluyen entre las plagas más importantes del mundo entero. El número total de especies de áfidos registrados en Argentina entre 2003 y 2013 se incrementó de 200 hasta 237, lo que demuestra la permanente introducción y hallazgo de nuevas especies en el territorio. Por lo tanto, son necesarios constantes estudios faunísticos en las áreas de interés. El objetivo de este estudio fue determinar si existían especies de áfidos en Tucumán, Argentina, que no habían sido citadas anteriormente en la provincia. Los pulgones se recolectaron con trampas amarillas de agua tipo Moericke durante dos temporadas de cultivo de papa, en tres regiones de Tucumán. Entre las 47 especies identificadas, 17 y el género Illinoia, representaron nuevas citas para la provincia.EEA JunínInstituto de Patología VegetalFil: Avila, Ana Lucía. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; ArgentinaFil: Vera, M. Alejandro. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Ortego, Jaime. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Junín; ArgentinaFil: Willink, Eduardo. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Ploper, Leonardo Daniel. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; ArgentinaFil: Conci, Vilma Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Kanizsa-figure object completion gates selection in the attentional blink

Previous work has demonstrated that perceptual grouping modulates the selectivity of attention across space. By contrast, how grouping influences the allocation of attention over time is much less clear. This study investigated this issue, using an attentional blink (AB) paradigm to test how grouping influences the initial selection and the subsequent short-term memory consolidation of a target. On a given trial, two red Kanizsa-type targets (T1 and T2) with varying grouping strength were embedded in a rapid serial visual presentation stream of irrelevant distractors. Our results showed the typical AB finding: impaired identification of T2 when presented close in time following T1. Moreover, the AB was modulated by the T2 grouping?independently of the T1 structure?with stronger grouping leading to a decreased AB and overall higher performance. Conversely, a reversed pattern, namely an increased AB with increasing grouping strength was observed when the Kanizsa figure was not task-relevant. Together, these findings suggest that the grouping benefit emerges at early perceptual stages, automatically drawing attentional resources, thereby leading to either sustained benefits or transient costs?depending on the task-relevance of the grouped object. This indicates that grouping modulates processing of objects in time