RESUMO
The ability to perceive and remember the spatial layout of a scene is critical to understanding the visual world, both for navigation and for other complex tasks that depend upon the structure of the current environment. However, surprisingly little work has investigated how and when scene layout information is maintained in memory. One prominent line of work investigating this issue is a scene-priming paradigm (e.g., Sanocki & Epstein, 1997), in which different types of previews are presented to participants shortly before they judge which of two regions of a scene is closer in depth to the viewer. Experiments using this paradigm have been widely cited as evidence that scene layout information is stored across brief delays and have been used to investigate the structure of the representations underlying memory for scene layout. In the present experiments, we better characterize these scene-priming effects. We find that a large amount of visual detail rather than the presence of depth information is necessary for the priming effect; that participants show a preview benefit for a judgment completely unrelated to the scene itself; and that preview benefits are susceptible to masking and quickly decay. Together, these results suggest that "scene priming" effects do not isolate scene layout information in memory, and that they may arise from low-level visual information held in sensory memory. This broadens the range of interpretations of scene priming effects and suggests that other paradigms may need to be developed to selectively investigate how we represent scene layout information in memory.
Assuntos
Memória de Curto Prazo/fisiologia , Rememoração Mental/fisiologia , Percepção Espacial/fisiologia , Percepção Visual/fisiologia , Adulto , Humanos , Julgamento , Estimulação Luminosa/métodos , Adulto JovemRESUMO
Tomato brown rugose fruit virus (ToBRFV) is a contact-transmitted tobamovirus affecting many tomato growing regions of the world. This study investigated the effects of different glasshouse surfaces on the survival of the virus; the efficacy of different disinfectants; and heat treatment against ToBRFV (surfaces included steel, aluminium, hard plastic, polythene, glass and concrete). A bioassay followed by ELISA was used to check virus viability. ToBRFV survived for at least 7 days on all surfaces tested and on some for at least 6 months. The virus survived for over two hours on hands and gloves. Hand washing was shown to be unreliable for the removal of the virus. Glutaraldehyde and quaternary ammonium compound disinfectants were effective at one hour on all surfaces. Some other disinfectants were effective at one hour of contact time, on all surfaces except concrete. Sodium hypochlorite was partially effective against ToBRFV, even on concrete. A 5 min soak of plastic trays in water at 90 °C was effective at denaturing ToBRFV; however, 5 min at 70 °C was not. Heating infected sap showed the thermal inactivation point to be 90 °C, confirming the hot water treatment results and showing that deactivation was due to the heat treatment and not a washing effect of the water.
Assuntos
Desinfetantes , Solanum lycopersicum , Tobamovirus , Vírus , Desinfecção/métodos , Frutas , Desinfetantes/farmacologiaRESUMO
The "spatial congruency bias" is a behavioral phenomenon where 2 objects presented sequentially are more likely to be judged as being the same object if they are presented in the same location (Golomb, Kupitz, & Thiemann, 2014), suggesting that irrelevant spatial location information may be bound to object representations. Here, we examine whether the spatial congruency bias extends to higher-level object judgments of facial identity and expression. On each trial, 2 real-world faces were sequentially presented in variable screen locations, and subjects were asked to make same-different judgments on the facial expression (Experiments 1-2) or facial identity (Experiment 3) of the stimuli. We observed a robust spatial congruency bias for judgments of facial identity, yet a more fragile one for judgments of facial expression. Subjects were more likely to judge 2 faces as displaying the same expression if they were presented in the same location (compared to in different locations), but only when the faces shared the same identity. On the other hand, a spatial congruency bias was found when subjects made judgments on facial identity, even across faces displaying different facial expressions. These findings suggest a possible difference between the binding of facial identity and facial expression to spatial location. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
RESUMO
To interact successfully with objects, we must maintain stable representations of their locations in the world. However, their images on the retina may be displaced several times per second by large, rapid eye movements. A number of studies have demonstrated that visual processing is heavily influenced by gaze-centered (retinotopic) information, including a recent finding that memory for an object's location is more accurate and precise in gaze-centered (retinotopic) than world-centered (spatiotopic) coordinates (Golomb & Kanwisher, 2012b). This effect is somewhat surprising, given our intuition that behavior is successfully guided by spatiotopic representations. In the present experiment, we asked whether the visual system may rely on a more spatiotopic memory store depending on the mode of responding. Specifically, we tested whether reaching toward and tapping directly on an object's location could improve memory for its spatiotopic location. Participants performed a spatial working memory task under four conditions: retinotopic vs. spatiotopic task, and computer mouse click vs. touchscreen reaching response. When participants responded by clicking with a mouse on the screen, we replicated Golomb & Kanwisher's original results, finding that memory was more accurate in retinotopic than spatiotopic coordinates and that the accuracy of spatiotopic memory deteriorated substantially more than retinotopic memory with additional eye movements during the memory delay. Critically, we found the same pattern of results when participants responded by using their finger to reach and tap the remembered location on the monitor. These results further support the hypothesis that spatial memory is natively retinotopic; we found no evidence that engaging the motor system improves spatiotopic memory across saccades.
Assuntos
Memória de Curto Prazo/fisiologia , Rememoração Mental/fisiologia , Desempenho Psicomotor/fisiologia , Retina/fisiologia , Percepção Espacial/fisiologia , Memória Espacial/fisiologia , Percepção Visual/fisiologia , Adulto , Humanos , Adulto JovemRESUMO
Despite frequent eye movements that rapidly shift the locations of objects on our retinas, our visual system creates a stable perception of the world. To do this, it must convert eye-centered (retinotopic) input to world-centered (spatiotopic) percepts. Moreover, for successful behavior we must also incorporate information about object features/identities during this updating - a fundamental challenge that remains to be understood. Here we adapted a recent behavioral paradigm, the "spatial congruency bias," to investigate object-location binding across an eye movement. In two initial baseline experiments, we showed that the spatial congruency bias was present for both gabor and face stimuli in addition to the object stimuli used in the original paradigm. Then, across three main experiments, we found the bias was preserved across an eye movement, but only in retinotopic coordinates: Subjects were more likely to perceive two stimuli as having the same features/identity when they were presented in the same retinotopic location. Strikingly, there was no evidence of location binding in the more ecologically relevant spatiotopic (world-centered) coordinates; the reference frame did not update to spatiotopic even at longer post-saccade delays, nor did it transition to spatiotopic with more complex stimuli (gabors, shapes, and faces all showed a retinotopic congruency bias). Our results suggest that object-location binding may be tied to retinotopic coordinates, and that it may need to be re-established following each eye movement rather than being automatically updated to spatiotopic coordinates.
Assuntos
Reconhecimento Visual de Modelos/fisiologia , Retina/fisiologia , Movimentos Sacádicos/fisiologia , Percepção Espacial/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
Traditionally, recognizing the objects within a scene has been treated as a prerequisite to recognizing the scene itself. However, research now suggests that the ability to rapidly recognize visual scenes could be supported by global properties of the scene itself rather than the objects within the scene. Here, we argue for a particular instantiation of this view: That scenes are recognized by treating them as a global texture and processing the pattern of orientations and spatial frequencies across different areas of the scene without recognizing any objects. To test this model, we asked whether there is a link between how proficient individuals are at rapid scene perception and how proficiently they represent simple spatial patterns of orientation information (global ensemble texture). We find a significant and selective correlation between these tasks, suggesting a link between scene perception and spatial ensemble tasks but not nonspatial summary statistics In a second and third experiment, we additionally show that global ensemble texture information is not only associated with scene recognition, but that preserving only global ensemble texture information from scenes is sufficient to support rapid scene perception; however, preserving the same information is not sufficient for object recognition. Thus, global ensemble texture alone is sufficient to allow activation of scene representations but not object representations. Together, these results provide evidence for a view of scene recognition based on global ensemble texture rather than a view based purely on objects or on nonspatially localized global properties. (PsycINFO Database Record
Assuntos
Reconhecimento Visual de Modelos/fisiologia , Percepção Espacial/fisiologia , Adolescente , Adulto , Humanos , Adulto JovemRESUMO
One of the fundamental challenges of visual cognition is how our visual systems combine information about an object's features with its spatial location. A recent phenomenon related to object-location binding, the "spatial congruency bias," revealed that two objects are more likely to be perceived as having the same identity or features if they appear in the same spatial location, versus if the second object appears in a different location. The spatial congruency bias suggests that irrelevant location information is automatically encoded with and bound to other object properties, biasing perceptual judgments. Here we further explored this new phenomenon and its role in object-location binding by asking what happens when an object moves to a new location: Is the spatial congruency bias sensitive to spatiotemporal contiguity cues, or does it remain linked to the original object location? Across four experiments, we found that the spatial congruency bias remained strongly linked to the original object location. However, under certain circumstances-for instance, when the first object paused and remained visible for a brief time after the movement-the congruency bias was found at both the original location and the updated location. These data suggest that the spatial congruency bias is based more on low-level visual information than on spatiotemporal contiguity cues, and reflects a type of object-location binding that is primarily tied to the original object location and that may only update to the object's new location if there is time for the features to be re-encoded and rebound following the movement.
Assuntos
Viés de Atenção/fisiologia , Movimento (Física) , Processamento Espacial/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Cognição , Sinais (Psicologia) , Humanos , Julgamento , Adulto JovemRESUMO
Barley yellow mosaic virus (BaYMV) and Barley mild mosaic virus (BaMMV) are economically-important, soil-borne pathogens of winter barley. Until recently, laboratory diagnosis of these pathogens has relied upon ELISA using polyclonal antiserum. However, due to the unstable nature of these viruses, combined with the inability to sap transmit BaYMV, high quality antiserum has been difficult to obtain and as a result the performance of ELISA is often unsatisfactory. As an alternative approach two TaqMan assays (one BaYMV-specific and the other BaMMV-specific) have been developed. These assays have been validated for three seasons, by testing samples in parallel with ELISA. This testing indicates that TaqMan is a more reliable detection method than ELISA, especially with late-season and mixed infection samples. Data is also provided on a comparison of using simplex assays versus a multiplex assay for detecting BaYMV and BaMMV. The results indicate that while multiplexing does lead to a small reduction in sensitivity, it can be used reliably to streamline routine diagnosis. Further improvements in the development of a routine diagnostic procedure are also described including details of a rapid automated extraction procedure (Kingfisher) and the use of a novel cereal-specific control assay.
Assuntos
Hordeum/virologia , Vírus do Mosaico/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Sequência de Bases , Primers do DNA , Ensaio de Imunoadsorção Enzimática/métodos , Vírus do Mosaico/classificação , Vírus do Mosaico/patogenicidade , Doenças das Plantas/virologia , RNA Viral/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodosRESUMO
Internal necrosis of carrot has been observed in UK carrots for at least 10 years, and has been anecdotally linked to virus infection. In the 2009 growing season some growers had up to 10% of yield with these symptoms. Traditional diagnostic methods are targeted towards specific pathogens. By using a metagenomic approach with high throughput sequencing technology, other, as yet unidentified causes of root necrosis were investigated. Additionally a statistical analysis has shown which viruses are most closely associated with disease symptoms. Carrot samples were collected from a crop exhibiting root necrosis (102 Affected: 99 Unaffected) and tested for the presence of the established carrot viruses: Carrot red leaf virus (CtRLV), Carrot mottle virus (CMoV), Carrot red leaf associated viral RNA (CtRLVaRNA) and Parsnip yellow fleck virus (PYFV). The presence of these viruses was not associated with symptomatic carrot roots either as single viruses or in combinations. A sub-sample of carrots of mixed symptom status was subjected to MiSeq sequencing. The results from these tests suggested Carrot yellow leaf virus (CYLV) was associated with symptomatic roots. Additionally a novel Torradovirus, a novel Closterovirus and two novel Betaflexiviradae related plant viruses were detected. A specific diagnostic test was designed for CYLV. Of the 102 affected carrots, 98% were positive for CYLV compared to 22% of the unaffected carrots. From these data we conclude that although we have yet to practically demonstrate a causal link, CYLV appears to be strongly associated with the presence of necrosis of carrots.
Assuntos
Closterovirus/genética , Daucus carota/virologia , Necrose , Doenças das Plantas/virologia , Closterovirus/classificação , Genoma Viral , Proteínas de Choque Térmico HSP72/genética , Fenótipo , Filogenia , Análise de Sequência de DNA , Proteínas Virais/genéticaRESUMO
OBJECTIVE: This study examined the associations between eating pathology and narcissism in an eating-disordered group. Narcissism was conceptualized in terms of both its core element (entitlement, grandiosity) and the narcissistic defenses that are used to maintain self-esteem. METHOD: Seventy non-clinical and 84 eating-disordered patients completed a measure of the different elements of narcissism, and a standardized measure of eating pathology. RESULTS: The eating-disordered group scored higher than the non-clinical women on the measures of core narcissism and of the narcissistically abused style ("poor me" defense). The pattern of dimensional associations between narcissism and eating pathology was highly similar across the clinical and nonclinical groups, with the narcissistic defenses playing the strongest role. The poisonous pedagogy style ("bad you" defense) was positively associated with restrictive attitudes toward eating, while the narcissistically abused style was positively associated with restraint, eating concern, body shape concern, and body weight concern. CONCLUSION: The narcissistic defenses are particularly relevant in understanding the eating disorders. Implications for future research are outlined, and suggestions are made about the need to assess and respond to these associations in treatment.