Flash-lag chimeras: the role of perceived alignment in the composite face effect

Spatial alignment of different face halves results in a configuration that mars the recognition of the identity of either face half (). What would happen to the recognition performance for face halves that were aligned on the retina but were perceived as misaligned, or were misaligned on the retina but were perceived as aligned? We used the 'flash-lag' effect () to address these questions. We created chimeras consisting of a stationary top half-face initially aligned with a moving bottom half-face. Flash-lag chimeras were better recognized than their stationary counterparts. However when flashed face halves were presented physically ahead of moving halves thereby nulling the flash-lag effect, recognition was impaired. This counters the notion that relative movement between the two face halves per se is sufficient to explain better recognition of flash-lag chimeras. Thus, the perceived spatial alignment of face halves (despite retinal misalignment) impairs recognition, while perceived misalignment (despite retinal alignment) does not

Bistable Gestalts reduce activity in the whole of V1, not just the retinotopically predicted parts

Activity in the primary visual cortex reduces when certain stimuli can be perceptually organized as a unified Gestalt. This reduction could offer important insights into the nature of feedback computations within the human visual system; however, the properties of this response reduction have not yet been investigated in detail. Here we replicate this reduced V1 response, but find that the modulation in V1 (and V2) to the perceived organization of the input is not specific to the retinotopic location at which the sensory input from that stimulus is represented. Instead, we find a response modulation that is equally evident across the primary visual cortex. Thus in contradiction to some models of hierarchical predictive coding, the perception of an organized Gestalt causes a broad feedback effect that does not act specifically on the part of the retinotopic map representing the sensory input

Monitoring, reporting and vrification for national REDD+programmes: two proposals

Different options have been suggested by Parties to the UNFCCC (United Framework Convention on Climate Change) for inclusion in national approaches to REDD and REDD + (reduced deforestation, reduced degradation, enhancement of forest carbon stocks, sustainable management of forest, and conservation of forest carbon stocks). This paper proposes that from the practical and technical points of view of designing action for REDD and REDD + at local and sub-national level, as well as from the point of view of the necessary MRV (monitoring, reporting and verification), these should be grouped into three categories: conservation, which is rewarded on the basis of no changes in forest stock, reduced deforestation, in which lowered rates of forest area loss are rewarded, and positive impacts on carbon stock changes in forests remaining forest, which includes reduced degradation, sustainable management of forest of various kinds, and forest enhancement. Thus we have moved degradation, which conventionally is grouped with deforestation, into the forest management group reported as areas remaining forest land, with which it has, in reality, and particularly as regards MRV, much more in common. Secondly, in the context of the fact that REDD/REDD + is to take the form of a national or near-national approach, we argue that while systematic national monitoring is important, it may not be necessary for REDD/REDD + activities, or for national MRV, to be started at equal levels of intensity all over the country. Rather, areas where interventions seem easiest to start may be targeted, and here data measurements may be more rigorous (Tier 3), for example based on stakeholder self-monitoring with independent verification, while in other, untreated areas, a lower level of monitoring may be pursued, at least in the first instance. Treated areas may be targeted for any of the three groups of activities (conservation, reduced deforestation, and positive impact on carbon stock increases in forest remaining forest)

Age group, location or pedagogue: factors affecting parental choice of kindergartens in Hungary

Hungary has experienced significant political, economic, demographic and social changes since the end of Soviet domination in the 1990s. The gradual move towards liberal-democracy has been accompanied by growing emphasis on individualism, choice and diversity. Universal kindergarten provision for 5-6 year olds is a long established feature of the Hungarian education system, but little is known about parental choice (Török, 2004). A case study (Yin, 2004) of factors influencing parental choice and satisfaction was undertaken in one Hungarian town. This was based on a survey of 251 parents of children attending both mixed-age and same-age groups across 12 kindergartens. Parents suggested that the most important influences were geographical location and the individual pedagogue(s). Given that traditionally each pedagogue follows ‘their’ cohort from kindergarten entry to primary school, their influence appears heightened. Although generally satisfied with their chosen arrangement, parents from same-age groups expressed significantly more confidence and satisfaction, particularly in relation to cognitive development and preparation for school. Parents appear less convinced about the trend towards mixed-age groups and questions are raised about sufficiency of evidence of their benefits in a Hungarian context and the driving factors behind change

Secondary school teachers' attitudes to and beliefs about ability grouping

Background. Internationally and historically considerable research has been undertaken regarding the attitudes of secondary school teachers towards different types of ability grouping. There has been no recent research taking account of the changing educational context in the UK. Aims. This paper aims to explore secondary school teachers’ attitudes and beliefs about ability grouping taking account of school type, gender, experience and qualifications. Sample. The sample comprised over 1500 teachers from 45 schools divided into three groups based on their ability grouping practices in years 7-9. The sample included all the lower school teachers of mathematics, science and English and a random sample of teachers from other subjects in each school. Methods. Teachers responded to a questionnaire which explored their attitudes towards ability grouping through the use of rating scales and open ended questions. Results. The findings showed that the teachers’ beliefs broadly reflected research findings on the actual effects of ability grouping, although there were significant 3 differences relating to the type of school they taught in and the subject that they taught. Separate analysis of school types showed that length of time teaching, individual school differences and teacher qualifications were also significant predictors of attitudes. Conclusions. Teachers’ beliefs about ability grouping are influenced by the type of groupings adopted in the school where they work, the subject that they teach, their experience and qualifications. As pedagogical practices are known to be influenced by beliefs these findings have important implications for teacher training

Cortical Synchronization and Perceptual Framing

How does the brain group together different parts of an object into a coherent visual object representation? Different parts of an object may be processed by the brain at different rates and may thus become desynchronized. Perceptual framing is a process that resynchronizes cortical activities corresponding to the same retinal object. A neural network model is presented that is able to rapidly resynchronize clesynchronized neural activities. The model provides a link between perceptual and brain data. Model properties quantitatively simulate perceptual framing data, including psychophysical data about temporal order judgments and the reduction of threshold contrast as a function of stimulus length. Such a model has earlier been used to explain data about illusory contour formation, texture segregation, shape-from-shading, 3-D vision, and cortical receptive fields. The model hereby shows how many data may be understood as manifestations of a cortical grouping process that can rapidly resynchronize image parts which belong together in visual object representations. The model exhibits better synchronization in the presence of noise than without noise, a type of stochastic resonance, and synchronizes robustly when cells that represent different stimulus orientations compete. These properties arise when fast long-range cooperation and slow short-range competition interact via nonlinear feedback interactions with cells that obey shunting equations.Office of Naval Research (N00014-92-J-1309, N00014-95-I-0409, N00014-95-I-0657, N00014-92-J-4015); Air Force Office of Scientific Research (F49620-92-J-0334, F49620-92-J-0225)