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Eye movements cause rapid motion of the retinal image, potentially confusable with external motion. A recent study shows that neurons in mouse primary visual cortex distinguish self-generated from external motion by combining sensory input with saccade-related signals from the thalamic pulvinar nucleus.

Crowding is the inability to recognize peripheral objects in clutter, usually considered a fundamental low-level bottleneck to object recognition. Here we advance and test an alternative hypothesis, that crowding, like “serial dependence”, results from optimizing strategies that exploit redundancies in natural scenes. This notion leads to several testable predictions: (1) crowding should be greatest for unreliable targets and reliable flankers; (2) crowding-induced biases should be maximal when target and flankers have similar orientations, falling off for differences around 20°; (3) flanker interference should be associated with higher precision in orientation judgements, leading to lower overall error rate; (4) effects should be maximal when the orientation of the target is near that of the average of the flankers, rather than to that of individual flankers. All these effects were verified, and well simulated with ideal-observer models that maximize performance. The results suggest that while crowding can impact strongly on object recognition, it is best understood not as a processing bottleneck, but as a consequence of efficient exploitation of the spatial redundancies of the natural world.

When different images are presented to the eyes, the brain is faced with ambiguity, causing perceptual bistability: visual perception continuously alternates between the monocular images, a phenomenon called binocular rivalry. Many models of rivalry suggest that its temporal dynamics depend on mutual inhibition among neurons representing competing images. These models predict that rivalry should be different in autism, which has been proposed to present an atypical ratio of excitation and inhibition [the E/I imbalance hypothesis; Rubenstein & Merzenich, 2003]. In line with this prediction, some recent studies have provided evidence for atypical binocular rivalry dynamics in autistic adults. In this study, we examined if these findings generalize to autistic children. We developed a child‐friendly binocular rivalry paradigm, which included two types of stimuli, low‐ and high‐complexity, and compared rivalry dynamics in groups of autistic and age‐ and intellectual ability‐matched typical children. Unexpectedly, the two groups of children presented the same number of perceptual transitions and the same mean phase durations (times perceiving one of the two stimuli). Yet autistic children reported mixed percepts for a shorter proportion of time (a difference which was in the opposite direction to previous adult studies), while elevated autistic symptomatology was associated with shorter mixed perception periods. Rivalry in the two groups was affected similarly by stimulus type, and consistent with previous findings. Our results suggest that rivalry dynamics are differentially affected in adults and developing autistic children and could be accounted for by hierarchical models of binocular rivalry, including both inhibition and top‐down influences. Autism Res 2017. ©2017 The Authors Autism Research published by Wiley Periodicals, Inc. on behalf of International Society for Autism Research Autism Res 2017, 10: 1096–1106. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Introduction: Reports linking long-term use of bisphosphonates (BPs) with atypical fractures of the femur led the leadership of the American Society for Bone and Mineral Research (ASBMR) to appoint a Task Force to address key questions related to this problem. Methods: A multi-disciplinary expert group reviewed pertinent published reports concerning atypical femur fractures, as well as pre-clinical studies that could provide insight into their pathogenesis. Results and Conclusions: A case definition was developed so that subsequent studies report on the same condition. The Task Force defined major and minor features of complete and incomplete atypical femoral fractures and recommends that all major features, including their location in the subtrochanteric region and femoral shaft, transverse or short oblique orientation, minimal or no associated trauma and absence of comminution, be present to designate a femoral fracture as atypical. Minor features include their associations with cortical thickening, a periosteal reaction of the lateral cortex, a medial spike when the fracture is complete, prodromal pain, bilaterality, comorbid conditions and concomitant drug exposures, including BPs, other antiresorptive agents, glucocorticoids and proton pump inhibitors. Preclinical data evaluating the effects of BPs on collagen cross-linking and maturation, accumulation of microdamage and advanced glycation end-products, mineralization, remodeling, vascularity and angiogenesis, lend biological plausibility to a potential association with long-term BP use. Based on published and unpublished data and the widespread use of BPs, the incidence of atypical femoral fractures associated with BP therapy for osteoporosis appears to be very low, particularly compared to the number of vertebral, hip and other fractures that are prevented by BPs. Moreover, a causal association between BPs and atypical fractures has not been established. However, recent observations suggest that the risk rises with increasing duration of exposure and there is concern that lack of awareness and under-reporting may mask the true incidence of the problem. Recommendations: Given the relative rarity of atypical femoral fractures, the Task Force recommends that specific diagnostic and procedural codes be created and that an international registry be established to facilitate studies of the clinical and genetic risk factors and optimal surgical and medical management of these fractures. Physicians and patients should be made aware of the possibility of atypical femoral fractures and of the potential for bilaterality through a change in labeling of BPs. Research directions should include development of animal models, increased surveillance and additional epidemiological and clinical data to establish the true incidence of and risk factors for this condition and to inform orthopaedic and medical management.

Dante's age was notable both for the sheer variety of heresies and heterodoxies identified by contemporaries and for the vigour with which the institutional Church attacked them. By 1300 papal inquisitors, following established procedures and normally able to rely on substantial force, worked in collaboration with local bishops to enforce orthodoxy. It was a struggle. The thirteenth century had been a period of spiritual and theological creativity. To recognize this much we need only look at the Dominicans and Franciscans. Both orders appeared early in the century and soon proved their value as a response to the needs of an expanding urban culture with a religiously enthusiastic, increasingly well-educated laity. Both orders also threw themselves into the world of scholastic thought and developed it rapidly. On both the institutional and intellectual levels, the new mendicant orders gave Europe a sense of direction as it negotiated an important period of western history; yet the nature and wisdom of that direction was open to serious debate. The new orders were seen as interlopers by a number of university masters and secular clergy; Dominicans and Franciscans often resented one another's presence; and, among the Franciscans themselves, factions differed as to what the order should be doing. Such tensions might have been easier to deal with had they not interacted with a strong tendency on the part of the laity and lower clergy to develop new patterns of religious life. By 1300 Church leaders had long since decided it was necessary to rein in further novelty and contain exuberance within stable, controllable, orthodox channels. The mendicant orders were potentially useful for that purpose, and for more reasons than that they made excellent inquisitors (although they did). It seemed possible to limit dangerous experimentation by enticing pious Christians into existing religious structures tied especially to the Franciscans. But if the Franciscans themselves were at odds over who they were, that strategy could have its dangers. In the dynamic religious world of the early fourteenth century it was often hard to decide precisely where the boundary lay between official and unofficial Church, or who should be identified as heterodox and who orthodox. There were, to be sure, old heresies that continued into the fourteenth century as unfinished business, Catharism and Waldensianism being the major examples.

Moines et religieux dans la ville (XIIe-XVe siecle). Edited by Nicole Beriou and Cecile Caby. [Cahiers de Fanjeaux, 44.] (Toulouse: Editions Privat. 2009. Pp. 639, with 1 CD. euro35,00. ISBN 978-2-7089-3447-4.)This volume of the Cahiers de Fanjeaux is based on the 2008 colloquy, the theme of which is stated in the title. Religieux here represents those subject to some rule (as opposed to the secular clergy) but not cloistered (as the moines were) and who were ordinarily in close contact with the laity.The first essay, by Nicole Beriou, provides a general overview of the relationship between religious orders and the cities of Europe between the twelfth and fifteenth centuries. He emphasizes that, despite the close connection between urbanization and the mendicant orders noted by Jacques Le Goff and others, older orders found their way into the cities well before the mendicants appeared. Yves Esquieu then traces a general history of the clergy in southern French cities from the fourth to the eleventh centuries.The next section concentrates on religious orders other than the mendicants. The first of them, by Jorg Oberste, traces the successive appearances of various monastic communities at Toulouse, emphasizing the roles they played and their contests for power, prestige, and income. As he proceeds from Benedictine monasticism through Cluniac reform and its amplification in the hands of a rising papacy, then through the Cistercians and the new military orders, Oberste furnishes a miniaturized history of western monasticism from the beginning to the early-thirteenth century as it played out in the rising cities, offering another reminder that, long before the mendicants appeared, monastic institutions performed an important role in satisfying the spiritual needs of those cities.Daniel Le Blevec, too, concentrates on a single city (Montpelier), whereas other articles specialize in other ways. Damien Carraz concentrates on the military orders and Alexis Grelois on the Cistercians, whereas Henri Gilles discusses monks at the universities. Yannick Veyrenche examines the canons regular of Saint-Ruf at Avignon and Valence, whereas Denyse Riche deals with the Cluniacs at Moissac.The next section turns to the mendicants, who understandably receive a lion's share of the attention. The book comes with a CD, but individual historians' enthusiasm about utilizing it depends on their project. Nelly Pousthomis-Dalle employs it admirably in her survey of mendicant settlement in southwestern France, as does Francois Guyonnet in his tour of mendicant houses in southeastern France. Both clarify their presentation with a plethora of maps and photographs. …

It is fitting that the teachers of tomorrow are provided with the correct modeling of technology in their first education class. To separate technology from education is both impossible and foolish. The sooner college students are exposed to the latest forms of technology, the more equipped they will be to integrate these tools into their teaching strategies for the benefit of future learners.

On November 11, 1328, a group of heretics was condemned at Carcassonne.1 Most were beguins, but the group also included Cathars, Waldensians, Sorcerers and a single spiritual Franciscan. Most were alive, a few were dead. All but one of the living had recanted. Those who had been found guilty simply of aiding, abetting or not reporting heretics were sentenced to wear crosses and go on pilgrimages. Others who were judged genuine believers in heresy were given perpetual imprisonment. The lone recusant was turned over to the secular government for punishment. No sentence except the recusant's was final. Within a year some of those condemned to imprisonment would see their sentences commuted to crosses and pilgrimages, and those who set out obediently on their pilgrimages might hope they would someday be allowed to remove their crosses. Conversely, those who failed to mend their ways and were again denounced to the inquisitor might expect to see their situations worsen. Among the twelve sentenced to prison that day, four were singled out whose crimes deserved special punishment. One was then in turn named as rating special punishment even among those four. He was the lone Franciscan in the group. Stripped of ecclesiastical orders, he was assigned to the worst part of the prison, where he was to be kept in irons.2 It is that Franciscan who concerns us here. He was called

Although we blink every 4 to 6 seconds, we notice neither the act of blinking nor the mini-blackouts they cause. A new study using imaging techniques identifies the neural structures in humans involved in suppressing vision processing and visual awareness during blinking.

A long-standing problem for vision researchers is how our perception of the world remains stable despite the continual motion of our eyes. Three recent studies begin to shed light on how the visual system suppresses the motion generated by these eye movements.

SummaryA recent study shows that objects changing in colour, luminance, size or shape appear to stop changing when they move. These and other compelling illusions provide tantalizing clues about the mechanisms and limitations of object analysis.

The ability to attend to multiple objects that move in the visual field is important for many aspects of daily functioning. The attentional capacity for such dynamic tracking, however, is highly limited and undergoes age-related decline. Several aspects of the tracking process can influence performance. Here, we investigated effects of feature-based interference from distractor objects that appear in unattended regions of the visual field with a hemifield-tracking task. Younger and older participants performed an attentional tracking task in one hemifield while distractor objects were concurrently presented in the unattended hemifield. Feature similarity between objects in the attended and unattended hemifields as well as motion speed and the number of to-be-tracked objects were parametrically manipulated. The results show that increasing feature overlap leads to greater interference from the unattended visual field. This effect of feature-based interference was only present in the slow speed condition, indicating that the interference is mainly modulated by perceptual demands. High-performing older adults showed a similar interference effect as younger adults, whereas low-performing adults showed poor tracking performance overall.