Contrast summation across eyes and space is revealed along the entire dipper function by a "Swiss cheese" stimulus.

Previous contrast discrimination experiments have shown that luminance contrast is summed across ocular (T. S. Meese, M. A. Georgeson, & D. H. Baker, 2006) and spatial (T. S. Meese & R. J. Summers, 2007) dimensions at threshold and above. However, is this process sufficiently general to operate across the conjunction of eyes and space? Here we used a "Swiss cheese" stimulus where the blurred "holes" in sine-wave carriers were of equal area to the blurred target ("cheese") regions. The locations of the target regions in the monocular image pairs were interdigitated across eyes such that their binocular sum was a uniform grating. When pedestal contrasts were above threshold, the monocular neural images contained strong evidence that the high-contrast regions in the two eyes did not overlap. Nevertheless, sensitivity to dual contrast increments (i.e., to contrast increments in different locations in the two eyes) was a factor of ∼1.7 greater than to single increments (i.e., increments in a single eye), comparable with conventional binocular summation. This provides evidence for a contiguous area summation process that operates at all contrasts and is influenced little, if at all, by eye of origin. A three-stage model of contrast gain control fitted the results and possessed the properties of ocularity invariance and area invariance owing to its cascade of normalization stages. The implications for a population code for pattern size are discussed.

[Review of] Eigler, Friederike, and Jens Kugele, eds. Heimat. At the Intersection of Memory and Space. Berlin: de Gruyter, 2012. 268 pp. $126.00 hardcover

Book review: Eigler, Friederike, and Jens Kugele, eds. Heimat. At the Intersection of Memory and Space. Berlin: de Gruyter, 2012. 268 pp. $126.00 hardcover.

Visualising and controlling the flow in biomolecular systems at and between multiple scales:from atoms to hydrodynamics at different locations in time and space

A novel framework for modelling biomolecular systems at multiple scales in space and time simultaneously is described. The atomistic molecular dynamics representation is smoothly connected with a statistical continuum hydrodynamics description. The system behaves correctly at the limits of pure molecular dynamics (hydrodynamics) and at the intermediate regimes when the atoms move partly as atomistic particles, and at the same time follow the hydrodynamic flows. The corresponding contributions are controlled by a parameter, which is defined as an arbitrary function of space and time, thus, allowing an effective separation of the atomistic 'core' and continuum 'environment'. To fill the scale gap between the atomistic and the continuum representations our special purpose computer for molecular dynamics, MDGRAPE-4, as well as GPU-based computing were used for developing the framework. These hardware developments also include interactive molecular dynamics simulations that allow intervention of the modelling through force-feedback devices.

Africa's World Cup:critical reflections on play, patriotism, spectatorship, and space

Africas World Cup: Critical Reflections on Play, Patriotism, Spectatorship, and Space focuses on a remarkable month in the modern history of Africa and in the global history of football. Peter Alegi and Chris Bolsmann are well-known experts on South African football, and they have assembled an impressive team of local and international journalists, academics, and football experts to reflect on the 2010 World Cup and its broader significance, its meanings, complexities, and contradictions. The World Cups sounds, sights, and aesthetics are explored, along with questions of patriotism, nationalism, and spectatorship in Africa and around the world. Experts on urban design and communities write on how the presence of the World Cup worked to refashion urban spaces and negotiate the local struggles in the hosting cities. The volume is richly illustrated by authors photographs, and the essays in this volume feature chronicles of match day experiences; travelogues; ethnographies of fan cultures; analyses of print, broadcast, and electronic media coverage of the tournament; reflections on the World Cups private and public spaces; football exhibits in South African museums; and critiques of the World Cups processes of inclusion and exclusion, as well as its political and economic legacies. The volume concludes with a forum on the World Cup, including Thabo Dladla, Director of Soccer at the University of KwaZulu-Natal, Mohlomi Kekeletso Maubane, a well-known Soweto-based writer and a soccer researcher, and Rodney Reiners, former professional footballer and current chief soccer writer for the Cape Argus newspaper in Cape Town. This collection will appeal to students, scholars, journalists, and fans. Cover illustration: South African fan blowing his vuvuzela at South Africa vs. France, Free State Stadium, Bloemfontein, June 22, 2010. Photo by Chris Bolsmann.

A common rule for integration and suppression of luminance contrast across eyes, space, time, and pattern

Visual perception begins by dissecting the retinal image into millions of small patches for local analyses by local receptive fields. However, image structures extend well beyond these receptive fields and so further processes must be involved in sewing the image fragments back together to derive representations of higher order (more global) structures. To investigate the integration process, we also need to understand the opposite process of suppression. To investigate both processes together, we measured triplets of dipper functions for targets and pedestals involving interdigitated stimulus pairs (A, B). Previous work has shown that summation and suppression operate over the full contrast range for the domains of ocularity and space. Here, we extend that work to include orientation and time domains. Temporal stimuli were 15-Hz counter-phase sine-wave gratings, where A and B were the positive and negative phases of the oscillation, respectively. For orientation, we used orthogonally oriented contrast patches (A, B) whose sum was an isotropic difference of Gaussians. Results from all four domains could be understood within a common framework in which summation operates separately within the numerator and denominator of a contrast gain control equation. This simple arrangement of summation and counter-suppression achieves integration of various stimulus attributes without distorting the underlying contrast code.