Whole-body motion discrimination in the visually impaired

Visually impaired people show superior abilities in various perception tasks such as auditory attention, auditory temporal resolution, auditory spatial tuning, and odor discrimination. However, with the use of psychophysical methods, auditory and olfactory detection thresholds typically do not differ between visually impaired and sighted participants. Using a motion platform we investigated thresholds of passive whole-body motion discrimination in nine visually impaired participants and nine age-matched sighted controls. Participants were rotated in yaw, tilted in roll, and translated along the y-axis at two different frequencies (0.3 Hz and 2 Hz). An adaptive 3-down 1-up staircase procedure was used along with a two-alternative direction (leftward vs. rightward) discrimination task. Superior performance of visually impaired participants was found in the 0.3 Hz roll tilt condition. No differences between the visually impaired and controls were observed in all other types of motion. The superior performance in the 0.3 Hz roll tilt condition could reflect differences in the integration of extra-vestibular cues and increased sensitivity towards changes in the direction of the gravito-inertial force. In the absence of visual information, roll tilts entail a more pronounced risk of falling, and this could eventually account for the group difference. It is argued that differences in experimental procedures (i.e. detection vs. discrimination of stimuli) explain the discrepant findings across perceptual tasks comparing blind and sighted participants.

Light-quark and gluon jet discrimination in pp collisions at √s=7 TeV with the ATLAS detector

A likelihood-based discriminant for the identification of quark- and gluon-initiated jets is built and validated using 4.7 fb−1 √ of proton–proton collision data at √s = 7 TeV collected with the ATLAS detector at the LHC. Data sampleswith enriched quark or gluon content are used in the construction and validation of templates of jet properties that are the input to the likelihood-based discriminant. The discriminating power of the jet tagger is established in both data and Monte Carlo samples within a systematic uncertainty of ≈ 10–20 %. In data, light-quark jets can be tagged with an efficiency of ≈ 50% while achieving a gluon-jet mis-tag rate of ≈ 25% in a pT range between 40 GeV and 360 GeV for jets in the acceptance of the tracker. The rejection of gluon-jets found in the data is significantly below what is attainable using a Pythia 6Monte Carlo simulation, where gluon-jet mis-tag rates of 10% can be reached for a 50% selection efficiency of light-quark jets using the same jet properties.

The use of evidence in public debates in the media: the case of Swiss direct-democratic campaigns in the health policy sector

This article analyses the reporting of evidence in Swiss direct-democratic campaigns in the health policy sector, assuming that an informed public helps democracy function successfully. A content analysis of the media’s news reporting shows that of 5030 media items retrieved, a reference to evidence is found in 6.8%. The voter receives evidence in the form of substantiating arguments, equally distributed among proponents and opponents. Experts have the highest chance of providing evidence, but appear most rarely. Integrating more evidence might provide voters with the diversity of arguments needed to make a truly informed decision.

Self-motion direction discrimination in the visually impaired

Despite the close interrelation between vestibular and visual processing (e.g., vestibulo-ocular reflex), surprisingly little is known about vestibular function in visually impaired people. In this study, we investigated thresholds of passive whole-body motion discrimination (leftward vs. rightward) in nine visually impaired participants and nine age-matched sighted controls. Participants were rotated in yaw, tilted in roll, and translated along the interaural axis at two different frequencies (0.33 and 2 Hz) by means of a motion platform. Superior performance of visually impaired participants was found in the 0.33 Hz roll tilt condition. No differences were observed in the other motion conditions. Roll tilts stimulate the semicircular canals and otoliths simultaneously. The results could thus reflect a specific improvement in canal–otolith integration in the visually impaired and are consistent with the compensatory hypothesis, which implies that the visually impaired are able to compensate the absence of visual input.

Book Review: Public Service Media and Policy in Europe

Much has happened in the past fifty years, and the broadcasting system and in fact the entire media landscape have changed in many significant ways. Yet, the debate on the role of public service media and the involvement of the state in them still perseveres. It has indeed been reinvigorated due to the tectonic shifts in media production, distribution, access and consumption caused by digital technologies in general, and the Internet in particular. The gist of the debates has however curiously remained almost the same and is still focused on a set of economic arguments that call for state intervention in public media, and not unimportantly, on the various political interpretations of these economic arguments. In Europe, the debate has another essential core too, as Public Service Broadcasting (PSB) has been traditionally entrusted to serve some higher goals intrinsically related to key democratic and cultural processes. Accordingly, PSB in Western Europe has developed as the core media institution at the national level and has become deeply embedded in many facets of the nation’s economic, political, social and cultural life. Against the backdrop of PSB’s history, its vital tasks in society, as well as the dramatic changes brought about by the digitally networked environment, the question on the future of PSB and its transition into Public Service Media (PSM) is very interesting, to say the least, and highly challenging at the same time. The book by Karen Donders, Public Service Media and Policy in Europe (Palgrave, 2012), makes an essential contribution to these complex debates, and more importantly, adds some new value to an otherwise saturated discourse.