@misc{RisseKliegl2011, author = {Risse, Sarah and Kliegl, Reinhold}, title = {Adult age differences in the perceptual span during reading}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-56935}, year = {2011}, abstract = {Following up on research suggesting an age-related reduction in the rightward extent of the perceptual span during reading (Rayner, Castelhano, \& Yang, 2009), we compared old and young adults in an N+2-boundary paradigm in which a nonword preview of word N+2 or word N+2 itself is replaced by the target word once the eyes cross an invisible boundary located after word N. The intermediate word N+1 was always three letters long. Gaze durations on word N+2 were significantly shorter for identical than nonword N+2 preview both for young and for old adults with no significant difference in this preview benefit. Young adults, however, did modulate their gaze duration on word N more strongly than old adults in response to the difficulty of the parafoveal word N+1. Taken together, the results suggest a dissociation of preview benefit and parafoveal-on-foveal effect. Results are discussed in terms of age-related decline in resilience towards distributed processing while simultaneously preserving the ability to integrate parafoveal information into foveal processing. As such, the present results relate to proposals of regulatory compensation strategies older adults use to secure an overall reading speed very similar to that of young adults.}, language = {en} } @misc{KlieglBates2011, author = {Kliegl, Reinhold and Bates, Douglas}, title = {International Collaboration in Psychology is on the Rise}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57045}, year = {2011}, abstract = {There has been a substantial increase in the percentage for publications with co-authors located in departments from different countries in 12 major journals of psychology. The results are evidence for a remarkable internationalization of psychological research, starting in the mid 1970s and increasing in rate at the beginning of the 1990s. This growth occurs against a constant number of articles with authors from the same country; it is not due to a concomitant increase in the number of co-authors per article. Thus, international collaboration in psychology is obviously on the rise.}, language = {en} } @article{WeissHuisinga2011, author = {Weiss, Andrea Y. and Huisinga, Wilhelm}, title = {Error-controlled global sensitivity analysis of ordinary differential equations}, series = {Journal of computational physics}, volume = {230}, journal = {Journal of computational physics}, number = {17}, publisher = {Elsevier}, address = {San Diego}, issn = {0021-9991}, doi = {10.1016/j.jcp.2011.05.011}, pages = {6824 -- 6842}, year = {2011}, abstract = {We propose a novel strategy for global sensitivity analysis of ordinary differential equations. It is based on an error-controlled solution of the partial differential equation (PDE) that describes the evolution of the probability density function associated with the input uncertainty/variability. The density yields a more accurate estimate of the output uncertainty/variability, where not only some observables (such as mean and variance) but also structural properties (e.g., skewness, heavy tails, bi-modality) can be resolved up to a selected accuracy. For the adaptive solution of the PDE Cauchy problem we use the Rothe method with multiplicative error correction, which was originally developed for the solution of parabolic PDEs. We show that, unlike in parabolic problems, conservation properties necessitate a coupling of temporal and spatial accuracy to avoid accumulation of spatial approximation errors over time. We provide convergence conditions for the numerical scheme and suggest an implementation using approximate approximations for spatial discretization to efficiently resolve the coupling of temporal and spatial accuracy. The performance of the method is studied by means of low-dimensional case studies. The favorable properties of the spatial discretization technique suggest that this may be the starting point for an error-controlled sensitivity analysis in higher dimensions.}, language = {en} } @article{PilariPreusseHuisinga2011, author = {Pilari, Sabine and Preusse, Cornelia and Huisinga, Wilhelm}, title = {Gestational influences on the pharmacokinetics of gestagenic drugs a combined in silico, in vitro and in vivo analysis}, series = {European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences, EUFEPS}, volume = {42}, journal = {European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences, EUFEPS}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0928-0987}, doi = {10.1016/j.ejps.2010.12.003}, pages = {318 -- 331}, year = {2011}, abstract = {During preclinical development of a gestagenic drug, a significant increase of the total plasma concentration was observed after multiple dosing in pregnant rabbits, but not in (non-pregnant) rats or monkeys. We used a PBPK modeling approach in combination with in vitro and in vivo data to address the question to what extent the pharmacologically active free drug concentration is affected by pregnancy induced processes. In human, a significant increase in sex hormone binding globulin (SHBG), and an induction of hepatic CYP3A4 as well as plasma esterases is observed during pregnancy. We find that the observed increase in total plasma trough levels in rabbits can be explained as a combined result of (i) drug accumulation due to multiple dosing, (ii) increase of the binding protein SHBG, and (iii) clearance induction. For human, we predict that free drug concentrations in plasma would not increase during pregnancy above the steady state trough level for non-pregnant women.}, language = {en} } @article{vonKleistMenzStockeretal.2011, author = {von Kleist, Max and Menz, Stephan and Stocker, Hartmut and Arasteh, Keikawus and Schuette, Christof and Huisinga, Wilhelm}, title = {HIV quasispecies dynamics during pro-active treatment switching impact on multi-drug resistance and resistance archiving in latent reservoirs}, series = {PLoS one}, volume = {6}, journal = {PLoS one}, number = {3}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0018204}, pages = {12}, year = {2011}, abstract = {The human immunodeficiency virus (HIV) can be suppressed by highly active anti-retroviral therapy (HAART) in the majority of infected patients. Nevertheless, treatment interruptions inevitably result in viral rebounds from persistent, latently infected cells, necessitating lifelong treatment. Virological failure due to resistance development is a frequent event and the major threat to treatment success. Currently, it is recommended to change treatment after the confirmation of virological failure. However, at the moment virological failure is detected, drug resistant mutants already replicate in great numbers. They infect numerous cells, many of which will turn into latently infected cells. This pool of cells represents an archive of resistance, which has the potential of limiting future treatment options. The objective of this study was to design a treatment strategy for treatment-naive patients that decreases the likelihood of early treatment failure and preserves future treatment options. We propose to apply a single, pro-active treatment switch, following a period of treatment with an induction regimen. The main goal of the induction regimen is to decrease the abundance of randomly generated mutants that confer resistance to the maintenance regimen, thereby increasing subsequent treatment success. Treatment is switched before the overgrowth and archiving of mutant strains that carry resistance against the induction regimen and would limit its future re-use. In silico modelling shows that an optimal trade-off is achieved by switching treatment at \& 80 days after the initiation of antiviral therapy. Evaluation of the proposed treatment strategy demonstrated significant improvements in terms of resistance archiving and virological response, as compared to conventional HAART. While continuous pro-active treatment alternation improved the clinical outcome in a randomized trial, our results indicate that a similar improvement might also be reached after a single pro-active treatment switch. The clinical validity of this finding, however, remains to be shown by a corresponding trial.}, language = {en} } @article{WischnewskiMackayApplebyetal.2011, author = {Wischnewski, Juliane and Mackay, Anson W. and Appleby, Peter G. and Mischke, Steffen and Herzschuh, Ulrike}, title = {Modest diatom responses to regional warming on the southeast Tibetan Plateau during the last two centuries}, series = {Journal of paleolimnolog}, volume = {46}, journal = {Journal of paleolimnolog}, number = {2}, publisher = {Springer}, address = {Dordrecht}, issn = {0921-2728}, doi = {10.1007/s10933-011-9533-x}, pages = {215 -- 227}, year = {2011}, abstract = {A general mean annual temperature increase accompanied with substantial glacial retreat has been noted on the Tibetan Plateau during the last two centuries but most significantly since the mid 1950s. These climate trends are particularly apparent on the southeastern Tibetan Plateau. However, the Tibetan Plateau (due to its heterogeneous mountain landscape) has very complex and spatially differing temperature and precipitations patterns. As a result, intensive palaeolimnological investigations are necessary to decipher these climatic patterns and to understand ecological responses to recent environmental change. Here we present palaeolimnological results from a (210)Pb/(137)Cs-dated sediment core spanning approximately the last 200 years from a remote high-mountain lake (LC6 Lake, working name) on the southeastern Tibetan Plateau. Sediment profiles of diatoms, organic variables (TOC, C:N) and grain size were investigated. The (210)Pb record suggests a period of rapid sedimentation, which might be linked to major tectonic events in the region ca. 1950. Furthermore, unusually high (210)Pb supply rates over the last 50 years suggest that the lake has possibly been subjected to increasing precipitation rates, sediment focussing and/or increased spring thaw. The majority of diatom taxa encountered in the core are typical of slightly acidic to circumneutral, oligotrophic, electrolyte-poor lakes. Diatom species assemblages were rich, and dominated by Cyclotella sp., Achnanthes sp., Aulacoseira sp. and fragilarioid taxa. Diatom compositional change was minimal over the 200-year period (DCCA = 0.85 SD, p = 0.59); only a slightly more diverse but unstable diatom assemblage was recorded during the past 50 years. The results indicate that large-scale environmental changes recorded in the twentieth century (i.e. increased precipitation and temperatures) are likely having an affect on the LC6 Lake, but so far these impacts are more apparent on the lake geochemistry than on the diatom flora. Local and/or regional peculiarities, such as increasing precipitation and cloud cover, or localized climatic phenomena, such as negative climate feedbacks, might have offset the effects of increasing mean surface temperatures.}, language = {en} } @article{WischnewskiMischkeWangetal.2011, author = {Wischnewski, Juliane and Mischke, Steffen and Wang, Yongbo and Herzschuh, Ulrike}, title = {Reconstructing climate variability on the northeastern Tibetan Plateau since the last Lateglacial - a multi-proxy, dual-site approach comparing terrestrial and aquatic signals}, series = {Quaternary science reviews : the international multidisciplinary research and review journal}, volume = {30}, journal = {Quaternary science reviews : the international multidisciplinary research and review journal}, number = {1-2}, publisher = {Elsevier}, address = {Oxford}, issn = {0277-3791}, doi = {10.1016/j.quascirev.2010.10.001}, pages = {82 -- 97}, year = {2011}, abstract = {A sediment core from a closed basin lake (Lake Kuhai) from the semi-arid northeastern Tibetan Plateau was analysed for its pollen record to infer Lateglacial and post glacial vegetation and climatic change. At Lake Kuhai five major vegetation and climate shifts could be identified: (1) a change from cold and dry to relatively warmer and more moist conditions at 14.8 cal ka BP: (2) a shift to conditions of higher effective moisture and a stepwise warmer climate at 13.6 cal ka BP; (3) a further shift with increased moisture but colder conditions at 7.0 cal ka BP; (4) a return to a significantly colder and drier phase at 6.3 cal ka BP; (5) and a change back to relatively moist conditions at 2.2 cal ka BP. To investigate the response of lake ecosystems to climatic changes, statistical comparisons were made between the lake Kuhai pollen record and a formerly published ostracod and sedimentary record from the same sediment core. Furthermore, the pollen and lacustrine proxies from lake Kuhai were compared to a previously published pollen and lacustrine record from the nearby Lake Koucha. Statistical comparisons were done using non-metric multidimensional scaling and Procrustes rotation. Differences between lacustrine and pollen responses within one site could be identified, suggesting that lacustrine proxies are partly influenced by in-lake or local catchment processes, whereas the terrestrial (pollen) proxy shows a regional climate signal. Furthermore, we found regional differences in proxy response between lake Kuhai and Lake Koucha. Both pollen records reacted in similar ways to major environmental changes, with minor differences in the timing and magnitude of these changes. The lacustrine records were very similar in their timing and magnitude of response to environmental changes; however, the nature of change was at times very distinct. To place the current study in the context of Holocene moisture evolution across the Tibetan Plateau, we applied a five-scale moisture index and average link clustering to all available continuous palaeo-climate records from the Tibetan Plateau to possibly find general patterns of moisture evolution on the Plateau. However, no common regional pattern of moisture evolution during the Holocene could be detected. We assign this to complex responses of different proxies to environmental and atmospheric changes in an already very heterogeneous mountain landscape where minor differences in elevation can cause strong variation in microenvironments.}, language = {en} } @article{WangHerzschuh2011, author = {Wang, Yongbo and Herzschuh, Ulrike}, title = {Reassessment of Holocene vegetation change on the upper Tibetan Plateau using the pollen-based REVEALS model}, series = {Review of palaeobotany and palynology : an international journal}, volume = {168}, journal = {Review of palaeobotany and palynology : an international journal}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0034-6667}, doi = {10.1016/j.revpalbo.2011.09.004}, pages = {31 -- 40}, year = {2011}, abstract = {Previous studies based on fossil pollen data have reported significant changes in vegetation on the alpine Tibetan Plateau during the Holocene. However, since the relative proportions of fossil pollen taxa are largely influenced by individual pollen productivities and the dispersal characteristics, such inferences on vegetation have the potential to be considerably biased. We therefore examined the modern pollen-vegetation relationships for four common pollen species on the Tibetan Plateau, using Extended R-value (ERV) models. Assuming an average radius of 100 m for the sampled lakes, we estimated the relevant source area of pollen (RSAP) to be 2200 m (which represents the distance from the lake). Using Poaceae as the reference taxa (Pollen Productivity Estimate, PPE = 1), ERV Submodel 2 derived relative high PPEs for the steppe and desert taxa: 2.079 +/- 0.432 for Artemisia and 5.379 +/- 1.077 for Chenopodiaceae. Low PPEs were estimated for the Cyperaceae (1.036 +/- 0.012). whose plants are characteristic of the alpine Kobresia meadows. Applying these PPEs to four fossil pollen sequences since the Late Glacial, the plant abundances on the central and north-eastern Tibetan Plateau were quantified using the "Regional Estimates of Vegetation Abundance from Large Sites" (REVEALS) model. The proportions of Artemisia and Chenopodiaceae were greatly reduced compared to their original pollen percentages in the reconstructed vegetation, owing to their high productivities and their dispersal characteristics, while Cyperaceae showed a relative increase in the vegetation reconstruction. The reconstructed vegetation assemblages of the four pollen sequence sites always yielded smaller compositional species turnovers than suggested by the pollen spectra, as revealed by Detrended Canonical Correspondence Analyses (DCCA) of the Holocene sections. The strength of the previously reported vegetation changes may therefore have been overestimated, which indicates the importance of taking into account pollen-vegetation relationships when discussing the potential drivers (such as climate, land use, atmospheric CO(2) concentrations) and implications (such as for land surface-climate feedbacks, carbon storage, and biodiversity) of vegetation change.}, language = {en} } @article{WischnewskiKramerKongetal.2011, author = {Wischnewski, Juliane and Kramer, Annette and Kong, Zhaochen and Mackay, Anson W. and Simpson, Gavin L. and Mischke, Steffen and Herzschuh, Ulrike}, title = {Terrestrial and aquatic responses to climate change and human impact on the southeastern Tibetan Plateau during the past two centuries}, series = {Global change biology}, volume = {17}, journal = {Global change biology}, number = {11}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {1354-1013}, doi = {10.1111/j.1365-2486.2011.02474.x}, pages = {3376 -- 3391}, year = {2011}, abstract = {Rapid population growth and economic development have led to increased anthropogenic pressures on the Tibetan Plateau, causing significant land cover changes with potentially severe ecological consequences. To assess whether or not these pressures are also affecting the remote montane-boreal lakes on the SE Tibetan Plateau, fossil pollen and diatom data from two lakes were synthesized. The interplay of aquatic and terrestrial ecosystem response was explored in respect to climate variability and human activity over the past 200 years. Nonmetric multidimensional scaling and Procrustes rotation analysis were undertaken to determine whether pollen and diatom responses in each lake were similar and synchronous. Detrended canonical correspondence analysis was used to develop quantitative estimates of compositional species turnover. Despite instrumental evidence of significant climatic warming on the southeastern Plateau, the pollen and diatom records indicate very stable species composition throughout their profiles and show only very subtle responses to environmental changes over the past 200 years. The compositional species turnover (0.36-0.94 SD) is relatively low in comparison to the species reorganizations known from the periods during the mid-and early-Holocene (0.64-1.61 SD) on the SE Plateau, and also in comparison to turnover rates of sediment records from climate-sensitive regions in the circum arctic. Our results indicate that climatically induced ecological thresholds are not yet crossed, but that human activity has an increasing influence, particularly on the terrestrial ecosystem in our study area. Synergistic processes of post-Little Ice Age warming, 20th century climate warming and extensive reforestations since the 19th century have initiated a change from natural oak-pine forests to seminatural, likely less resilient pine-oak forests. Further warming and anthropogenic disturbances would possibly exceed the ecological threshold of these ecosystems and lead to severe ecological consequences.}, language = {en} } @article{GrossartFrindteDziallasetal.2011, author = {Grossart, Hans-Peter and Frindte, Katharina and Dziallas, Claudia and Eckert, Werner and Tang, Kam W.}, title = {Microbial methane production in oxygenated water column of an oligotrophic lake}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {108}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {49}, publisher = {National Acad. of Sciences}, address = {Washington}, issn = {0027-8424}, doi = {10.1073/pnas.1110716108}, pages = {19657 -- 19661}, year = {2011}, abstract = {The prevailing paradigm in aquatic science is that microbial methanogenesis happens primarily in anoxic environments. Here, we used multiple complementary approaches to show that microbial methane production could and did occur in the well-oxygenated water column of an oligotrophic lake (Lake Stechlin, Germany). Oversaturation of methane was repeatedly recorded in the well-oxygenated upper 10 m of the water column, and the methane maxima coincided with oxygen oversaturation at 6 m. Laboratory incubations of unamended epilimnetic lake water and inoculations of photoautotrophs with a lake-enrichment culture both led to methane production even in the presence of oxygen, and the production was not affected by the addition of inorganic phosphate or methylated compounds. Methane production was also detected by in-lake incubations of lake water, and the highest production rate was 1.8-2.4 nM.h(-1) at 6 m, which could explain 33-44\% of the observed ambient methane accumulation in the same month. Temporal and spatial uncoupling between methanogenesis and methanotrophy was supported by field and laboratory measurements, which also helped explain the oversaturation of methane in the upper water column. Potentially methanogenic Archaea were detected in situ in the oxygenated, methane-rich epilimnion, and their attachment to photoautotrophs might allow for anaerobic growth and direct transfer of substrates for methane production. Specific PCR on mRNA of the methyl coenzyme M reductase A gene revealed active methanogenesis. Microbial methane production in oxygenated water represents a hitherto overlooked source of methane and can be important for carbon cycling in the aquatic environments and water to air methane flux.}, language = {en} } @article{NiHerzschuh2011, author = {Ni, Jian and Herzschuh, Ulrike}, title = {Simulating biome distribution on the Tibetan Plateau using a modified global vegetation model}, series = {Arctic, antarctic, and alpine research : an interdisciplinary journal}, volume = {43}, journal = {Arctic, antarctic, and alpine research : an interdisciplinary journal}, number = {3}, publisher = {Institute of Arctic and Alpine Research, University of Colorado}, address = {Boulder}, issn = {1523-0430}, doi = {10.1657/1938-4246-43.3.429}, pages = {429 -- 441}, year = {2011}, abstract = {We used a regionally modified global vegetation model (BIOME4-Tibet) to simulate biome distribution on the Tibetan Plateau under current climate conditions derived from regional meteorological observations. The bioclimatic limits (mean temperatures of the coldest and warmest months, minimum temperature, growing degree-days on 5 degrees C and 0 degrees C bases) for some key alpine plant functional types (temperate deciduous and conifer trees, boreal deciduous and conifer trees, desert woody plants, tundra shrubs, cold herbaceous plants, and lichens/forbs) were redefined based on regional vegetation-climate relationships. Modern vegetation maps confirmed that the BIOME4-Tibet model does a better job of simulating biome patterns on the plateau (gridcell agreement 52\%) than the original BIOME4 model (35\%). This improved model enhanced our ability to simulate temperate conifer forest, cool conifer and mixed forest, evergreen taiga, temperate xerophytic shrubland, temperate grassland and desert, and steppe and shrub tundra biomes, but made a negligible or reduced difference to the prediction of temperate deciduous forest, warm-temperate mixed forest, and three tundra biomes (erect dwarf-shrub tundra, prostrate dwarf-shrub tundra, and cushion forb, lichen, and moss tundra). Future modification of the vegetation model, by increasing the number of shrub and herb plant functional types, re-parameterization of more precise bioclimatic constraints, and improved representation of soil, permafrost, and snow processes, will be needed to better characterize the distribution of alpine vegetation on the Tibetan Plateau.}, language = {en} } @article{HirschmuellerKonstantinidisBauretal.2011, author = {Hirschm{\"u}ller, Anja and Konstantinidis, Lukas and Baur, Heiner and M{\"u}ller, Steffen and Mehlhorn, Alexander and Kontermann, Julia and Grosse, Ulrich and S{\"u}dkamp, Norbert P. and Helwig, Peter}, title = {Do changes in dynamic plantar pressure distribution, strength capacity and postural control after intra-articular calcaneal fracture correlate with clinical and radiological outcome?}, series = {Injury : international journal of the care of the injured}, volume = {42}, journal = {Injury : international journal of the care of the injured}, number = {10}, publisher = {Elsevier}, address = {Oxford}, issn = {0020-1383}, doi = {10.1016/j.injury.2010.09.040}, pages = {1135 -- 1143}, year = {2011}, abstract = {Fractures of the calcaneus are often associated with serious permanent disability, a considerable reduction in quality of life, and high socio-economic cost. Although some studies have already reported changes in plantar pressure distribution after calcaneal fracture, no investigation has yet focused on the patient's strength and postural control. Method: 60 patients with unilateral, operatively treated, intra-articular calcaneal fractures were clinically and biomechanically evaluated >1 year postoperatively (physical examination, SF-36, AOFAS score, lower leg isokinetic strength, postural control and gait analysis including plantar pressure distribution). Results were correlated to clinical outcome and preoperative radiological findings (Bohler angle, Zwipp and Sanders Score). Results: Clinical examination revealed a statistically significant reduction in range of motion at the tibiotalar and the subtalar joint on the affected side. Additionally, there was a statistically significant reduction of plantar flexor peak torque of the injured compared to the uninjured limb (p < 0.001) as well as a reduction in postural control that was also more pronounced on the initially injured side (standing duration 4.2 +/- 2.9 s vs. 7.6 +/- 2.1 s, p < 0.05). Plantar pressure measurements revealed a statistically significant pressure reduction at the hindfoot (p = 0.0007) and a pressure increase at the midfoot (p = 0.0001) and beneath the lateral forefoot (p = 0.037) of the injured foot. There was only a weak correlation between radiological classifications and clinical outcome but a moderate correlation between strength differences and the clinical questionnaires (CC 0.27-0.4) as well as between standing duration and the clinical questionnaires. Although thigh circumference was also reduced on the injured side, there was no important relationship between changes in lower leg circumference and strength suggesting that measurement of leg circumference may not be a valid assessment of maximum strength deficits. Self-selected walking speed was the parameter that showed the best correlation with clinical outcome (AOFAS score). Conclusion: Calcaneal fractures are associated with a significant reduction in ankle joint ROM, plantar flexion strength and postural control. These impairments seem to be highly relevant to the patients. Restoration of muscular strength and proprioception should therefore be aggressively addressed in the rehabilitation process after these fractures.}, language = {en} } @article{BaurHirschmuellerMuelleretal.2011, author = {Baur, Heiner and Hirschm{\"u}ller, Anja and M{\"u}ller, Steffen and Mayer, Frank}, title = {Neuromuscular activity of the peroneal muscle after foot orthoses therapy in runners}, series = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine}, volume = {43}, journal = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine}, number = {8}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {0195-9131}, doi = {10.1249/MSS.0b013e31820c64ae}, pages = {1500 -- 1506}, year = {2011}, abstract = {BAUR, H., A. HIRSCHMULLER, S. MULLER, and F. MAYER. Neuromuscular Activity of the Peroneal Muscle after Foot Orthoses Therapy in Runners. Med. Sci. Sports Exerc., Vol. 43, No. 8, pp. 1500-1506, 2011. Purpose: Foot orthoses are a standard option to treat overuse injury. Biomechanical data providing mechanisms of foot orthoses' effectiveness are sparse. Stability of the ankle joint complex might be a key factor. The purpose was therefore to analyze neuromuscular activity of the musculus peroneus longus in runners with overuse injury symptoms treated with foot orthoses. Methods: A total of 99 male and female runners with overuse injury symptoms randomized in a control group (CO) and an orthoses group (OR) were analyzed on a treadmill at 3.3 m.s(-1) before and after an 8-wk foot orthoses intervention. Muscular activity of the musculus peroneus longus was measured and quantified in the time domain (initial onset of activation (T-ini), time of maximal activity (T-max), total time of activation (T-tot)) and amplitude domain (amplitude in preactivation (A(pre)), weight acceptance (A(wa)), push-off (A(po))). Results: Peroneal activity in the time domain did not differ initially between CO and OR, and no effect was observed after therapy (T-ini: CO = -0.88 +/- 0.09, OR = -0.88 +/- 0.08 / T-max: CO = 0.14 +/- 0.06, OR = 0.15 +/- 0.06 / T-tot: CO = 0.40 +/- 0.09, OR = 0.41 +/- 0.09; P > 0.05). In preactivation (Apre), muscle activity was higher in OR after intervention (CO = 0.97 +/- 0.32, 95\% confidence interval = 0.90-1.05; OR = 1.18 +/- 0.43, 95\% confidence interval = 1.08-1.28; P = 0.003). There was no group or intervention effect during stance (A(wa): CO = 2.33 +/- 0.66, OR = 2.33 +/- 0.74 / A(po): CO = 0.80 +/- 0.41, OR = 0.88 +/- 0.40; P > 0.05). Conclusions: Enhanced muscle activation of the musculus peroneus longus in preactivation suggests an altered preprogrammed activity, which might lead to better ankle stability providing a possible mode of action for foot orthoses therapy.}, language = {en} } @article{MuellerMayerBauretal.2011, author = {M{\"u}ller, Steffen and Mayer, Patrizia and Baur, Heiner and Mayer, Frank}, title = {Higher velocities in isokinetic dynamometry a pilot study of new test mode with active compensation of inertia}, series = {Isokinetics and exercise science : official journal of the European Isokinetic Society}, volume = {19}, journal = {Isokinetics and exercise science : official journal of the European Isokinetic Society}, number = {2}, publisher = {IOS Press}, address = {Amsterdam}, issn = {0959-3020}, doi = {10.3233/IES-2011-0398}, pages = {63 -- 70}, year = {2011}, abstract = {Isokinetic dynamometry is a standard technique for strength testing and training. Nevertheless reliability and validity is limited due to inertia effects, especially for high velocities. Therefore in a first methodological approach the purpose was to evaluate a new isokinetic measurement mode including inertia compensation compared to a classic isokinetic measurement mode for single and multijoint movements at different velocities. Isokinetic maximum strength measurements were carried out in 26 healthy active subjects. Tests were performed using classic isokinetic and new isokinetic mode in random order. Maximum torque/force, maximum movement velocity and time for acceleration were calculated. For inter-instrument agreement Bland and Altman analysis, systematic and random error was quantified. Differences between both methods were assessed (ANOVA alpha = 0.05). Bland and Altman analysis showed the highest agreement between the two modes for strength and velocity measurements (bias: < +/- 1.1\%; LOA: < 14.2\%) in knee flexion/extension at slow isokinetic velocity (60 degrees/s). Least agreement (range: bias: -67.6\% +/- 119.0\%; LOA: 53.4\% 69.3\%) was observed for shoulder/arm test at high isokinetic velocity (360 degrees/s). The Isokin(new) mode showed higher maximum movement velocities (p < 0.05). For low isokinetic velocities the new mode agrees with the classic mode. Especially at high isokinetic velocities the new isokinetic mode shows relevant benefits coupled with a possible trade-off with the force/torque measurement. In conclusion, this study offers for the first time a comparison between the 'classical' and inertia-compensated isokinetic dynamometers indicating the advantages and disadvantages associated with each individual approach, particularly as they relate to medium or high velocities in testing and training.}, language = {en} } @article{HirschmuellerBaurMuelleretal.2011, author = {Hirschm{\"u}ller, Anja and Baur, Heiner and M{\"u}ller, Steffen and Helwig, Peter and Dickhuth, Hans-Hermann and Mayer, Frank}, title = {Clinical effectiveness of customised sport shoe orthoses for overuse injuries in runners a randomised controlled study}, series = {British journal of sports medicine : the journal of sport and exercise medicine}, volume = {45}, journal = {British journal of sports medicine : the journal of sport and exercise medicine}, number = {12}, publisher = {BMJ Publ. Group}, address = {London}, issn = {0306-3674}, doi = {10.1136/bjsm.2008.055830}, pages = {959 -- 965}, year = {2011}, abstract = {Background and objectives Treatment of chronic running-related overuse injuries by orthopaedic shoe orthoses is very common but not evidence-based to date. Hypothesis Polyurethane foam orthoses adapted to a participant's barefoot plantar pressure distribution are an effective treatment option for chronic overuse injuries in runners. Design Prospective, randomised, controlled clinical trial. Intervention 51 patients with running injuries were treated with custom-made, semirigid running shoe orthoses for 8 weeks. 48 served as a randomised control group that continued regular training activity without any treatment. Main outcome measures Evaluation was made by the validated pain questionnaire Subjective Pain Experience Scale, the pain disability index and a comfort index in the orthoses group (ICI). Results There were statistically significant differences between the orthoses and control groups at 8 weeks for the pain disability index (mean difference 3.2; 95\% CI 0.9 to 5.5) and the Subjective Pain Experience Scale (6.6; 2.6 to 10.6). The patients with orthoses reported a rising wearing comfort (pre-treatment ICI 69/100; post-treatment ICI 83/100) that was most pronounced in the first 4 weeks (ICI 80.4/100). Conclusion Customised polyurethane running shoe orthoses are an effective conservative therapy strategy for chronic running injuries with high comfort and acceptance of injured runners.}, language = {en} } @phdthesis{Risse2011, author = {Risse, Sarah}, title = {Processing in the perceptual span : investigations with the n+2-boundary paradigm}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-60414}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Cognitive psychology is traditionally interested in the interaction of perception, cognition, and behavioral control. Investigating eye movements in reading constitutes a field of research in which the processes and interactions of these subsystems can be studied in a well-defined environment. Thereby, the following questions are pursued: How much information is visually perceived during a fixation, how is processing achieved and temporally coordinated from visual letter encoding to final sentence comprehension, and how do such processes reflect on behavior such as the control of the eyes' movements during reading. Various theoretical models have been proposed to account for the specific eye-movement behavior in reading (for a review see Reichle, Rayner, \& Pollatsek, 2003). Some models are based on the idea of shifting attention serially from one word to the next within the sentence whereas others propose distributed attention allocating processing resources to more than one word at a time. As attention is assumed to drive word recognition processes one major difference between these models is that word processing must either occur in strict serial order, or that word processing is achieved in parallel. In spite of this crucial difference in the time course of word processing, both model classes perform well on explaining many of the benchmark effects in reading. In fact, there seems to be not much empirical evidence that challenges the models to a point at which their basic assumptions could be falsified. One issue often perceived as being decisive in the debate on serial and parallel word processing is how not-yet-fixated words to the right of fixation affect eye movements. Specifically, evidence is discussed as to what spatial extent such parafoveal words are previewed and how this influences current and subsequent word processing. Four experiments investigated parafoveal processing close to the spatial limits of the perceptual span. The present work aims to go beyond mere existence proofs of previewing words at such spatial distances. Introducing a manipulation that dissociates the sources of long-range preview effects, benefits and costs of parafoveal processing can be investigated in a single analysis and the differing impact is tracked across a three-word target region. In addition, the same manipulation evaluates the role of oculomotor error as the cause of non-local distributed effects. In this respect, the results contribute to a better understanding of the time course of word processing inside the perceptual span and attention allocation during reading.}, language = {en} } @misc{BostonHaleVasishthetal.2011, author = {Boston, Marisa Ferrara and Hale, John T. and Vasishth, Shravan and Kliegl, Reinhold}, title = {Parallel processing and sentence comprehension difficulty}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57159}, year = {2011}, abstract = {Eye fixation durations during normal reading correlate with processing difficulty but the specific cognitive mechanisms reflected in these measures are not well understood. This study finds support in German readers' eyefixations for two distinct difficulty metrics: surprisal, which reflects the change in probabilities across syntactic analyses as new words are integrated, and retrieval, which quantifies comprehension difficulty in terms of working memory constraints. We examine the predictions of both metrics using a family of dependency parsers indexed by an upper limit on the number of candidate syntactic analyses they retain at successive words. Surprisal models all fixation measures and regression probability. By contrast, retrieval does not model any measure in serial processing. As more candidate analyses are considered in parallel at each word, retrieval can account for the same measures as surprisal. This pattern suggests an important role for ranked parallelism in theories of sentence comprehension.}, language = {en} } @phdthesis{Gendt2011, author = {Gendt, Anja}, title = {Eye movements under the control of working memory : the challenge of a reading-span task}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69224}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {During reading oculomotor processes guide the eyes over the text. The visual information recorded is accessed, evaluated and processed. Only by retrieving the meaning of a word from the long-term memory, as well as through the connection and storage of the information about each individual word, is it possible to access the semantic meaning of a sentence. Therefore memory, and here in particular working memory, plays a pivotal role in the basic processes of reading. The following dissertation investigates to what extent different demands on memory and memory capacity have an effect on eye movement behavior while reading. The frequently used paradigm of the reading span task, in which test subjects read and evaluate individual sentences, was used for the experimental review of the research questions. The results speak for the fact that working memory processes have a direct effect on various eye movement measurements. Thus a high working memory load, for example, reduced the perceptual span while reading. The lower the individual working memory capacity of the reader was, the stronger was the influence of the working memory load on the processing of the sentence.}, language = {en} } @phdthesis{Giesewetter2011, author = {Giesewetter, Stefan}, title = {Resolute readings of later Wittgenstein and the challenge of avoiding hierarchies in philosophy}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57021}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {This dissertation addresses the question: How did later Wittgenstein aim to achieve his goal of putting forward a way of dissolving philosophical problems which centered on asking ourselves what we mean by our words - yet which did not entail any claims about the essence of language and meaning? This question is discussed with reference to "resolute" readings of Wittgenstein. I discuss the readings of James Conant, Oskari Kuusela, and Martin Gustafsson. I follow Oskari Kuusela's claim that in order to fully appreciate how later Wittgenstein meant to achieve his goal, we need to clearly see how he aimed to do away with hierarchies in philosophy: Not only is the dissolution of philosophical problems via the method of clarifying the grammar of expressions to be taken as independent from any theses about what meaning must be - but furthermore, it is to be taken as independent from the dissolution of any particular problem via this method. As Kuusela stresses, this also holds for the problems involving rule-following and meaning: the clarification of the grammar of "rule" and "meaning" has no foundational status - it is nothing on which the method of clarifying the grammar of expressions as such were meant to in any way rely on. The lead question of this dissertation then is: What does it mean to come to see that the method of dissolving philosophical problems by asking "How is this word actually used?" does not in any way rely on the results of our having investigated the grammar of the particular concepts "rule" and "meaning"? What is the relation of such results - results such as "To follow a rule, [...], to obey an order, [...] are customs (uses, institutions)" or "The meaning of a word is its use in the language" - to this method? From this vantage point, I concern myself with two aspects of the readings of Gustafsson and Kuusela. In Gustafsson, I concern myself with his idea that the dissolution of philosophical problems in general "relies on" the very agreement which - during the dissolution of the rule-following problem - comes out as a presupposition for our talk of "meaning" in terms of rules. In Kuusela, I concern myself with his idea that Wittgenstein, in adopting a way of philosophical clarification which investigates the actual use of expressions, is following the model of "meaning as use" - which model he had previously introduced in order to perspicuously present an aspect of the actual use of the word "meaning". This dissertation aims to show how these two aspects of Gustafsson's and Kuusela's readings still fail to live up to the vision of Wittgenstein as a philosopher who aimed to do away with any hierarchies in philosophy. I base this conclusion on a detailed analysis of which of the occasions where Wittgenstein invokes the notions of "use" and "application" (as also "agreement") have to do with the dissolution of a specific problem only, and which have to do with the dissolution of philosophical problems in general. I discuss Wittgenstein's remarks on rule-following, showing how in the dissolution of the rule-following paradox, notions such as "use", "application", and "practice" figure on two distinct logical levels. I then discuss an example of what happens when this distinction is not duly heeded: Gordon Baker and Peter Hacker's idea that the rule-following remarks have a special significance for his project of dissolving philosophical problems as such. I furnish an argument to the effect that their idea that the clarification of the rules of grammar of the particular expression "following a rule" could answer a question about rules of grammar in general rests on a conflation of the two logical levels on which "use" occurs in the rule-following remarks, and that it leads into a regress. I then show that Gustafsson's view - despite its decisive advance over Baker and Hacker - contains a version of that same idea, and that it likewise leads into a regress. Finally, I show that Kuusela's idea of a special significance of the model "meaning as use" for the whole of the method of stating rules for the use of words is open to a regress argument of a similar kind as that he himself advances against Baker and Hacker. I conclude that in order to avoid such a regress, we need to reject the idea that the grammatical remark "The meaning of a word is its use in the language" - because of the occurrence of "use" in it - stood in any special relation to the method of dissolving philosophical problems by describing the use of words. Rather, we need to take this method as independent from this outcome of the investigation of the use of the particular word "meaning".}, language = {en} } @misc{SicardLenhard2011, author = {Sicard, Adrien and Lenhard, Michael}, title = {The selfing syndrome a model for studying the genetic and evolutionary basis of morphological adaptation in plants}, series = {Annals of botany}, volume = {107}, journal = {Annals of botany}, number = {9}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0305-7364}, doi = {10.1093/aob/mcr023}, pages = {1433 -- 1443}, year = {2011}, abstract = {Background In angiosperm evolution, autogamously selfing lineages have been derived from outbreeding ancestors multiple times, and this transition is regarded as one of the most common evolutionary tendencies in flowering plants. In most cases, it is accompanied by a characteristic set of morphological and functional changes to the flowers, together termed the selfing syndrome. Two major areas that have changed during evolution of the selfing syndrome are sex allocation to male vs. female function and flower morphology, in particular flower (mainly petal) size and the distance between anthers and stigma. Scope A rich body of theoretical, taxonomic, ecological and genetic studies have addressed the evolutionary modification of these two trait complexes during or after the transition to selfing. Here, we review our current knowledge about the genetics and evolution of the selfing syndrome. Conclusions We argue that because of its frequent parallel evolution, the selfing syndrome represents an ideal model for addressing basic questions about morphological evolution and adaptation in flowering plants, but that realizing this potential will require the molecular identification of more of the causal genes underlying relevant trait variation.}, language = {en} } @article{KielMoehwaldBargheer2011, author = {Kiel, Mareike and M{\"o}hwald, Helmuth and Bargheer, Matias}, title = {Broadband measurements of the transient optical complex dielectric function of a nanoparticle/polymer composite upon ultrafast excitation}, series = {Physical review : B, Condensed matter and materials physics}, volume = {84}, journal = {Physical review : B, Condensed matter and materials physics}, number = {16}, publisher = {American Physical Society}, address = {College Park}, issn = {1098-0121}, doi = {10.1103/PhysRevB.84.165121}, pages = {6}, year = {2011}, abstract = {We determined experimentally the complex transient optical dielectric function of a well-characterized polyelectrolyte/gold-nanoparticle composite system over a broad spectral range upon short pulse laser excitation by simultaneously measuring the time-dependent reflectance and transmittance of white light pulses with femtosecond pump-probe spectroscopy. We extracted directly the ultrafast changes in the real and imaginary parts of the effective dielectric function, epsilon(eff)(r) (omega,t)and epsilon(eff)(i) (omega,t), from the experiment. This complete experimental set of information on the time-dependent complex dielectric function challenges theories modeling the transient dielectric function of gold particles and the effective medium.}, language = {en} } @article{RisseKliegl2011, author = {Risse, Sarah and Kliegl, Reinhold}, title = {Adult age differences in the perceptual span during reading}, series = {Psychology and aging}, volume = {26}, journal = {Psychology and aging}, number = {2}, publisher = {American Psychological Association}, address = {Washington}, issn = {0882-7974}, doi = {10.1037/a0021616}, pages = {451 -- 460}, year = {2011}, abstract = {Following up on research suggesting an age-related reduction in the rightward extent of the perceptual span during reading (Rayner, Castelhano, \& Yang, 2009), we compared old and young adults in an N + 2-boundary paradigm in which a nonword preview of word N + 2 or word N + 2 itself is replaced by the target word once the eyes cross an invisible boundary located after word N. The intermediate word N + I was always three letters long. Gaze durations on word N + 2 were significantly shorter for identical than nonword N + 2 preview both for young and for old adults, with no significant difference in this preview benefit. Young adults, however, did modulate their gaze duration on word N more strongly than old adults in response to the difficulty of the parafoveal word N + I. Taken together, the results suggest a dissociation of preview benefit and parafoveal-on-foveal effect. Results are discussed in terms of age-related decline in resilience towards distributed processing while simultaneously preserving the ability to integrate parafoveal information into foveal processing. As such, the present results relate to proposals of regulatory compensation strategies older adults use to secure an overall reading speed very similar to that of young adults.}, language = {en} } @article{KlieglWeiDambacheretal.2011, author = {Kliegl, Reinhold and Wei, Ping and Dambacher, Michael and Yan, Ming and Zhou, Xiaolin}, title = {Experimental effects and individual differences in linear mixed models estimating the relationship between spatial, object, and attraction effects in visual attention}, series = {Frontiers in psychology}, volume = {2}, journal = {Frontiers in psychology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-1078}, doi = {10.3389/fpsyg.2010.00238}, pages = {12}, year = {2011}, abstract = {Linear mixed models (LMMs) provide a still underused methodological perspective on combining experimental and individual-differences research. Here we illustrate this approach with two-rectangle cueing in visual attention (Egly et al., 1994). We replicated previous experimental cue-validity effects relating to a spatial shift of attention within an object (spatial effect), to attention switch between objects (object effect), and to the attraction of attention toward the display centroid (attraction effect), also taking into account the design-inherent imbalance of valid and other trials. We simultaneously estimated variance/covariance components of subject-related random effects for these spatial, object, and attraction effects in addition to their mean reaction times (RTs). The spatial effect showed a strong positive correlation with mean RT and a strong negative correlation with the attraction effect. The analysis of individual differences suggests that slow subjects engage attention more strongly at the cued location than fast subjects. We compare this joint LMM analysis of experimental effects and associated subject-related variances and correlations with two frequently used alternative statistical procedures.}, language = {en} } @article{KlieglBates2011, author = {Kliegl, Reinhold and Bates, Douglas}, title = {International collaboration in psychology is on the rise}, doi = {10.1007/s11192-010-0299-0}, year = {2011}, abstract = {There has been a substantial increase in the percentage for publications with co-authors located in departments from different countries in 12 major journals of psychology. The results are evidence for a remarkable internationalization of psychological research, starting in the mid 1970s and increasing in rate at the beginning of the 1990s. This growth occurs against a constant number of articles with authors from the same country; it is not due to a concomitant increase in the number of co-authors per article. Thus, international collaboration in psychology is obviously on the rise.}, language = {en} } @article{RisseKliegl2011, author = {Risse, Sarah and Kliegl, Reinhold}, title = {Adult age difference in the perceptual span during reading}, year = {2011}, abstract = {Following up on research suggesting an age-related reduction in the rightward extent of the perceptual span during reading (Rayner, Castelhano, \& Yang, 2009), we compared old and young adults in an N + 2-boundary paradigm in which a nonword preview of word N + 2 or word N + 2 itself is replaced by the target word once the eyes cross an invisible boundary located after word N. The intermediate word N + 1 was always three letters long. Gaze durations on word N + 2 were significantly shorter for identical than nonword N + 2 preview both for young and for old adults, with no significant difference in this preview benefit. Young adults, however, did modulate their gaze duration on word N more strongly than old adults in response to the difficulty of the parafoveal word N + 1. Taken together, the results suggest a dissociation of preview benefit and parafoveal-on-foveal effect. Results are discussed in terms of age-related decline in resilience towards distributed processing while simultaneously preserving the ability to integrate parafoveal information into foveal processing. As such, the present results relate to proposals of regulatory compensation strategies older adults use to secure an overall reading speed very similar to that of young adults. (PsycINFO Database Record (c) 2011 APA, all rights reserved)}, language = {en} } @article{BostonHalbeVasishthetal.2011, author = {Boston, Marisa Ferrara and Halbe, John T. and Vasishth, Shravan and Kliegl, Reinhold}, title = {Parallel processing and entence comprehension difficulty}, doi = {10.1080/01690965.2010.492228}, year = {2011}, abstract = {Eye fixation durations during normal reading correlate with processing difficulty, but the specific cognitive mechanisms reflected in these measures are not well understood. This study finds support in German readers' eye fixations for two distinct difficulty metrics: surprisal, which reflects the change in probabilities across syntactic analyses as new words are integrated; and retrieval, which quantifies comprehension difficulty in terms of working memory constraints. We examine the predictions of both metrics using a family of dependency parsers indexed by an upper limit on the number of candidate syntactic analyses they retain at successive words. Surprisal models all fixation measures and regression probability. By contrast, retrieval does not model any measure in serial processing. As more candidate analyses are considered in parallel at each word, retrieval can account for the same measures as surprisal. This pattern suggests an important role for ranked parallelism in theories of sentence comprehension.}, language = {en} } @article{OhlBrandtKliegl2011, author = {Ohl, Sven and Brandt, Stephan A. and Kliegl, Reinhold}, title = {Secondary (micro-)saccades the influence of primary saccade end point and target eccentricity on the process of postsaccadic fixation}, series = {Vision research : an international journal for functional aspects of vision.}, volume = {51}, journal = {Vision research : an international journal for functional aspects of vision.}, number = {23-24}, publisher = {Elsevier}, address = {Oxford}, issn = {0042-6989}, doi = {10.1016/j.visres.2011.09.005}, pages = {2340 -- 2347}, year = {2011}, abstract = {We examine how the size of saccadic under-/overshoot and target eccentricity influence the latency, amplitude and orientation of secondary (micro-)saccades. In our experiment, a target appeared at an eccentricity of either 6 degrees or 14 degrees of visual angle. Subjects were instructed to direct their gaze as quickly as possible to the target and hold fixation at the new location until the end of the trial. Typically, increasing saccadic error is associated with faster and larger secondary saccades. We show that secondary saccades at distant in contrast to close targets have in a specific error range a shorter latency, larger amplitude, and follow more often the direction of the primary saccade. Finally, we demonstrate that an undershooting primary saccade is followed almost exclusively by secondary saccades into the same direction while overshooting primary saccades are followed by secondary saccades into both directions. This supports the notion that under- and overshooting imply different consequences for postsaccadic oculomotor processing. Results are discussed using a model, introduced by Rolfs, Kliegl, and Engbert (2008), to account for the generation of microsaccades. We argue that the dynamic interplay of target eccentricity and the magnitude of the saccadic under-/overshoot can be explained by a different strength of activation in the two hemispheres of the saccadic motor map in this model.}, language = {en} } @article{KlieglBates2011, author = {Kliegl, Reinhold and Bates, Douglas}, title = {International collaboration in psychology is on the rise}, series = {Scientometrics : an international journal for all quantitative aspects of the science of science, communication in science and science policy}, volume = {87}, journal = {Scientometrics : an international journal for all quantitative aspects of the science of science, communication in science and science policy}, number = {1}, publisher = {Springer}, address = {Dordrecht}, issn = {0138-9130}, doi = {10.1007/s11192-010-0299-0}, pages = {149 -- 158}, year = {2011}, abstract = {There has been a substantial increase in the percentage for publications with co-authors located in departments from different countries in 12 major journals of psychology. The results are evidence for a remarkable internationalization of psychological research, starting in the mid 1970s and increasing in rate at the beginning of the 1990s. This growth occurs against a constant number of articles with authors from the same country; it is not due to a concomitant increase in the number of co-authors per article. Thus, international collaboration in psychology is obviously on the rise.}, language = {en} } @misc{DimigenSommerHohlfeldetal.2011, author = {Dimigen, Olaf and Sommer, Werner and Hohlfeld, Annette and Jacobs, Arthur M. and Kliegl, Reinhold}, title = {Coregistration of eye movements and EEG in natural reading analyses and review}, series = {Journal of experimental psychology : General}, volume = {140}, journal = {Journal of experimental psychology : General}, number = {4}, publisher = {American Psychological Association}, address = {Washington}, issn = {0096-3445}, doi = {10.1037/a0023885}, pages = {552 -- 572}, year = {2011}, abstract = {Brain-electric correlates of reading have traditionally been studied with word-by-word presentation, a condition that eliminates important aspects of the normal reading process and precludes direct comparisons between neural activity and oculomotor behavior. In the present study, we investigated effects of word predictability on eye movements (EM) and fixation-related brain potentials (FRPs) during natural sentence reading. Electroencephalogram (EEG) and EM (via video-based eye tracking) were recorded simultaneously while subjects read heterogeneous German sentences, moving their eyes freely over the text. FRPs were time-locked to first-pass reading fixations and analyzed according to the cloze probability of the currently fixated word. We replicated robust effects of word predictability on EMs and the N400 component in FRPs. The data were then used to model the relation among fixation duration, gaze duration, and N400 amplitude, and to trace the time course of EEG effects relative to effects in EM behavior. In an extended Methodological Discussion section, we review 4 technical and data-analytical problems that need to be addressed when FRPs are recorded in free-viewing situations (such as reading, visual search, or scene perception) and propose solutions. Results suggest that EEG recordings during normal vision are feasible and useful to consolidate findings from EEG and eye-tracking studies.}, language = {en} } @article{ShuZhouYanetal.2011, author = {Shu, Hua and Zhou, Wei and Yan, Ming and Kliegl, Reinhold}, title = {Font size modulates saccade-target selection in Chinese reading}, series = {Attention, perception, \& psychophysics : AP\&P ; a journal of the Psychonomic Society, Inc.}, volume = {73}, journal = {Attention, perception, \& psychophysics : AP\&P ; a journal of the Psychonomic Society, Inc.}, number = {2}, publisher = {Springer}, address = {New York}, issn = {1943-3921}, doi = {10.3758/s13414-010-0029-y}, pages = {482 -- 490}, year = {2011}, abstract = {In alphabetic writing systems, saccade amplitude (a close correlate of reading speed) is independent of font size, presumably because an increase in the angular size of letters is compensated for by a decrease of visual acuity with eccentricity. We propose that this invariance may (also) be due to the presence of spaces between words, guiding the eyes across a large range of font sizes. Here, we test whether saccade amplitude is also invariant against manipulations of font size during reading Chinese, a character-based writing system without spaces as explicit word boundaries for saccade-target selection. In contrast to word-spaced alphabetic writing systems, saccade amplitude decreased significantly with increased font size, leading to an increase in the number of fixations at the beginning of words and in the number of refixations. These results are consistent with a model which assumes that word beginning (rather than word center) is the default saccade target if the length of the parafoveal word is not available.}, language = {en} } @article{BostonHaleVasishthetal.2011, author = {Boston, Marisa Ferrara and Hale, John T. and Vasishth, Shravan and Kliegl, Reinhold}, title = {Parallel processing and sentence comprehension difficulty}, series = {Language and cognitive processes}, volume = {26}, journal = {Language and cognitive processes}, number = {3}, publisher = {Wiley}, address = {Hove}, issn = {0169-0965}, doi = {10.1080/01690965.2010.492228}, pages = {301 -- 349}, year = {2011}, abstract = {Eye fixation durations during normal reading correlate with processing difficulty, but the specific cognitive mechanisms reflected in these measures are not well understood. This study finds support in German readers' eye fixations for two distinct difficulty metrics: surprisal, which reflects the change in probabilities across syntactic analyses as new words are integrated; and retrieval, which quantifies comprehension difficulty in terms of working memory constraints. We examine the predictions of both metrics using a family of dependency parsers indexed by an upper limit on the number of candidate syntactic analyses they retain at successive words. Surprisal models all fixation measures and regression probability. By contrast, retrieval does not model any measure in serial processing. As more candidate analyses are considered in parallel at each word, retrieval can account for the same measures as surprisal. This pattern suggests an important role for ranked parallelism in theories of sentence comprehension.}, language = {en} } @article{SchmelzbachScherbaumTronickeetal.2011, author = {Schmelzbach, C. and Scherbaum, Frank and Tronicke, Jens and Dietrich, P.}, title = {Bayesian frequency-domain blind deconvolution of ground-penetrating radar data}, series = {Journal of applied geophysics}, volume = {75}, journal = {Journal of applied geophysics}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0926-9851}, doi = {10.1016/j.jappgeo.2011.08.010}, pages = {615 -- 630}, year = {2011}, abstract = {Enhancing the resolution and accuracy of surface ground-penetrating radar (GPR) reflection data by inverse filtering to recover a zero-phased band-limited reflectivity image requires a deconvolution technique that takes the mixed-phase character of the embedded wavelet into account. In contrast, standard stochastic deconvolution techniques assume that the wavelet is minimum phase and, hence, often meet with limited success when applied to GPR data. We present a new general-purpose blind deconvolution algorithm for mixed-phase wavelet estimation and deconvolution that (1) uses the parametrization of a mixed-phase wavelet as the convolution of the wavelet's minimum-phase equivalent with a dispersive all-pass filter, (2) includes prior information about the wavelet to be estimated in a Bayesian framework, and (3) relies on the assumption of a sparse reflectivity. Solving the normal equations using the data autocorrelation function provides an inverse filter that optimally removes the minimum-phase equivalent of the wavelet from the data, which leaves traces with a balanced amplitude spectrum but distorted phase. To compensate for the remaining phase errors, we invert in the frequency domain for an all-pass filter thereby taking advantage of the fact that the action of the all-pass filter is exclusively contained in its phase spectrum. A key element of our algorithm and a novelty in blind deconvolution is the inclusion of prior information that allows resolving ambiguities in polarity and timing that cannot be resolved using the sparseness measure alone. We employ a global inversion approach for non-linear optimization to find the all-pass filter phase values for each signal frequency. We tested the robustness and reliability of our algorithm on synthetic data with different wavelets, 1-D reflectivity models of different complexity, varying levels of added noise, and different types of prior information. When applied to realistic synthetic 2-D data and 2-D field data, we obtain images with increased temporal resolution compared to the results of standard processing.}, language = {en} } @article{SchmelzbachTronickeDietrich2011, author = {Schmelzbach, C. and Tronicke, Jens and Dietrich, P.}, title = {Three-dimensional hydrostratigraphic models from ground-penetrating radar and direct-push data}, series = {Journal of hydrology}, volume = {398}, journal = {Journal of hydrology}, number = {3-4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2010.12.023}, pages = {235 -- 245}, year = {2011}, abstract = {Three-dimensional models of hydraulic conductivity and porosity are essential to understand and simulate groundwater flow in heterogeneous geological environments. However, considering the inherent limitations of traditional hydrogeological field methods in terms of resolution, alternative field approaches are needed to establish such 3-D models with sufficient accuracy. In this study, we developed a workflow combining 3-D structural information extracted from ground penetrating radar (GPR) images with 1-D in situ physical-property estimates from direct-push (DP) logging to construct a 3-D hydrostratigraphic model. To illustrate this workflow, we collected an similar to 70 m x 90 m 100 MHz 3-D GPR data set over a shallow sedimentary aquifer system resolving six different GPR facies down to similar to 15 m depth. DP logs of the relative dielectric permittivity, the relative hydraulic conductivity, the cone resistance, the sleeve friction and the pore pressure provided crucial data (1) to establish a GPR velocity model for 3-D depth migration and to check the time-to-depth conversion of the GPR data, and (2) to construct a 3-D hydrostratigraphic model. This model was built by assigning porosity values, which were computed from the DP relative dielectric permittivity logs, and DP relative hydraulic conductivity estimates to the identified GPR facies. We conclude that the integration of 3-D GPR structural images and 1-D DP logs of target physical parameters provides an efficient way for detailed 3-D subsurface characterization as needed, for example, for groundwater flow simulations.}, language = {en} }