Recent Submissions

  • Journal Article

    Tree Species Shape Soil Bacterial Community Structure and Function in Temperate Deciduous Forests 

    Dukunde, Amélie; Schneider, Dominik; Schmidt, Marcus; Veldkamp, Edzo; Daniel, Rolf
    Frontiers in Microbiology 2019; 10: Art. 1519
    Amplicon-based analysis of 16S rRNA genes and transcripts was used to assess the effect of tree species composition on soil bacterial community structure and function in a temperate deciduous forest. Samples were collected from mono and mixed stands of Fagus sylvatica (beech), Carpinus betulus (hornbeam), Tilia sp. (lime), and Quercus sp. (oak) in spring, summer, and autumn. Soil bacterial community exhibited similar taxonomic composition at total (DNA-based) and potentially active community (RNA-based) level, with fewer taxa present at active community level. Members of Rhizobiales dominated at both total and active bacterial community level, followed by members of Acidobacteriales, Solibacterales, Rhodospirillales, and Xanthomonadales. Bacterial communities at total and active community level showed a significant positive correlation with tree species identity (mono stands) and to a lesser extent with tree species richness (mixed stands). Approximately 58 and 64% of indicator operational taxonomic units (OTUs) showed significant association with only one mono stand at total and active community level, respectively, indicating a strong impact of tree species on soil bacterial community composition. Soil C/N ratio, pH, and P content similarly exhibited a significant positive correlation with soil bacterial communities, which was attributed to direct and indirect effects of forest stands. Seasonality was the strongest driver of predicted metabolic functions related to C fixation and degradation, and N metabolism. Carbon and nitrogen metabolic processes were significantly abundant in spring, while C degradation gene abundances increased from summer to autumn, corresponding to increased litterfall and decomposition. The results revealed that in a spatially homogenous forest soil, tree species diversity and richness are dominant drivers of structure and composition in soil bacterial communities.
    View Document Abstract
  • Journal Article

    Is implicit Theory of Mind real but hard to detect? Testing adults with different stimulus materials 

    Kulke, Louisa; Wübker, Marieke; Rakoczy, Hannes
    Royal Society Open Science 2019; 6(7): Art. 190068
    Recently, Theory of Mind (ToM) research has been revolutionized by new methods. Eye-tracking studies measuring subjects' looking times or anticipatory looking have suggested that implicit and automatic forms of ToM develop much earlier in ontogeny than traditionally assumed and continue to operate outside of subjects’ awareness throughout the lifespan. However, the reliability of these implicit methods has recently been put into question by an increasing number of non-replications. What remains unclear from these accumulating non-replication findings, though, is whether they present true negatives (there is no robust phenomenon of automatic ToM) or false ones (automatic ToM is real but difficult to tap). In order to address these questions, the current study implemented conceptual replications of influential anticipatory looking ToM tasks with a new variation in the stimuli. In two separate preregistered studies, we used increasingly realistic stimuli and controlled for potential confounds. Even with these more realistic stimuli, previous results could not be replicated. Rather, the anticipatory looking pattern found here remained largely compatible with more parsimonious explanations. In conclusion, the reality and robustness of automatic ToM remains controversial.
    View Document Abstract
  • Journal Article

    Impact of Nitriles on Bacterial Communities 

    Egelkamp, Richard; Zimmermann, Till; Schneider, Dominik; Hertel, Robert; Daniel, Rolf
    Frontiers in Environmental Science 2019; 7: Art. 103
    Nitriles are organic molecules with –C≡N as functional group and often toxic for living organisms. Detoxification can occur via nitrilases that degrade nitriles directly to carboxylic acids and ammonia, or with nitrile hydratases and amidases that convert nitriles to amides and subsequently to carboxylic acids and ammonia. Despite the knowledge of enzymatic degradation pathways, the influence of these compounds on the composition of bacterial communities is unknown. The tolerances of four phylogenetically different bacterial strains without known nitrile detoxification systems (Agrobacterium tumefaciens, Bacillus subtilis, Corynebacterium glutamicum, and Escherichia coli) to the toxic effects of nine nitriles and the corresponding carboxylic acids were determined. Based on these results, the effect of nitriles on diversity and composition of compost-derived bacterial communities was monitored over time by 16S rRNA gene amplicon-based andmetagenome analyses. Acetone cyanohydrin, 2-phenylpropionitrile, and pyruvonitrile exhibited a lethal, phenylacetonitrile, 4-hydroxybenzonitrile, and cyclohexanecarbonitrile a growth-suppressing and succinonitrile, acetonitrile, and crotononitrile a growth-promoting effect on the studied communities. Furthermore, each nitrile had a specific community-shaping effect, e.g., communities showing growth-suppression exhibited high relative abundance of Paenibacillus. In general, analysis of all data indicated a higher resistance of Gram-positive than Gram-negative bacterial community members and test organisms to growth-suppressing nitriles. More than 70 putative nitrilase-encoding and over 20 potential nitrile hydratase-encoding genes were identified during analysis of metagenomes derived from nitrile-enrichments, underlining the high yet often unexplored abundance of nitrile-degrading enzymes.
    View Document Abstract
  • Journal Article

    COP9 Signalosome Interaction with UspA/Usp15 Deubiquitinase Controls VeA-Mediated Fungal Multicellular Development 

    Meister, Cindy; Thieme; Karl G.; Thieme, Sabine; Köhler, Anna M.; Schmitt, Kerstin; Valerius, Oliver; Braus, Gerhard H.
    Biomolecules 2019; 9(6): Art. 238
    COP9 signalosome (CSN) and Den1/A deneddylases physically interact and promote multicellular development in fungi. CSN recognizes Skp1/cullin-1/Fbx E3 cullin-RING ligases (CRLs) without substrate and removes their posttranslational Nedd8 modification from the cullin scaffold. This results in CRL complex disassembly and allows Skp1 adaptor/Fbx receptor exchange for altered substrate specificity. We characterized the novel ubiquitin-specific protease UspA of the mold Aspergillus nidulans, which corresponds to CSN-associated human Usp15 and interacts with six CSN subunits. UspA reduces amounts of ubiquitinated proteins during fungal development, and the uspA gene expression is repressed by an intact CSN. UspA is localized in proximity to nuclei and recruits proteins related to nuclear transport and transcriptional processing, suggesting functions in nuclear entry control. UspA accelerates the formation of asexual conidiospores, sexual development, and supports the repression of secondary metabolite clusters as the derivative of benzaldehyde (dba) genes. UspA reduces protein levels of the fungal NF-kappa B-like velvet domain protein VeA, which coordinates differentiation and secondary metabolism. VeA stability depends on the Fbx23 receptor, which is required for light controlled development. Our data suggest that the interplay between CSN deneddylase, UspA deubiquitinase, and SCF-Fbx23 ensures accurate levels of VeA to support fungal development and an appropriate secondary metabolism.
    View Document Abstract
  • Journal Article

    Cold-water corals and hydrocarbon-rich seepage in Pompeia Province (Gulf of Cádiz) – living on the edge 

    Rincón-Tomás, Blanca; Duda, Jan-Peter; Somoza, Luis; González, Francisco Javier; Schneider, Dominik; Medialdea, Teresa; Santofimia, Esther; López-Pamo, Enrique; Madureira, Pedro; Hoppert, Michael; et al.
    Reitner, Joachim
    Biogeosciences 2019; 16(7) p.1607-1627
    Azooxanthellate cold-water corals (CWCs) have a global distribution and have commonly been found in areas of active fluid seepage. The relationship between the CWCs and these fluids, however, is not well understood. This study aims to unravel the relationship between CWC development and hydrocarbon-rich seepage in Pompeia Province (Gulf of Cádiz, Atlantic Ocean). This region is comprised of mud volcanoes (MVs), coral ridges and fields of coral mounds, which are all affected by the tectonically driven seepage of hydrocarbon-rich fluids. These types of seepage, for example, focused, scattered, diffused or eruptive, is tightly controlled by a complex system of faults and diapirs. Early diagenetic carbonates from the currently active Al Gacel MV exhibit δ13C signatures down to −28.77 ‰ Vienna Pee Dee Belemnite (VPDB), which indicate biologically derived methane as the main carbon source. The same samples contain 13C-depleted lipid biomarkers diagnostic for archaea such as crocetane (δ13C down to −101.2 ‰ VPDB) and pentamethylicosane (PMI) (δ13C down to −102.9 ‰ VPDB), which is evidence of microbially mediated anaerobic oxidation of methane (AOM). This is further supported by next generation DNA sequencing data, demonstrating the presence of AOM-related microorganisms (ANMEs, archaea, sulfate-reducing bacteria) in the carbonate. Embedded corals in some of the carbonates and CWC fragments exhibit less negative δ13C values (−8.08 ‰ to −1.39 ‰ VPDB), pointing against the use of methane as the carbon source. Likewise, the absence of DNA from methane- and sulfide-oxidizing microbes in sampled coral does not support the idea of these organisms having a chemosynthetic lifestyle. In light of these findings, it appears that the CWCs benefit rather indirectly from hydrocarbon-rich seepage by using methane-derived authigenic carbonates as a substratum for colonization. At the same time, chemosynthetic organisms at active sites prevent coral dissolution and necrosis by feeding on the seeping fluids (i.e., methane, sulfate, hydrogen sulfide), allowing cold-water corals to colonize carbonates currently affected by hydrocarbon-rich seepage.
    View Document Abstract
  • Journal Article

    Functional Metagenomics Reveals a New Catalytic Domain, the Metallo-β-Lactamase Superfamily Domain, Associated with Phytase Activity 

    Castillo Villamizar, Genis Andrés; Funkner, Katrina; Nacke, Heiko; Foerster, Karolin; Daniel, Rolf
    mSphere 2019; 4(3)
    Inositol-6-phosphate, also known as phytic acid, is a phosphorus source that plays several important roles in the phosphorus cycle and in cell metabolism. The known characterized enzymes responsible for its degradation, the phytases, are mostly derived from cultured individual microorganisms. The catalytic signatures of phytases are restricted to the molecular domains of four protein superfamilies: histidine phosphatases, protein tyrosine phosphatases, the purple acid phosphatases and the β-propeller phosphatases. During function-based screening of previously generated forest soil metagenomic libraries for Escherichia coli clones conferring phytase activity, two positive clones harboring the plasmids pLP05 and pLP12 were detected. Analysis of the insert sequences revealed the absence of classic phosphatase/phytase signatures of the proteins deduced from the putative genes, but the genes mblp01 (pLP05) and mblp02 (pLP12) encoded putative metallo-β-lactamases (MBLs). Several MBL representatives are promiscuous proteins with phosphoesterase activity, but phytase activity was previously not reported. Both mblp01 and mblp02 were subcloned, expressed, and analyzed. Mblp01 and Mblp02 are members of the lactamase B2 family. Protein modeling showed that the closest structural homologue of both proteins was ZipD of E. coli Mblp01 and Mblp02 showed activity toward the majority of the tested phosphorylated substrates, including phytate. The maximal enzyme activities were recorded for Mblp01 at 50°C under acidic conditions and for Mblp02 at 35°C and a neutral pH. In the presence of Cu2+ or SDS, the activities of Mblp01 and Mblp02 were strongly inhibited. Analyses of the minimal inhibitory concentrations of several β-lactam antibiotics revealed that recombinant E. coli cells carrying mblp01 or mblp02 showed reduced sensitivity toward β-lactam antibiotics.IMPORTANCE Phytic acid is a phosphorus storage molecule in many plant tissues, a source of phosphorus alternative to phosphate rocks, but it can also be a problematic antinutrient. In comparison to other phosphorus sources, phytic acid exhibits reduced bioavailability. Additionally, it influences functions of secondary messengers and acts as antioxidant in tumor growth prevention. The enzymatic capability to process phytate has been reported for a limited number of protein families. This might be due to the almost exclusive use of proteins derived from individual microorganisms to analyze phytase activity. With such a restriction, the study of the complexity and diversity of the phytases remains incomplete. By using metagenome-derived samples, this study demonstrates the existence of phytase activity in one of the most promiscuous superfamilies, the metallo-β-lactamases. Our results increase the general knowledge on phytase diversity in environmental samples and could provide new avenues for the study and engineering of new biocatalysts.
    View Document Abstract
  • Journal Article

    Sacred groves hold distinct bird assemblages within an Afrotropical savanna 

    Kühnert, Katharina; Grass, Ingo; Waltert, Matthias
    Global Ecology and Conservation 2019; 18: Art. e00656
    Riparian forests, an integral part of savanna ecosystems, are threatened across West Africa by agricultural expansion. However, some patches of original riparian vegetation are protected by traditional beliefs as ‘Sacred Groves’. We assessed the role of Sacred Groves in maintaining landscape-scale bird assemblages by conducting 144 1-h point counts, distributed over 24 plots in eastern Guinea-Bissau. The plots were situated in three riparian habitat types with different levels of human modification (Sacred Grove, Young Secondary Forest, Annual Cultures) and the adjacent Wooded Savanna. We accumulated 4572 records of 174 species and compared total species richness, composition, and functional traits among the four habitat types. At the plot level, species richness was higher in Wooded Savannas and Annual Cultures compared to Secondary Forests and Sacred Groves. Bird communities in Wooded Savannas were similar to those in Annual Cultures and differed the most from those of Sacred Groves. Bird community composition in Young Secondary Forests was similar to that in Annual Cultures but showed a shift towards the community composition found in Sacred Groves. Certain traits were strongly specific to habitat type. For example, Sacred Groves were characterized by a high number of forest specialists and insectivorous birds. Our results suggest that the rapid successional dynamics in riparian habitats enable disturbance tolerant forest species to recolonize fallow areas after a relatively short period of time. However, Sacred Groves hold a distinct avifauna and their conservation may therefore be crucial for forest specialist species and the re-establishment of bird assemblages in fallow riparian areas. Our findings also stress the importance of respecting and strengthening traditional forms of nature protection.
    View Document Abstract
  • Journal Article

    Review of the mite genus Ololaelaps (Acari, Laelapidae) and redescription of O. formidabilis Berlese 

    Beaulieu, Frédéric; Quintero-Gutiérrez, Edwin Javier; Sandmann, Dorotee; Klarner, Bernhard; Widyastuti, Rahayu; Cómbita-Heredia, Orlando; Scheu, Stefan
    ZooKeys 2019; 853 p.1-36
    A species of laelapid mite, Ololaelapsformidabilis, is redescribed based on male and female adults from soil in Sumatra, Indonesia. This species is distinguished from other Ololaelaps species by its metapodal platelet narrowly fused with the parapodal plate and by its hologastric shield having two inverted-V-like ridges. The genus is redescribed based on a review of the literature and examination of specimens of some species. Valid species of Ololaelaps are listed and accompanied by notes on morphological characters to assist future revision of the genus.
    View Document Abstract
  • Journal Article

    Future Directions for Personality Research: Contributing New Insights to the Understanding of Animal Behavior 

    Wilson, Vanessa; Guenther, Anja; Øverli, Øyvind; Seltmann, Martin W.; Altschul, Drew
    Animals 2019; 9(5): Art. 240
    As part of the European Conference on Behavioral Biology 2018, we organized a symposium entitled, "Animal personality: providing new insights into behavior?" The aims of this symposium were to address current research in the personality field, spanning both behavioral ecology and psychology, to highlight the future directions for this research, and to consider whether differential approaches to studying behavior contribute something new to the understanding of animal behavior. In this paper, we discuss the study of endocrinology and ontogeny in understanding how behavioral variation is generated and maintained, despite selection pressures assumed to reduce this variation. We consider the potential mechanisms that could link certain traits to fitness outcomes through longevity and cognition. We also address the role of individual differences in stress coping, mortality, and health risk, and how the study of these relationships could be applied to improve animal welfare. From the insights provided by these topics, we assert that studying individual differences through the lens of personality has provided new directions in behavioral research, and we encourage further research in these directions, across this interdisciplinary field.
    View Document Abstract
  • Journal Article

    Microbial cell factories for the sustainable manufacturing of B vitamins 

    Acevedo-Rocha, Carlos G.; Gronenberg, Luisa S.; Mack, Matthias; Commichau, Fabian M.; Genee, Hans J.
    Current Opinion in Biotechnology 2019; 56 p.18-29
    Vitamins are essential compounds in human and animal diets. Their demand is increasing globally in food, feed, cosmetics, chemical and pharmaceutical industries. Most current production methods are unsustainable because they use non-renewable sources and often generate hazardous waste. Many microorganisms produce vitamins naturally, but their corresponding metabolic pathways are tightly regulated since vitamins are needed only in catalytic amounts. Metabolic engineering is accelerating the development of microbial cell factories for vitamins that could compete with chemical methods that have been optimized over decades, but scientific hurdles remain. Additional technological and regulatory issues need to be overcome for innovative bioprocesses to reach the market. Here, we review the current state of development and challenges for fermentative processes for the B vitamin group.
    View Document Abstract
  • Journal Article

    Integration of Fungus-Specific CandA-C1 into a Trimeric CandA Complex Allowed Splitting of the Gene for the Conserved Receptor Exchange Factor of CullinA E3 Ubiquitin Ligases in Aspergilli 

    Köhler, Anna M.; Harting, Rebekka; Langeneckert, Annika E.; Valerius, Oliver; Gerke, Jennifer; Meister, Cindy; Strohdiek, Anja; Braus, Gerhard H.
    mBio 2019; 10(3)
    E3 cullin-RING ubiquitin ligase (CRL) complexes recognize specific substrates and are activated by covalent modification with ubiquitin-like Nedd8. Deneddylation inactivates CRLs and allows Cand1/A to bind and exchange substrate recognition subunits. Human as well as most fungi possess a single gene for the receptor exchange factor Cand1, which is split and rearranged in aspergilli into two genes for separate proteins. Aspergillus nidulans CandA-N blocks the neddylation site, and CandA-C inhibits the interaction to the adaptor/substrate receptor subunits similar to the respective N-terminal and C-terminal parts of single Cand1. The pathogen Aspergillus fumigatus and related species express a CandA-C with a 190-amino-acid N-terminal extension domain encoded by an additional exon. This extension corresponds in most aspergilli, including A. nidulans, to a gene directly upstream of candA-C encoding a 20-kDa protein without human counterpart. This protein was named CandA-C1, because it is also required for the cellular deneddylation/neddylation cycle and can form a trimeric nuclear complex with CandA-C and CandA-N. CandA-C and CandA-N are required for asexual and sexual development and control a distinct secondary metabolism. CandA-C1 and the corresponding domain of A. fumigatus control spore germination, vegetative growth, and the repression of additional secondary metabolites. This suggests that the dissection of the conserved Cand1-encoding gene within the genome of aspergilli was possible because it allowed the integration of a fungus-specific protein required for growth into the CandA complex in two different gene set versions, which might provide an advantage in evolution.IMPORTANCE Aspergillus species are important for biotechnological applications, like the production of citric acid or antibacterial agents. Aspergilli can cause food contamination or invasive aspergillosis to immunocompromised humans or animals. Specific treatment is difficult due to limited drug targets and emerging resistances. The CandA complex regulates, as a receptor exchange factor, the activity and substrate variability of the ubiquitin labeling machinery for 26S proteasome-mediated protein degradation. Only Aspergillus species encode at least two proteins that form a CandA complex. This study shows that Aspergillus species had to integrate a third component into the CandA receptor exchange factor complex that is unique to aspergilli and required for vegetative growth, sexual reproduction, and activation of the ubiquitin labeling machinery. These features have interesting implications for the evolution of protein complexes and could make CandA-C1 an interesting candidate for target-specific drug design to control fungal growth without affecting the human ubiquitin-proteasome system.
    View Document Abstract
  • Journal Article

    The Relationship Between Austrian Tax Auditors and Self-Employed Taxpayers: Evidence From a Qualitative Study 

    Gangl, Katharina; Hartl, Barbara; Hofmann, Eva; Kirchler, Erich
    Frontiers in Psychology 2019; 10: Art. 1034
    A constructive, highly professional relationship between tax authorities and taxpayers is essential for tax compliance. The aim of the present paper was to explore systematically the determinants of this relationship and related tax compliance behaviors based on the extended slippery slope framework. We used in-depth qualitative interviews with 33 self-employed taxpayers and 30 tax auditors. Interviewees described the relationship along the extended slippery slope framework concepts of power and trust. However, also novel sub-categories of power (e.g., setting deadlines) and trust (e.g., personal assistance) were mentioned. Furthermore, also little-studied categories of tax behavior emerged, such as accepting tax behavior, e.g., being available to the tax authorities, or stalling tax behavior, e.g., the intentional creation of complexity. The results comprehensively summarize the determinants of the tax relationship and tax compliance behaviors. Additionally, results highlight future research topics and provide insights for policy strategies.
    View Document Abstract
  • Journal Article

    Catalyzing Transitions to Sociality: Ecology Builds on Parental Care 

    Socias-Martínez, Lluís; Kappeler, Peter M.
    Frontiers in Ecology and Evolution 2019; 7: Art. 160
    In the context of social evolution research, great emphasis on kin-selected benefits has led to an understanding of parental care as one of the activities that helpers can perform in extended cooperative families. Nevertheless, this perspective might have precluded a deeper understanding of the implications of parental care for social evolution. We argue that parental care is a broader set of processes playing a key role both before and during the emergence of sociality. The care system of a species may be understood as the result of long coevolutionary processes with environmental pressures during presocial stages that impact transitions to sociality. We evaluate the present framework against evidence on the evolution of parental care and transitions toward sociality in subsocial and parasocial vertebrate and invertebrate species. Moreover, following previous evidence for the importance of modes of foraging and resting, we structure our inquiry by classifying societies into three types. Our results suggest that in “central place foragers” and “fortress defenders”, ecological factors promoting the evolution of parental care foster a set of coevolutionary feedback loops resulting in increases in parental effort and offspring needs. Offspring needs alone or in combination with limited breeding options enhance the relative benefits of positive social interactions, catalyzing transitions to sociality. In “itinerant foragers”, sociality is associated with colonizing new niches. Changes in predation pressure entail changes in the modes of care or selection for certain types of care already present in solitary ancestors. Further changes in the form of collective defense may be needed for permanent sociality to evolve. We conclude that there is evidence that social transitions to different types of societies are the result of long coevolutionary processes between environmental pressures and the care systems in a wide variety of taxa. Therefore, advances in the study of the origins of sociality may require further investigation of parental care evolution in solitary ancestors of today’s social species.
    View Document Abstract
  • Journal Article

    Chimpanzees monopolize and children take turns in a limited resource problem 

    Knofe, Hagen; Engelmann, Jan; Tomasello, Michael; Herrmann, Esther
    Scientific Reports 2019; 9(1): Art. 7597
    Competition over scarce resources is common across the animal kingdom. Here we investigate the strategies of chimpanzees and children in a limited resource problem. Both species were presented with a tug-of-war apparatus in which each individual in a dyad received a tool to access a reward, but tools could not be used simultaneously. We assessed the equality of tool use as well as the frequency of turn taking. Both species managed to overcome this conflict of interest but used different strategies to do so. While there was substantial variation in chimpanzee behaviour, monopolization was the common course of action: tool use was asymmetric with individual chimpanzees monopolizing the resource. In children, turn-taking emerged as the dominant strategy: tool use was symmetric and children alternated access to the tool at a high rate. These results suggest that while both species possess strategies for solving limited resource problems, humans might have evolved species unique motivations and socio-cognitive skills for dealing with such conflicts of interest.
    View Document Abstract
  • Journal Article

    Formation and development of the male copulatory organ in the spider Parasteatoda tepidariorum involves a metamorphosis-like process 

    Quade, Felix Simon Christian; Holtzheimer, Jana; Frohn, Jasper; Töpperwien, Mareike; Salditt, Tim; Prpic, Nikola-Michael
    Scientific Reports 2019; 9(1): Art. 6945
    Spiders have evolved a unique male copulatory organ, the pedipalp bulb. The morphology of the bulb is species specific and plays an important role in species recognition and prezygotic reproductive isolation. Despite its importance for spider biodiversity, the mechanisms that control bulb development are virtually unknown. We have used confocal laser scanning microscopy (CLSM) and diffusible iodine-based contrast-enhanced micro computed tomography (dice-µCT) to study bulb development in the spider Parasteatoda tepidariorum. These imaging technologies enabled us to study bulb development in situ, without the use of destructive procedures for the first time. We show here that the inflated pedipalp tip in the subadult stage is filled with haemolymph that rapidly coagulates. Coagulation indicates histolytic processes that disintegrate tibia and tarsus, similar to histolytic processes during metamorphosis in holometabolous insects. The coagulated material contains cell inclusions that likely represent the cell source for the re-establishment of tarsus and tibia after histolysis, comparable to the histoblasts in insect metamorphosis. The shape of the coagulated mass prefigures the shape of the adult tarsus (cymbium) like a blueprint for the histoblasts. This suggests a unique role for controlled coagulation after histolysis in the metamorphosis-like morphogenesis of the male pedipalp.
    View Document Abstract
  • Journal Article

    formr: A study framework allowing for automated feedback generation and complex longitudinal experience-sampling studies using R 

    Arslan, Ruben C.; Walther, Matthias P.; Tata, Cyril S.
    Behavior Research Methods p.1-12
    Open-source software improves the reproducibility of scientific research. Because existing open-source tools often do not offer dedicated support for longitudinal data collection on phones and computers, we built formr, a study framework that enables researchers to conduct both simple surveys and more intricate studies. With automated email and text message reminders that can be sent according to any schedule, longitudinal and experience-sampling studies become easy to implement. By integrating a web-based application programming interface for the statistical programming language R via OpenCPU, formr allows researchers to use a familiar programming language to enable complex features. These can range from adaptive testing, to graphical and interactive feedback, to integration with non-survey data sources such as self-trackers or online social network data. Here we showcase three studies created in formr: a study of couples with dyadic feedback; a longitudinal study over months, which included social networks and peer and partner ratings; and a diary study with daily invitations sent out by text message and email and extensive feedback on intraindividual patterns.
    View Document Abstract
  • Journal Article

    Measuring approach–avoidance tendencies towards food with touchscreen-based arm movements 

    Meule, Adrian; Richard, Anna; Lender, Anja; Dinic, Radomir; Brockmeyer, Timo; Rinck, Mike; Blechert, Jens
    Psychological Research p.1-12
    Most tasks for measuring automatic approach-avoidance tendencies do not resemble naturalistic approach-avoidance behaviors. Therefore, we developed a paradigm for the assessment of approach-avoidance tendencies towards palatable food, which is based on arm and hand movements on a touchscreen, thereby mimicking real-life grasping or warding movements. In Study 1 (n = 85), an approach bias towards chocolate-containing foods was found when participants reached towards the stimuli, but not when these stimuli had to be moved on the touchscreen. This approach bias towards food observed in grab movements was replicated in Study 2 (n = 60) and Study 3 (n = 94). Adding task features to disambiguate distance change through either corresponding image zooming (Study 2) or emphasized self-reference (Study 3) did not moderate this effect. Associations between approach bias scores and trait and state chocolate craving were inconsistent across studies. Future studies need to examine whether touchscreen-based approach-avoidance tasks reveal biases towards other stimuli in the appetitive or aversive valence domain and relate to relevant interindividual difference variables.
    View Document Abstract
  • Journal Article

    Stimulus dependencies of an illusory motion: Investigations of the Motion Bridging Effect 

    Stein, Maximilian; Fendrich, Robert; Mattler, Uwe
    Journal of Vision 2019; 19(5) p.1-23: Art. 13
    The Motion Bridging Effect (MBE) is an illusion in which a motion that is not consciously visible generates a visible motion aftereffect that is predominantly in the same direction as the adapter motion. In the initial study of the MBE (Mattler & Fendrich, 2010), a ring of 16 points was rotated at angular velocities as high as 2250°/s so that observers saw only an unbroken outline circle and performed at chance when asked to report the ring's rotation direction. However, when the rotating ring was replaced by a veridically stationary ring of 16 points, the stationary ring appeared to visibly spin to a halt, principally in the same direction as the initial ring's rotation. Here we continue to investigate the stimulus dependencies of the MBE. We find the MBE, measured by the correspondence between the direction of the invisible rotation of the spinning ring and perceived rotation of the stationary ring, increases as the number of points used to construct the rings decreases and grows stronger as the diameter of the rings get larger. We consider the potential contributions of temporal frequency, retinal eccentricity, luminance levels, and the separation between the points forming the rings as mediators of these effects. Data is discussed with regard to the detection of real movement and apparent motion. We conclude that the detection of the rapid rotation of the spinning ring is likely to be modulated by temporal frequency of luminance changes along the ring perimeter while the point-distance may modulate an apparent motion produced by the transition from the perceptually unbroken spinning ring to the point-defined stationary ring.
    View Document Abstract
  • Journal Article

    Action priming suppression by forward masks 

    Becker, Nicolas; Mattler, Uwe
    Journal of Vision 2019; 19(5) p.1-16: Art. 1085
    Visual stimuli may produce strong and reliable effects on subsequent actions irrespective of their visibility. This dissociation between action priming and conscious perception of the stimuli suggests two ways of processing of visual stimuli. One way of processing leads to the emergence of conscious visual perception, and another way leads to action priming effects. Here we examined the influence of forward masks that precede the prime on processing for action. In three experiments, we found that forward masks can suppress and even abolish priming effects. Suppression was larger with strong rather than weak forward masks and with short rather than long prime durations. Similar suppression effects occurred with surrounding paracontrast masks and with overlapping pattern masks. Our findings emphasize that processing for action depends crucially on preceding stimuli suggesting that action priming may depend on the initial part of the response to the prime. Results indicate that the use of forward masks to reduce prime visibility may also reduce action priming and potentially other priming effects.
    View Document Abstract
  • Journal Article

    The impact of powerful authorities and trustful taxpayers: evidence for the extended slippery slope framework from Austria, Finland, and Hungary 

    Gangl, Katharina; Hofmann, Eva; Hartl, Barbara; Berkics, Mihály
    Policy Studies p.1-14
    Tax authorities utilize a wide range of instruments to motivate honest taxpaying ranging from strict audits to fair procedures or personalized support, differing from country to country. However, little is known about how these different instruments and taxpayers’ trust influence the generation of interaction climates between tax authorities and taxpayers, motivations to comply, and particularly, tax compliance. The present research examines the extended slippery slope framework (eSSF), which distinguishes tax authorities’ instruments into different qualities of power of authority (coercive and legitimate) and trust in authorities (reason-based and implicit), to shed light on the effect of differences between power and trust. We test eSSF assumptions with survey data from taxpayers from three culturally different countries (N = 700) who also vary concerning their perceptions of power, trust, interaction climates, and tax motivations. Results support assumptions of the eSSF. Across all countries, the relation of coercive power and tax compliance was mediated by implicit trust. The connection from legitimate power to tax compliance is partially mediated by reason-based trust. The relationship between implicit trust and tax compliance is mediated by a confidence climate and committed cooperation. Theoretical and practical implications are discussed.
    View Document Abstract

View more