@article{KopfDreslerReichertsetal.2013,
  author    = {Kopf, Juliane and Dresler, Thomas and Reicherts, Philipp and Herrmann, Martin J. and Reif, Andreas},
  title     = {The Effect of Emotional Content on Brain Activation and the Late Positive Potential in a Word n-back Task},
  series = {PLoS ONE},
  journal   = {PLoS ONE},
  doi       = {10.1371/journal.pone.0075598},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96687},
  year      = {2013},
  abstract  = {Introduction There is mounting evidence for the influence of emotional content on working memory performance. This is particularly important in light of the emotion processing that needs to take place when emotional content interferes with executive functions. In this study, we used emotional words of different valence but with similar arousal levels in an n-back task. Methods We examined the effects on activation in the prefrontal cortex by means of functional near-infrared spectroscopy (fNIRS) and on the late positive potential (LPP). FNIRS and LPP data were examined in 30 healthy subjects. Results Behavioral results show an influence of valence on the error rate depending on the difficulty of the task: more errors were made when the valence was negative and the task difficult. Brain activation was dependent both on the difficulty of the task and on the valence: negative valence of a word diminished the increase in activation, whereas positive valence did not influence the increase in activation, while difficulty levels increased. The LPP also differentiated between the different valences, and in addition was influenced by the task difficulty, the more difficult the task, the less differentiation could be observed. Conclusions Summarized, this study shows the influence of valence on a verbal working memory task. When a word contained a negative valence, the emotional content seemed to take precedence in contrast to words containing a positive valence. Working memory and emotion processing sites seemed to overlap and compete for resources even when words are carriers of the emotional content.},
  language  = {en}
}
@article{StreinzerBrockmannNagarajaetal.2013,
  author    = {Streinzer, Martin and Brockmann, Axel and Nagaraja, Narayanappa and Spaethe, Johannes},
  title     = {Sex and Caste-Specific Variation in Compound Eye Morphology of Five Honeybee Species},
  series = {PLoS ONE},
  journal   = {PLoS ONE},
  doi       = {10.1371/journal.pone.0057702},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96412},
  year      = {2013},
  abstract  = {Ranging from dwarfs to giants, the species of honeybees show remarkable differences in body size that have placed evolutionary constrains on the size of sensory organs and the brain. Colonies comprise three adult phenotypes, drones and two female castes, the reproductive queen and sterile workers. The phenotypes differ with respect to tasks and thus selection pressures which additionally constrain the shape of sensory systems. In a first step to explore the variability and interaction between species size-limitations and sex and caste-specific selection pressures in sensory and neural structures in honeybees, we compared eye size, ommatidia number and distribution of facet lens diameters in drones, queens and workers of five species (Apis andreniformis, A. florea, A. dorsata, A. mellifera, A. cerana). In these species, male and female eyes show a consistent sex-specific organization with respect to eye size and regional specialization of facet diameters. Drones possess distinctly enlarged eyes with large dorsal facets. Aside from these general patterns, we found signs of unique adaptations in eyes of A. florea and A. dorsata drones. In both species, drone eyes are disproportionately enlarged. In A. dorsata the increased eye size results from enlarged facets, a likely adaptation to crepuscular mating flights. In contrast, the relative enlargement of A. florea drone eyes results from an increase in ommatidia number, suggesting strong selection for high spatial resolution. Comparison of eye morphology and published mating flight times indicates a correlation between overall light sensitivity and species-specific mating flight times. The correlation suggests an important role of ambient light intensities in the regulation of species-specific mating flight times and the evolution of the visual system. Our study further deepens insights into visual adaptations within the genus Apis and opens up future perspectives for research to better understand the timing mechanisms and sensory physiology of mating related signals.},
  language  = {en}
}