@article{TelkemeyerRossiNierhausetal.2011,
  author    = {Telkemeyer, Silke and Rossi, Sonja and Nierhaus, Till and Steinbrink, Jens and Obrig, Hellmuth and Wartenburger, Isabell},
  title     = {Acoustic processing of temporally modulated sounds in infants evidence from a combined near-infrared spectroscopy and EEG study},
  series = {Frontiers in psychology},
  volume    = {2},
  journal   = {Frontiers in psychology},
  number    = {2},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-1078},
  doi       = {10.3389/fpsyg.2011.00062},
  pages     = {14},
  year      = {2011},
  abstract  = {Speech perception requires rapid extraction of the linguistic content from the acoustic signal. The ability to efficiently process rapid changes in auditory information is important for decoding speech and thereby crucial during language acquisition. Investigating functional networks of speech perception in infancy might elucidate neuronal ensembles supporting perceptual abilities that gate language acquisition. Interhemispheric specializations for language have been demonstrated in infants. How these asymmetries are shaped by basic temporal acoustic properties is under debate. We recently provided evidence that newborns process non-linguistic sounds sharing temporal features with language in a differential and lateralized fashion. The present study used the same material while measuring brain responses of 6 and 3 month old infants using simultaneous recordings of electroencephalography (EEG) and near-infrared spectroscopy (NIRS). NIRS reveals that the lateralization observed in newborns remains constant over the first months of life. While fast acoustic modulations elicit bilateral neuronal activations, slow modulations lead to right-lateralized responses. Additionally, auditory-evoked potentials and oscillatory EEG responses show differential responses for fast and slow modulations indicating a sensitivity for temporal acoustic variations. Oscillatory responses reveal an effect of development, that is, 6 but not 3 month old infants show stronger theta-band desynchronization for slowly modulated sounds. Whether this developmental effect is due to increasing fine-grained perception for spectrotemporal sounds in general remains speculative. Our findings support the notion that a more general specialization for acoustic properties can be considered the basis for lateralization of speech perception. The results show that concurrent assessment of vascular based imaging and electrophysiological responses have great potential in the research on language acquisition.},
  language  = {en}
}
@article{RossiJuergensonHanulikovaetal.2011,
  author    = {Rossi, Sonja and J{\"u}rgenson, Ina B. and Hanulikova, Adriana and Telkemeyer, Silke and Wartenburger, Isabell and Obrig, Hellmuth},
  title     = {Implicit processing of phonotactic cues evidence from electrophysiological and vascular responses},
  series = {Journal of cognitive neuroscience},
  volume    = {23},
  journal   = {Journal of cognitive neuroscience},
  number    = {7},
  publisher = {MIT Press},
  address   = {Cambridge},
  issn      = {0898-929X},
  doi       = {10.1162/jocn.2010.21547},
  pages     = {1752 -- 1764},
  year      = {2011},
  abstract  = {Spoken word recognition is achieved via competition between activated lexical candidates that match the incoming speech input. The competition is modulated by prelexical cues that are important for segmenting the auditory speech stream into linguistic units. One such prelexical cue that listeners rely on in spoken word recognition is phonotactics. Phonotactics defines possible combinations of phonemes within syllables or words in a given language. The present study aimed at investigating both temporal and topographical aspects of the neuronal correlates of phonotactic processing by simultaneously applying ERPs and functional near-infrared spectroscopy (fNIRS). Pseudowords, either phonotactically legal or illegal with respect to the participants' native language, were acoustically presented to passively listening adult native German speakers. ERPs showed a larger N400 effect for phonotactically legal compared to illegal pseudowords, suggesting stronger lexical activation mechanisms in phonotactically legal material. fNIRS revealed a left hemispheric network including fronto-temporal regions with greater response to phonotactically legal pseudowords than to illegal pseudowords. This confirms earlier hypotheses on a left hemispheric dominance of phonotactic processing most likely due to the fact that phonotactics is related to phonological processing and represents a segmental feature of language comprehension. These segmental linguistic properties of a stimulus are predominantly processed in the left hemisphere. Thus, our study provides first insights into temporal and topographical characteristics of phonotactic processing mechanisms in a passive listening task. Differential brain responses between known and unknown phonotactic rules thus supply evidence for an implicit use of phonotactic cues to guide lexical activation mechanisms.},
  language  = {en}
}