Sentence comprehension in second language (L2) learners was examined using event-related brain potentials (ERPs). Native Japanese speakers who had learned German as a second language after puberty listened to German sentences which were either correct, semantically incorrect, syntactically incorrect or both semantically and syntactically incorrect. Brain responses were registered while participants listened to these sentences. Grammaticality judgments required after each sentence revealed that their overall performance was not perfect but clearly above chance. When comparing the L2-learners' brain responses to those of native listeners, a variety of differences were observed. Whereas semantically incorrect sentences showed an ERP pattern similar to that of native listeners (a centro-parietal N400-effect), correct sentences elicited a greater positivity in L2-learners than in native listeners, possibly in reflection of greater difficulties in syntactic integration. For sentences containing a phrase structure violation, L2-learners did not show significant modulations of the syntax-related ERP components usually seen in native listeners (i.e. the early anterior negativity and the P600). Furthermore, sentences containing a pure semantic or a combined syntactic and semantic violation elicited a late right anterior-central negativity, an effect which has not been observed for native language processing. The topography of the effect may suggest that these additional processes are based on conceptual-semantic rather than on lexical-semantic aspects.

Cochlear implantation constitutes a successful therapy of inner ear deafness, with the majority of patients showing good outcomes. There is, however, still some unexplained variability in outcomes with a number of cochlear-implant (CI) users, showing major limitations in speech comprehension. The current study used a multimodal diagnostic approach combining single-photon emission computed tomography (SPECT) and electroencephalography (EEG) to examine the mechanisms underlying speech processing in postlingually deafened CI users (N = 21). In one session, the participants performed a speech discrimination task, during which a 96channel EEG was recorded and the perfusions marker 99m Tc-HMPAO was injected intravenously. The SPECT scan was acquired 1.5 h after injection to measure the cortical activity during the speech task. The second session included a SPECT scan after injection without stimulation at rest. Analysis of EEG and SPECT data showed N400 and P600 event-related potentials (ERPs) particularly evoked by semantic violations in the sentences, and enhanced perfusion in a temporo-frontal network during task compared to rest, involving the auditory cortex bilaterally and Broca's area. Moreover, higher performance in testing for word recognition and verbal intelligence strongly correlated to the activation in this network during the speech task. However, comparing CI users with lower and higher speech intelligibility [median split with cutoff + 7.6 dB signalto-noise ratio (SNR) in the Göttinger sentence test] revealed for CI users with higher performance additional activations of parietal and occipital regions and for those with lower performance stronger activation of superior frontal areas. Furthermore, SPECT activity was tightly coupled with EEG and cognitive abilities, as indicated by correlations between (1) cortical activation and the amplitudes in EEG, N400 (temporal and occipital

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