2003). Another stimulus that has become increasingly common in recent studies of speech perception is SCN (Mummery et al. 1999; Rodd et al. 2005; Coleman et al. 2007; Davis et al. 2007; Little et al. 2010; Peelle et al. 2010; Zheng et al. 2010; Travis et al. 2011). SCN

is created by calcitriol?hormone replacing all the spectral detail in the original speech stimulus with noise, while maintaining the envelope of the original waveform (Schroeder 1968). Paragraphs processed in this manner retain speech-like rhythmic onsets, but they do not control for other features Inhibitors,research,lifescience,medical of speech (e.g., pitch, phonemic structure). We contrasted listening to Hebrew speech against these two baselines, reversed speech and SCN. As far as we know, this is the first study to compare the efficacy of these commonly used baseline conditions in localizing the core language areas of individual subjects. In particular, we compared the efficacy of each of these baselines in removing responses in primary auditory cortex, and in retaining Inhibitors,research,lifescience,medical responses in known frontal and temporal speech processing regions. We further examined the temporal profile of the responses to different stimulus conditions within frontal and temporal regions. The results point to similar specificity of both baselines around primary auditory cortex, but a clear sensitivity advantage for the baseline of

SCN Inhibitors,research,lifescience,medical in inferior frontal cortex. Methods Subjects Participants were twelve healthy adult volunteers (seven females, mean age 27.3 ± 4). All were native speakers of Hebrew, without any history of hearing or language impairment. All participants Inhibitors,research,lifescience,medical were strongly right handed (70% or higher in the Edinburgh Handedness Inventory; Oldfield 1971). All of them gave informed consent to participate in the study, in accordance with a protocol approved by the Helsinki Committee of Tel Aviv Sourasky Medical Center. Stimuli Four short speech epochs were recorded in Hebrew by a female native speaker in a silent chamber. We used excerpts from children’s poems, suitable for a

wide age range including Inhibitors,research,lifescience,medical young children (Gefen 1974; Atlas 1977). The recorded segments, each lasting 15 sec, were digitized at a sampling rate of 44 kHz, and scaled to an average intensity of 75 dB. Using Carfilzomib Praat software (http://www.praat.org), we applied two forms of distortion to these paragraphs, resulting in two unintelligible baseline conditions. Both baselines largely preserve aspects of the spectral profile and amplitude envelope of the original speech stimulus, but their acoustic properties are markedly different. Example audio files are included as supplementary material. Signal correlated noise The SCN baseline was created by extracting the amplitude envelope of a speech segment and applying it to a pink noise segment, band-pass filtered to maintain the original frequency spectrum of speech.