Poster C69, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
The influence of the cortical thickness of Planum Temporale on word tone processing in Swedish native speakers
Andrea Schremm1, Mikael Novén1, Merle Horne1, Mikael Roll1; 1Lund University
In Swedish, tones on word stems function as predictive cues to upcoming grammatical suffixes. Invalid matching of these linguistic tonal cues to suffixes affects native speakers of Swedish in their linguistic processing (Roll et al., 2010). Planum Temporale (PT) has previously been found to be involved in processing Thai (Xu et al., 2006) and Swedish tones (Roll et al., 2015), and in phonological processing generally (Graves et al., 2008). The present study investigated the relationship between cortical thickness (CT) of PT and the processing of tones in suffixed word stimuli by Swedish native speakers using magnetic resonance imaging (MRI). The average CT of PT was extracted from each participant using the Freesurfer analysis suite on T1-weighted image volumes. The results show that individual participants’ response time advantage for valid over invalidly cued suffixes positively correlated with CT in the left PT which suggests that the CT of left PT affects native linguistic tone processing. Interestingly, comparing responses to real word (stem + suffix) stimuli with comparable pseudoword test stimuli (pseudostem + suffix), similar results for CT are found, albeit not in PT, but instead in Broadmann Area 44. This might suggest that suffixed pseudowords cannot be processed in the same way as existing inflected words. PT has been proposed to play a role in lexical phonological access (Graves et al., 2007, 2008). Thus, the present results might indicate that the CT of the left PT facilitates accessing stored whole-word phonological representations of inflected word forms, not available for pseudowords.
Topic Area: LANGUAGE: Other