Relational and morphophonological processing within the left fronto-temporal language
network
Anastasia Klimovich-Smith, Mirjana Bozic, William Marslen-Wilson
University of Cambridge
ak798@cam.ac.uk
Complex syntax and inflectional morphology produce similar activations in the left frontotemporal language network. Inflectionally complex forms trigger both morphophonological
parsing, which decomposes these forms into stems and affixes, and grammatical (relational)
processing driven by the grammatical functions of these affixes. Using fMRI, we can separate
the contributions of each type of process to left hemisphere activation by exploiting the rich
inflectional morphology of Russian. We compared complex inflected forms (e.g., the participle
‘chitaushie’), that require extensive morphophonological parsing, with phrases (e.g., the
participle phrase ‘te kto chitaut’) that contain the same relational information but which make
arguably weaker parsing demands. Univariate analyses of data from 20 participants showed that
both conditions equally activated left inferior frontal (LIFG) regions (BA 44, 45) together with
bilateral left and right temporal lobes, suggesting that no additional processing load was
associated with inflectional parsing requirements.
To unpack these results further, we used a multivariate RSA Searchlight technique, designed to
pick up qualitative differences in types of neural process elicited by different conditions. Within
the left fronto-temporal network we identified a set of areas (posterior and mid STG, left
temporo-parietal junction) that responded to the relational (grammatical) properties of the
stimuli. A different set of areas, with LIFG and bilateral temporal involvement, responded to the
morphophonological properties of the stimuli. These results, though still preliminary, suggest
that multivariate analysis of fMRI makes it possible to distinguish the different neural
expressions of contrasting functional roles within the left fronto-temporal network.
Keywords: syntax, inflection, fMRI, multivariate analysis
243 words