More interesting stuff has recently been published in JoCN by William Graves and company. Previous work by this group, highlighted here on Talking Brains, found that a regions of the pSTG showed frequency effects in naming. Now this group has used repetition priming with pseudowords to identify regions involved in lexical phonological access. Check it out:
The Left Posterior Superior Temporal Gyrus Participates Specifically in Accessing Lexical Phonology
William W. Graves1, Thomas J. Grabowski2, Sonya Mehta2 and Prahlad Gupta2
1 Medical College of Wisconsin, 2 University of Iowa
Reprint requests should be sent to William W. Graves, Medical College of Wisconsin, Neuro Lab, MEB 4550, 8701 Watertown Plank Road, Milwaukee, WI 53226, or via e-mail: firstname.lastname@example.org.
Impairments in phonological processing have been associated with damage to the region of the left posterior superior temporal gyrus (pSTG), but the extent to which this area supports phonological processing, independent of semantic processing, is less clear. We used repetition priming and neural repetition suppression during functional magnetic resonance imaging (fMRI) in an auditory pseudoword repetition task as a semantics-free model of lexical (whole-word) phonological access. Across six repetitions, we observed repetition priming in terms of decreased reaction time and repetition suppression in terms of reduced neural activity. An additional analysis aimed at sublexical phonology did not show significant effects in the areas where repetition suppression was observed. To test if these areas were relevant to real word production, we performed a conjunction analysis with data from a separate fMRI experiment which manipulated word frequency (a putative index of lexical phonological access) in picture naming. The left pSTG demonstrated significant effects independently in both experiments, suggesting that this area participates specifically in accessing lexical phonology.