Repetitive transcranial magnetic stimulation modulates action naming over the left but not right inferior frontal gyrus.

fMRI language mapping studies report right-hemispheric contribution to language in healthy individuals. However, it remains unclear whether these right-hemispheric patterns of activity are critical for language, which is highly relevant for clinical preoperative language mapping. The available findings are controversial. In this study, we first measured individual patterns of language lateralization with an fMRI language localizer in healthy participants with different handedness (N = 31). Then, the same participants received rTMS over the individual coordinates of peak fMRI-based activation in the left and right inferior frontal gyri. During rTMS, participants performed a picture naming task. It included both objects and actions to test whether naming of nouns and verbs would be equally modulated by rTMS. Stimulation of the left inferior frontal gyrus resulted in accuracy facilitation of verb production regardless of individual language lateralization. No modulation of object naming was found at any stimulation site in terms of accuracy nor reaction time. This study causally confirmed the critical contribution of the left, but not the right hemisphere to verb production regardless of the language lateralization patterns observed with fMRI. Also, the results stress that action rather than object naming is the task of choice for mapping language in the frontal lobe.

Effects of phonological features on reading-aloud latencies: A cross-linguistic comparison.

Most psycholinguistic models of reading aloud and of speech production do not include linguistic representations more fine-grained than the phoneme, despite the fact that the available empirical evidence suggests that feature-level representations are activated during reading aloud and speech production. In a series of masked-priming experiments that employed the reading aloud task, we investigated effects of phonological features, such as voicing, place of articulation, and constriction location, on response latencies in English and Russian. We propose a hypothesis that predicts greater likelihood of obtaining feature-priming effects when the onsets of the prime and the target share more feature values than when they share fewer. We found that prime-target pairs whose onsets differed only in voicing (e.g., /p/-/b/) primed each other consistently in Russian, as has already been found in English. Response latencies for prime-target pairs whose onsets differed in place of articulation (e.g., /b/-/d/) patterned differently in English and Russian. Prime-target pairs whose onsets differed in constriction location only (e.g., /s/ and /ʂ/) did not yield a priming effect in Russian. We conclude that feature-priming effects are modulated not only by the phonological similarity between the onsets of primes and targets but also by the dynamics of feature activation and by the language-specific relationship between orthography and phonology. Our findings suggest that feature-level representations need to be included in models of reading aloud and of speech production if we are to move forward with theorizing in these research domains. (PsycInfo Database Record (c) 2022 APA, all rights reserved).