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.

Attention capture by brief abrupt-onset cues in deaf individuals.

Auditory loss in deaf individuals has been associated with an enhancement in the visual modality. Visual attention is one domain where such plasticity-induced changes have been observed, although which specific attentional mechanisms are improved is still not clear. Using a modified spatial cueing paradigm, we examined attention capture in deaf and normal-hearing participants. Brief abrupt-onset cues were presented for 16 ms either in attended or ignored locations. The to-be-attended locations for each trial were indicated by a horizontal or a vertical bar at the centre of the screen. These were presented either in vertical- or horizontal-only blocks or mixed together. We observed greater negative cueing effects in the NH group compared to deaf. Additionally, people with deafness showed greater capture by cues at ignored locations in the slower responses. These findings shed further light on orienting mechanisms in deaf and help in understanding the specificity of the differences in visual processing between deaf and normal-hearing individuals.