TMS-Lab

Inhibition of the occipital face area modulates the electrophysiological signals of face familiarity: a combined cTBS-EEG study

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Charlotta Eick, Géza Gergely Ambrus,  Gyula Kovács
Cortex, Volume 141, August 2021, Pages 156-167

We used an offline, inhibitory continuous theta-burst stimulation (cTBS) protocol over the right OFA and the vertex as control site. Electroencephalographic (EEG) recording of event-related potentials (ERPs), elicited by visually presented familiar (famous) and unfamiliar faces was performed before and after stimulation. We observed a difference in ERPs for famous and unfamiliar faces in a time-window corresponding to the N250 component. Importantly, this difference was significantly increased by cTBS of the right OFA, suggesting its causal role in the differential processing of familiar and unfamiliar faces. The enhancement occurred focally, at electrodes close to the right hemispheric cTBS site, as well as over similar occipito-temporal sites of the contralateral hemisphere.

Géza Gergely Ambrus, Karolina Janacsek, Anna B. C. Trimborn, Gyula Kovács, Dezső Németh
Journal of Memory and Language, Volume 114, October 2020, 104144

The aim of the present study was to test the causal role of the dorsolateral prefrontal cortex (DLPFC) in implicit statistical learning of non-adjacent dependencies. We applied 1 Hz inhibitory transcranial magnetic stimulation or sham stimulation over both the left and right DLPFC intermittently during the learning. The DLPFC stimulation group showed better performance compared to the sham group after a 24-hour consolidation period. This finding suggests that the disruption of DLPFC induced qualitative changes in picking up non-adjacent statistical regularities during learning, which support the less-is-more hypothesis.

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Géza Gergely Ambrus, Catarina Amado, Laura Krohn, Gyula Kovács
Brain Structure and Function  Volume 224, Issue 1, pp 149–157, January 2019

To test if the OFA is sensitive to sematic information we implemented a cross-domain, name-face priming paradigm in a  state-dependent TMS study. Volunteers performed a familiarity decision task for target face images preceded by primes that were congruent, incongruent or the character string 'XXXXX'. TMS of the rOFA reduced the behavioral disadvantage of incongruent primes, while performance in the congruent and no prime conditions remained intact. This suggests the existence of neural populations in the rOFA that take part in the semantic processing of identity, probably in interplay with other nodes in the extended face network.

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Géza Gergely Ambrus, Maria Dotzer, Stefan R. Schweinberger, Gyula Kovács
Brain Structure and Function
Volume 222, Issue 9, December 2017, Pages 4271-4282

We combined a priming paradigm with TMS, using photographs of familiar and unfamiliar faces in a design that was aimed at assessing image-specific and image-independent representations in the rOFA. Our study is the first to demonstrate image-independent identity processing in the rOFA in healthy human participants. In addition, our study also demonstrates the potential of state-dependent brain stimulation techniques as an effective tool to gain a finer-grained understanding of cortical functions where more conventional virtual lesion techniques are insufficient.

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Géza Gergely Ambrus, Fabienne Windel, A. Mike Burton, Gyula Kovács
NeuroImage Volume 148, 1 March 2017, Pages 212–218

We have shown that disrupting the functions of the rOFA by TMS during a training phase abolishes identity information acquisition, thereby, for the first time we have demonstrated that the rOFA plays a causal role in the formation of image-independent representations for facial identities. These findings indicate that the rOFA is involved in identity learning from multiple instances and in the creation of identity-dependent memory traces.

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