Publications of the TMS Laboratory


TMS of the occipital face area modulates cross-domain identity priming

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.


Géza Gergely Ambrus, Karolina Janacsek, Anna B. C. Trimborn, Gyula Kovács, Dezső Németh
bioRxiv  2017
The aim of the present study was to directly test the causal role of the prefrontal cortex (PFC) in striatum-mediated implicit statistical learning and its consolidation using brain stimulation. Healthy young adults were trained on a probabilistic sequence learning task. 1 Hz transcranial magnetic stimulation (TMS) or sham stimulation of both the left and right dorsolateral PFCs (DLPFC) was applied intermittently during the learning session to disrupt frontal lobe functions.
In line with the predictions of a competitive relationship between DLPFC functions and statistical learning, the DLPFC stimulation group showed better performance compared to the sham group after the 24-hour consolidation period. This finding suggests that the disruption of DLPFC induced qualitative changes in picking up statistical regularities during learning that became salient in behavior after a stabilization period.

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.

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. 

Mareike Grotheer, Géza Gergely Ambrus, Gyula Kovács
NeuroImage   Volume 132, 15 May 2016, Pages 314-319
Double pulse TMS targeted at the right NFA significantly impaired the detection of briefly presented and masked Arabic numbers in comparison to vertex stimulation. This suggests the NFA to be necessary for fluent number processing. Surprisingly, TMS of the NFA also impaired the detection of Roman letters. On the other hand, stimulation of the lateral occipital complex (LO) had neither an effect on the detection of numbers nor on letters. Our results show forthe first time, that the NFA is causally involved in the early visual processing of numbers as well as of letters.