title: Selective perturbation of cognitive conflict in the human brain-A combined fMRI and rTMS study.
abstract: We investigated if single and double conflicts are processed separately in different brain regions and if they are differentially vulnerable to TMS perturbation. Fifteen human volunteers performed a single (Flanker or Simon) conflict task or a double (Flanker and Simon) conflict task in a combined functional Magnetic Resonance Imaging (fMRI) and Transcranial Magnetic Stimulation (TMS) study. The fMRI approach aimed at localizing brain regions involved in interference resolution induced by single Flanker (stimulus-stimulus, S-S) and Simon (stimulus-response, S-R) conflicts as well as regions involved in the double conflict condition. The data revealed a distinct activation in the right intraparietal sulcus (IPS) for Flanker interference and in the right middle frontal gyrus (MFG) for the double interference condition. The causal functional role of these brain regions was then examined in the same volunteers by using offline TMS over right IPS and right MFG. TMS perturbation of the right IPS increased the Flanker effect, but had no effect in the Simon or double conflict condition. In contrast, perturbation of the right MFG had no effect on any of the conflict types. These findings suggest a causal role of the right IPS in the processing of the single conflict of Flanker (stimulus-stimulus) interference.
authors.affiliation: Department of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.|School of Humanities and Social Sciences, Jacobs University Bremen, Bremen, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Peschke
authors.affiliation: Center for Advanced Imaging, Department of Neuropsychology and Behavioral Neurobiology, Bremen University, Bremen, Germany.|Institute of Cognitive Neuroscience, University College London, London, United Kingdom.
authors.forename: Raphael
authors.initials: R
authors.lastname: Köster
authors.affiliation: Center for Advanced Imaging, Department of Neuropsychology and Behavioral Neurobiology, Bremen University, Bremen, Germany.
authors.forename: Margarethe
authors.initials: M
authors.lastname: Korsch
authors.affiliation: Center for Advanced Imaging, Department of Neuropsychology and Behavioral Neurobiology, Bremen University, Bremen, Germany.|Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland.
authors.forename: Sascha
authors.initials: S
authors.lastname: Frühholz
authors.affiliation: Biological Psychology Lab, Department of Psychology, European Medical School, Carl von Ossietzky University Oldenburg, Oldenburg, Germany.
authors.forename: Christiane M
authors.initials: CM
authors.lastname: Thiel
authors.affiliation: Center for Advanced Imaging, Department of Neuropsychology and Behavioral Neurobiology, Bremen University, Bremen, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Herrmann
authors.affiliation: Department of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.|Department of Health Sciences, Boston University, Boston, MA, USA.
authors.forename: Claus C
authors.initials: CC
authors.lastname: Hilgetag
mesh_terms: D000328:Adult; D003071:Cognition / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010296:Parietal Lobe / Q000000981:diagnostic imaging / Q000502:physiology; D050781:Transcranial Magnetic Stimulation