title: Human Hippocampal Dynamics during Response Conflict.
abstract: Besides its relevance for declarative memory functions, hippocampal activation has been observed during disambiguation of uncertainty and conflict. Uncertainty and conflict may arise on various levels. On the perceptual level, the hippocampus has been associated with signaling of contextual deviance and disambiguation of similar items (i.e., pattern separation). Furthermore, conflicts can occur on the response level. Animal experiments showed a role of the hippocampus for inhibition of prevailing response tendencies and suppression of automatic stimulus-response mappings, potentially related to increased theta oscillations (3-8 Hz). In humans, a recent fMRI study demonstrated hippocampal involvement in approach-avoidance conflicts. However, the more general significance of hippocampal activity for dealing with response conflicts also on a cognitive level is still unknown. Here, we investigated the role of the hippocampus for response conflict in the Stroop task by combining intracranial electroencephalography (iEEG) recordings from the hippocampus of epilepsy patients with region of interest-based fMRI in healthy participants. Both methods revealed converging evidence that the hippocampus is recruited in a regionally specific manner during response conflict. Moreover, our iEEG data show that this activation depends on theta oscillations and is relevant for successful response conflict resolution.
authors: Department of Epileptology, University of Bonn, 53105 Bonn, Germany; Department of Neuropsychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, 44801 Bochum, Germany.
authors: Carina R
authors: CR
authors: Oehrn
authors: Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, 52074 Aachen, Germany; JARA-Translational Brain Medicine, 52074 Aachen, Germany.
authors: Conrad
authors: C
authors: Baumann
authors: Department of Epileptology, University of Bonn, 53105 Bonn, Germany.
authors: Juergen
authors: J
authors: Fell
authors: German Center for Neurodegenerative Diseases, 53175 Bonn, Germany.
authors: Hweeling
authors: H
authors: Lee
authors: Department of Psychosomatic Medicine and Psychotherapy, LWL-University Clinic Bochum, Ruhr University Bochum, 44791 Bochum, Germany.
authors: Henrik
authors: H
authors: Kessler
authors: Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, 52074 Aachen, Germany; JARA-Translational Brain Medicine, 52074 Aachen, Germany.
authors: Ute
authors: U
authors: Habel
authors: School of Psychology, University of Birmingham, Birmingham B15 2TT, UK.
authors: Simon
authors: S
authors: Hanslmayr
authors: Department of Epileptology, University of Bonn, 53105 Bonn, Germany; German Center for Neurodegenerative Diseases, 53175 Bonn, Germany; Department of Neuropsychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, 44801 Bochum, Germany. Electronic address: nikolai.axmacher@rub.de.
authors: Nikolai
authors: N
authors: Axmacher
mesh_terms: D000328:Adult; D003220:Conflict, Psychological; D000069280:Electrocorticography; D004827:Epilepsy / Q000503:physiopathology; D005260:Female; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011930:Reaction Time; D057190:Stroop Test