title: Feedback modulates the temporal scale-free dynamics of brain electrical activity in a hypothesis testing task.
abstract: We used the electroencephalogram (EEG) to investigate whether positive and negative performance feedbacks exert different long-lasting modulations of electrical activity in a reasoning task. Nine college students serially tested hypotheses concerning a hidden rule by judging its presence or absence in triplets of digits, and revised them on the basis of an exogenous performance feedback. The scaling properties of the transition period between feedback and triplet presentation were investigated with detrended fluctuation analysis (DFA). DFA showed temporal scale-free dynamics of EEG activity in both feedback conditions for time scales larger than 150 ms. Furthermore, DFA revealed that negative feedback elicits significantly higher scaling exponents than positive feedback. This effect covers a wide network comprising parieto-occipital and left frontal regions. We thus showed that specific task demands can modify the temporal scale-free dynamics of the ongoing brain activity. Putative neural correlates of these long-lasting feedback-specific modulations are proposed.
authors.affiliation: Laboratoire de Neurophysique et Physiologie, Université Paris Descartes, CNRS UMR 8119, and Cognitive Neuroimaging Unit, INSERM U562, Service Hospitalier Frederic Joliot, CEA/DRM/DSV, Orsay, France. marco.buiatti@unitn.it
authors.forename: M
authors.initials: M
authors.lastname: Buiatti
authors.forename: D
authors.initials: D
authors.lastname: Papo
authors.forename: P-M
authors.initials: PM
authors.lastname: Baudonnière
authors.forename: C
authors.initials: C
authors.lastname: van Vreeswijk
mesh_terms: D000328:Adult; D000465:Algorithms; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D004594:Electrophysiology; D005133:Eye Movements / Q000502:physiology; D005246:Feedback / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology