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Feedback processing in hypothesis testing: A Laplacian ERP study


  • We thank Jean-Luc Peris for his computer science contribution and Sonia Allain and Dominique Reybaud for their technical assistance. The first author was supported by a grant from the French Ministry of Research and Education.

Address correspondence to: Dr. Laurence Carbonnell, Institut de Recherche Biomédicale des Armées, Antenne Toulon, Boulevard Sainte Anne, BP 20548, 83041 Toulon cedex 9, France. E-mail:


The capacity to adjust behavior and evaluate performance in a changing environment is highly related to taking feedback into account. Using feedback is, hence, crucial for different cognitive capacities. The present study focused on feedback processing in hypothetico-deductive reasoning. Electroencephalographical (EEG) activity was recorded while participants performed a hypothesis-testing task in which a feedback signal allowing the evaluation of performance was delivered at each trial. To ameliorate the spatial resolution of EEG signals, the surface Laplacian was estimated. Results showed three distinct patterns of activation. At central and centro-parietal electrodes, the activity was sensitive to participants' expectancies in a binary and a gradual way, respectively. At the parieto-occipital electrode, the activity was sensitive to the evaluation of performance itself: correct versus false. In conclusion, the processing of feedback signal depends on at least three separate processes.