Contradiction in universal and particular reasoning

Research output: Contribution to journalArticle


  • MT Medaglia
  • F Tecchio
  • S Seri
  • G Di Lorenzo
  • PM Rossini

Colleges, School and Institutes


A wide range of essential reasoning tasks rely on contradiction identification, a cornerstone of human rationality, communication and debate founded on the inversion of the logical operators "Every" and "Some." A high-density electroencephalographic (EEG) Study was performed in 11. normal young adults. The cerebral network involved in the identification of contradiction included the orbito-frontal and anterior-cingulate cortices and the temporo-polar cortices. The event-related dynamic of this network showed an early negative deflection lasting 500 ms after sentence presentation. This was followed by a positive deflection lasting 1.5 s, which was different for the two logical operators. A lesser degree of network activation (either in neuron number or their level of phase locking or both) occurred while processing statements with "Some," suggesting that this was a relatively simpler scenario with one example to be figured out, instead of the many examples or the absence of a counterexample searched for while processing statements with "Every." A self-generated reward system seemed to resonate the recruited circuitry when the contradictory task is Successfully completed. Hum Brain Mapp 30:4187-4197, 2009. (C) 2009 Wiley-Liss, Inc.


Original languageEnglish
Pages (from-to)4187-4197
Number of pages11
JournalHuman Brain Mapping
Issue number12
Publication statusPublished - 1 Dec 2009


  • logical operators, contradictory reasoning, independent component analysis (ICA), electroencephalography (EEG)