Abstract

Duringmonitoringofthediscourse,thedetectionoftherelevanceofincominglexicalinformationcouldbecriticalforitsincorporationtoupdatementalrepresentationsinmemory.Because,inthesesituations,therelevanceforlexicalinformationisdefinedbyabstractrulesthataremaintainedinmemory,acentralaspecttoelucidateishowanabstractlevelofknowledgemaintainedinmindmediatesthedetectionofthelower-levelsemanticinformation.Inthepresentstudy,weproposethatneuronaloscillationsparticipateinthedetectionofrelevantlexicalinformation,basedon“keptinmind”rulesderivingfrommoreabstractsemanticinformation.Wetestedourhypothesisusinganexperimentalparadigmthatrestrictedthedetectionofrelevancetoinferencesbasedonexplicitinformation,thuscontrollingforambiguitiesderivedfromimplicitaspects.Weusedacategorizationtask,inwhichthesemanticrelevancewaspreviouslydefinedbasedonthecongruencybetweenakeptinmindcategory(abstractknowledge),andthelexicalsemanticinformationpresented.Ourresultsshowthatduringthedetectionoftherelevantlexicalinformation,phasesynchronizationofneuronaloscillationsselectivelyincreasesindeltaandthetafrequencybandsduringtheintervalofsemanticanalysis.Theseincrementsoccurredirrespectiveofthesemanticcategorymaintainedinmemory,hadatemporalprofilespecificforeachsubject,andweremainlyinduced,astheyhadnoeffectontheevokedmeanglobalfieldpower.Also,recruitmentofanincreasednumberofpairsofelectrodeswasarobustobservationduringthedetectionofsemanticcontingentwords.Theseresultsareconsistentwiththenotionthatthedetectionofrelevantlexicalinformationbasedonaparticularsemanticrule,couldbemediatedbyincreasingtheglobalphasesynchronizationofneuronaloscillations,whichmaycontributetotherecruitmentofanextendednumberofcorticalregions.