Oscillatory dynamics related to the Unagreement pattern in Spanish

► Oscillatory brain activity help to understand the neural underpinnings of agreement processes. ► Beta-low band reflect difficulties in syntactic unification in the Unagreement sentences. ► Alpha band reflect larger attentional and/or semantic processing demands for Unagreement. ► Theta band reflect that working memory integration of morphosyntactic features may be inhibited. ► Synchronization in beta band reflects the successful resolution of an agreement dependency.