Descriptive Analysis of Negation Cues in Biomedical Texts

AbstractIn this paper we present a description of negation cues and their scope in biomedical texts, based on the cues that occur in the BioScope corpus. We provide information about the morphological type of the cue, the characteristics of the scope in relation to the morpho-syntactic features of the cue and of the clause, and the ambiguity level of the cue by describing in which cases certain negation cues do not express negation. Additionally, we provide positive and negative examples per cue from the BioScope corpus. We show that the scope depends mostly on the part-of-speech of the cue and on the syntactic features of the clause. Although several studies have focused on processing negation in biomedical texts, we are not aware of publicly available resources that describe the scope of negation cues in detail. This paper aims at providing information for producing guidelines to annotate corpora with a negation layer, and for building resources that find the scope of negation cues automatically.