Found:

Negative polarity item

SEMANTICS: expression which needs to be in the scope of a negation (or more generally: a monotone decreasing element). EXAMPLE: if the sentence I don't need anybody has the negation taken out, we don't get *I need anybody but I need somebody. Therefore, the part any is taken to be a negative polarity item. Because the negation of I need somebody is not I don't need somebody, the part some is considered to be a positive polarity item: it resists the presence of a negation (or its equivalent).

LIT.	Ladusaw, W.A. (1980)