In general, in LIS negative non-manual markers alone cannot negate a predicate or a whole sentence, they must be articulated with a manual negative marker or n-words (SYNTAX 1.5). However, in some central and southern varieties of LIS, we can find negation conveyed through the typical negative non-manual marker, namely headshaking (hs) alone, occurring with the sign for the verb.
hs
cata dogb bchasea
‘The dog does not chase the cat.’