Existential problems: On the processing of irrealis in simultaneous interpreting

Clauses containing elements of irrealis seem to cause problems in simultaneous interpretation, primarily round negation and epistemic modality. An experiment was conducted to test a) if this area produced more mistakes than straightforward statements of fact, b) if increased top-down processing made any difference, and c) if so, if this applied more particularly to professional interpreters or to less experienced students.
From eight protocols obtained it appeared that the four professionals made all their mistakes under the scope of irrealis; better knowledge of the text was made available through immediate repetition of the same task, but this did not bring down the number of mistakes. The four students in the same task corrected mistakes more frequently than the professionals.
It is concluded that all irrealis is cognitively cumbersome and therefore vulnerable in interpretation if there is a choice of scopes; however it is primarily epistemic modality elements that are in danger of not registering as carriers of salient meaning, thereby giving rise to misleading inferences.