In this situation, the language processing demands of an activity go beyond the language processing limits of the learner. It produces anxiety and stress, as well as affecting learning.
A teacher introduces learners to the passive by explaining all its uses in English in one class. The learners experience a cognitive overload due to the large amount of information and they are unable to understand, or integrate the new knowledge with what they already know.
In the classroom
It is important to be selective when asking learners to process information, particularly in terms of the amount of new information a task asks learners to cope with. If necessary, a large amount of information can be broken up into several classes.