n the unattended channel are salient enough to be brought up into primary attention. In other words, what is the attenuator and what is the attenuator control the basis of its function? Is the attenuator control itself controlled by an attenuator control controller? Treismans model therefor does not generate clear predictions owing to these and these and other issues related to the complexity and the ambiguity of its design. Another historical reason why Treismans model was unpopular was that it did not fit into the two-process model of memory.What seems to emerge from the research and theory discussed above is that some tasks require a greater attention than others do. This is why more than one thing can be done at the same time no one of them requires the full capacity of the attention system. But however skilled one is at a particular activity and therefore, however much attention can be devoted to some other concurrent task or tasks, surely there is some overall limit to how many things we can do simultaneously. Furthermore our capacity for dividing attention between tasks increases with practice on them. It may then be possible to develop our cognitive resources in more efficient ways once the principles are more clearly mapped out....
