model, information in the unattended stream is not processed all the way into working memory, as Treisman's model would imply. Instead, information on the unattended stream is passed through a secondary filter after pattern recognition. If the unattended information is recognized and deemed unimportant by the secondary filter, it is prevented from entering working memory. In this way, only immediately important information from the unattended channel can come to awareness. Kahneman Daniel Kahneman also proposed a model of attention, but it differs from previous models in that he describes attention not in terms of selection, but in terms of capacity. For Kahneman, attention is a resource to be distributed among various stimuli, a proposition which has received some support. This model describes not when attention is focused, but how it is focused. According to Kahneman, attention is generally determined by arousal; a general state of physiological activity. The Yerkes-Dodson law predicts that arousal will be optimal at moderate levels - performance will be poor when one is over- or under-aroused. Of particular relevance, Narayan et al. discovered a sharp decline in the ability to discriminate between auditory stimuli when background noises were too numerous and complex - this is evidence of the negative effect of overarousal on attention. Thus, arousal determines our available capacity for attention. Then, an allocation policy acts to distribute our available attention among a variety of possible activities. Those deemed most important by the allocation policy will have the most attention given to them. The allocation policy is affected by enduring dispositions (automatic influences on attention) and momentary intentions (a conscious decision to attend to something). Momentary intentions requiring a focused direction of attention rely on substantially more attention resources than enduring dispositions. Additionally, there is an ongoing evaluation of the particular demands of certain activities on attention capacity. That is to say, activities that are particularly taxing on attention resources will lower attention capacity and will influence the allocation policy - in this case, if an activity is too draining on capacity, the allocation policy will likely cease directing resources to it and instead focus on less taxing tasks. Kahneman's model explains the cocktail party phenomenon in that momentary intentions might allow one to expressly focus on a particular auditory stimulus, but that enduring dispositions (which can include new events, and perhaps words of particular semantic importance) can capture our attention. It is important to