The Biased Competition Model suggests that stimuli matching the contents of working memory increase the likelihood that memorymatching items will be attended. According to this account, the representations in working memory create an involuntary capture of attention toward memory-matching items in the visual field. This influential assumption proposed by the biased competition model has been explored in a number of studies, showing that the contents of working memory exert an automatic bias in favor of memory matching items. These studies showed that active maintenance of objects in working memory automatically shift attention toward the memory matching-object and produce a negative early lateralized event related potential (ERP), the N2pc, toward the side of visual field where the memorized item appeared. This component, the N2pc is an important tool to investigate the allocation of attention by working memory representations, especially for the activity the activity that is specific to the hemisphere which is contralateral with respect to the hemifield containing e.g. the to-be-remembered items could be measured. This characteristic of the N2pc facilitates measuring the general direction of attention with fine-grained temporal resolution. Therefore, the N2pc could be used as an index to describe the lateralization effect of memorized items on attention related studies.

The olfactory system is vital mechanism for our survival to interact with the environment, influencing not only on odor detection but also on nutrition, social behavior and well-being. Current findings suggest that before the onset of any cognitive decline reflecting early sign of dementia, dysfunction in the areas processing olfactory information is present at the early stages of Alzheimer’s disease (AD). Behavioral test including thresholds, odor identification, recognition memory tasks are the most common types of odor measurement. However, recent neuroimaging techniques using measures of brain response, including Olfactory Event Related Potentials (OERPs) suggested the potential for detection of AD at the early preclinical stage. The importance of olfactory event related potentials and their relation with AD appear to be very promising.