The impact of numeration on visual attention during a psychophysical task; An ERP study

Attention is amongst the high level cognitive task which is associated with complex process in the brain. But in almost all researches, this process is associated with a secondary task, (like numeration). Some believe that the link between these two cognitive activities (i.e. attention and numeration) in human brain is very close and intricate. However, the goal of this research is to evaluate the side effects of counting on visual attention in order to clarify the definition of Attention through brain signals. In previous related researches, only the qualitative impacts of counting have been dealt with and endeavor in this field is a new effort. We used a novel psychophysics task to explore the impact of this extra task on visual top-down attention. EEG was recorded during the task from 48 subjects in occipital, Parietal and frontal lobes. Target-locked ERPs for attention with and without numerating were constructed. Time features corresponding to P300 component were extracted for all eight channels separately. Common feature selection method and classifiers were employed to separate two classes (attention with numeration and pure attention). The results indicate that our task was capable of separation and some of the predefined ERP, time features are meaningful while attention is with numeration. As a result, we have introduced ERP features which belong to this separation and also determined the most relevant brain areas. To our knowledge, this is the first time that this quantitative separation is performed.