Behavior And Neural By Event-Related Potentials Research Of Cognitive Styles Individuals Differences On Visual Working Memory Capacity

The capacity of visual working memory is highly limited, maintaining only three to four objects simultaneously . Memory capacity varies considerably across individuals, ranging from 1.5 objects to about 5 objects. However, the capacity of visual working memory of individual is different. Field Independence---Field Dependence are always important aspects of individual differences. To examine whether memory selection efficiency varies across memory capacity, we divided some subjects into two groups: Field Independence and Field Dependence. These two groups differed markedly in lots of cognitive abilities. This we used the CDA as a direct neurophysiological measure of items that encoding and maintenance in the visual working memory. Vogel(2004) provided this electrophysiological evidence for lateralized activity in humans that re?ects the encoding and maintenance of items in visual memory. The amplitude of CDA is strongly modulated by the number of objects being held in the memory at the time, but approaches a limit asymptotically for arrays that meet or exceed storage capacity.To be concrete, the results were as follows:Fisrt, Field Independence individuals and Field Dependence individuals are not different in the simple visual working memory task.Second, in visual working memory task, the load of task affected the score of memory both for the Field Independence individuals and Field Dependence individuals. However, the initial seconds in the maintenance stage failed to make a contribution.Third, in visual working memory task, Retention interval affected the score of memory both for the Field Independence individuals and Field Dependence individuals. Forth, our results suggest that the contralateral delay activity indexes the currently active representations maintained in visual memory. The results show that there was a significant increase in amplitude from arrays of two items per side to arrays of four items per side.Fifth, for the Field Independence group, the amplitude of the distractors-present condition was significantly smaller than that of Field Dependence's, indicating that Field Independence subjects were very efficient at excluding the distractors from consuming memory capacity. Field Dependence, who inefficiently encode and maintain information about the irrelevant items present in the display. These results provide evidence that under many circumstances Field Dependence individuals may actually store more information in memory than Field Independence individuals. Indeed, this ancillary allocation of memory capacity to irrelevant objects may be a primary source of putative differences in overall storage capacity. These results indicate that Field Dependence subjects were highly inefficient at keeping the irrelevant items from being stored in memory. By this view, an individual's specific memory capacity does not simply re?ect'how many'items can be stored, but also'how efficient'the individual is at excluding irrelevant information from reaching this highly limited memory system.