The Interaction Between Visual Selective Attention And Working Memory: A Cognitive Behavioral And ERP Study

Selective attention and working memory are regarded as the two essential cognitive processes underlying the dynamic interaction among perception, thought and action. The interaction between the two processes is a central mechanism of information processing system. By using cognitive behavioral and event-related brain potentials (ERPs) techniques, the present study investigated explicitly, operationally and systematically the role of visual selective attention in working memory, the role of working memory in visual selective attention, and the mechanism of the interaction between the two processes. The study consists of three parts. The first part examined the influence of selective attention on the representation and retention of working memory with spatial cueing and attentional interfering paradigms respectively. The second part investigated the effect of working memory contents on the goal orienting of visual selective attention through a complex procedure combining the delayed match-to-sample task and perceptual discrimination task. And the third part explored the interaction between visual selective attention and working memory in a coherent information processing stream by using ERPs technique. The results showed: (a) Selective attention played an important role during the transferring from perceptual representation into working memory representation, with more significant effect on spatial information than on object information, and more facilitation for color-location and color-shape conjunction than color-color conjunction which suggests a tendency that the further are the feature dimensions constructing a object, the larger is the attentional effect. The influence of attention on the representation of single-feature object might be caused by gain control, while both gain control and feature binding might underlie the facilitation of attention on the representation of object with conjunctive features. (2) Selective attention was required to maintain the contents ofworking memory after the transformation from perceptual representation into memory representation. Spatial and object working memory shared the same attention-based rehearsal mechanism. (3) Information maintained in working memory could elicit attentional orienting towards stimulus identical with it in search array while no search goal was designated. Such orienting phenomenon could also be observed when a search stimulus was a part of the memory content, and when the number of memory items increased to 4. The attentional orienting effect was larger when the search stimulus and the memory content were completed same than when only part of them was overlapped. (4) The influence of selective attention on working memory and the influence of working memory on selective attention were interrelated but not separated, which could coexist in the same cognitive task. The attention-on-memory effect was the prerequisite of the memory-on-attention effect. The nature of the interaction between selective attention and object working memory was different from that between selective attention and spatial working memory. The former was underlain by both attention-based rehearsal and attentional biased competition, while the latter was only the consequence of attention-based rehearsal. (5) The attentional effect was reflected by amplification of P3 at anterior scalp in the beginning of the transferring from perceptual representation into working memory. The amplification of negative slow wave SW with time window between 450~800ms at left occipital-parietal scalp indicated the spatial cueing effect during formation of integrated representation. The attentional orienting guided by working memory content triggered the classical P1-N1 effect at bilateral occipital-parietal and occipital-temporal area of brain. The implications of the results above for the research of working memory, selective attention, information processing system and consciousness were discussed.