Journal Article

Enhancing long-term memory with stimulation tunes visual attention in one trial

Reinhart, Robert M. G., Woodman, Geoffrey F.

2015

Overview

Significance Theories of attention propose that we rely on working memory to control attention by maintaining target presentations in this active store as our visual systems are used to search for certain objects. Here, we show that the tuning of perceptual attention can be sharply accelerated by noninvasive brain stimulation. Our electrophysiological measurements showed that these improvements in attentional tuning were preceded by changes in event-related potentials thought to index long-term memory, but not those potentials that index working memory. Our findings support the hypothesis that changes in the storage of target representations in long-term memory may underlie rapid changes in how target objects are selected by visual attention. Scientists have long proposed that memory representations control the mechanisms of attention that focus processing on the task-relevant objects in our visual field. Modern theories specifically propose that we rely on working memory to store the object representations that provide top-down control over attentional selection. Here, we show that the tuning of perceptual attention can be sharply accelerated after 20 min of noninvasive brain stimulation over medial-frontal cortex. Contrary to prevailing theories of attention, these improvements did not appear to be caused by changes in the nature of the working memory representations of the search targets. Instead, improvements in attentional tuning were accompanied by changes in an electrophysiological signal hypothesized to index long-term memory. We found that this pattern of effects was reliably observed when we stimulated medial-frontal cortex, but when we stimulated posterior parietal cortex, we found that stimulation directly affected the perceptual processing of the search array elements, not the memory representations providing top-down control. Our findings appear to challenge dominant theories of attention by demonstrating that changes in the storage of target representations in long-term memory may underlie rapid changes in the efficiency with which humans can find targets in arrays of objects.

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: Adolescent / Adult / Attention - physiology / Biological Sciences / Brain / Cerebral Cortex - physiology / electrophysiology / Evoked Potentials / Female / Humans / Male / Memory / Memory, Long-Term - physiology / Memory, Short-Term - physiology / Models, Neurological / Photic Stimulation / Sensory perception / Transcranial Direct Current Stimulation / Visual task performance / Young Adult