Blink-related momentary activation of the default mode network while viewing videos

Spontaneous eyeblinks occur more often than needed to keep the eyes moist. While people watch videos, blinks tend to happen at natural breakpoints in attention. Brain scans show that immediately after a blink, activity briefly drops in the dorsal attention network and rises in the default-mode network, which is linked to internal thought. Physical blackouts of the video do not cause the same brain-network changes. This suggests that eyeblinks actively help disengage attention by momentarily shifting brain activity from external focus to internal processing.

Study at a glance

Abstract

It remains unknown why we generate spontaneous eyeblinks every few seconds, more often than necessary for ocular lubrication. Because eyeblinks tend to occur at implicit breakpoints while viewing videos, we hypothesized that eyeblinks are actively involved in the release of attention. We show that while viewing videos, cortical activity momentarily decreases in the dorsal attention network after blink onset but increases in the default-mode network implicated in internal processing. In contrast, physical blackouts of the video do not elicit such reciprocal changes in brain networks. The results suggest that eyeblinks are actively involved in the process of attentional disengagement during a cognitive behavior by momentarily activating the default-mode network while deactivating the dorsal attention network.