Blink-related dynamic switching between internal and external orienting networks while viewing videos

Abstract

Humans spontaneously generate eyeblinks every few seconds. However, because this blink rate is several times more common than is required for ocular lubrication, the function of most spontaneous eyeblinks remains unknown. Because spontaneous eyeblinks tend to occur at implicit breakpoints in video stories, I hypothesized that spontaneous eyeblinks play an active role in attentional disengagement from external stimuli. Consistent with this, we previously found that spontaneous eyeblinks involve the concurrent deactivation of the dorsal attention network and activation of the default mode network when individuals are viewing videos. However, this previous study examined only the upper brain regions to increase the temporal resolution of the data. Therefore, the present study examined whether the temporal and subcortical regions exhibited blink-related activations or deactivations using the same visual stimuli as in the previous study. Data revealed that the bilateral hippocampus and cerebellum showed a prominent but momentary activation after the blink onset. In contrast, a blink-related deactivation was observed in both the right ventral and dorsal attention networks. These results suggest that spontaneous eyeblinks are involved in the attentional disengagement from external visual information via the massive and dynamic alteration of brain activity between the external and internal orienting networks.

Cognitive loading via mental arithmetic modulates effects of blink‐related oscillations on precuneus and ventral attention network regions

“…A previous fMRI study examining the effect of spontaneous blinking while viewing videos also reported blink-related activation of the bilateral hippocampal regions (Nakano, 2015). This is in line with the blink-related parahippocampal activations and theta-band effects observed in this study, as theta oscillations are known to be associated with hippocampal and parahippocampal activity, particularly in the context of memory-related processes (Buzsáki, 2002;H.…”

“…In other words, the brain must act earlier to prepare itself to process blink-related information during high cognitive loading conditions. Moreover, EEG also has inherent limitations due to electrical field distortions in volume conduction (Nunez et al, 1994), while MEG is much less susceptible to this effect given that the propagation of magnetic fields is not impacted by differences in tissue conductivity (Marinova & Mateev, 2010 A previous fMRI study examining the effect of spontaneous blinking while viewing videos also reported blink-related activation of the bilateral hippocampal regions (Nakano, 2015). Similarly, the earlier offset of the alpha ERD in the left posterior precuneus during MA may represent the brain's attempt to quickly complete any blink-related processing in order to return to the cognitive task at hand.…”

Conceptual Closure Elicited by Event Boundary Transitions Affects Commercial Communication Effectiveness

“…They found that blinks tend to occur at what the authors describe as 'breakpoints' or points in time coinciding with event boundaries such as a pause in speaking or the end of a sentence while reading (Nakano et al, 2013). The blink related changes in brain activity reported by Nakano et al (2013), Nakano (2015) reveal richer detail in the changes in brain activity associated with blink related event boundaries. Specifically, brain activity increases immediately following blinks were primarily restricted to the default mode network (DMN), including the hippocampus while activity in the dorsal attention network, a task positive network, was reduced (Nakano et al, 2013, Nakano, 2015.…”

“…Furthermore, while increases in brain activity have been observed to coincide with the occurrence of consciously identified event boundaries, there may be other events that are processed as event boundaries but are not consciously recognized as such. Nakano et al (2013), Nakano (2015) examined the brain activity correlates of blinks. They found that blinks tend to occur at what the authors describe as 'breakpoints' or points in time coinciding with event boundaries such as a pause in speaking or the end of a sentence while reading (Nakano et al, 2013).…”

“…Specifically, brain activity increases immediately following blinks were primarily restricted to the default mode network (DMN), including the hippocampus while activity in the dorsal attention network, a task positive network, was reduced (Nakano et al, 2013, Nakano, 2015. This was interpreted as a transient disengagement from sensory or external perception and the engagement of internally oriented networks (Nakano, 2015).…”