A common element impacting object identification in the peripheral visual field is spatial crowding, which happens when an item is crowded amid other objects in space. In order to measure crowding, crowded stimuli are often shown in an eccentric position while observers fixate on a certain point in space. However, even during fixation, the eyes move slightly (called microsaccades) and it had recently been hypothesized that these microsaccades are influenced by changes in attentional allocation. 

In the present investigation, researchers tracked microsaccadic activity (perhaps an attentional correlate) to comprehend the attentional adjustments that normally take place after the presentation of cluttered stimuli. Each observer’s right eye was captured using a tracking scanning laser ophthalmoscope (TSLO) while doing a psychophysical activity. Sloan numbers (0–9) were used as the stimuli, briefly shown either unflanked or surrounded by Sloan numbers at 1 of 4 nominal spacings. 

On trials when incongruent microsaccades were present, the degree of crowding was observed to decrease by 26% (proposed to suggest attentional capture). The results added to the body of research that already existed on the positive effects of deliberate changes of spatial attention to the location of a crowded stimulus.

Reference: jov.arvojournals.org/article.aspx?articleid=2783654