Discovered by Hermann von Helmholtz (1821-1894), discussed at length by William James (1842-1910) in his Principles of psychology (1890) and subsequently contrasted with overt attention, it is the selection of targets in the absence of actual eye movements, and thus without any fixation shift to a cued location (e.g., when ‘looking out of the corner of one’s eye’, ‘keeping half eye on’, every day terms that are better labeled as ‘peripheral and mental focus’). Covert attention improves discriminability in many visual tasks such as contrast sensitivity, texture segmentation, and visual search. It also appears to speed up the rate at which information is processed through enabling the observer to exclude task-irrelevant information. Changes in gaze (i.e., overt attention) require shifts in covert attention, and the latter involves disengagement of attention from a stimulus or locus and inhibition of return (a bias against reorienting attention to a previously cued location). Covert attention is often studied using ‘filtering’ tasks (observing an array of stimuli, but only attending to one). Evidence suggests that the covert attention system becomes functional during the first six months of life, with it rapidly achieving greater consistency and flexibility after the third month.
See Attention, Contrast sensitivity, Information-processing theories, Frontal eye fields (FEF), Mutual gaze, Overt attention, Saccade/antisaccade movements, Superior colliculus