Trans-saccadic integration of peripheral and foveal feature information is close to optimal

Abstract

Due to the inhomogenous visual representation across the visual field, humans use peripheral vision to select objects of interest and foveate them by saccadic eye movements for further scrutiny. Thus, there is usually peripheral information available before and foveal information after a saccade. In this study we investigated the integration of information across saccades. We measured reliabilities--i.e., the inverse of variance-separately in a presaccadic peripheral and a postsaccadic foveal orientation--discrimination task. From this, we predicted trans-saccadic performance and compared it to observed values. We show that the integration of incongruent peripheral and foveal information is biased according to their relative reliabilities and that the reliability of the trans-saccadic information equals the sum of the peripheral and foveal reliabilities. Both results are consistent with and indistinguishable from statistically optimal integration according to the maximum-likelihood principle. Additionally, we tracked the gathering of information around the time of the saccade with high temporal precision by using a reverse correlation method. Information gathering starts to decline between 100 and 50 ms before saccade onset and recovers immediately after saccade offset. Altogether, these findings show that the human visual system can effectively use peripheral and foveal information about object features and that visual perception does not simply correspond to disconnected snapshots during each fixation.

The relationship between visual attention and visual working memory encoding: A dissociation between covert and overt orienting.

“…Subsequent studies have found that secondary tasks engaging spatial attention produce no specific decrement in binding memory, with robust memory for binding in the absence of sustained visual attention (Delvenne, Cleeremans, & Laloyaux, 2010; Gajewski & Brockmole, 2006; Johnson et al, 2008; Shen, Huang, & Gao, 2015; Wijdenes, Marshall, & Bays, 2015). Complementary evidence has been observed in studies focusing on executive attention (Allen, Baddeley, & Hitch, 2006; Morey & Bieler, 2013; Von Grünau & Dubé, 1992; Wolf & Schütz, 2015). Recently, Snowden and Milne (1997) showed that several object-based attention tasks selectively impair binding in VWM, but this is to be expected given that their tasks, such as mental rotation and delayed feature report, directly depend on VWM themselves (e.g., Hyun & Luck, 2007).…”

Saccade Preparation Reshapes Sensory Tuning

“…These findings reveal how eye movements reshape feature processing at the site of a saccade target, and could represent underlying mechanisms of presaccadic enhancement [1–4] and perceptual stability [43, 45–47] reported in the literature, which illustrate functional benefits of the tight coupling between perception and movements.…”

“…Human observers can maintain a stable percept of a saccade target by integrating its presaccadic (in the periphery) and postsaccadic (at the fovea) representations of both SF [45] and orientation [46, 47]. The tuning modulations we found suggest that saccade preparation modifies the representation of the saccade target to be more fovea-like –i.e., higher resolution and finer orientation tuning– just before saccade onset.…”

Object files across eye movements: Previous fixations affect the latencies of corrective saccades

“…Recent studies on transsaccadic integration of object features has shown that pre-saccadically-acquired peripheral information and subsequent foveal information are integrated after a saccade has been completed (Herwig 2015; Oostwoud Wijdenes et al, 2015; Wolf & Schütz, 2015). These studies showed that the visual system weighs both peripheral and foveal information and creates one percept.…”

“…These studies showed that the visual system weighs both peripheral and foveal information and creates one percept. Even more, integration is only present when the visual system considers the pre- and postsaccadic information to belong to the same object (Ganmor, Landy, & Simoncelli, 2015; Wolf & Schütz, 2015). The phenomenon of transsaccadic integration implies that VWM representations are not stable over time, but rather are constantly updated by new visual information.…”