Proximal procrastination of saccades: "paradoxical" delays to larger objects explained by a simple payoff-time...

Our most common decision is rife with procrastination: saccade latencies are typically 2-5x minimum sensorimotor pathway delays. Procrastination is explained as time to accumulate sensory evidence for target selection. Larger targets, or those nearer the fovea, have larger cortical representation and salience, and thus should elicit faster targeting. Paradoxically, the opposite is true. We present the largest parametric effect on saccade preparation timing in simple objects (>100 ms). Proximal or larger targets were systematically delayed, with relative eccentricity explaining 88% of latency variance. A payoff-time model pitting information gained from peripheral preview against that from foveation explained both object-sized and foveal microsaccade latency peaks. Free choices between proximal (high salience-by-proximity) and distal (high motor-priority) targets found priority dominating. Collectively, these results unite disparate findings in oculomotor literature around a proximal procrastination rule. The extraordinary structure and strength of the latency data, coupled with naturalistic saccades being object-targeted, imply wide scientific and, potentially, applied importance.