Shorter fixation durations for up-directed saccades during saccadic exploration: A meta-analysis

Area of Science:

• Cognitive Neuroscience
• Visual Perception
• Human Factors

Background:

• Understanding saccadic exploration is crucial for modeling visual attention.
• Presaccadic fixation durations influence the initiation and direction of eye movements.
• Previous research has not comprehensively analyzed fixation duration asymmetries during naturalistic visual exploration.

Purpose of the Study:

• To conduct a meta-analysis on the asymmetry of presaccadic fixation durations.
• To investigate differences in fixation durations for saccades directed above versus below the eye fixation point.
• To determine the robustness of this asymmetry in complex visual displays without gaze-contingent manipulations.

Main Methods:

• Meta-analysis of 23 independent datasets.
• Inclusion criteria: saccadic exploration of complex visual displays without gaze-contingent manipulations.
• Quantification of effect sizes using Hedge's g for the observed asymmetry.

Main Results:

• Significant asymmetry in presaccadic fixation durations was identified.
• Fixations preceding saccades into the upper visual field were reliably shorter than those preceding saccades into the lower visual field.
• This effect was consistent across various saccadic exploration tasks.

Conclusions:

• A robust asymmetry exists in presaccadic fixation durations during visual exploration.
• The findings have significant implications for computational models of saccade initiation.
• The observed asymmetry provides critical data for predicting eye movement behavior based on saccade direction.