When do you look where you look? A visual field asymmetry

Area of Science:

• Oculomotor research
• Cognitive neuroscience
• Visual perception

Background:

• Understanding saccadic eye movements is crucial for cognitive neuroscience and visual perception research.
• Saccades are rapid eye movements that shift fixation points.
• Pre-saccadic fixation duration is a key parameter in analyzing eye movement behavior.

Purpose of the Study:

• To investigate directional differences in pre-saccadic fixation durations during endogenous attention tasks.
• To determine if saccade direction influences the duration of the preceding fixation.
• To assess the implications for computational models of saccadic scanning.

Main Methods:

• Comparison of pre-saccadic fixation durations across different saccade directions (upward, downward, horizontal).
• Utilized three endogenous-attention tasks: visual search and scene viewing.
• Analysis focused on fixation durations immediately preceding saccade execution.

Main Results:

• Pre-saccadic fixation durations were consistently shorter before upward saccades compared to downward saccades.
• Saccades were more frequently directed upward than downward.
• Horizontally directed saccades exhibited symmetric and longer pre-saccadic fixation durations.
• Vertical visual field asymmetry suggests influences beyond the currently fixated element.

Conclusions:

• Vertical asymmetry in pre-saccadic fixation durations indicates non-foveal influences on eye movement control.
• Findings support the inclusion of directional constraints in computational models of saccadic scanning.
• Predicting pre-saccadic fixation durations is vital for accurate real-time saccadic scanning models.