No Evidence for a Saccadic Range Effect for Visually Guided and Memory-Guided Saccades in Simple Saccade-Targeting...

Area of Science:

• Neuroscience
• Ophthalmology
• Cognitive Psychology

Background:

• Saccades, rapid eye movements, typically exhibit an undershoot bias in peripheral vision.
• The saccadic range effect (SRE) suggests a bias towards the center of target eccentricities within a block of trials.

Purpose of the Study:

• To replicate and test the saccadic range effect (SRE) under varying task demands and target presentation durations.
• To investigate the influence of top-down cognitive control on the SRE.
• To determine if saccadic eye movements exhibit a bias towards a constant, optimal amplitude.

Main Methods:

• Replication of Kapoula's [1] paradigm involving two sets of target eccentricities.
• Experiments included visual discrimination tasks and simple saccade-targeting tasks with varied target presentation durations.
• Voluntary saccades to remembered target locations were also tested.

Main Results:

• The saccadic range effect (SRE) was not observed in any of the experimental conditions.
• Findings were consistent across different tasks, including those with minimal top-down influence.
• Results align with previous studies that also failed to find the SRE in specific saccade tasks.

Conclusions:

• The saccadic range effect (SRE) appears to be absent in saccadic eye movements, unlike in arm movements.
• Saccadic eye movements do not demonstrate a bias towards a constant, optimal amplitude for the task.
• Task demands and top-down control do not appear to induce the SRE in saccadic behavior.