Target-Distractor Competition Modulates Saccade Trajectories in Space and Object Space

Area of Science:

• Neuroscience
• Cognitive Psychology
• Ophthalmology

Background:

• Saccade planning and execution are influenced by factors in target selection tasks.
• Target-distractor similarity affects saccade trajectory curvature due to competition.
• Understanding target-distractor competition is crucial for comprehending neural circuitry.

Purpose of the Study:

• To investigate the effects of distance and similarity between complex targets and distractors on human saccade trajectories.
• To elucidate the nature of target-distractor competition and its impact on neural circuitry.
• To differentiate between active and completed decision-making processes based on saccade trajectories.

Main Methods:

• A delayed match-to-sample task was employed.
• The distance and similarity between complex target and distractor objects were systematically varied.
• Human saccade trajectories and saccadic reaction times (SRTs) were analyzed.

Main Results:

• At short SRTs, distractors were attractive, deviating saccades toward them, consistent with saccade vector averaging.
• Similarity effects indicated an object-based suppressive surround.
• At longer SRTs, distractors became repulsive, deviating saccades away, reflecting a spatial suppressive surround.

Conclusions:

• Saccade trajectories reveal target-distractor competition influenced independently by spatial and object-based suppressive surrounds.
• Saccadic reaction times differentiate between active and completed decision-making processes.
• Distance and similarity effects on saccade trajectories were independent throughout competition.