Bias in Visual Short-Term Memory for Motion Induced by Perceptually Suppressed Distractors

Area of Science:

• Cognitive Neuroscience
• Visual Perception
• Memory Research

Background:

• Visual short-term memory (VSTM) is susceptible to interference from task-irrelevant sensory distractors.
• The precise origin of this interference—physical retinal input versus subjective perception—remains debated.
• Previous studies faced limitations in dissociating retinal input from perceptual experience.

Purpose of the Study:

• To investigate whether physical retinal motion or subjective perception drives VSTM interference for motion speed.
• To differentiate the roles of retinal stimulation and conscious awareness in VSTM distractor effects.
• To test if VSTM bias for motion speed requires conscious perception.

Main Methods:

• Utilized smooth pursuit eye movements to create perceptual invariance for retinal motion.
• Presented distractors as either physical object motion or apparent motion (induced by eye movements) with identical retinal motion but distinct perceptions.
• Employed a motion speed comparison task with intervening distractors and a classifier analysis.

Main Results:

• Retinal motion distractors systematically biased memorized motion speed.
• The magnitude of VSTM bias was similar for physical and apparent motion distractors.
• A classifier trained on physical motion data successfully predicted distraction effects from apparent motion.

Conclusions:

• VSTM bias for motion speed can be induced by retinal motion input alone, independent of subjective perception.
• These findings challenge the notion that conscious perception is a prerequisite for VSTM interference.
• Distractors impact VSTM for motion speed via retinal signals rather than solely through conscious awareness.