Behavioral asymmetries in visual short-term memory occur in retinotopic coordinates

Area of Science:

• Cognitive Neuroscience
• Visual Perception
• Human Memory

Background:

• Visual short-term memory (VSTM) is crucial for integrating visual information but has limited capacity.
• Existing VSTM research suggests spatial biases linked to brain asymmetries and object location.
• Visual representations are known to be retinotopic (relative to the retina).

Purpose of the Study:

• To investigate whether spatial biases in VSTM are retinotopic or spatiotopic (relative to the external world).
• To differentiate between retinal and external world coordinates in VSTM performance.
• To explore the relationship between behavioral VSTM measures and visual representation.

Main Methods:

• Manipulated eye position to dissociate retinotopic and spatiotopic coordinates.
• Participants performed a color change-detection task across the visual field.
• Stimuli were presented while participants maintained central or peripheral fixation.

Main Results:

• VSTM biases were consistently linked to the stimulus' location on the retina.
• These retinotopic biases were observed irrespective of the stimulus' screen location.
• Eye position manipulation confirmed the retinotopic nature of VSTM spatial biases.

Conclusions:

• Spatial biases in VSTM are fundamentally retinotopic, not spatiotopic.
• This finding highlights a direct link between behavioral VSTM performance and the underlying visual representations in the brain.
• Results suggest that VSTM encoding is anchored to retinal coordinates.