Number adaptation survives spatial displacement

Area of Science:

• Cognitive Neuroscience
• Visual Perception
• Computational Neuroscience

Background:

• Canonical visual adaptation effects (color, orientation) are spatially specific, linked to early retinotopic visual areas.
• Number adaptation effects are localized to the intraparietal sulcus (IPS), a higher-level region involved in object tracking.
• This contrast suggests number adaptation may reveal non-retinotopic effects.

Purpose of the Study:

• To investigate whether number adaptation effects persist under conditions of changing spatial positions.
• To determine if number adaptation is retinotopic or object-based.
• To explore the binding of number adaptation to objects, even when they are moving.

Main Methods:

• Six experiments measured adaptation to number using dots presented within translating visible or invisible discs.
• Stimuli included static and moving dots, with constant changes in spatial positions.
• Adaptation was measured by comparing responses to adapted and test stimuli.

Main Results:

• Object-specific number adaptation was observed, persisting even with constant spatial rearrangement.
• Adaptation was bound to specific objects or bounding regions, not transferring to other objects.
• The magnitude of the adaptation effect was similar for moving and static stimuli.

Conclusions:

• Number adaptation is not retinotopic, unlike adaptation to early visual features.
• Adaptation effects for number can be bound to moving objects, indicating object-based processing in higher visual areas.
• The findings support the role of the IPS in representing number in an object-centered or non-retinotopic frame of reference.