Numbers are associated with different types of spatial information depending on the task

Area of Science:

• Cognitive Psychology
• Neuroscience
• Human Perception

Background:

• The spatial-numerical association (SNARC) effect describes the tendency to associate smaller numbers with the left space and larger numbers with the right space.
• Previous research suggested a common spatial code underlies various behavioral signatures of spatial-numerical associations.

Purpose of the Study:

• To investigate the nature of spatial-numerical associations by examining the SNARC effect under different working memory loads.
• To differentiate between verbal and spatial working memory contributions to the SNARC effect in parity judgment and magnitude comparison tasks.

Main Methods:

• Participants performed a parity judgment task and a magnitude comparison task while under either a verbal or spatial working memory load.
• The SNARC effect was measured by analyzing response patterns in relation to number magnitude and spatial location.

Main Results:

• A double dissociation was observed between the type of working memory load and the task performed.
• The SNARC effect was eliminated under verbal load during the parity judgment task.
• The SNARC effect was eliminated under spatial load during the magnitude comparison task.

Conclusions:

• Findings provide direct evidence against a single, common spatial code for all spatial-numerical associations.
• Numbers are associated with distinct spatial codes, which can be either visuospatial or verbally mediated depending on the task demands.