Spatiotemporal Dynamics of Successive Activations across the Human Brain during Simple Arithmetic Processing

Area of Science:

• Neuroscience
• Cognitive Science
• Computational Neuroscience

Background:

• Previous neuroimaging lacked subsecond timing and individual brain precision.
• The order of brain region engagement in cognitive tasks remains largely unknown.
• Human-unique symbolic processing, like arithmetic, offers a model for studying brain organization.

Purpose of the Study:

• To investigate the precise timing and anatomical order of brain activations during arithmetic tasks.
• To explore the sequence of neural engagement across different brain regions at the subsecond scale.
• To provide a basis for mechanistic computational models of symbolic processing.

Main Methods:

• Intracranial electroencephalography (iEEG) was used to record from 10,076 brain sites in 85 human subjects.
• Experimental arithmetic tasks were employed as a prototype for symbolic processing.
• Analysis focused on the spatial and temporal organization of brain activity and functional connectivity.

Main Results:

• A distributed change in brain activity was observed across nearly half of the sampled sites.
• Juxtaposed neuronal populations with specific condition preferences were found within activated regions.
• Anatomically consistent, orderly, and replicable temporal activation sequences across brain regions were identified in individual brains.
• Functional connectivity decreased with increasing temporal distance between regions, suggesting information processing chains.

Conclusions:

• This study provides novel insights into the subsecond timing of brain events during arithmetic processing.
• The findings reveal a structured, sequential engagement of brain regions critical for symbolic cognition.
• The results support the development of computational models for human-specific cognitive symbolic systems.