Sub-processes of working memory in the N-back task: an investigation using ERPs

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Psychology

Background:

• The N-back task is a standard tool for studying working memory.
• Previous research has not fully explored the specific sub-processes within the N-back task.
• A logical task analysis identified three key sub-processes: matching, replacement, and shift.

Purpose of the Study:

• To investigate domain-specific lateralization in spatial and verbal working memory within the N-back task.
• To test a proposed three-sub-process model of N-back task performance.
• To differentiate conceptual (top-down) and data-driven (bottom-up) processing within the N-back task.

Main Methods:

• Two electroencephalography (ERP) experiments were conducted during N-back tasks.
• One experiment focused on conceptual (top-down) processing.
• The other experiment focused on data-driven (bottom-up) processing.

Main Results:

• Domain-specific lateralization was observed in the shift sub-process of the conceptual task.
• Domain-specific lateralization was found in the replacement sub-process of the data-driven task.
• Match-specific lateralization was also identified.

Conclusions:

• The results validate the proposed three-sub-process model of the N-back task.
• Replacement is characterized as a data-driven process with a posterior neural locus.
• Shift is identified as a conceptual process with a more frontal neural locus.