Background: The main manifestation of dementia is a defect in working memory. N-back tasks are frequently used in research on working memory. Researchers can study differences between different loadings by controlling N factors. Furthermore, the interface of N-back tasks can be verbal or visual-spatial.
Methods: Event-related potentials under verbal and spatial tasks and different loadings were recorded using a digital electroencephalogram, and analyzed together with behavior results.
Results: The differences between spatial and verbal processing were found mainly inter-component, where P3 was enhanced in verbal tasks and P2a was enhanced in spatial tasks. Furthermore, P3 was only enhanced in the left hemisphere in the target stimulus. N2 was enhanced by verbal non-target with similar amplitudes. The lateralization was not significant between spatial and verbal tasks.
Conclusion: The difference between spatial and verbal N-back tasks is not only lateralization but also more complex presentations, including P2a (for spatial tasks),P3 (for verbal tasks), and N2 (for non-target detection in verbal tasks).