Spectra-temporal patterns underlying mental addition: An ERP and ERD/ERS study

• Published in: Neuroscience letters 2010-03, Vol.472 (1), p.5-10
• Main Authors: Ku, Yixuan, Hong, Bo, Gao, Xiaorong, Gao, Shangkai
• Format: Article
• Language: English
• Subjects: Acoustic Stimulation; Adult; Alpha Rhythm; Beta oscillation; Beta Rhythm; Biological and medical sciences; Cortical Synchronization; Electroencephalography; ERD/ERS; ERP; Evoked Potentials; Female; Frontal Lobe - physiology; Fundamental and applied biological sciences. Psychology; Humans; Male; Mathematical Concepts; Mental calculation; Parietal Lobe - physiology; Phonologic loop; Photic Stimulation; Problem Solving; Theta Rhythm; Time Factors; Vertebrates: nervous system and sense organs; Young Adult
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2010.01.040

Functional neuroimaging data have shown that mental calculation involves fronto-parietal areas that are composed of different subsystems shared with other cognitive functions such as working memory and language. Event-related potential (ERP) analysis has also indicated sequential information changes during the calculation process. However, little is known about the dynamic properties of oscillatory networks in this process. In the present study, we applied both ERP and event-related (de-)synchronization (ERS/ERD) analyses to EEG data recorded from normal human subjects performing tasks for sequential visual/auditory mental addition. Results in the study indicate that the late positive components (LPCs) can be decomposed into two separate parts. The earlier element LPC1 (around 360 ms) reflects the computing attribute and is more prominent in calculation tasks. The later element LPC2 (around 590 ms) indicates an effect of number size and appears larger only in a more complex 2-digit addition task. The theta ERS and alpha ERD show modality-independent frontal and parietal differential patterns between the mental addition and control groups, and discrepancies are noted in the beta ERD between the 2-digit and 1-digit mental addition groups. The 2-digit addition (both visual and auditory) results in similar beta ERD patterns to the auditory control, which may indicate a reliance on auditory-related resources in mental arithmetic, especially with increasing task difficulty. These results coincide with the theory of simple calculation relying on the visuospatial process and complex calculation depending on the phonological process.