engleski

The change of the brain activity during balance scale task solving

Aim: The purpose of this study was to investigate the brain activity of healthy adults during proportional reasoning. Methods: We measured the EEG signals of 20 adult subjects while performing the balance scale task (1) and employed the high resolution EEG techniques (2) in order to estimate and map their Power Spectral Density (PSD) on a realistic head model. 12 subjects did not know the torque rule, needed to solve properly the task. After Run 1 they were told the torque rule and then participated in Run 2 and Run 3. The remaining 8 subjects participated only in Run 2 and Run 3. Subjects were divided into Proportional Reasoning (PR) and Non-Proportional Reasoning (NPR) group according their score on the Test of Logical Thinking (3). Results: Behavioral data showed increased accuracy and longer reaction times (RTs) in Run 2 compared to Run 1 implying that subjects probably just guessed the answers in the Run 1. PSD maps revealed an increased parietal cortical activity in the beta band in Run 2 related to the application of the torque rule. All subjects showed the training effect, i.e. they were more accurate and faster in the Run 3 than in the Run 2. Corresponding cortical maps highlighted significant increase of PSD in the alpha band in the parietal region together with a decreased activity for higher frequency, especially in the gamma band. Although we did not find any difference in the accuracy and RTs between the PR and NPR groups, our EEG data suggested larger activity in the beta and gamma bands for the PR group. Conclusion: We found changes in the brain activity concerning the learning of the torque rule as well as the training effect. Moreover, different brain activity for PR and NPR groups indicates that proportional reasoning involves more complex skills than just learning to solve the balance scale task. Further analysis of the functional cortical connections is needed to validate these results. References: 1. Three aspects of cognitive development. Siegler RS, Cognitive Psychology 8 (1976) 481–520. 2. High-resolution electro-encephalogram: source estimates of Laplacian-transformed somatosensory-evoked potentials using a realistic subject head model constructed from magnetic resonance images. Babiloni F, Babiloni C, Locche L, Cincotti F, Rossini PM, Carducci F, Medical and Biological Engineering and Computing. 38 (2000) 512–519. 3. Development and validation of a group test of logical thinking. Tobin K, Capie W, Educational and Psychological Measurement 41(1981) 413–424. Acknowledgments: Funded by the “Fondazione Santa Lucia” and COST Action BM0601

Electroencephalography (EEG); proportional reasoning

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