Electrocortical Activity Differences Related to Saccadic Movements between Bipolar Patients and Healthy Subjects

Objective: The present study aimed to investigate and to compare the electrophysiological changes in bipolar patients and healthy subjects during the execution of a saccade task. Materials and Methods: The subjects had to respond to a fixed visual stimulus presented by a LEDs bar. We executed an ANOVA (one-way) and post hoc Scheffé test to examine the difference of absolute alpha power and reaction time among four groups: control, depression, manic and euthymic. We observed the frontal, parietal and occipital regions. The paired t test was realized on each electrode and group to compare the pre and post moment in the task. Results: We observed a statistical difference among the groups for the behavioral variable—saccade reaction time. For the electrophysiological variable—absolute alpha power, we did not find significant difference between the moments (pre and post stimulus presentation) for none of the electrodes of each bipolar group. However, the results pointed out to a difference between the moments for F3, P3, O1 and O2 electrodes for control group. Conclusion: We cannot affirm that the task influences the cortical activity of the patients. It is possible that the method used to analyze the data is not the adequate. The time-frequency analysis could be better to analyze the present data. We also observed that the absolute alpha power could be considered a marker of bipolar disorder, but not of the different states (i.e., mania, depression, euthymia).