Electroencephalography Study of Frontal Lobe Evoked by Dynamic Random-Dot Stereogram

PURPOSE: The purpose of this study was to investigate the cortical electrical activity and electroencephalography (EEG) features of the frontal lobe evoked by dynamic random dot stereogram (DRDS) and to probe the functional connectivity (FC) between the frontal lobe and occipital lobe when processing 3D perception based on the binocular disparity. METHODS: The EEG experiment involved 14 healthy adults with normal stereopsis (<60″) and normal corrected visual acuity (20/20). The Neuroscan system and 32-channel EEG cap were used to record EEG signals based on the DRDS stimuli. The maximum energies of 3 frequency bands (theta-/alpha- /beta-wave) from 13 interesting channels (FP1, FP2, F7, F3, FZ, F4, F8, FC3, FCZ, FC4, O1, OZ, and O2) located in the frontal and occipital lobes were calculated and analyzed. The FC between any two electrodes from the frontal and occipital lobes was calculated based on the Phase lag index (PLI). RESULTS: The maximum powers of theta- and alpha-waves in most channels of the frontal and occipital lobes were significantly increased (P < 0.05) when the depth perception was evoked by DRDS above the threshold, compared with that without stereo vision. The changes in the maximum powers of both theta- and alpha-waves were significantly different among the 13 electrodes (P = 0.0004 and 0.0015, respectively). Tukey's multiple comparisons showed that the changes in the maximum powers of theta-wave were significantly different in F8 vs. O1, F8 vs. OZ, and F4 vs. O1 (P = 0.0186, 0.0444, and 0.0412, respectively). Moreover, the changes in the maximum powers of alpha-waves were significantly different in FP1 vs. O1 (P = 0.0182). The FCs of theta-waves between the frontal channels and the occipital channels were significantly enhanced when processing the depth perception, compared with those without stereopsis. There was no significant change in the FCs of the alpha-waves when having 3D perception except for FC between F8 and O1 and FC between F8 and OZ. CONCLUSIONS: The cortical electrical activity in the frontal lobe and the functional connectivity between the frontal lobe and the occipital lobe increase when participating in the processing binocular disparity and obtaining 3D perception. Theta-waves in the frontal lobe may be crucial in the stereo vision.