The Dynamic EEG Microstates in Mental Rotation

Abstract

Mental rotation is generally analyzed based on event-related potential (ERP) in a time domain with several characteristic electrodes, but neglects the whole spatial-temporal brain pattern in the cognitive process which may reflect the underlying cognitive mechanism. In this paper, we mainly proposed an approach based on microstates to examine the encoding of mental rotation from the spatial-temporal changes of EEG signals. In particular, we collected EEG data from 11 healthy subjects in a mental rotation cognitive task using 12 different stimulus pictures representing left and right hands at various rotational angles. We applied the microstate method to investigate the microstates conveyed by the event-related potential extracted from EEG data during mental rotation, and obtained four microstate modes (referred to as modes A, B, C, D, respectively). Subsequently, we defined several measures, including microstate sequences, topographical map, hemispheric lateralization, and duration of microstate, to characterize the dynamics of microstates during mental rotation. We observed that (1) the microstates sequence had a specified progressing mode, i.e., A→B→A; (2) the activation of the right parietal occipital region was stronger than that of the left parietal occipital region according to the hemispheric lateralization of the microstates mode A; and (3) the duration of the second microstates mode A showed the shorter duration in the vertical stimuli, named “angle effect”.

Does mental rotation emulate motor processes? An electrophysiological study of objects and body parts

“…This anterior localization, together with the relatively late occurrence of Map 8, is compatible with decision processes related to response selection ( Seepanomwan et al, 2015 ). This interpretation is supported by previous studies which have similarly identified late electrophysiological components occurring after the spatial transformations during MR ( Overney et al, 2005 ; Kong et al, 2018 ).…”

Does mental rotation emulate motor processes? An electrophysiological study of objects and body parts

“…This anterior localization, together with the relatively late occurrence of Map 8, is compatible with decision processes related to response selection 52 . This interpretation is supported by previous studies which have similarly identified late electrophysiological components occurring after the spatial transformations during MR 53,54 .…”

Estimating person-specific neural correlates of mental rotation: A machine learning approach

“…As artificially delaying a response may invoke processes unrelated to the decision [ 45 ], novel algorithms processing EEG signals which deal with varying epoch sizes may be as beneficial. Finally, comparing different time windows (e.g., initial 500 vs last 500 ms) informed by EEG microstate analysis may reveal how spectral and spatial EEG features differ between stages of cognitive processing (e.g., encoding of visual information, mental rotation, and decision making) [ 39 ].…”

“…As the application of SPoC to extract spatial filters required epochs of equal size, we exclusively kept the initial 500 ms from each epoch (i.e., from 0 to 500 ms) and removed epochs with less data available. We chose the initial 500 over the last 500 ms per epoch as EEG microstates indicate that the initial period contains processes related to the encoding of visual information and mentally rotating an object [ 39 ]. After removing on average 15.3% of epochs with 3D figures presented due to missing or too early responses, this procedure yielded on average across all participants 163 epochs (min = 105, max = 186 epochs) with 500 x 32 samples per epoch.…”