Related Experiment Video
Updated: Jul 2, 2026

Extracting Visual Evoked Potentials from EEG Data Recorded During fMRI-guided Transcranial Magnetic Stimulation
Published on: May 12, 2014
Temporal spectral evolution of pre-stimulus brain activity in visual and visuomotor tasks
Esteban Sarrias-Arrabal1, Marika Berchicci2, Valentina Bianco2
1Department of Experimental Psychology, Faculty of Psychology, University of Seville, Seville, Spain.
Abstract:
The aim of this study was to describe the spectral features of pre-stimulus event-related potential (ERP) components elicited in visual tasks such as the Bereitschaftspotential (BP), prefrontal negativity (pN) and visual negativity (vN). ERPs are considered time-locked and phase-locked (evoked) activity, but we have also analyzed the non-phase but time-locked (induced) activity in the same interval by applying the temporal spectral evolution (TSE) method. Participants (N = 26) were tested in a passive task, a simple response task (SRT) and a discriminative response task (DRT), where EEG activity was recorded with 64 scalp electrodes. We analyzed the time-frequency modulations (phase and non-phase) prior to the onset of the stimuli in the sub-delta, delta, theta, alpha, beta, and gamma frequency bands. The results showed that all the pre-stimulus ERP components were mainly regulated by evoked activity in the sub-delta band. On the other hand, induced activity seems to be linked to evoked responses but with a different psychophysiological role. We concluded that other preparatory cognitive mechanisms associated with ERPs can also be detected by the TSE method. This finding may suggest underlying mechanisms in non-phase activity and requires the addition of non-phase activity analysis to the traditional analysis (phase and evoked activity).
Related Concept Videos
Vision
Photoreceptors and Visual Pathways
Visual System
Once through the pupil, the light passes through the lens, a...
Color Vision
Parallel Processing

