From: The steady-state visual evoked potential in vision research: A review Journal of Vision. 2015;15(6):4. doi:10.1167/15.6.4 Figure Legend: Hierarchical SSVEPs to a coherent-motion stimulus. (a) Schematic illustration of the coherent-motion onset/offset VEP stimulus in the coherent-motion phase. The position of a large number of bright dots is shifted, either in a consistent fashion for each dot (coherent global motion) or in a random fashion (incoherent local motion), at a rapid rate (F2 = 30 Hz). The display also alternates between coherent and incoherent states, but at a much lower frequency (F1 = 1 Hz). (b) In the frequency domain, a response is visible at the rapid 30-Hz update rate of the individual dots (f2) and at 1 Hz and its harmonics (1f1, 2f1, 3f1, …), which is the rate at which the global motion structure changes. Responses are also visible at 1f1 ± 1f2 (see Multi-input interactions as an objective measurement of system nonlinearities and neural convergence). (c) The cycle average of the coherent-motion onset/offset response in the time domain shows a mixture of long- and short-period fluctuations. The red curve is synthesized from the signals at nf1, where n ranges up to 15; see red shading in (b). The black curve is synthesized from responses over a band of frequencies centered on 1f2, as indicated by the gray shading in (b). Figure derived from Hou et al. (2008). Date of download: 12/24/2017 The Association for Research in Vision and Ophthalmology Copyright © 2017. All rights reserved.