Patients in the complete locked-in state (CLIS) are unable to interact with the reality around them and to manifest their condition, although they are aware of what is happening around them. Due to a complete interruption between the cortex neurons of the Central Nervous System and the motor neurons responsible for movement, the impulses from the brain cannot reach all the extremities involved in movement. The only technological support able to compensate for the lack of functionality of these neurons is the BCI. Specifically, in SSVEP-based BCIs, the signal components that are derived in response to a visual stimulus are the SSVEPs, which can be recorded on the primary visual cortex with a non-invasive electroencephalogram (EEG).