**2. SSVEP in BCIs**

A BCI is an artificial intelligence system that has the ability to identify particular set of patterns in the brain signals to provide an additional output channel for the control of artificial devices like restoring motor function, robot arm, communication program, etc. [43, 44]. SSVEPs based BCIs are classified into following categories:


**iii.** Pseudorandom code modulated (c-VEP) BCI: In this BCI, a pseudorandom sequence defines the duration of ON and OFF states of each stimulus. This mode yields highest communication speed.
