Table 6 Advantages and disadvantages of different spelling paradigms

MI

Without external stimulation;

Requires the users to undergo specialized training;

Suitable for specific applications

Typing speed is relatively low;

Prolonged use can cause fatigue

P300

Stimulating with a single frequency signal;

Reaction time is relatively long;

Clear signals

Relies on external visual stimuli

SSVEP

Relies on different frequency stimuli;

When the frequency is close or harmonics are present, performance decreases;

Enabling real-time typing;

May cause user fatigue

Fast typing speed, large command set

Hybrid

Combining the advantages of multiple BCI paradigms;

Increasing user cognitive load;

Improving typing accuracy and flexibility

High system complexity increases the computational burden