New Spatial Filtering Methods

To fill the research gaps and demonstrate that the proposed LS framework could facilitate the development of new methods, 5 new spatial filtering methods are designed by integrating the strategies.

New TRCA-related methods

1. ms-eTRCA-R-2:

   • Only include the projection matrix in \(\mathbf{P}_\mathbf{E}\) (NOT \(\mathbf{P}_\mathbf{K}\));

   • \(\mathbf{L}_\mathbf{E}\), \(\mathbf{L}_\mathbf{K}\) and \(\mathbf{Z}\) are designed following the TDCA;

   • The utilization strategies of spatial filters follow the eTRCA (Combine spatial filters of multiple stimuli).

2. ms-eTRCA-R-1:

   • Include the projection matrix in both \(\mathbf{P}_\mathbf{E}\) and \(\mathbf{P}_\mathbf{K}\);

   • \(\mathbf{L}_\mathbf{E}\), \(\mathbf{L}_\mathbf{K}\) and \(\mathbf{Z}\) are designed following the TDCA;

   • The utilization strategies of spatial filters follow the eTRCA (Combine spatial filters of multiple stimuli).

New MsetCCA-related methods

1. ms-MsetCCA-2:

   • Combine multi-stimulus data in \(\mathbf{Z}\) of the MsetCCA;

   • Only include the projection matrix in \(\mathbf{P}_\mathbf{E}\) (NOT \(\mathbf{P}_\mathbf{K}\));

   • \(\mathbf{L}_\mathbf{E}\), \(\mathbf{L}_\mathbf{K}\) and \(\mathbf{Z}\) are designed following the TDCA;

   • The utilization strategies of spatial filters follow the ms-eTRCA (Combine spatial filters of multiple trials of multiple stimuli).

2. ms-MsetCCA-1:

   • Combine multi-stimulus data in \(\mathbf{Z}\) of the MsetCCA;

   • Include the projection matrix in both \(\mathbf{P}_\mathbf{E}\) and \(\mathbf{P}_\mathbf{K}\);

   • \(\mathbf{L}_\mathbf{E}\), \(\mathbf{L}_\mathbf{K}\) and \(\mathbf{Z}\) are designed following the TDCA;

   • The utilization strategies of spatial filters follow the ms-eTRCA (Combine spatial filters of multiple trials of multiple stimuli).

3. ms-MsetCCA-3:

   • Combine multi-stimulus data in \(\mathbf{Z}\) of the MsetCCA;

   • Include the projection matrix in both \(\mathbf{P}_\mathbf{E}\) and \(\mathbf{P}_\mathbf{K}\);

   • \(\mathbf{L}_\mathbf{E}\), \(\mathbf{L}_\mathbf{K}\), mathbf{P}_mathbf{E}, \(\mathbf{P}_\mathbf{K}\) and \(\mathbf{Z}\) are designed following the TDCA;

   • The utilization strategies of spatial filters follow the ms-eTRCA (Combine spatial filters of multiple trials of multiple stimuli).

Performance evaluation of new TRCA- and MsetCCA-related methods

• Compare TRCA-related methods in Benchmark Dataset:

  

• Compare MsetCCA-related methods in Benchmark Dataset:

  

• Compare multi-stimulus methods in Benchmark Dataset: