The .mat files have dimensions of 35x6x9 for the benchmark and 70x4x9 for the BETA datasets. The final dimension represents different signal lengths: the first position corresponds to 0.2 sec, the second to 0.3 sec, and so on, culminating in 1.0 sec for the last position. The dimensions 35x6 and 70x4 indicate the number of participants and blocks, respectively. As an example, the entry at the first row and column represents the test result for the first participant when the first block is reserved for testing, and the remaining blocks are used for training.