Figure 2.

The symbolization of two EEG signals. The amplitudes of source and target signals, X and Y , are symbolized with the ranks of vector components in ascending order. In this example, the embedding dimension is m=3 and the time delay τ=1. Thus, the vector components are symbolized with 0, 1 and 2. For instance, X² = (1,6,2) is symbolized to (0,2,1) in ascending order. The grey shaded parts are X^P(=X²), Y ^P(=Y ²) and Y ^F(=Y ⁵), corresponding to the pasts of source and target EEG signals and the future of target EEG signal, respectively. Here, δ=3 is the interaction delay between the source and target EEG signals. (Courtesy of Jordan et al. [49].)