## 3 Results
This analysis provides valuable insights into the distinctions between healthy, interictal, and ictal states. Figure 4: Time–frequency spectrograms (TFS) of EEG signals across brain states. Representative TFS depicting neural activity in healthy (Z and O), interictal (F and N), and ictal (S) states. The figure showcases key TFS features, including the mean frequency range, spectral power, stability, dominant frequency, and % of significant frequency transitions. Z and O--Healthy State: These states exhibit moderate neural activity, as evidenced by the mean frequency range around 14.47 Hz. Their highest spectral power is within the range of 804 dB, indicating that extreme spikes in activity are relatively infrequent. The stability of neural dynamics is observed in the mean of the standard deviation of TFR, which remains around 65.6 Hz. The mean of total power suggests that there is a substantial amount of spectral power in these signals, at approximately 5.9241 \(\times\) 10\({}^{4}\) dB. Both Z and O have a peak frequency around 3 Hz, indicating the frequency with the maximum power. The mean of dominant frequency for healthy states is about 5.4 Hz, which is relatively low. These states also exhibit 28% of significant frequency transitions, implying a moderate variability in neural dynamics. F and N--Interictal State: These states show a lower level of neural activity, as indicated by a mean frequency range of around 10 Hz. Their highest spectral power is within the range of 550 dB, lower than in the healthy state. The stability of neural dynamics remains moderate, at approximately 42 Hz. The mean of total power in the interictal state is about 4.1827 \(\times\) 10\({}^{4}\) dB, indicating less spectral power. Surprisingly, the peak frequency for interictal states reaches 500 Hz, suggesting a shift toward higher frequencies. A distinctive feature of the interictal state is the mean of dominant frequency, which is approximately 97 Hz, indicating increased activity in higher frequency bands. These states also have a moderate 5% of significant frequency transitions. S--Ictal State: The ictal state stands apart with notably distinct TFS characteristics. This state is marked by a substantially higher mean frequency range, at approximately 1.6776 \(\times\) 10\({}^{3}\) Hz, pointing to intense neural activity during seizures. The mean of maximum TFS reaches around 6.3788 \(\times\) 10\({}^{4}\) dB, signifying high levels of neural activity during ictal events. However, this heightened activity also results in a significantly elevated stability of TFS. In terms of mean total power, the state exhibits notably high values, reaching approximately 6.8699 \(\times\) 10\({}^{6}\) dB, indicating a substantial amount of spectral power in these signals. Unlike healthy and interictal states, the ictal state exhibits a peak frequency close to 0 Hz, which suggests a wide range of frequency activity during seizures. The mean dominant frequency is remarkably low, approximately 0.0072 Hz, underlining the diversity of neural dynamics during seizures. In contrast to the other states, ictal states have a low significant frequency transition, around 0.0244%, suggesting relatively stable frequency patterns during seizures. The TFS image of each EEG segment was used as input to the CNN for classifying various combinations of healthy and epileptic states. The results of each case are described below.