Single-Channel EEG Analysis - Quantitative EEG Analysis Methods and Clinical Applications - page 82

10 9

1 ×

0.5

0

0.5

−

− 1

1

0.5

1

0

0.8

0.6

0.4

0.2

τ 1 (seconds)

0.5

−

0.2 0

0.4 −

0.6 −

− 0.8 −

τ 2 (seconds)

− 1

− 1

(a)

1 × 10 8

0.5

0

− 0.5

− 1

1

0.5

1

0

0.8

0.6

0.4

0.2

τ 1 (seconds)

− 0.5 0

0.4 −

0.2

0.6 −

0.8 −

τ 2 (seconds)

−

− 1

− 1

(b)

10 9

1 ×

0.5

0

− 0.5

− 1

1

0.5

1

0

0.8

0.6

0.4

0.2

− 0.5 0

− 0.2

0.4

−

0.6

−

− 0.8

− 1

τ 1 (seconds)

− 1

τ 2 (seconds)

(c)

Figure 3.23 Cumulant C 3 ( τ 1 , τ 2 ) estimated from 10-second EEG segments located at one focal elec-
trode (a) 10 seconds prior to, (b) 20 seconds after, and (c) 10 seconds after the end of an epileptic sei-
zure of temporal lobe origin. The positive peaks observed in the ictal cumulant are less localized in the
( τ 1 , τ 2 ) space than the ones observed during the preictal and postictal periods.