Figure 3.   Single sweep wave identification (SSWI) method. (a) Five single sweeps filtered in the theta range (4-7 Hz),  and (c) their averaged waveform are presented. The wave extrema in the single sweeps are detected according to the local maxima and minima, shown as vertical bars in (a). The same vertical bars (b) located at the corresponding latency positions represent maxima coded with (+1) and minima coded with (-1). SSWI-histogram (d) is obtained by summing the coded extrema across the trials presented in (b). In addition, an example of single-trial set from one experiment is given:  48 single sweeps filtered in the theta range are (e) superimposed, and (g) averaged. The corresponding SSWI-histogram (f) is rectified (h), thus presenting the absolute values of (f). For quantitative evaluation, the sum of the absolute values in two time windows is calculated:  T1 (0-300 ms) and T2 (300-600 ms).