Fig. 3.
Topographic distribution of N400 component activity (319–419 ms in normal controls and 343–443 ms in schizophrenics) and Mann-Whitney Z-SPM. Left and middle panels: These voltage maps show that normal controls produced a relatively symmetrical pattern of negativity (darker greys equal greater negativity), with a posterior minima at the midline. By contrast, schizophrenics showed a slightly greater negativity over right scalp than left. Grey-coded voltages are scaled differently for schizophrenics and normal controls to make scalp distributions clearly visible. Voltage scale maxima and minima are the following: normal controls = 0.0 to –4.0 μV; schizophrenics = 0.0 to –2.0 μV. Right panel, SPM: scale maxima and minima were the following: Z = + 3.0 to 0.0. The largest Z-values were in the left temporal-occipital scalp region (TCPl, P3, 01) with Z-values ranging from 2.02 to 2.60. The Z-values of neighboring centro-temporal electrodes (T3, C3, Cz, C4, T4) were 0.02 to 1.76.
