Perception of complex sounds: N1 latency codes pitch and topography codes spectra  S Crottaz-Herbette, R Ragot  Clinical Neurophysiology  Volume 111, Issue 10, Pages 1759-1766 (October 2000) DOI: 10.1016/S1388-2457(00)00422-3

Fig. 2 Isopotential scalp distribution of raw data averaged for the 16 subjects illustrating the frontal displacement of the N1 peak occurring as the stimulus spectrum changes from ‘LOW’ to ‘MID’ to ‘HIGH’ for each of the 3 fundamental frequencies (Fo) (62.5, 125 and 250 Hz). Amplitude/frequency spectra of the 9 stimuli are plotted underneath each map, with harmonics represented by vertical bars. The diagram on the right indicates electrode names and positions (corresponding to the 10–20 system). Clinical Neurophysiology 2000 111, 1759-1766DOI: (10.1016/S1388-2457(00)00422-3)

Fig. 1 Grand mean for the 16 subjects of the evoked potentials obtained in the 9 experimental conditions. Vertical dotted lines allow a comparison of latency differences observed with different periodicity pitches. Clinical Neurophysiology 2000 111, 1759-1766DOI: (10.1016/S1388-2457(00)00422-3)

Fig. 3 Angular orientation of dipoles projected onto the x-y-z coordinates of the stereotaxic atlas of Talairach and Tournoux (1988) on the mid-brain sagittal (x=0) and coronal (y=0) planes. Top to bottom: fundamental frequencies (Fo) of 62.5, 125 and 250 Hz. The dipoles (black, ‘LOW’; gray, ‘MID’; white, ‘HIGH’) fit the scalp potential distribution of N1 components obtained in the experiment. Resulting angular dipole orientations (ω values) are printed below the corresponding stimulus spectra. Clinical Neurophysiology 2000 111, 1759-1766DOI: (10.1016/S1388-2457(00)00422-3)

Fig. 4 Results showing spectral coding by N1 topography (a) and pitch coding by N1 latency (b). Mean values of angular orientations of the right and left dipoles in each hemisphere and of N1 peak latencies in response to the ‘LOW’, ‘MID’ and ‘HIGH’ spectra for the 3 fundamental frequencies (Fo). Clinical Neurophysiology 2000 111, 1759-1766DOI: (10.1016/S1388-2457(00)00422-3)