Figure 1.
A composite spectrogram of the seven complex tones used in the experiment.
The duration of each complex tone was 70 ms, including 10 ms rise and decay time. Each complex tone included shoulder tones of 1200 Hz and 2400 Hz. Internal sidebands were synthesized in 100 Hz steps inward from the shoulder tones in six of the seven stimuli to induce the inferred fundamental components.
Table 1.
Spectral values of the auditory stimuli.
Figure 2.
Comparison of the MEG waveforms to a pure sinusoid (in this case, 600 Hz) and tone complex with the corresponding inferred fundamental (in this case, 12-18-24) for a representative subject.
Data is the RMS from 10 channels (five sink, five source) in the left hemisphere. The peak around 100 ms post-onset of the target (0 ms represents the onset of the target) is the M100. The peak latency of the M100 to the pure sinusoid and its corresponding tone complex were closely matched. The head-models represent the magnetic field contours for the M100. The red regions represent the source of the dipole and the blue regions represent the sink of the dipole.
Figure 3.
M100 RMS latencies to single sinusoid tones, tone complexes (plotted by their inferred fundamental component), and the 12-17-19-24 kHz tone complex, whose fundamental component is 100 Hz.
Error bars refer to ±1 standard error of the group mean.