Table 1.

M100 response latencies, amplitudes, and dipole strengths

Tone	ISI, ms	M100 latency, ms		M100 rms, fT		M100 ∥Q∥, nA-m
		Poor readers	Good readers	Poor readers	Good readers	Poor readers	Good readers
First 20-ms	500	106  ±  8	96  ±  5	116  ±  8	130  ±  16	35  ±  7	47  ±  9
Second 20-ms	500	89  ± 9	109  ±  10	59  ±  9	69  ±  7	31  ±  6	21  ±  13
Second 20-ms	200	107  ±  7	115  ±  12	79  ±  9*	110  ±  13	20  ±  3*	34  ±  6

Model-independent (rms) and model-dependent (∥Q∥) amplitudes are shown for the different conditions. These data were obtained from the averaged evoked response in each sensor filtered between 0 and 20 Hz, for each ISI condition. In spite of the interference between the responses to each stimulus in the 200-ms ISI condition, significant differences were observed between the M100 responses after the second stimuli. All of these single-equivalent current dipoles were localized to within primary auditory cortex and its immediate environs, and the locations were neither significantly different across these different conditions nor between poor and good readers 4.0 ± 0.3 cm antero-posterior, 5.0 ± 0.1 cm latero-medial, 5.8 ± 0.2 cm inferio-superior, see Methods for coordinate system). Note that there were also no significant differences in M100 latencies. Values shown are mean ± SEM. ∗, P < 0.05.