(b)

Timing gains	Average	SEM	Upper 97.5% CL	Lower 97.5% CL
PIIIit to PIIit*	1.54	0.12	1.88	1.19
PIIit to pSTRit #	0.71	0.05	0.85	0.56
PIIit to nSTRit #	0.88	0.03	0.97	0.78

The average, SEM, and 95% confidence limits for the ERG regressions established from 5 trials in Figure 3. Amplitude (a) and timing (b) ERG gains whose 95% confidence limits encompass 1 indicate an ERG gain of unity. Those that are significantly greater than 1 indicate an amplification in gain (*) and significantly less than 1 a compression in gain (^#). This indicates that the PIII_amp to PII_amp has a gain which encompasses unity whereas there is an amplification of gain between the PII_amp to pSTR_amp and the PII_amp to nSTR_amp. In terms of timing, there is an amplification of gain between the PIII_it to PII_it in contrast to a compression of gain between the PII_it to pSTR_it and the PII_it to nSTR_it.