TABLE 1.

Regression coefficients, standard errors (se) and p Values for the modeling using Actiwatch spectral R, G, B outputs to predict photoreceptor excitations under daylight illuminants or fluorescent illuminants.

	Photoreceptor	β(RW)	se	p Value	β(GW)	se	p Value	β(BW)	se	p Value	R2	Mean error
Daylight illuminants
Our Actiwatch	S-cone	1.707	0.124	<0.001	−9.126	0.351	<0.001	27.947	0.288	<0.001	1.000	0.0022
	L-cone	1.732	0.003	<0.001	5.789	0.010	<0.001	0.249	0.008	<0.001	1.000	0.0001
	Rod	0.962	0.049	<0.001	4.114	0.138	<0.001	10.822	0.114	<0.001	1.000	0.0008
	ipRGC	0.930	0.066	<0.001	1.563	0.189	<0.001	14.692	0.155	<0.001	1.000	0.0011
Price et al.’s Typical Actiwatch	S-cone	2.364	0.191	<0.001	−12.029	0.501	<0.001	33.148	0.483	<0.001	1.000	0.0031
	L-cone	1.738	0.009	<0.001	5.890	0.025	<0.001	0.022	0.024	0.359	0.999	0.0001
	Rod	1.160	0.067	<0.001	2.815	0.176	<0.001	12.616	0.170	<0.001	1.000	0.0010
	ipRGC	1.221	0.095	<0.001	−0.147	0.250	0.563	17.258	0.241	<0.001	1.000	0.0014
Fluorescent illuminants
Our Actiwatch	S-cone	−0.133	0.064	0.837	−2.930	2.223	0.200	20.465	2.875	<0.001	0.873	0.0437
	L-cone	1.676	0.064	<0.001	6.496	0.223	<0.001	−0.555	0.289	0.066	0.796	0.0040
	Rod	0.983	0.870	0.270	−0.294	3.036	0.924	15.051	3.925	0.001	0.611	0.0607
	ipRGC	0.902	1.036	0.393	−3.344	3.614	0.364	19.242	4.673	<0.001	0.630	0.0649
Price et al.’s Typical Actiwatch	S-cone	−1.044	0.965	0.290	−1.350	3.928	0.734	18.616	5.372	0.002	0.800	0.0545
	L-cone	1.858	0.099	<0.001	5.924	0.405	<0.001	0.084	0.554	0.881	0.664	0.0053
	Rod	−1.071	1.180	0.373	7.497	4.804	0.132	4.701	6.570	0.481	0.508	0.0607
	ipRGC	−1.662	1.445	0.261	6.271	5.882	0.297	6.596	8.046	0.420	0.504	0.0845

R² is calculated by the square of the correlation between the observed and predicted values, a conservative statistic for describing the fitting quality of regression through the origin model. The error is computed by |log (Ŷ/Y)|, where Y and Ŷ are observed and predicted values, respectively.