Table 1.

Performance of the different methods for classifying fixation as central vs para-central

	Simple threshold (method 1)	Discriminant analysis (method 2)
		2D	3D	4D
	$\frac{\left(P_{2.5}+P_{6.5}\right)}{P_{4.5}}$	$\frac{\left(P_{2.5}+P_{6.5}\right)}{P_{4.5}}vs\frac{\left(P_{3.5}+P_{5.5}\right)}{P_{4.5}}$	$\frac{P_{6.5}}{P_{4.5}}vs\frac{P_{2.5}}{P_{4.5}}vs\frac{\left(P_{3.5}+P_{5.5}\right)}{P_{4.5}}$	$\frac{P_{6.5}}{P_{4.5}}vs\frac{P_{2.5}}{P_{4.5}}vs\frac{P_{3.5}}{P_{4.5}}vs\frac{P_{5.5}}{P_{4.5}}$
	θ = 0.8750	a 0 = 0.743, a 1 = 0.318	a 0 = 0.768, a 1 = 0.056, a 2 = −0.289	a 0 = 0.779, a 1 = 0.016, a 2 = −0.283, a 3 = 0.083
Sensitivity	0.9917	0.9083	0.9417	0.9417
Specificity	0.9625	0.9771	1.0000	1.0000

All methods use spectral power at odd multiples of half the scanning frequency f _s. Method 1 uses optimized simple threshold, whereas Method 2 utilizes 2-, 3-, and 4-way linear discriminant functions, whose coefficients are shown in the table