Table 2. PCA components’ loadings for each illusion.

	PCA 1 (36%)	PCA 2 (23%)	PCA 3 (17%)	PCA 4 (14%)	PCA 5 (10%)
Ponzo	0.40	0.48	0.37	−0.66	−0.20
vertical-horizontal	0.41	−0.25	−0.80	−0.35	−0.07
Muller-Lyer	0.55	−0.25	0.21	0.46	−0.61
Ebbinghaus	0.60	0.17	0.06	0.30	0.72
Contrast	−0.07	0.79	−0.42	0.37	−0.25

Variance explained by each component is given in brackets for each component.