Fig. 1.

Schematic diagram of stimulation patterns. O: objective; and R: retina. Black dash lines indicate the normal axis of retinal surface. Red solid lines indicate the incident directions. Top panels are cross-section view (transverse or $x–z$ plane) and the bottom panels are enface view (axial or $x–y$ plane). (a1) Rectangular stimulus (bottom panel) with 30-deg incident angle with respect to the normal axis of retinal surface (top panel). (a2) Rectangular stimulus (bottom panel) with $-30\text{-}\mathrm{deg}$ incident angle (top panel). (b) Circular stimulus (bottom panel) with 0-deg incident angle (top panel). The retina was placed with the ganglion cell layer facing toward the objective.