Apparent movement and appearance of periodic stripes during eye movements across a stroboscopically illuminated random dot pattern

Summary

When the eyes follow a small target moving across a stationary random dot pattern illuminated stroboscopically at 3–45 flashes · s^-1, the structure of the random dot pattern is seen as moving in the direction of the eye pursuit movements (σ-movement). At flash frequencies above 9.5 flashes · s^-1, periodic stripes oriented perpendicularly to the direction of the pursuit eye movements appear and are also seen as moving in the direction of the eye pursuit movement. The period P_s* of the apparent stripes depended on the flash frequency f_s and the angular speed of the eyes V_e:

$${\text{P}}_{\text{S}} * = \frac{{{\text{k*V}}_{\text{e}} }}{{{\text{f}}_{\text{S}} }}[\deg ];0.76 \leqslant {\text{k*}} \leqslant {\text{1}}{\text{.06}}$$

Apparent sigma-movement and apparent stripes were also seen when eye pursuit movements were initiated outside of the random dot pattern and they continued autonomously without a moving target across the pattern. The angular velocity of the σ-pursuit movement across the random dot pattern depended on the flash frequency and the angular velocity of the initiating target.

With the eyes stationary but a moving random dot pattern, the apparent stripes also appeared at flash frequencies f_s ≥ 9.5 flashes · s^-1. Eq. (1) was valid when V_e was replaced by the target angular velocity V_s (k* = 1).