Their work in the 1960s and 1970s on how the visual system developed.

The classic model of the critical period has been the visual system.

This is the first level to require a visual system.

Another criticism comes from investigation into the human visual system.

Cells in the visual system are looking for places to run or pass the ball.

There are two strategies for finding out how the visual system works.

The main one has been to make us think more closely about how the visual system might be organized.

We might, therefore, expect them to work in the same sort of way as the visual system.

But the visual system is not the only one that can perform such functions.

This visual binary system has a period of 49.6 years.