how many changes are there?

I have this kind of data (column 1-2-3, respectively):

 Right= [1 1 1 0 0 0 0 0 1 0 1 1 1]
 Center=[0 0 0 1 1 1 0 0 0 1 0 0 0]
 Left=  [0 0 0 0 0 0 1 1 0 0 0 0 0]

I want to count how many changes there are between right and left, not considering the center. In my example there are 2 changes in total from right to left and from left to right. Thank you in advance.

[Geoff Hayes]

Gisella - please clarify what you mean by a change. How do you get two changes when all the ones in the left and right are in different positions?

[Thorsten]

What exactly are the "2 changes in total from right to left and from left to right"? Please expand.

[Gisella Decarli]

Here attached you can find an exemple of data. 1 means that subject is looking at the screen (left, right or center) and 0 that is not looking. So, I want to know how many times a subject switches the eyes from right to left and from left to right, not considering the center column. E.g. in the file (Trial5), here attached, the first switch is from right to left at 3.2,the second at 19.5 from right to left, the third at 20.4 from left to right and the fourth at 22.2 from right to left), so, in total there are 4 switches. Hope you will understand now. Thank you!