if condition is true record value from next row

I am looking to latency of a trial IF the previous row was incorrect "0" and the current row is correct "1" to answer the question to people answer faster if they get the previous question wrong

I have tried using the code below

tabm.Error = tabm.Correct;
%tabm.Error is a new column I am trying to create
if istable (tabm.Error)
    [r,c] = size(tabm.Error);
    for i=1:r
        A = tabm.Correct(r)==0;
        B = tabm.Correct(r+1)==1;
        if A && B
            tabm.Error = 1;
        else tabm.Error = 0;
        end
    end
end

Currently, the Error column is just a copy of the Correct Column

Thank you!

[dpb]

You didn't subscript the Error variable in the assignment so each assignment writes the whole vector of 1|0.

Excepting your loop over i doesn't use i at all; every refererence to tabm.Correct is to the last and (non-existant) last + one elements. That looks like should have error'ed on an out-of-bounds reference.

Try something more like

ix=[0;diff(tabm.Correct)==1];
tabm.Error=ix;