By the way, your code wouzld be much cleaner and shorter, if you use arrays instead of hiding indices in the field names: Define list.stimpair as nan(1, NBlock) and your code becomes:
for bnum = 1:Nblocks
index = randi(8);
chosenstim.s(index) = list.stimpair(index);
end
To avoid repetition use randperm:
index = randperm(8, 8)
chosenstim.s(index) = list.stimpair(index);
No loop, no switch, no bunch of case blocks, and even:
stimlist = [list.stimpair1; list.stimpair2; list.stimpair3; list.stimpair4; list.stimpair5; list.stimpair6; list.stimpair7; list.stimpair8];
becomes:
stimlist = list.stimpair;
Do you see the power of arrays instead of numbered field names?
A hint:
stimpairpresented = [];
stimpairpresented = [stimpairpresented,randi(8)];
% is exactly the same as:
stimpairpresented = randi(8);
