No...psych 1A and psych 1B are different subjects, usually A and B subjects complement each other (just not in the case of psych, you can do 1B without having done 1A).
Electives are just that - you do what ever you want. I did Physics 1A in session 1, but decided I didn't want to continue with physics, so I didn't pick physics 1B in session 2 and did electrical engineering instead.
So in session 2, you can either continue with the subject you want to continue with, or pick something completely new.
My suggest is to continue with something, so that you can continue with the study in that field in later years - because if you're scattered all over the place in first/second year, when you pick electives for 3rd year you might find yourself at a dead end because you haven't done pre requisites for 3rd year electives.