Removed X0 fixation in multisession

[cgoldman123]

Hello,

I hope you're doing well. I'm using VBA to fit behavioral data from a two-armed bandit task, where participants completed 40 blocks of 5 or 9 trials each, with learning resetting at the start of each block. I was hoping to use the same initial state parameters across multiple experimental sessions. However, I noticed that the line for fixing X0 in multisession was commented out in this commit.

Is there an alternative way to fix the initial state across sessions?

Best,
Carter