the novel arm was 90%), a different procedure was used for the selected line experiments. On trial 1, no partition was used to obstruct one of the arms, so the mouse was allowed to enter either arm. The mouse was then restrained in the chosen arm for ≈30 sec, the added partition was removed, and the mouse then entered either the novel arm or the arm it was placed in at the start of the test. The apparatus was cleaned between the testing of individual mice.
