Self-punitive avoidance behavior in the mouse

Mice were trained to avoid shock by leaving a startbox and traversing a straight alley. During the first extinction phase (Phase I), two groups were given 30 regular extinction (RE) trials, while another two received punished extinction (PE) trials in the center of the alley. During the last 50 extinction trials (Phase II), conditions were reversed for one of the two groups receiving the same treatment in Phase I. This resulted in two nonshifted groups (RE-RE and PE-PE) and two shifted groups (RE-PE and PE-RE). PE treatment led to higher running speed in both phases and reversed an extinction trend. Furthermore, punishment-induced facilitation was greater for the group receiving PE following RE than for the group receiving PE immediately after avoidance training.