Collateral behavior of the pigeon during conditioned suppression of key pecking.
A signal that predicts shock freezes every move, not just the target response.
01Research in Context
What this study did
Researchers watched pigeons peck a key for food. A buzzer warned that a mild shock was coming.
They counted how the birds moved when the buzzer sounded. They tracked side moves, wing shifts, and freezing.
What they found
The buzzer froze everything. Key pecks stopped and extra body moves vanished.
After the shock ended, the birds still moved less than before. The silence spread beyond the key.
How this fits with other research
Dunham et al. (1969) saw the opposite. When key pecks earned shock, off-key pecks rose. Same species, same shock, but punishment boosted nearby moves while conditioned suppression froze them. The tasks differ: one links shock to the key, the other links shock to a signal.
Hoffman et al. (1966) showed the same buzzer-shock setup can keep pigeons quiet for years. Ginsburg et al. (1971) zooms in on the first minutes and shows the freeze hits every muscle, not just the beak.
Henton (1972) swapped shock for extinction and still got near-zero pecks. The common thread: any feared stimulus can lock a pigeon in place.
Why it matters
For your clients, watch what surrounds the punished response. If the punisher is tied to a signal, you may see wide stillness. If the punisher is tied to the response itself, watch for a burst in other moves. Choose your contingency to fit the change you want.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Before adding a warning stimulus, record baseline levels of three collateral behaviors so you can spot a global freeze or a contrast burst early.
02At a glance
03Original abstract
Ethological recording procedures measured collateral behavior in pigeons whose key-pecking performance was suppressed during a tone that ended with unavoidable electric shock. Independent recordings of gross behavior were made by two observers throughout 60-sec intervals immediately before, during, and after tone presentation. Results indicated significant reductions in the frequency of collateral movements and an increase in the time between successive movements during tone presentations. These effects were observed in all subjects, despite differences in the sequential patterns of behavior. Only partial recovery of the behavior evidenced before tone presentation was found during a 60-sec interval following shock. It was concluded that conditioned suppression procedures caused the bird to "freeze" during tone presentation and in this fashion produced a general inhibitory effect on ongoing overt activity, including key pecking.
Journal of the experimental analysis of behavior, 1971 · doi:10.1901/jeab.1971.15-83