Conditioned suppression by a stimulus associated with nalorphine in morphine-dependent monkeys.
Fear shuts work down, but new pairings with safety turn it back on.
01Research in Context
What this study did
Scientists worked with monkeys that depended on morphine.
A tone sounded before each dose of nalorphine. Nalorphine makes morphine users feel sick.
The monkeys soon stopped pressing a lever for food when they heard the tone.
Later the team paired the same tone with plain salt water. Lever pressing came back.
They repeated the steps to show the effect was real.
What they found
A neutral sound can turn into a danger signal after just a few pairings.
The danger signal shuts down food-motivated work.
New pairings with safe events erase the fear and work returns.
The whole cycle can run again, proving the change is learned.
How this fits with other research
Blue et al. (1971) got the same shutdown using shock instead of sickness.
Together the studies show the effect works across many kinds of bad news.
Azrin et al. (1969) flipped the idea: a cue for free food also slowed lever pressing.
That means even good news can pause work if it signals something new is coming.
Hake et al. (1969) used the same fear tone to spot social boosts.
They found a friend nearby sped pecking only when fear was strong.
The 1967 paper gives the baseline they all build on.
Why it matters
You can create or remove fear-based avoidance with simple pairings.
If a client stops working when the bell rings, test what that bell once predicted.
Re-pair the sound with safe, boring events and watch the work come back.
The same logic applies to any stimulus that kills motivation.
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Pick one feared cue, deliver it five times with a neutral item, then measure if work resumes.
02At a glance
03Original abstract
Three rhesus monkeys, physically dependent on morphine, were trained to press a lever for food on a fixed ratio of 10 responses. A tone, initially a neutral stimulus, was aperiodically presented every third or fourth session, 5 min before and after the intravenous injection of nalorphine, a morphine antagonist which produces an immediate withdrawal syndrome in morphine-dependent monkeys. After several sessions, conditioned suppression of food-lever response rate was observed. Conditioned bradycardia, emesis, and excessive salivation also occurred. In 40 to 45 sessions the conditioned suppression of food-lever response rate and the conditioned autonomic changes were extinguished by presenting pairings of a tone and saline injection. The monkeys were then reconditioned by presenting the tone aperiodically, every third or fourth session, 5 min before and after the intravenous injection of nalorphine. Results were similar to the initial conditioning sessions. Two rhesus monkeys not dependent on morphine were stabilized on a food schedule similar to that used for the first three monkeys. These monkeys showed no change in food-lever response rate during or after nalorphine injections.
Journal of the experimental analysis of behavior, 1967 · doi:10.1901/jeab.1967.10-235