Variable location of punishment in a response sequence.
One shock per long response chain gives uneven suppression and longer pauses, so punish early or use other tactics.
01Research in Context
What this study did
Dardano (1972) looked at where punishment lands inside a long chain of 100 lever presses.
One electric shock was given only once during each 100-response fixed-ratio.
The shock could hit early, middle, or late in the chain, and the team watched which part of the chain slowed down.
What they found
Shocks early in the chain made the rat pause longer right after food.
The first half of the chain dropped, but the second half stayed about the same.
No spot in the chain gave a clear, repeatable drop in pressing — effects were messy.
How this fits with other research
Garcia et al. (1971) saw big, clean suppression when every self-injury was shocked.
The messy pattern in Dardano (1972) shows punishment can fail if it lands only once and in different spots.
Oliver et al. (2002) say we still lack rules for making punishment work with smaller, safer stimuli — these mixed data are why.
Kuroda et al. (2019) later proved shock still works as a punisher in fish, so the tool is valid; the problem is how we place it in the response chain.
Why it matters
If you use punishment, deliver it right after the first response you want to stop. Spacing one aversive event across many responses gives spotty suppression and longer pauses. When you write a behavior plan, either punish every target response or switch to a reinforcement-based chain instead.
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02At a glance
03Original abstract
Key pecking of pigeons under a fixed-ratio 100, grain reinforcer schedule was followed by electric shock occurring once in each sequence of 100 responses with the shocked response varying irregularly in successive sequences. Under this shock schedule, a localized suppression of responding in a response sequence was not correlated with the probability of shock at different points in the sequence. High shock levels increased the duration of post-reinforcement pauses and suppressed responding during the first half of the response sequence. This suppression often persisted after the shocked response when shock occurred early in the sequence. The shock schedule did not produce a consistent suppressing effect on responding during the last half of the response sequence.
Journal of the experimental analysis of behavior, 1972 · doi:10.1901/jeab.1972.17-433