Is bar-holding with negative reinforcement preparatory or perseverative.

The team taught rats to press two bars in order to escape mild shock. They compared two ways to build the chain: teach bar one first, or teach bar two first.

They watched where the rats held the bar. Did holding happen to get ready for the next move, or did it linger from the last move?

Forward chaining (bar one first) worked faster. Rats held the second bar longer, not the first. The hold looked like a leftover from the first bar, not a warm-up for escape.

This supports a perseverative view: the animal keeps doing what it just did.

MIGLELong (1963) showed that bar holding grows stronger when escape needs releasing the bar, not pressing it. D (1967) adds the timing rule: hold shows up on the later link of a chain, not the early one.

Nighbor et al. (2018) found that old responses pop back when the setting stays the same. The long hold on bar two is one of those pop-backs, driven by the first link’s history.

Together, the three papers say: watch the response shape, watch the chain order, and watch for ghosts of past reinforcement.

When you chain escape or avoidance skills, teach the steps in forward order. Expect extra holds, repeats, or stalls on later steps; they are perseveration, not lack of motivation. Build in brief pauses or release cues to break the loop. This keeps the chain clean and reduces problem behavior that can grow out of stuck motor patterns.