Reinforced behavioral variability in the valproate rat model of autism spectrum disorder

Galizio et al. (2022) tested rats exposed to valproate before birth. This drug creates an animal model of autism traits.

Half the rats had to vary their lever-press sequences to get food. The rest could repeat the same pattern.

The team tracked how often each rat changed its sequence when the rules switched.

When reinforcement required variety, both groups produced the same amount of novel sequences.

During non-reinforced phases, the VPA rats were slightly more variable than controls.

The data show that the autism model rats can flex when the contingency demands it.

Dugdale et al. (2000) and Gardner et al. (2009) found that children with autism quickly boost variety when a lag schedule pays for new responses. The rat data mirror this: variability contingencies work even in an autism model.

Doughty et al. (2015) showed pigeons need explicit variability rules, not just change-overs, to produce high variety. The rats here followed the same explicit rule, so the mechanism looks similar across species.

Nergaard et al. (2020) argue that "reinforced variability" is really reinforcement plus extinction of old forms. The VPA rats’ intact performance fits this view: the contingency simply made old sequences stop paying off.

The study tells us that restricted, repetitive behavior may not come from a built-in rigidity engine. If the payoff flips to novelty, the animal (and maybe the child) can shift. When you write a plan for stereotypy, build in lag schedules or multiple-exemplar requirements instead of assuming the learner cannot vary. Try reinforcing a different toy placement each time during play, or a new word each time during mand training, and watch flexibility grow.