A method for increasing the reinforcement magnitude of intracranial stimulation.

Researchers wired rat brains so each lever press delivered tiny electric pulses. They changed how many pulse trains came with one press. The rats worked for one, two, four, or eight trains. Response rate was counted across sessions.

More trains per press made the rats press faster. Fewer trains slowed them down. The change was smooth and orderly. The team showed pulse count is a dial you can turn to set reinforcer strength.

Doughty et al. (2002) later tested bigger food pellets under DRL schedules. Bigger pellets also sped responding, but they ruined the schedule's efficiency. The two studies line up: magnitude boosts rate, yet can hurt timing tasks.

Reed (2003) added a 500-ms signal before food on FI schedules. The signal helped or hurt depending on the rat's local rate right before it. Together the papers warn that magnitude and signaling effects hinge on the schedule in use.

Ivancic et al. (1996) looked at clients with profound disabilities. Even highly preferred items sometimes failed to work as reinforcers. The 1967 study gives a mechanistic reason: if magnitude is too low, the brain may not register it as reinforcement at all.

You now have a clean lab proof that 'how much' is a free parameter. When a token, edible, or praise seems weak, try stacking more units before delivery. Watch the response curve rise just like the rat's lever press rate. Use this when thinning reinforcement or when clients with limited movement need extra punch from each reward.