Discrimination of brightness differences by rats with food or brain-stimulation reinforcement.
Brain stimulation pushes visual learning as well as food does, so you can swap reinforcers without losing skill gains.
01Research in Context
What this study did
The team worked with rats in a small lab box.
Each rat had to press a lever only when a bright light came on.
Half the rats earned food pellets for correct presses.
The other half earned a tiny buzz of brain stimulation instead of food.
Training ran for seven to eight short sessions.
What they found
Both groups learned to pick the bright light with almost no errors.
Rats worked for brain stimulation just as hard as they worked for food.
Fine visual discrimination grew at the same speed no matter the payoff.
How this fits with other research
Morse et al. (1966) showed that blocking trials beats stair-step trials for the same brightness task.
Hart et al. (1968) used the better block method and swapped the reinforcer, so the two papers stack like Lego.
Neuringer et al. (1967) proved that plain blackouts can act as reinforcers when scheduled right.
That trio together says: pick the method first, then pick any reinforcer that keeps the rat moving.
Why it matters
You now know that non-food rewards can drive sharp discrimination.
Try brain stimulation, music clips, or brief games with learners who tire of edibles.
Keep the task blocked, deliver the new reward fast, and watch accuracy climb just like it did for the rats.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Pick one visual discrimination target and test a non-food reinforcer (iPad blink, short song) in blocked trials.
02At a glance
03Original abstract
Rats were trained to respond to the brighter of two keys. Four animals were trained with food pellets and four with electrical brain stimulation. Each discrimination sequence was initiated when the animal broke a light beam at the rear of the chamber, turning on the key lights and starting a 30-sec reinforcement period. An initial response on the brighter key was immediately reinforced, and further responses on the brighter key were then intermittently reinforced. Any time the dimmer key was pressed, a 30-sec timeout was introduced. During timeout, no response had any programmed consequence. When the reinforcement period or the timeout ended, a new discrimination sequence could be initiated. Daily 1-hr training sessions were conducted, and after seven or eight sessions, all animals were at or near errorless performance levels. The luminance of the brighter key was then systematically reduced, in seven steps, with two 30-min test sessions at each step. Orderly psychometric functions were generated for individual animals. Initial acquisition, once position preferences were broken, was equally rapid for food and for brain-stimulation animals, and the two reinforcement procedures yielded comparable levels of brightness discriminability.
Journal of the experimental analysis of behavior, 1968 · doi:10.1901/jeab.1968.11-29