The development of fixed-ratio performance under the influence of ribonucleic acid.
Fixed-ratio pauses and bursts develop in a set order, and only low-dose yeast RNA slightly speeds the process.
01Research in Context
What this study did
Six pigeons pecked a key for grain. First they got food every peck. Then the requirement grew: 5, 10, 20, up to 30 pecks.
Before each session the birds got a shot. Some days it was salt water. Other days it was yeast RNA: 250 mg/kg or 500 mg/kg.
The team tracked every peck and pause with a computer. They wanted to see if RNA changed how the birds learned the ratio.
What they found
Low-dose RNA made the birds peck a bit faster. High-dose RNA did not help; the birds hit their top speed early and stayed there.
No drug stopped the classic FR pattern: long pause after food, then quick steady pecks to the next payoff.
The pause grew and the burst shortened in the same order every time, showing FR micro-structure develops like clockwork.
How this fits with other research
Halpern et al. (1966) first drew the FR pause map: bigger ratio, longer pause. McLaughlin et al. (1972) add computer-level detail and show RNA can nudge, not rewrite, that map.
Gettinger (1993) later split behavior into pause vs. response parts. His yoked VR-VI data prove the pause drives the downturn on ratios, backing the 1972 finding that pause shape stays stable even under drugs.
Dove et al. (1974) extended the idea: birds trained on FR later peck faster under fixed-time food. Together these papers say FR history stamps a lasting rhythm on any future schedule.
Why it matters
You can’t buy yeast RNA on Chewy, but you can copy the lesson: ratio micro-structure is stubborn. When you shape a client from FR-1 to FR-30, expect the pause-to-burst pattern to appear in that same order every time. If performance stalls, check the pause first—reinforce early responses to shorten it, just as the 1972 birds shortened theirs with low-dose help.
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Join Free →Graph the post-reinforcement pause length as you move from FR-1 to FR-5; reinforce the first response after 2 s to keep the pause from growing.
02At a glance
03Original abstract
The transition from fixed-ratio 1 performance (every response reinforced) to fixed-ratio 30 performance (every thirtieth response reinforced) was studied in nine pigeons. These were divided into three treatment groups given daily oral doses of saline, or 250 mg/kg/day or 500 mg/kg/day of yeast ribonucleic acid. Detailed computer-assisted analyses of how fixed-ratio behavior develops revealed the following typical sequence. After the transition, the first few ratios typically were emitted without long interresponse times within the ratio. Steady responding then ceased, and numerous long interresponse times occurred, with no systematic relationship to ordinal position within the ratio. Gradually, a new pattern evolved, characterized by a consistently long post-reinforcement time, a border region of the next few interresponse times within which the mean interresponse time monotonically decreased, and short interresponse times within the last 80% of the ratio. Long interresponse times were eliminated from this last section of the ratio without regard to proximity to reinforcement. Various analytical procedures suggested that the final pattern can be conceived, in part, as the shaping of a reliable response topography. The group of three pigeons given 250 mg/kg/day of yeast ribonucleic acid responded at higher rates than the saline and 500 mg/kg/day groups. The latter group, in contrast to the saline and lower dose groups, which continued to increase their rates, reached a rate asymptote very early.
Journal of the experimental analysis of behavior, 1972 · doi:10.1901/jeab.1972.18-481