Behavioral and pharmacological modulation of respiration in rhesus monkeys.
Lever pressing on FR or FI schedules locks breathing into matching rhythms, proving respiration can be operant behavior.
01Research in Context
What this study did
Matson et al. (1994) watched rhesus monkeys press a lever for food. The team used two classic schedules: fixed ratio (FR) and fixed interval (FI). They taped tiny masks to the animals to record every breath. After baseline, they gave a drug that slows responding and added CO2 to the air.
The goal was simple: see if steady lever pressing creates its own breathing rhythm.
What they found
Each schedule produced its own breath signature. FR sessions showed quick bursts of air. FI sessions showed slower, steady waves. When the drug stopped the lever presses, the breathing patterns vanished at the same moment.
Extra CO2 made the animals breathe faster, but the schedule shape stayed the same. Behavior and breathing were locked together.
How this fits with other research
Gardner et al. (1976) and Dykens et al. (1991) used the same FR/FI cocaine setup. They focused on how fast the monkeys pressed. Matson et al. (1994) added the missing piece: the lungs follow the same schedule rules.
Jack et al. (2003) later showed humans with panic-style hyperventilation also breathe in learned, predictable ways. The monkey data help explain why: breathing can be operant behavior, not just a reflex.
Richman et al. (2001) treated breath holding in a child by treating the breath as an operant. The 1994 study gives the basic-science backbone: if breath can be reinforced, it can also be shaped or reduced.
Why it matters
You now have a yardstick. If a client’s breathing pattern looks like an FR burst or an FI wave, ask what social or automatic reinforcer keeps that schedule running. You can test the idea by briefly blocking the behavior and watching the chest. If the pattern fades with the reinforcer, you have an operant, not a medical problem. Treat the contingency, not just the symptom.
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02At a glance
03Original abstract
Changes in respiration associated with schedule-controlled behavior were determined in seated rhesus monkeys prepared with a pressure-displacement head plethysmograph for monitoring ventilation continuously during behavioral experiments. Subjects were trained to press a lever under fixed-ratio 40 and fixed-interval 300-s schedules of stimulus termination. Episodic increases in ventilation were closely associated with periods of responding under both schedules. Recurring episodes of increased ventilation occurred during fixed-ratio responding, and were separated by brief 10-s timeouts during which ventilation decreased. Under the fixed-interval schedule, both ventilation and response rate typically increased as the 300-s interval elapsed. The effects of cocaine, caffeine, and two adenosine agonists, 5'-N-ethylcarboxamidadenosine (NECA) and 2-(carboxyethylphenylamino)adenosine-5'-carboxamide (CGS 21680), on behavior and respiration were determined using a cumulative-dosing procedure. Drug-induced suppression of behavior eliminated the episodic increases in ventilation during the performance components of both schedules. Schedule-related increases in ventilation were compared to those produced by elevated levels of CO2 in inspired air. Exposure to 4% CO2 mixed in air increased ventilation in all subjects, and the combined effects of CO2 exposure and schedule-controlled responding on respiration appeared to be additive. The results suggest that behavioral activities may increase ventilation through increased metabolic demand and increased CO2 production.
Journal of the experimental analysis of behavior, 1994 · doi:10.1901/jeab.1994.62-57