Effects of food deprivation and reinforcement magnitude on conditioned suppression.
Hunger level drives response strength more than the size of the reward you offer.
01Research in Context
What this study did
The team worked with hungry pigeons in a lab. They changed two things: how long the birds went without food and how big the grain reward was.
Then they watched how these changes altered conditioned suppression — the brief pause in pecking that happens when a warning signal predicts a mild puff of air.
What they found
Making the birds hungrier made them peck more, even during the scary warning signal.
Changing the grain size had only small, order-dependent effects. Motivation beat reward size.
How this fits with other research
Cashon et al. (2013) later showed the same thing in reverse: bigger rewards actually cut the variety of responses you are trying to reinforce. Together the two papers show magnitude is a weak lever once the bird is already working.
Bacon et al. (1998) added hunger to a drug study and saw the same pattern: food level, not pill size, shifted the dose curve.
Noordenbos et al. (2012) mixed apomorphine with reward size and again found smaller rewards made the drug punch harder. All three later studies echo the 1977 message: deprivation sets the stage, magnitude just tweaks the dial.
Why it matters
If your client is not responding, check motivation first. A larger edible or longer iPad turn may not help if the child is only mildly hungry or tired. Try shortening the time since the last meal or adding a quick exercise warm-up before you bump reinforcer size.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Track each learner’s meal schedule and run sessions right before lunch or snack time.
02At a glance
03Original abstract
In Experiment I, the responding of rats lever pressing on a variable-interval schedule for sucrose solution was partially suppressed by a variable duration conditioned stimulus followed by shock. When food deprivation was increased, response rates during and before the conditioned stimulus increased monotonically. Varying the concentration of sucrose across blocks of sessions or from session to session in a semi-random sequence had little effect on response rates either before or during the conditioned stimulus. With a fixed sequence of increasing concentrations across a five-session block, increased concentration produced much more rapid increases in response rates before than during the conditioned stimulus. In Experiment II, rats were presented with the same sequence of increasing concentrations across a five-session block. When tested at 80% body weight, response rates increased rapidly as concentration increased, but at 100%, body-weight rates increased only slightly. The effect of a change in body weight in Experiment II thus mimicked the effect of the conditioned stimulus in the latter part of Experiment I. These findings support the view that the effect of a pre-aversive conditioned stimulus is similar to that of a change in food deprivation, but unlike that of a change in reinforcement magnitude.
Journal of the experimental analysis of behavior, 1977 · doi:10.1901/jeab.1977.28-107