The effects of brief-stimulus presentations in fixed-ratio second-order schedules.
Brief stimuli paired with food can suppress, not boost, responding when ratio schedules are dense.
01Research in Context
What this study did
James et al. (1981) worked with pigeons on fixed-ratio schedules. They added tiny light flashes right before food. The flashes were meant to act like little 'attaboys' to keep the birds pecking.
The team tested different ratio sizes. Some birds had to peck only a few times per food. Others pecked many times. They watched how the brief lights changed the birds' speed and pauses.
What they found
The light flashes slowed the birds down instead of helping. Key-pecking rates dropped. The birds also paused longer before starting each ratio.
The problem was worst when the ratio was small but the total work demand was large. The 'conditioned reinforcer' turned into a mini-punisher.
How this fits with other research
Stubbs et al. (1970) saw the opposite. Their brief stimuli paired with food improved pigeons' accuracy in a discrimination task. The difference: A et al. used lean food schedules and a choice task. L et al. used dense ratio schedules and simple pecking. Same stimulus, different context, opposite effect.
Reid et al. (1983) also showed that timing matters with food schedules. They found that short intervals between food deliveries created frantic, feeder-directed stereotypy. L et al. extend this idea: brief events tied to food can reshape behavior in unexpected ways.
Bryant et al. (1984) showed pigeons hate long initial ratios when given a choice. L et al. add a twist: even a tiny light can make a small ratio feel harder if the overall work is big.
Why it matters
For BCBAs, the takeaway is simple: a 'reinforcer' is only reinforcing if the context supports it. Brief praise, tokens, or lights can backfire under heavy work demands. Check your ratio size and total task load before adding conditioned reinforcers. If a client stalls after praise, try thinning the ratio or dropping the extra stimulus. Let the primary reinforcer do the work.
Get CEUs on This Topic — Free
The ABA Clubhouse has 60+ on-demand CEUs including ethics, supervision, and clinical topics like this one. Plus a new live CEU every Wednesday.
Count responses between reinforcers; if the client pauses after tokens or praise, test removing the brief stimulus and thinning the ratio.
02At a glance
03Original abstract
Pigeons' responses were reinforced according to a three-component multiple schedule. In Component 1, key pecks produced food according to a fixed-ratio second-order schedule with fixed-ratio units. Here, a fixed number of fixed-ratio units produced food, and the brief stimulus terminating each unit also accompanied food. Responses in Component 2 produced food on an identical schedule except that the brief stimulus was not paired with food. Component 3 contained a simple fixed-ratio schedule whose response requirement equaled that of Components 1 and 2. Across conditions the size of the fixed-ratio unit (five, ten, twenty, forty, and eighty responses) and the total number of responses per reinforcement were parametrically manipulated. The highest response rates and shortest preratio pauses were observed in Component 3 (no brief stimulus). The lowest rates and longest pauses were found in the component with paired brief-stimulus presentations, indicating that the food-paired brief stimulus suppressed responding. The suppressive effects were greatest when the fixed-ratio units were small (e.g., fixed-ratio 5) and the total fixed-ratio requirement was large (e.g., fixed-ratio 160). Under no conditions did the paired brief stimulus facilitate responding. The nonpaired brief stimulus also suppressed responding but to a lesser extent. The suppressive effects of nonpaired brief stimuli were greatest when the fixed-ratio units were small and the total response requirement was large. These data suggest that the suppressive effects of the brief stimuli may have masked the conditioned-reinforcing effects reported in other studies, and that conditions that maximize suppression in second-order schedules involve the use of fixed-ratio schedule units and the presentation of many brief stimuli per reinforcer.
Journal of the experimental analysis of behavior, 1981 · doi:10.1901/jeab.1981.36-329