Conditional discrimination learning: a critique and amplification.
Name and test the exact cue you think the learner sees—single rule, fused picture, or two parts—or your matching-to-sample data may mislead.
01Research in Context
What this study did
Locurto et al. (1980) wrote a theory paper, not an experiment.
They looked at old matching-to-sample data and asked: do primates learn one broad rule, or do they just memorize each picture pair?
The authors said researchers were mixing up two ideas: configuration (treating a pair as one new picture) and compound cues (noticing two things at once).
They urged clearer words and stricter tests.
What they found
The team found the single-rule idea was still alive for monkeys and humans.
They warned that sloppy labels made results look like contradictions when they were not.
How this fits with other research
Grey et al. (2024) later gave a concrete way to test the warning. Their case study shows you must check each part of a compound picture-word set alone; otherwise you may think the learner sees the whole when only one piece controls the choice.
Miranda-Linné et al. (1992) picked up the same measurement thread. They predicted that the wrong stimulus (the one that should be ignored) can secretly guide choices and distort equivalence-test scores. Their fix: add probe trials and watch for negative-stimulus control.
Blough (1980), written the same year, adds a second red flag: accuracy alone can fool you. A score near 70% might hide the fact that the learner is using the wrong cue. Together, the two 1980 notes tell you to doubt both the label you use and the number you report.
Why it matters
When you run matching-to-sample lessons, say exactly what you think the learner is looking at: one fused picture or two side-by-side cues. Probe each part alone before you claim concept learning. Add brief checks for negative-stimulus control and do not trust accuracy as your only proof. These small steps keep your data clean and your teaching honest.
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02At a glance
03Original abstract
Carter and Werner recently reviewed the literature on conditional discrimination learning by pigeons, which consists of studies of matching-to-sample and oddity-from-sample. They also discussed three models of such learning: the "multiple-rule" model (learning of stimulus-specific relations), the "configuration" model, and the "single-rule" model (concept learning). Although their treatment of the multiple-rule model, which seems most applicable to the pigeon data, is generally excellent, their discussion of the other two models is incomplete and sometimes inaccurate. Potential problems of terminology are discussed in the present paper, as are additional lines of research that deserve consideration by those interested in further work in this area. The issue of response versus stimulus selection (configuration versus compound-cue learning) is discussed in connection with the configuration model. Particular attention is given to Carter and Werner's criticism of the application, in studies with other species, of the learning set procedure in testing for single-rule learning. Some of the important related issues are: the bias for improvement on new problems in a series, the adequacy of a multiple-rule model to explain learning set formation, and evidence in favor of the single-rule model, at least in primates. Consideration of these additional contributions to the study of conditional discrimination learning emphasizes the usefulness of this task in the comparative study of cognitive processes.
Journal of the experimental analysis of behavior, 1980 · doi:10.1901/jeab.1980.33-291