Two experiments with artificial languages

Two experiments are reported where subjects learnt simple artificial languages which contained synonyms: i.e. there were two equally correct verbal responses paired with each “referent” in the language: “referents” were simple visual patterns. In the first experiment (a memory task) subjects performed better with material of low auditory discriminability than with material of high auditory discriminability when they were asked to use one synonym of each pair more often than the other; the reverse was the case when they were asked to use each synonym equally often. In the second experiment (a two-person communication task with a noisy channel) the degree to which pairs of subjects tended to use the same synonym for the same meaning was found to be non-monotonic with the noise level in the communication channel: subjects tended to use the same synonyms for moderately high noise and very low noise more often than they did for very high noise and moderately low noise.

The concept of decision cost (Smith, 1968) is used to explain these results. Decision cost is a complex function both of discriminability and of response bias, and it is proposed that changes in decision cost in response to changes in response bias are responsible for the results observed in these experiments.