Effects of instructional contact, specificity and instructional history on contingency change insensitivity in first order matching-to-sample tasks in humans [Efecto del contacto con instrucciones, la especificidad e historia instruccional en la insensibilidad al cambio contingencial en tareas de igualación de la muestra de primer orden en humanos]

The objective of the present study was to explore if the provision of explicit instructions prior to contingency contact, the degree of instructional specificity, as well as the instructional history of the subjects, affect the sensitivity to the change of contingencies. 20 undergraduate students were assigned to one of five experimental groups that were different both in the type of received instruction (i.e. specific, generic and/or minimum) and in the maintenance or change of the instruction between conditions, using a first order matching-to-sample task. In the first condition, the correct relation during all sessions was one of similarity, whereas in the second phase, during the second half of each session's trials the relation criterion (i.e. contingency) was modified without previous warning from similarity to difference (i.e. the Comparative Stimuli did not share any of the characteristics of the Sample Stimulus). Unlike a previous study by Ortiz et al. (in press), the results showed that providing contact with the instructions produced higher insensitivity indexes, as well as greater differences between groups, an indication that the description given prior to the contact with the contingencies of the task could acquire an instructional function