Effects of varying the second-order stimuli through trials on the acquisition and transfer in a conditional discrimination task

Abstract

The effect of three conditions of variation of the second-order stimuli (SOSi) across trials in a conditional discrimination task was investigated in human adult participants. The conditions were: (a) no variation; (b) partial variation (only in shape and color); and (c) total variation (in shape, color, size and filling weft). Identity and difference relations were examined. Each group received only a single combination of type of relation and type of SOSi variation. For all groups there were four Phases: baseline (A); training with a new set of sample and comparison stimuli and feedback (B); intramodal transfer test with the same sample and comparison stimuli of the Phase A (C); and extramodal transfer test (D). The partial and total variation conditions generated the highest percentages of correct responses in Phases B and C, but only in some participants from the identity groups in these two conditions evidence of extramodal transfer was clearly attained. These results suggest that a greater variety of the SOSi facilitates the discrimination of the relation between these stimuli and, this way, the development of abstract performances in this kind of tasks.