Stroop-like effects for derived stimulus-stimulus relations

Automaticity can be established by consistently reinforcing contingencies during practice. During reinforcement learning, however, new relations can also be derived, which were never directly reinforced. For instance, reinforcing the overlapping contingencies A → B and A → C, can lead to a new relation B-C, which was never directly reinforced. Across five experiments we investigated if such derived relations can also induce automatic effects. We first trained participants to derive a relation between a nonsense word and a color word, and then used the nonsense words as distractors in a Stroop task. Results indicate that derived color-word associates induce Stroop effects. This effect, however, is present only when sufficient attention is allocated to the distractor words during the Stroop task, and is driven by a response conflict. We conclude that, under the present training conditions, derived color-word associates became related to the corresponding color word at the lexical level, but did not gain direct access to the corresponding semantic color representation.