Implicit imagery tasks facilitate learning in declarative memory: Congruence between imagery modality and verb type enhances recognition

Explicit mental imagery (i.e., voluntary and conscious) can enhance learning in declarative memory. In the present work, we assessed whether implicit imagery tasks also enhances memory, and whether specific imagery modalities (motor, visual) selectively benefit the learning of related material. Seventy-two young adults completed a recognition task in which they learned action and non-action verbs presented after an implicit motor imagery task (i.e., hand mental rotation) or an implicit visual imagery task (i.e., number mental rotation). Results from both frequentist and Bayesian generalized mixed-effects models revealed a significant interaction between verb type and imagery modality. Congruent imagery modality (i.e., motor for action verbs, visual for non-action verbs) enhanced subsequent recognition compared to incongruent modality (i.e., motor for non-action verbs, visual for action verbs). These findings provide novel evidence that the effectiveness of mental imagery for learning is influenced by the congruence between imagery modality and the sensorimotor features of the learned items. They also suggest that mental imagery does not need to be fully voluntary or fully conscious to improve learning.