Differential Modulation of Retroactive Emotional Learning on Concrete and Abstract Word Processing

The present study employed a sensory preconditioning paradigm combined with behavioral measures and event-related potential (ERP) techniques to investigate whether emotional information could retroactively modulate the processing of previously encoded neutral concrete and abstract words. Behavioral results indicated that word memory performance was retroactively modulated by subsequent emotional conditioning: when the objects paired with abstract words were associated with aversive (vs. neutral) sounds subsequently, recognition accuracy was significantly higher and reaction times faster; for concrete words, however, no significant differences in accuracy or reaction time emerged between the two sound conditions. Additionally, liking ratings for both word types decreased overall. ERP results elicited by the words revealed that, in early attentional stages, abstract words whose paired objects were associated with aversive sounds evoked larger P200 amplitudes than those in the neutral condition. During memory retrieval, abstract words indirectly linked to aversive sounds (compared to the neutral condition) elicited smaller N400 and larger late positive component (LPC) amplitudes, reflecting enhanced early attentional capture, increased familiarity, and optimized recollection. In contrast, concrete words whose paired objects were associated with aversive sounds (compared to the neutral condition) elicited a larger right-lateralized early posterior negativity (EPN), suggesting rapid activation of early emotional processing, but showed no significant changes in mid-to-late memory-related components. These findings indicate that retroactive emotional learning selectively enhances memory for abstract words, supporting the representational substitution hypothesis and behavioral tagging theory, whereas its influence on concrete words is primarily manifested in early emotional modulation, consistent with partial expectations of the multimodal induction hypothesis.