Emotion, as an indispensable psychological aspect of learning experiences, constitutes a central area of inquiry in applied psycholinguistics. Psycholinguists have recently debated the potential impact of emotional factors on the acquisition of language skills. The present study aimed to investigate whether the emotional arousal dimension, which refers to the level of excitement associated with a word, could improve students' success in learning foreign language vocabulary. Forty-one Persian-speaking intermediate students participated in twelve training sessions focused on learning low-frequency English words with varying levels of emotional arousal. Based on these lexical characteristics, we randomly selected a total of 324 English words from the VAD lexicon (Mohammad, 2018) as stimuli. The words were taught to participants using a task-based instructional approach, which aimed to enhance the authenticity of the learning experience. One week after the final session, participants were asked to complete a free recall task, which was administered again a month later. The recall responses were analyzed using generalized mixed-effects regression models. The post-test analysis did not reveal any significant effect of arousal value. However, the delayed post-test results demonstrated a significant impact of arousal value
on learners' word recall. Results indicated that participants demonstrated better recall for low arousal words compared to high-arousal words. Furthermore, a statistically significant difference was observed between the scores of the post-test (M=59.61, SD=31.68) and the delayed post-test (M=38.41, SD=13.84), t(40) = 6.106, p < 0.0001 (two-tailed). These findings provide evidence of the long-term influence of emotional factors on foreign language acquisition. The emotional
arousal of words should be taken into consideration by language teachers and textbook designers in order to make informed decisions when selecting words for educational purposes.