Celebration of Scholarship and Creative Activity 2023
According to Folkard people placed more reliance on verbal maintenance processing in the morning than in the evening, meaning that more memory errors occurred for phonologically similar words in the early hours. However, it is still unknown whether a specificity of verbal material or the modality in which words were presented are subject to diurnal changes. We aimed at testing short- and long-term memory performance for auditorily presented stimuli that lack a language component in order to verify whether only auditory-verbal material were sensitive to diurnal changes. Sets of similar environmental sounds that did not contain a language component and that engaged only auditory modality were used. Participants studied sets of similar meaningful and meaningless sounds and responded to a single probe that was either studied, non-studied but acoustically similar or non-studied and acoustically different. Non-studied and acoustically similar sounds were recognized more often following evening presentations as compared to morning ones. This effect was noticed for both types of sounds, meaningful and meaningless in STM. In LTM no difference between morning and evening presentations was reported. These results suggest that additionally to a phonological component, an acoustic component plays a crucial role in diurnal changes.