Impact of Music on Memory Performance: Exploring Hemispheric Interference During Encoding and Retrieval

Abstract

The Hemispheric Encoding/Retrieval Asymmetry (HERA) model posits that the left hemisphere is more active during memory encoding, whereas the right hemisphere is more engaged during memory retrieval. Interestingly, previous studies have also demonstrated a brain asymmetry in music processing, with greater involvement of the right hemisphere when listening to music. Therefore, if the HERA model holds true, listening to music during retrieval would be more detrimental to memory performance than listening to music during encoding. Building on these findings, we designed an experiment in which instrumental music was introduced either during memory encoding or retrieval to assess its impact on performance. We hypothesized that listening to music would impact memory retrieval more than memory encoding, due to overlapping demands on right-hemisphere resources. Participants were randomly assigned to one of three conditions: an encoding-with-music group (EG), a retrieval-with-music group (RG), or a silent control group (CG). Memory performance was quantified using a forgetting index (FI), calculated as the difference between immediate and delayed recall for each condition. Results showed that the RG group performed significantly worse than the EG group, consistent with the predictions of the HERA model. This difference was supported by a large effect size (Cohen’s d = 0.90), highlighting the functional relevance of hemispheric interference. However, neither music condition differed significantly from the control group, suggesting a relative rather than absolute interference effect. These findings indicate that the introduction of music during memory tasks may serve as a novel methodology for preferentially isolating the activity of one hemisphere over the other.