Andreea Micula1,2, Jerker Rönnberg2, Patrycja Książek3,4, Reena Murmu Nielsen1, Dorothea Wendt4,5, Lorenz Fiedler4, Elaine Hoi Ning Ng1,2
Oticon A/S, Smørum, Denmark
2Department of Behavioural Sciences and Learning, Linnaeus Centre HEAD, Swedish Institute for Disability Research, Linköping University, Linköping, Sweden
3Amsterdam UMC, Vrije Universiteit Amsterdam, Otolaryngology-Head and Neck Surgery, Ear and Hearing, Amsterdam Public Health Research Institute, Amsterdam, The Netherlands
4Eriksholm Research Centre, Snekkersten, Denmark
5Hearing Systems, Hearing Systems Group, Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark

In the current study, an auditory free recall test was combined with pupillometry to investigate whether task-evoked pupillary responses measured during encoding can predict which items will be subsequently recalled. In addition, the effect of individual working memory capacity on subsequent memory recall was investigated. Participants with mild to moderately severe symmetrical sensorineural hearing loss (n = 21) were included. The Sentence-final Word Identification and Recall (SWIR) test was administered in a speech-babble noise. The task involves listening to lists of seven sentences, repeating the last word immediately after each sentence and recalling as many of the repeated words as possible at the end of the list. Pupillometry was recorded while the participants listened to the sentences and encoded the target words. The task-evoked peak pupil dilation (PPD) was measured. The Reading Span (RS) test was used as a measure of individual working memory capacity. The PPD and RS test score were found to be significant predictors of subsequent memory recall. Larger PPD and higher RS test scores were associated with higher likelihood of subsequent memory recall. The interaction between PPD and RS test score was not significant. The magnitude of the PPD presumably reflects the intensity of attentional processing devoted to words during encoding, which affects the likelihood of subsequent memory recall. Furthermore, individuals with higher working memory capacity are able to allocate more attentional resources during encoding, which results in a higher probability of subsequent memory recall.