[PS-1.1] Effects of hearing impairment of complex sentence processing: neural mechanisms

Vogelzang, M. 1, 2 , Thiel, C. 1, 2 , Rosemann, S. 1, 2 , Rieger, J. W. 1, 2 & Ruigendijk, E. 1, 2

1 University of Oldenburg
2 Cluster of excellence 'Hearing4all'

We investigate the neural mechanisms underlying the processing of complex sentences in individuals with mild-to-moderate age-related hearing impairment (HI) compared to normal-hearing (NH) age-matched peers. In German, structurally complex object-initial sentences can be formed because of case-marking (e.g., Den Jungen wäscht der Vater, TheACC boy washes theNOM father). It is known that processing such sentences can be challenging for individuals with hearing loss, but it is unknown why: Do HI individuals process complex sentences differently from NH peers?
In an fMRI experiment, 20 NH and 20 HI participants (non-hearing aid users) perform a sentence-processing task while receiving hearing-loss-specific amplification (to eliminate effects related to word recognition). Preliminary fMRI analyses of data from 10 NH and 10 HI participants suggest that whereas NH participants show clear differential neural activity in both the left and right middle temporal gyrus (areas commonly associated with complex sentence processing) depending on subject-object order, HI participants only show small differential neural activity in the right superior temporal gyrus.
These findings suggest that even mild-to-moderate age-related hearing impairment influences the processing of structurally complex sentences. Thus, besides adding perceptual difficulties during sentence processing, hearing impairment also seems to affect the neural processing of complex structures.