Slide Slam L14
One-year re-test reliability of fMRI signals of auditory and visual language processing in elderly healthy adults
Stefan Heim1,2, Barbara Wellner1,2, Karsten Specht3; 1RWTH Aachen University, 2Research Centre Jülich, 3Haukeland University Hospital Bergen
Reliability of data is a current issue in cognitive neuroscience and neurolinguistics. Moreover, from a clinical perspective, the longitudinal stability of activation patterns in the brains of healthy seniors is an important prerequisite for the assessment of pathological development in neurodegenerative diseases or neural recovery after stroke. Consequently, we analysed the re-test reliability of fMRI activation patterns of word and pseudoword processing over the course of one year. Twenty-eight healthy adults (57-72 years, mean 62.6 years, 14 women) performed lexical decision tasks on these stimuli in both the auditory and the visual modality. Stimuli were presented in pseudo-randomised order for word type in two separate runs, one for each modality. The networks for auditory and visual lexical access at time point T1 were identified (cf. Heim et al. 2019) and served as masks for the present analysis of auditory or visual processing, respectively. Re-test reliability was assessed using voxel-wise inter-class correlations (ICC; Specht et al. 2003; Specht 2020) as ICC(3,1) = BMS-EMS/(BMS+EMS) using the individual spmT-images thresholded for such voxels that showed an activation of T>3.09 as input. At a threshold of ICC>.60 with cluster size k=20 voxels, ICCs>.80 were observed in the modality-specific language areas in both modalities. Auditory words and also auditory pseudowords yielded such effects in the auditory cortices and auditory association areas in the left and right STG. Similarly, visual words and also pseudowords had comparable ICC coefficients in the left and right MOG and the visual word form area in the left ITG/IOG. In Broca’s region in the left IFG, which forms a joint area for lexical access in both modalities, sufficiently high ICC coefficients were found for auditory words (ICC=.74) and visual pseudowords (also ICC=.74). The data indicate the overall reliability of fMRI activation patterns during word and pseudoword processing in both modalities, in particular in the modality-specific cortical areas but also in the amodal cortex of Broca’s region. These data support the notion that, for clinical studies, a one-time assessment of a healthy senior control group may suffice for the quantification of longitudinal changes in patient groups. References Heim, S., Wellner, B., Fimm, B., Jockwitz, C., Caspers, S., & Amunts, K. (2019). How cognitive abilities modulate the brain network for auditory lexical access in healthy seniors. 11th Annual Meeting of the Society for the Neurobiology of Language, p. 98. Specht, K., Willmes, K., Shah, N.J. and Jäncke, L. (2003), Assessment of reliability in functional imaging studies. J. Magn. Reson. Imaging, 17: 463-471. https://doi.org/10.1002/jmri.10277 Specht K. Current Challenges in Translational and Clinical fMRI and Future Directions. Front Psychiatry. 2020 Jan 8;10:924. doi: 10.3389/fpsyt.2019.00924.