J16 Multitasking processes are sensitive to early changes in pre-HD—evidence from longitudinal neurophysiological data

Abstract

<h3>Background</h3> Multitasking situations play a pivotal role in everyday life. To examine these processes we introduced a simple modification of the Stroop task by comibining this task with a task switching paradigm. This should increase sensitivity to detect early changes in HD. <h3>Method/techniques</h3> We analysed behavioural data and event-related potentials (ERPs). <h3>Results/outcome</h3> Behavioural data indicated, especially the parallel execution of conflict monitoring and flexible response adaptation was modulated across the examined cohorts. When both processes do not co-incide a high integrity of fronto-striatal loops seems to be dispensible. The neurophysiological data suggests that conflict monitoring (reflected by the N2 ERP) and working memory processes (reflected by the P3 ERP) differentially contribute to this pattern of results. Flexible response adaptation under the constraint of high conflict processing affected the N2 and P3 ERP, as well as their delta frequency band oscillations. Yet, modulatory effects were strongest for the N2 ERP and evoked wavelet oscillations in this time range. The N2 ERPs were localised in the anterior cingulate cortex (BA32, BA24). Modulations of the P3 ERP were localised in parietal areas (BA7). In addition, MRI-determined caudate head volume predicted modulations in conflict monitoring, but not working memory processes. <h3>Conclusions</h3> The longitudinal data after 16 month suggest that cognitive processes related to conflict monitoring provide a sensitive marker of pre-manifest disease progression.