Alzheimer’s Disease has a preclinical duration of many years before progressive neuronal changes give rise to clear-cut cognitive impairments, which can reliably be detected with neuropsychological tests. Before the stage of mild neurocognitive disorder (MCI) is reached, cognitive impairments are rather subtle, fluctuating and compensable, although they can be experienced and reported by affected subjects (a condition now termed Subjective Cognitive Decline, SCD). Discriminating „normal aging“ from early disease-related changes is a challenging task, but neuroscience-driven psychometric tools and qualitative research on the phenomenology of experienced cognitive changes offer new opportunities for early diagnosis in AD and other neurodegenerative diseases. The development and validation of novel methods for the assessment of objective and subjective cognitive impairment is a key aim of our group. Examples are procedures to assess associative encoding in short-term and long-term memory (Koppara et al. 2015 (PubMed LINK), Polcher et al. 2017 (Pubmed LINK), and the conceptualisation and measurement of SCD (Jessen et al. 2014, Buckley et al. 2015, Pubmed LINKS). With Emrah Düzels DZNE group in Magdeburg, we study computerized and mobile cognitive assessments with smartphone apps. The refinement of an interview scheme and rating scale for SCD, and automated text analysis for the detection of subtle speech and language impairments are recent themes of our research.
We are also interested in the analysis of cognitive data, including the use of confirmatory factor analysis in order to reduce cognitive test variables into more reliable and better comprehendible domain scores, or the use of cognitive composite scores. Latent variables linking cognition and everyday functional abilities can be derived from different assessment batteries and are particularly sensitive for disease risk factors (Koppara et a. 2016 LINK). These methods can also facilitate Integrated Data Analyses of DZNE studies with international AD-risk cohorts.
The goal of our analytical work is to contribute to the identification of risk and protective factors for cognitive impairment. We e.g. take advantage of the detailed assessment of “reserve” and “lifestyle” (occupational history and dietary habits. Supported by the BMBF-funded Diet-Body-Brain Research Cluster, we will examine the association of of nutritient levels and dietary patterns on structural and functional measures of brain health.
Finally, our group provides advice for the design of observational and interventional trials within the DZNE, as well as training and quality control for cognitive assessments.