Inclusion Criteria:  Diagnosis of amnestic MCI or AD dementia or clinical normal Able to provide written informed consent Unchanged pharmacotherapy within 4 days prior to the study specific assessments Fluent in German  Exclusion Criteria:  Unable to give informed consent or has a legal guardian Other severe mental disorder, e.g. schizophrenia or bipolar affective disorder Clinically relevant depression Acute suicidality Current alcohol, drug or medication abuse History of severe traumatic brain injury within 3 months prior to inclusion Structural lesions of the basal ganglia or brain stem Severe neurological disorder including (but not limited to) epilepsy, systemic disorders, stroke, repeated transient ischaemic attacks, increased brain intracranial pressure, normal pressure hydrocephalus Severe medical disorders including (but not limited to) heart failure, respiratory failure, uncontrolled severe arterial hypertension Electronic implants (e.g. cardiac pacemaker) or other MRI contraindication Renal failure > stage 3 (GFR < 30 mL/min) Pregnancy Unresolved malignancies within two years prior to inclusion Severe current infections or other chronic or systemic disorders Other circumstances which preclude participation based on the investigator's judgement