Brain Stimulation Method Can Evaluate Consciousness in Alzheimer’s Disease

As individuals with Alzheimer’s Disease (AD) move from the Mild Cognitive Impairment (MCI) stage to moderate and severe dementia, complex awareness deteriorates, although lower-level sensory awareness is relatively maintained. Most conscious processes also become more impaired as AD progresses, including attention, working memory, episodic memory, and executive function, while unconscious processes, such as procedural or muscle memory, operant conditioning (behavior controlled by consequences), and priming (where the experience of a stimulus affects the processing of a similar stimulus) are relatively spared. However, as damage spreads across different cortical regions in dementias such as AD, corresponding aspects of conscious awareness become diminished and then lost.