Nondeclarative associative learning in Alzheimer's disease: An overview of eyeblink, fear, and other emotion-based conditioning.

• Alzheimer's disease is a neurodegenerative disorder that affects cognitive functions, particularly declarative memory. • Nondeclarative associative learning, such as motor, fear, and emotion-based learning, involve distinct neural structures and are also affected by Alzheimer's disease. • Eyeblink conditioning, fear conditioning, and other emotion-based learning in Alzheimer's disease are investigated in this review. • Evidence suggests that some forms of nondeclarative associative learning such as eyeblink and fear conditioning are impaired in Alzheimer's disease, whereas emotion-based learning may be relatively preserved. • The review highlights the importance of studying nondeclarative associative learning in Alzheimer's disease to better understand the disease progression and develop new intervention strategies. Alzheimer's disease is a neurodegenerative disorder that is characterized by progressive cognitive decline, particularly in declarative memory, and the presence of β-amyloid plaques, neurofibrillary tangles, and cortical atrophy (especially in the temporal lobe). Unlike the relationship between the temporal cortex and declarative memory, nondeclarative memories (e.g., motor, fear, and other emotion-based memories) involve distinct neural structures. The present review investigates nondeclarative associative learning ability in Alzheimer's disease. We discuss eyeblink conditioning, fear conditioning, and other emotion-based learning and present the functions and brain areas that are involved in each type of learning. Evidence suggests that nondeclarative learning is also affected by Alzheimer's disease, although some forms of learning may be relatively preserved. Details about each nondeclarative associative learning process and the implications of these findings are presented. [ABSTRACT FROM AUTHOR]