Pictures improve memory over words, and patients with Alzheimer's disease (AD) show a much greater improvement than healthy older adults. This simple fact has tremendous implications for millions of patients with AD. If we were able to better understand exactly how pictures improve memory in these patients, new memory enhancing techniques could be developed to further increase their memory, improving quality of life and saving money for caregivers and the healthcare system. This proposal will use the techniques of experimental psychology (computer-based behavioral studies) and cognitive neuroscience (EEG-based event- related potential [ERP] studies) to examine the cognitive and neural processes that underlie the robust picture superiority effect in patients with AD.
Aim 1 examines the hypothesis that intact perceptual processing of distinctive visual information enhances the encoding, storage, and retrieval of pictures in patients with AD. Expts 1 and 2 examine whether adding or subtracting perceptual detail at encoding increases or decreases the picture superiority effect. Expt 3 uses a perceptual masked identification task to determine whether patients can recognize unidentifiable test pictures based only on stored perceptual information. Expt 4 examines whether removing distinctive visual information from the retrieval cues eliminates the picture superiority effect.
Aim 2 examines the hypothesis that intact conceptual processing enhances the encoding, storage, and retrieval of pictures in patients with AD. Expt 5 uses ERPs to determine whether picture stimuli allow for better encoding of conceptual information than ambiguous images with and without conceptual labels. Expt 6 uses a conceptual implicit memory test to determine whether the conceptual information stored for pictures is superior to the conceptual information stored for words. Expt 7 uses ERPs to examine whether patients demonstrate the picture superiority effect for a category-based retrieval task. Finally, Aim 3 examines the hypothesis that impaired encoding, storage, and retrieval of words contributes to the robust picture superiority effect in patients with AD. Expt 8 uses ERPs to examine differences in brain activity for successful encoding of pictures compared to successful encoding of visually and auditorily presented words. Expt 9 uses ERPs to examine whether limitations in the ability to generate an internal image representation of words at encoding contributes to the robust picture superiority effect in AD. Expt 10 examines whether forgetting rates of stored words and pictures are differentially affected by AD. Finally, Expt 11 examines whether words are less effective as retrieval cues compared to pictures. Successful completion of these aims and experiments will provide us with a detailed understanding of how pictures enhance memory in AD. This understanding could subsequently improve methods of clinical assessment, and serve as the basis of promising new learning techniques, such as errorless learning. These new techniques may help patients remember how and when to take their medications and perform activities of daily living, thereby improving their quality of life.
The hallmark of Alzheimer's disease, and often the presenting symptom, is significant impairment in episodic memory, which leads to societal and financial burden. Pictures improve memory in Alzheimer's disease and could potentially reduce the burdens placed on caregivers and the infrastructure of the healthcare system. The experiments in this grant proposal will investigate how and why pictures improve memory in patients with Alzheimer's disease in an effort to find better ways to help patients combat memory problems and live at home and in the community longer.
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