A new study published in Neuropsychology suggests that patients with AD seem to have trouble determining which pieces of information are more important than others. The researchers, led by Alan D. Castel of the University of California, Los Angeles, based their conclusions on a study of 109 people with an average age of 75. Some were in early stages of Alzheimer's, while others were cognitively healthy. Selecting what is important to remember, attending to this information, and then later recalling it can be thought of in terms of the strategic control of attention and the efficient use of memory. To examine whether aging and Alzheimer’s disease (AD) influenced this ability, the present study used a selectivity task, where the volunteers were asked to memorize a series of words, each of which had a point value associated with it. The higher the value of the word, they were told, the more important it was to remember it. The researchers said it might be that in early Alzheimer's the brain was already becoming less efficient at learning and memorizing. They added that it might be possible to train patients to improve their memory strategies.
New evidence suggests that in Alzheimer's Disease part of the initial impairment lies in attentional control (see Balota & Faust, 2001, and Perry & Hodges, 1999) and it can lead to impairments in:
(1) Enconding and maintaining relevant information in Working Memory
(2) Inhibitory control
(3) Retrieval and response control
According to this study, the ability to selectively encode information is likely dependent on several possibly interrelated abilities, including inhibitory control, working memory capacity, monitoring, and metacognitive control related to using performance on previous trials to update resource allocation strategies. Although previous research has widely documented impairments in memory in old age and AD, the present study shows that AD is also associated with a specific deficit in being selective and strategic about encoding operations, which likely contributes to their poorer memory efficiency.
Personally, I think that the results of this study are very interesting to gain an insight also into the nature of communication impairments in Alzheimer. Both, memory-attention and communication deficits are interconnected, so that, I am focusing my thesis project on how persons with AD manage knowledge in talk. I consider that, at the same time, it should be appropriated to carry out new studies on that issue but beyond the word-level and well-controlled experimental environments. That is, research with ecological validity into how persons with AD communicate and interact with their interlocutors in real world-settings are needed in order to comprehend how these strategies for knowledge management are set and which their real deficits in communication, memory and attention are.
Alan D. Castel, David A. Balota, and David P. McCabe. Memory Efficiency and the Strategic Control of Attention at Encoding: Impairments of Value-Directed Remembering in Alzheimer's Disease. Neuropsychology, Vol. 23, No. 3