5.5.09

MANAGEMENT OF KNOWLEGDE IN ALZHEIMER'S DISEASE

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.

Journal reference:

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

3 comments:

maria rosa said...

Muy interesante como siempre.
Te envio un beso desde Barcelona.

Lucas Manuel Bietti said...

I was thinking about how can we get the "ecological validation" you refer to. It's seem a quite difficult task. Could you please give me some examples of research which meet such requirement? I mean, how can we keep the cognitive approach, but at the same time incorporate features of the environment? Thanks very much!

fatima said...

Thanks, Lucas, for your comment! Your ideas and suggestions are always a great help and motivation!
Regarding "ecological validity" you are right, it's a difficult task. According to Dr. Cicourel, ecological validity focuses on how we seek to convince others of the viability and authenticity of our claims and can be understood by our use of primary and secondary data sources such as structured interviews, open-ended or unstructured interviews, and recorded discourse during social interaction. For example, direct observation of and participation in the everyday activities or practices of human actors during their daily life experiences by the use of audio or video recordings.
From a socio-cognitive approach, my aim is to study Alheimer discourse in talk (interaction)in order to identify and comprehend the aspects which have a role in the construction and damage of the human cognition: interlocutors (mind reading), grounding (shared knowledge), joint attention/action... in natural real world-setting.
I will appreciate your feedback!
Best,
fátima