Introduction.
Idea density means the number of logical statements in a given sample of communication or text. Arithmetically means the number of ideas conveyed per ten words in the last sentence of every autobiography. The ideas corresponds to basic predicates, typically adjectives, adverbs, verbs, noun and clause conjunctions. Propositions may turn to be true or false depending on mental ability of an individual. The ideas are considered to be true and vice versa when the text is written with no logical contradictions to the topic and in agreement with the context. For successful retrieval of information, the facts provided must match the subject of the query. It’s not a theory to explain knowledge but rather a supposition of how the mind of human beings encode and transmit information depending on cognitive functioning.
Idea density is measured by number of prepositions in a sample of text divided by the number of words .i.e. number of ideas divided by number of words times ten.eg (6 ideas in 17words= 3.5) means 3.5 ideas in every 10 words giving a low idea density. (12 ideas in 17 words= 7.1) means 7.1 ideas per 10 words giving high idea density. Idea density may be low or high depending on the amount of adjectives and other modifiers used. Every time modifiers are added, the basic predictions (ideas) are added and density increases. Positive emotions also increase idea density.
Idea density is positively related to cognitive abilities. Low idea density is directly proportional to low mental abilities .High idea density is positively correlated to high brain functioning. From the longitudinal study of about 180 nuns, the idea density of autobiographies which were written at average age off 22years correlated with their cognitive abilities in their old age and eventual death. : Lower idea density predicted decreased cognitive functioning, and dementia (Snowdon et al., 1996), exercising ones mental abilities offers protection more so from age related dementia. Sisters who were teachers and taught most of their lives showed marginal decline in cognitive abilities as compared to those who dedicated their lives to service based duties. Therefore stimulating the brain with nonstop intellectual tasks maintains neurons health and keeps them alive but it’s not the ultimate guard against cognitive impairment. Low linguistic ability in one’s early life is a strong indicator of poor cognitive function and Alzheimer's disease in late adulthood.
Normal cognitive functioning is age related changes in cognitive functions where an individual shows appropriate decline in performance on cognitive abilities from the previous period in life but brain functions at normal level for their age. Normal cognitive functions is associated with changes like decline in numerical abilities, processing speed, memory loss mostly between age 30 to 40yrs, reasoning, verbal ability and visuoperceptual abilities at age 50 to 60 yrs, word reading and vocabulary is always stable but may begin in late adult hood above 70 yrs. Abnormal cognitive functioning is pathological dynamics in cognitive tests greater than expected of age mostly associated with mild cognitive impairment and clinical dementia. Mostly characterized by senility, forgetfulness, mild cognitive disorder o, and nuerocognitive impairment.
Low idea density in autobiographies written in early life has concrete and consistent association with low cognitive functions in late life. Stroke and head trauma can predispose people to Alzheimer’s disease in late life. Thus linguistic ability can be used to predict brain degeneration in late life. Cognitive functions depend on degree of pathology present in brain and degree of adaptation to the clinical expression of neuropathology .Clinical impacts of neuropathological lesions is determined by the amount, type and most importantly the location of the lesions.
Annals of internal medicine Snowdon D’ Healthy Aging and Dementia: Findings from the Nun Study’ retrieved from (http://www.annals.org/content/139/5_Part_2/450.full.pdf)
David S.Knopman, MD; Bradley FMD; and Ronald C.Petersen PHD, MD Symposium on Geriatrics ‘essentials of the proper Diagnoses of M ild Cognitive Impairment, Dementia and Major Subtypes of Dementia’ retrieved from (http://geriatrics.uthscsa.edu/reading%20resources/Memory%20Evaluation.pdf)
Time magazine U.S ‘the nun study’ retrieved from (http://www.time.com/time/magazine/article/0,9171,999867-1,00.html)
