Sci. Aging Knowl. Environ., 22 December 2004
Novelist's final work reveals early signs of Alzheimer's disease
Bad reviews are an occupational hazard for writers, even for Iris Murdoch, whom many critics rank as one of the best 20th century British novelists. But reviewers who lamented the uncharacteristic emptiness and sloppiness of her 1995 novel Jackson's Dilemma had noticed more than a literary lapse. Alzheimer's disease (AD) was already eroding Murdoch's command of English, according to a new computer analysis of three of her novels.
AD saps memory and undermines the ability to speak and understand language (see "Detangling Alzheimer's Disease"). Some evidence suggests that linguistic portents of the disease appear years or even decades before diagnosis. In a famous study reported 8 years ago, cognitive neuropsychologist Susan Kemper of the University of Kansas, Lawrence, and colleagues scrutinized autobiographies penned in the 1930s by nuns who had just entered convents. Nuns whose writing was conceptually rich were less likely to develop AD in old age. In follow-up work, Kemper and colleagues showed that grammatical complexity and idea "density" gradually decline with age, but they plummet in AD.
Neurologist Peter Garrard of the Institute of Cognitive Neuroscience in London and colleagues decided to search for signs of cognitive weakening in Jackson's Dilemma, published 4 years before Murdoch died of AD. Murdoch (1919-1999) had earned plaudits from critics and peers for her 25 previous novels, winning Britain's top literary award in 1978. But Jackson's Dilemma was a trial to write, Murdoch reportedly told her husband, and many critics found it a trial to read. One likened it to "the work of a 13-year-old schoolgirl who doesn't get out enough." Murdoch's idiosyncratic creative procedure--she didn't rewrite passages repeatedly or countenance meddling by pesky editors--means that her prose accurately reflects her mental abilities at the time, says Garrard.
To gauge those abilities, the team digitized her first novel, Under the Net (1954); Jackson's Dilemma; and a selection from The Sea, The Sea (1978), which many literati consider to be her best. Using language-analysis software, they statistically compared the three novels. Murdoch included a smaller variety of words in Jackson's Dilemma than in the other two books, indicating that her vocabulary was dwindling. Sentence length and number of clauses per sentence were also lowest in Jackson's Dilemma. Taken together, the comparisons suggest that her last novel wasn't as intricate or verbally rich as were prior works, just as the critics argued. The result "proves that cognitive changes can be picked up before AD is diagnosed," says Garrard. The researchers are now parsing some of Murdoch's other 23 novels to try to determine when her mental deterioration began.
"It's a very interesting case study because you have a rare glimpse at cognitive function over time," says neuroscientist Randy Buckner of Washington University in St. Louis, Missouri. The work "helps to expand the domain of what you think of as early cognitive changes beyond [results of] specific memory tests." Kemper adds that similar studies might help determine whether the ability to comprehend words deteriorates at the same rate as the ability to construct sentences. "When it [language ability] goes, does it go all at once, or does it go in pieces?"
December 22, 2004
Science of Aging Knowledge Environment. ISSN 1539-6150