A fascinating presentation is taking place Wednesday in Stockholm, and the subject is the neurological brain damage suffered by Muhammad Ali over the course of his legendary boxing career.
From current news reports alone, there's little doubt that this scientific study will receive widespread – even global – attention once the details of the research are made available. That's because of what we already know about this intriguing research – specifically, the correlation being made between the boxer's deteriorating speech patterns to the head trauma Ali suffered year after year inside the ring.
In its attempt to show how head blows early in his career led to Ali's brain damage and slurred speech of his later years, the research team devised an interesting metric called "syllables per second." It was derived from analyzing his public remarks between 1968 and 1981, which they used to indicate how quickly Ali spoke at different times of his career, and later in his remarkable life, which ended last year at the age of 74.
Alongside this data, the team engaged a boxing statistics company to learn how many punches, fight by fight, that struck the head of the former heavyweight champ over his two-decade career. It's brilliant work, as it gives us unique insight into the timing, as well as the extent, of Ali's linguistic demise into Parkinson's syndrome, which was diagnosed in 1984, three years after his last professional fight.
Yet while it's eye-opening and attention-getting material being presented at this conference, Interspeech 2017, it's also worth noting that as far as we can tell now, while these two data sets appear to have a cause-and-effect relationship they are not necessarily or scientifically connected.
More exactly, what we're being shown by Professor Julie Liss and Asst. Prof. Visar Berisha, speech scientists at Arizona State University who conducted the research, is a surrogate measurement for tracking Ali's deteriorating brain function. As my colleague Dr. Josh Bloom points out, that is an indirect way to detect or quantify events or effects. And while surrogate measurements can be extremely accurate, they also can veer off into the territory of a plausible explanation or educated guess. Which is why we should retain a healthy skepticism when evaluating these results.
Here are two examples of surrogate measurements, involving urine, the first quite good and the second one terribly lacking.
First: Referring to one of Dr. Bloom's articles he states that, "the scientists used the presence of an artificial sweetener in pools as a surrogate for urine, since the only way that the sweetener could get in the pool would be if someone ingested it and peed in the pool."
Second, he says: "The measurement of BPA in urine is not a good measure of any toxicological effects or even the exposure level. This is because all of us have traces of BPA in our urine because any that we ingest is rapidly excreted in the urine. The amount in the urine tells us nothing about the amount in the blood, or the effect on health."
Using syllables/second as the surrogate to gauge Ali's relative brain health, here's what the researchers found, as cited by The Wall Street Journal:
"In 1968, Ali spoke at a rate of 4.1 syllables per second, which is close to average for healthy adults. By 1971, his rate of speech had fallen to 3.8 syllables per second, and it continued sliding steadily, year by year, fight by fight. An ordinary adult would see little or no decline in his speaking rate between the ages of 25 and 40, but Ali experienced a drop of more than 26% in that same period."
Not only that, immediate cognitive impacts were detected after individual fights. After a particularly brutal bout against Ernie Shavers in 1977, when Ali absorbed 266 blows – 209 of which were termed "power punches" by CompuBox Inc., the boxing statistics firm – the former champ's speech slowed dramatically. (Picture via Google Images.)
"Before his fight with Shavers, Ali spoke at a rate of 3.7 syllables per sec," the newspaper reported. "After the fight, his speaking rate fell 16% to 3.1 syllables per sec."
Changes in speech can be early indicators of brain damage or disease. Moreover, what we're learning about blows to the head as it relates to CTE, or chronic traumatic encephalopathy, is providing us with new clues in assessing brain injuries. However, it would be wise to remain clear-headed when intriguing, provocative information like this becomes available. At the same time, we're anxious to see what other findings emerge at this Swedish conference about Ali, once known as "The Louisville Lip" for his irrepressible demeanor, and of all things, his eagerness to talk.
