Lverbal memory defines the ability to retain new information acquired. Someone who has problems with verbal memory, for example, may ask questions about items discussed only a few minutes earlier.
Two researchers at University College London analyzed data from nearly 3,700 people aged 50 and over. Those who watched more than 3.5 hours of television per day, they said, exhibited a decline in their verbal memory over the next six years.
Researchers say they measured an 8 to 10 percent decline in verbal memory in them. Among participants who watched less than 3.5 hours of television per day, the decline was half the decline, 4 to 5 percent.
They explain that the passive nature of television – compared to more interactive activities, such as video games or surfing the Internet – possibly generates cognitive stress that contributes to memory decline.
“I totally disagree,” said Dr. Christian Bocti, from the neurology department of the Center hospitalier universitaire de Sherbrooke. We know that in the ten years before a diagnosis of Alzheimer’s disease or dementia, we have cognitive changes, so all the studies (…) that claim to find a causal association, but which are within ten years of a diagnosis, in my opinion are not valid. “
The causal link between watching more television and the observed cognitive decline needs to be seriously questioned, he believes.
He recalls that ten years may elapse between the onset of Alzheimer’s disease in the brain and a diagnosis. During these ten years, the patient risks reducing his activities gradually: the time previously devoted to reading or to more complicated activities will have to be filled, “and possibly by default I will watch more TV”.
“In my opinion, it is an activity that is a manifestation of early cognitive impairment rather than a cause of cognitive impairment that sets in,” he explained.
Canadian data published 20 years ago abounds in this direction, according to Dr. Bocti. A study published in the 1990s showed that loss of leisure time is one of the earliest signs of cognitive decline that can be detected.
“If you have three or four hobbies outside of your home, and you’re doing less and less hobby, what are you going to do? You will watch more television. So that’s probably what they (the UK researchers) observed in their study.
“I am very surprised that this paper was accepted by Nature because it is an association, in my opinion, which does not hold water at all, he said. The fact that it’s published in Nature … I’m almost on the verge of writing a letter to the editor to say I’m against it. “
The findings of this study are published by the journal Scientific Reports, which is part of the Nature family.