When the brain loses the meaning of words

Let’s take a simple word as “hammer” (Hammer): for most of us. Furthermore, his pronunciation immediately awakens a mental image. In addition, This capacity, called “imageability”, helps the brain to recognize the word faster.

But the researchers highlighted an even more fundamental mechanism: we also read thanks to the meaning. However, Now. In addition, after a stroke, some survivors lose this semantic link – their brain can no longer connect the word to its idea, and reading becomes laborious.

The wolf is in the upper temporal groove

To better understand. In addition, the researchers compared 56 patients who underwent a stroke in the left hemisphere (region dedicated to language) to 68 people free from stroke. Meanwhile, Thanks to targeted MRIs and advanced statistical analyzes – such as Lesion – Symptoms mapping by vector of support.

They spotted that the damage located in the when brain loses meaning words posterior upper temporal groove (and to neighboring areas such as medium. However, upper temporal gyri) abolish the advantage of “high imageability”. For example, Clearly: even an easy word to visualize no longer benefits from its semantic boost.

Another fascinating part: this injured region also appears involved in the meaningful connection – phonology. in other words the conversion of meaning into sounds – one of the pillars of the link between what we understand and what we pronounce.

It is not a simple phonological decoding deficit – an inability to “decipher” phonetically. frequent after a stroke – but a specific semantic disorder: the integration of meaning and the sound form is disturbed. The authors speak of a post -ethical reading deficit: despite a good understanding out of word written. the link between the word read and its mental concept is weakening, as if a bridge collapsed.

Meaning, rhythm, repair a delicate when brain loses meaning words balance

This discovery is not limited to cerebral explanation. It opens concrete rehabilitation paths: specifically targeting the repair or bypassing this inability to link concept and sound.

« We generally think that daily reading is a way to give meaning to our readings. but the reverse is also true: we rely on the meaning of words to recognize them. Some people recovering from a stroke manage to use the meaning of words to recognize them. which makes reading more difficult “Explains Peter E. Turkeltaub. MD, PHD, director of the Cognitive Recovery Lab from the University of Georgetown and the main study of the study.

« Our results clarify the neurobiology of reading. provide the most solid proof to date with a form of reading disorders which may occur after a stroke of the left hemisphere “, Continues Ryan Staples, co -author, Ph.D. and postdoctoral researcher in the Turkeltaub laboratory.

The when brain loses meaning words researchers notably evoke a five -year project funded by the NIH. which will compare the reading capacities of the elderly without stroke with those of stroke survivors of the left hemisphere. Objective: to better understand the evolution of the links – phonology. whether in normal or pathological aging, aims at the Georgetown University, at the origin of these discoveries.

Lifetime after -effects …

Each year. in the United States, around 800,000 people are victims of a stroke, a pathology affecting more particularly the marginalized populations from minorities. In a comparative study of 56 survivors of stroke of the left hemisphere. 68 people without stroke, it was observed that the disorders linked in the sense of words were much less frequent and less severe than phonological disorders.

In other words, the difficulties in pronouncing the words, much more typical among strokes. This study focused on strokes of the left hemisphere, when brain loses meaning words a region of the essential brain for language.

In Europe, the incidence of strokes remains high: it is estimated that in 2021, 967,000 Europeans underwent a stroke of the 11.9 million cases registered worldwide. However, thanks to progress in prevention and care, the mortality due to the stroke dropped by 68.3 % in Western Europe, 55.3 % in Central Europe and 43.3 % in Eastern Europe since 1990.

Nevertheless. the forecasts are worrying: between 2015 and 2035, the EU could experience an increase of 34 % of the total number of strokes, causing an influx of survivors, the number of which should go from 3.7 to 4.6 million, and an explosion of costs related to care, estimated at 45 billion euros from 2015. To illustrate this reality, in France, 122,422. Hospitalized for a stroke in 2022, and 1 million people lived with sequelae of this condition in early 2023.

Credits when brain loses meaning words Illustration: TUMISU CC 0

By Victor Of Sepposy
Contact : [email protected]