MOSCOW, November 2. /TASS/ Researchers from the Laboratory of Neurolinguistics at National Research Center Higher School of Economics (HSE) have gained new insights into the roots of semantic aphasia, the distortion of speech and perception of spatial relations. The development, recently presented in the journal Cortex, might be of a great importance for surgeons dealing with brain surgery, said the press service of HSE.
"By means of structural MRI imaging, we have succeeded in collecting new data which demonstrate that the disturbances in the brain’s temporal, parietal, and occipital cortex are present not for all patients, whereas the distortions in the funicles (bundles of neurons) or in the conductive paths which connect different brain areas are typical for the majority of cases," said Olga Dragoy, the Chief of Laboratory of Neurolinguistics at HSE and the principal author of the study.
In the case of semantic aphasia, spatial relations are impaired. For instance, the subjects cannot mirror the movements of other people and do not understand the meaning of words indicating the relative position of objects spatially, as e.g. "in", "behind", "over", "under", "above", "below".
About 70 years ago, the outstanding Soviet neuropsychologist Alexander Luria included semantic aphasia in his classification of aphasias (speech disturbances) by showing that the deficiency of logical connections between words in sentences is consistent with non-linguistic (spatial) disturbances. Luria studied the aftermath of gunshot victims from World War II veterans and came to the conclusion that the semantic aphasia appeared only in very particular disorders in the cortex parts of the left hemisphere: where the temporal, parietal, and occipital cortex areas intersect. The new study has added new insights into the previous data.
The study done by HSE researchers is of great importance not only for curing people with aphasia, but also for a deeper understanding of the brain’s working principles as this work has led to the idea that the usage of language is not solely connected with the functioning of basic "language" areas in the brain, but is the result of constant intercommunication between many of the brain’s divisions.