Obraz jazyka v našem mozku

Abstract

Language is one of the most important of the cognitive functions of the human brain. This article reviews contemporary knowledge on the in volvement of individual brain areas in the recognition and generation of human language. Traditional results of lesion studies are supplemented by results of recent studies done by modern imaging methods, such as posi tron emission tomography, functional magnetic resonance imaging and magnetoencephalography. The language function of the brain is always lateralized, i.e. only one hemisphere (in most cases the left) is the seat of the language recognition area (Wernicke area) and the language genera- tion area (Broca area). As the results of modern studies demonstrate, this basic principle is evident in the human brain in the processing of sign lan- guage in deaf people as well, although in the processing of sign language some part, although a less important one is played by the nondominant (mostly right) hemisphere. There is still controversy over the role of the two areas of the human brain in reading: the traditional view that the main role in reading is played by the angular gyrus in transferring visual information from the visual occipital cortex to the temporal language areas has recently shifted in favour of the fusiform gyrus, particularly on the basis of imaging studies. The part of this gyrus involved in the reading of text is now called the visual word form area. Finally the article describes a new approach to understanding the involvement of individual areas of the human brain in language processing based on combining genetic studies with imaging studies.

Po vyřešení záhady lidského genomu přichází na řadu mimořádný zájem o pochope- ní funkce lidského mozku. Funkce částí mozku, které se podílejí na vytváření lidského jazyka, začíná být známa od druhé poloviny 19. století, především na základě znalostí o následcích91 lézí jednotlivých částí mozku vyvolaných úrazy mozku či patologickými procesy, zejména krvácením či nádory. Moderní zobrazovací metody v současnosti nabízejí nový, detailnější obraz mozkových funkcí souvisejících s jazykem. Článek podává přehled o nejnovějších výsledcích v tomto směru, a to o různých formách jazyka: kromě mluveného jazyka je referováno o znalostech funkce mozku při znakování, četbě psaného slova a psaní textu. Autor tu vychází i z vlastních výzkumů. Na závěr je naznačena nová možnost zkoumání mozkové funkce, a to spojením genetických studií a studií vytvářených zobrazovacími metodami.

Language is one of the most important of the cognitive functions of the human brain. This article reviews contemporary knowledge on the in volvement of individual brain areas in the recognition and generation of human language. Traditional results of lesion studies are supplemented by results of recent studies done by modern imaging methods, such as positron emission tomography, functional magnetic resonance imaging and magnetoencephalography. The language function of the brain is always lateralized, i.e. only one hemisphere (in most cases the left) is the seat of the language recognition area (Wernicke area) and the language gener tion area (Broca area). As the results of modern studies demonstrate, this basic principle is evident in the human brain in the processing of sign language in deaf people as well, although in the processing of sign language some part, although a less important one is played by the nondominant (mostly right) hemisphere. There is still controversy over the role of the two areas of the human brain in reading: the traditional view that the main role in reading is played by the angular gyrus in transferring visual infor-mation from the visual occipital cortex to the temporal language areas has recently shifted in favour of the fusiform gyrus, particularly on the basis of imaging studies. The part of this gyrus involved in the reading of text is now called the visual word form area. Finally the article describes a new approach to understanding the involvement of individual areas of the human brain in language processing based on combining genetic studies with imaging studies.