Racial Differences in Brain Activity

Human speech consists of complex sounds of an involved pattern. To be able to speak, it is not enough to have good hearing. To a baby in its first months speech is nothing more than a kind of a noise. To master speech, a child must learn to single out from a flow of sounds the essential features, or the phonemes. What one needs to perceive speech is not so much a keen ear as an ear trained to the system of a particular language.

If you do not know a foreign language, you will not be able to distinguish the individual elements of that language in the flow of sounds. You will not be able to repeat the words and phrases you hear, let alone understand them.

It is an interesting and important fact that this process is performed not merely by the acoustic regions of the brain, but also by the articulatory organs, which take part in the utterance of speech sounds, and by the corresponding motor regions of the brain. Even adults, although they usually do not realize it, do not perceive speech eiiher by sounds or visual appearance (written text), but by so-called kinaesthetic perception, a vague, inner sensation arising in the muscles and tendons of the articulatory organs during speech.

Acoustic information is analyzed in the temporal lobes of the cerebral cortex. Like all the other analysers in the human brain, the temporal lobes of the cortex consist of the primary or projection zones, to which the nerve fibres from each ear come, and the secondary zones which receive information not from the periphery, but that already processed by the primary zones.

If the primary zones have been affected by disease, the patient will have hearing trouble. It is quite a different matter if the secondary zone of the left hemisphere is damaged. The hearing is practically intact, but speech hearing is gravely affected. They cannot distinguish d from t, b from p and z from s. Obviously, they fail to identify phonemes and consequently have difficulties in understanding words.

Physicians have an especially vast knowledge of the activity of the human brain, for they have always observed changes in psychic responses in patients with different afflictions of the brain. They have long since noticed that if certain areas of the cerebral hemispheres are injured, paralysis occurs, and when others, eyesight or hearing is a fleeted. A lesion of certain brain regions affects the speech most of all. When the temporal lobe of the left cerebral hemisphere is injured, a patient continues to hear speech, but cannot understand it. Injury to the frontal lobe of the same hemisphere mainly disturbs the articulation of sounds, while parietooccipital injuries affect the ability to count.

Some brain afflictions interfere with the ability to write or read. When sufficient observations had been accumulated, it was noticed that the lesions of the temporal lobes that made a European unable to cope with written speech had less grave consequences for a Japanese, and none for a Chinese. On the other hand, afflictions of the parietal lobe never greatly interfered with a European's faculty to write coherently, but greatly disturbed that of a Japanese, while a Chinese became absolutely incapable of writing comprehensively.

Does this mean that there are racial differences in the activity of the brain? Well, in order to answer this question, we need to discuss the organization of speech function. Just follow us in next posts.

If you were to talk to a group of North Americans who support the fight for Negroes' rights, would you not be surprised to learn that even they often regard Negroes as second-rate humans? Nowadays everybody knows that there are no essential differences in the functioning of the muscles and internal organs. So the proponents of racist doctrine allege that the main difference lies in the mental sphere, i. e. in the functioning of the brain.

Such views stem from the great difference in the level of cultural development that existed between different nations some three or four centuries ago in the epoch of great geographical discoveries and which even nowadays have not yet been completely smoothed out. Many outstanding personalities have come from Asia, Africa, North and South America, and Australia, but the overall contribution of many nations to the progress of human civilization still remains negligible. The living conditions of these nations are certainly responsible for this rather than any innate inferiority. The racialists, however, claim that the different levels of cultural development prove the inferiority of non-Europeans.

Are there any real differences in the work of the brain in different human races? The basic difference between the activity of the brain in man and animals is the use of speech, which Ivan Pavlov called the second signalling system. Speech is a purely human phenomenon, and racial differences, if any, will be manifested in the brain mechanisms of speech.