إدغار أدريان

استكمالاً لدراسات كيث لوكاس السابقة ، استخدم أدريان مقياسًا كهربائيًا شعيريًا وأنبوب أشعة كاثودية لتضخيم الإشارات الصادرة من الجهاز العصبي ، وتمكن من تسجيل التفريغ الكهربائي لألياف عصبية مفردة تحت تأثير التحفيز الفيزيائي. (يبدو أنه استخدم الضفادع في تجاربه ^{[ 6 ]} ). أثبت اكتشافٌ عرضيٌّ قام به أدريان عام 1928 وجود الكهرباء داخل الخلايا العصبية. قال أدريان:

كنت قد رتبت أقطابًا كهربائية على العصب البصري لضفدع في إطار تجارب أجريتها على شبكية العين. كانت الغرفة شبه مظلمة، وقد حيرني سماع أصوات متكررة من مكبر الصوت الموصول بجهاز التضخيم، وهي أصوات تشير إلى نشاط نبضي مكثف. لم أدرك أنني كنت ضمن مجال رؤية عين الضفدع، وأنها كانت تُرسل إشارات لما أفعله، إلا عندما قارنت تلك الأصوات بحركاتي في الغرفة.

A key result, published in 1928, stated that the excitation of the skin under constant stimulus is initially strong but gradually decreases over time, whereas the sensory impulses passing along the nerves from the point of contact are constant in strength, yet are reduced in frequency over time, and the sensation in the brain diminishes as a result.

Extending these results to the study of pain causes by the stimulus of the nervous system, he made discoveries about the reception of such signals in the brain and spatial distribution of the sensory areas of the cerebral cortex in different animals. These conclusions lead to the idea of a sensory map, called the homunculus, in the somatosensory system.

Later, Adrian used the electroencephalogram to study the electrical activity of the brain in humans. His work on the abnormalities of the Berger rhythm paved the way for subsequent investigation in epilepsy and other cerebral pathologies. He spent the last portion of his research career investigating olfaction.

Positions that he held during his career included Foulerton Professor 1929–1937; Professor of Physiology in the University of Cambridge 1937–1951; President of the Royal Society 1950–1955; Master of Trinity College, Cambridge, 1951–1965; president of the Royal Society of Medicine 1960–1962; Chancellor of the University of Cambridge 1967–1975; Chancellor of the University of Leicester 1957–1971. Adrian was elected a Foreign Honorary Member of the American Academy of Arts and Sciences and the American Philosophical Society in 1938.^[7][8] He was elected an International Member of the United States National Academy of Sciences in 1941.^[9] In 1946 he became foreign member of the Royal Netherlands Academy of Arts and Sciences.^[10] In 1942 he was awarded the Order of Merit and in the 1955 New Year Honours was created Baron Adrian of Cambridge in the County of Cambridge.^[11][12]