History of Neuroscience

Question 1

Two historical positions

Answer 1

Locationalist: language is housed in subcomponents of the brain. Distinct processors. (syntax is located here).

Unitarian: Brain functions as a unified organ. Language is not distinct of cognitive processors. Whole or gestalt processor.

Question 2

Aristotle

Answer 2

384-322 bc
First locationalist. believed the mind was located in the heart, which contained all emotions and thinking. The brain was instead a radiator used to cool the heart. He experimented by dissecting animals (human dissection was forbidden).

Question 3

Plato

Answer 3

427-347bc
Taught at the Athens Academy, which was the most influential school in the ancient world. Aristotle was his famous student. He believed the brain was the seat of mental processes.`

Question 4

Descartes

Answer 4

1596-1650
believed nerves contained fluids or “animal spirits” which are responsible for the flow of sensory and motor information in the body. He helped distinguish two positions dualism (mind and brain coexist) and monism (mind and brain are separate). Descartes was primarily a dualist. He asserted that the mind influences the body through the pineal gland but that the body could not influence the mind.

Question 5

Gall

Answer 5

1758-1828
Advocate of cerebral localization. One of the founders of phrenology, but used it more as a spectacle than as a scientist. Divided the brain into 35 separate functions, ranging from concrete concepts like language and color to abstract ones like hope or self-esteem. Discussed symmetrical halfs of the brain. External structure of the skull reflects areas of cortical development. Associated behaviors with specific areas of the head.

Question 6

Flourens

Answer 6

1794-1867
Flourens ablated the cortical tissue of dogs, rabbits and birds, showing that the eventual recovery was due to the brain’s aggregate field, where the entire brain participated in behavior. Advocated a holistic view of the brain, where other parts of the brain could take over the function of damaged ones. Experimental localizer in the nervous system but against localization of cerebral function.

Question 7

Dax

Answer 7

1791-1837
Noted that right hemiplegia was more common than left hemiplegia following an acquired disturbance in speech. In 1836, he diagnosed patients with speech problems or loss of speech. when he examined their brains after their deaths, he saw that all of these patients had damage to the left side of their brain. Never published his work in writing.

Question 8

Broca

Answer 8

1824-1880
Paul Broca built on Marc Dax’s work. advocated functional localization. Demonstrated that the brain lesions in the left frontal lobe caused speech problem but not an impairment in comprehension. This region has since been named Broca’s area. Looked at 8 case studies of severe speech disorder and reported in detail about 1 case. Dissected brain after their died and reported all patients had damage to left third frontal convolusion of frontal lobe. control of one patient who had damage to analogous right side with no speech problems.

Question 9

Wernicke

Answer 9

Wernicke showed a patient who could speak but made no sense. The damaged area was around where the temporal and parietal lobes meet in the posterior part of the left hemisphere.

Question 10

Classical Model of Aphasia, aka Wernickie Lichtime model

Answer 10

We have a motor processor, sensory processor, and an important connection pathway between the two. Language is localized to the left hemisphere. Damage to this region will cause a particular kind of deficit.

Question 11

Fritsch

Answer 11

1835- 1911
stimulated the brain surfaces of live dogs and frogs using electricity. This resulted in characteristic movements in the neck and hind legs. Localized centers, which produced various movements on the side of the dog opposite to the side of the brain stimulated were identified. (The way cells were organized provided a pathway).

Question 12

Hughlings Jackson

Answer 12

1835-1911
Jackson made discoveries of higher nervous activity and language. He suggested that the brain was divided into different sections organized hierarchically. Higher centers bring more refinement to neuronal processing but also inhibit lower centers. Suggested that the highest parts of the nervous system, known to be involved in conscious mental action (problem solving, feeling, volition), are built on the same ground-plan as the lower parts.

Founder of modern neuropsychology. Mental operations and behaviors. Need to point out that locating damage that destroys speech, and speech are different things. He directed the attention to the kinds of speech people lost. Not all speech was lost, just different kinds.

Question 13

Brodmann

Answer 13

1868-1918
Categorized the brain into 52 distinct areas based on the cellular organization of the cortex in the respective regions. Helped to support the localization view. This was accomplished through tissue stains in order to visualize the different cell types. The difference between individual cell regions is called cytoarchitectonics or cellular architecture.

Question 14

Freud

Answer 14

1853-1939
freud is best known for his theories of the unconscious mind and the defense mechanism of repression. He is also renowned for his theory of transference in the therapeutic relationship and the presumed value of dreams as sources of insight into unconscious desires.
Believed that in aphasia when a person’s brain is damaged the brain goes into a regression and they become more infantile and primitive.

Question 15

Cajal

Answer 15

1852-1934
discovered that neurons conducted electrical signals in only one direction. He established the neuron doctrine which proposed:
- neurons are discrete and autonomous cells that can interact
-synapses are gaps that separate neurons
-information in transmitted in one direction from dendrites to the axon