6 - The Development of Neuropsychology Flashcards
What seems to be the first written text about symptoms and treatments of brain injury?
As far as we know
Edwin Smith Papyrus (Ancient Egypt)
Where did Plato place the soul?
Divided into three parts: Brain (reasoning, immortal), heart (sensation) (these two are separated by the neck to protect the divine soul) and the liver (appetite)
Where did Aristotle place the soul? Why and what was the function of the brain?
The heart (bc: affected by emotion, all animals have a heart, source of blood, it is warm, connected with the senses, essential for life, first to form and in a central location of the body)
The brain was to cool down the heart
How did Galen contribute to the view of the brain’s functioning?
His findings on the voice coming from the brain (bitch severed a pigs’ nerve), anatomical studies of cow brains (which he fitted into a human skull, in his drawings) and the nerves
Albeit Galen’s research into the brain, what were his beliefs regarding the soul and the body?
Solid parts of the brain housed the soul, which commanded/produced animal spirits (whatever those are). The animal spirits were used by the soul to communicate with the body (spirits travelled through nerves and were stored in the ventricles)
What thoughts/developments were (mainly) made for the brain during the renaissance?
Andreas Vesalius & Gregor Reisch & da Vinci & Johann Schenk
Still focused on the ventricles; Identifed three
Front ventricle = information from senses (common sense), fantasy and imagination
Middle ventricle = thought and judgement
Latter ventricle = memory
Clinical observations after brain injure (e.g., brain damage could equate loss of speech)
What developments were made for brain functioning in the 1600s/1700s?
Thomas Willis
Moving away from the ventricles; layers of the cerebral hemispheres (cortex/grey matter/ and white matter)
Thomas Willis was one of the first to implicate grey matter in the functions of memory and will
Doubt of the existence of spirits in the nerves > instead contained fluids
Regarding brain developments of 16- and 1700s, why was there a struggle against the involvement of the cortex?
von Haller
(disgusting and horrid) animal studies showed that when the cortex was touched, the animal did not respond (which was not the case when going deeper into the brain, i.e., the white matter/ventricles)
Besides the switch for the brain in 17/18th century, what was another topic that gained much interest?
Reflexes (Galen = sympathy between body parts, Descartes = a sensory impression rushing to the brain and reflected back into a motor command and Prochaska = reflexes controlled by spinal cord and structures above it, not the brain)
Note: it would not affect treatment for quite a while
What were five breakthroughs in the 19th century that altered the model of brain functioning and made later neuro- possible?
- Cerobrospinal axis discoveries (brain and spinal cord)
- Impact of reflexes
- Localisation of brain functions
- Nerve cell discoveries
- Neuron communication
What was the discovery of the cerobrospinal axis and how did it affect views?
19th century
The view before was that only the brain was of origin of nerve signals.
1. Findings that the axis played a role in physical functions > hemispherical disconnection from the subcortical structures = body in vegative state.
2. I.e., many body functions do not rely on the hemispheres + Prochaska’s work pointed towards reflexes being mediated by the spinal cord
3. Findings concurrent with animals that have a spinal cord, but no brain > spinal cord evolutionary precedence
Discoveries regarding reflexes and their effects on views?
Marshall Hall, 19th century
- Discovery of afferent (bottom-up) and efferent (top-down) nerves - against previous views of nerves working both ways
- Hall’s extension > reflex arc (which was in the spinal cord)
- Reflex arc = signal pickup by sensory receptors > transmitted to spinal through afferant nerves > interneurons > activation of motor neurons > motor commond to efferent neurons to initiate action
- Extension of Hall’s theory to the brain > Sechenov theorized higher brain functions to be of a reflexive nature > Influenced Pavlov (history dun dun dun)
- I.e., reflex arc was used as the basis of mental functioning (influenced behaviourism)
Remember at least 5. okay
Discoveries brain localizations + affects on view?
19th century
- Moving away from brain equipotentionality (all brain parts are of equal significance and involved in each task) for the entire brain > localization theory (processes are localized). This took quite a while btw
- Evidence towards left and right frontal localization of language by Bouillaud (which was heavily opposed, e.g., by Flourens)
- Further evidence by Broca (left frontal in language production - Broca’s area)
- Wernicke’s area (rear left hemisphere, understanding of language)
Current evidence seems to support a balance for 1.
Discoveries nerve cell + effects of view
19th century
- Grey matter = billions of cells (aka neuronal dendrites and bodies) and white matter = the tails (aka axons)
- The above through better microscopes + colour staining of tissue (Golgi)
3. Better understanding of tissue + allowance for theories/later discoveries on neuron communication
Discoveries neuron communication + effects of view
- Is the network of globules (cell bodies) and branches (dendrites) a continuous structure or consistent of individual cells? Golgi believed the former
- Golgi was wrong > discovery of neurons and their communication without directly touching (end of 19th century, Cajal contributed to this)
- De-mystifying of nerve transmission (aka electrical currents). Galvani with initial evidence > Bois-Reymond with expansion
- Furthermore, Helmholtz with initial evidence that the electrical transmission was based on chemical processes (aka not like electrical wires)
» Exacts of this would be uncovered in the 20th century (aka synapses/neurotransmitters) > medications affecting neurotransmitters
bold = most important (obvs)
