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216 BCE
Brain VS Heart Debate
The origin of the brain VS heart debate can be traced back to the writings of Ancient Greek philosophers. Alcmaeon located mental processes in the brain, therefore is called the brain hypothesis. Empedocles located mental processes in the heart, therefore is called the heart hypothesis. The pros and cons of both hypotheses were debated for around 200 years.
A Greek physician Galen argued against the heart and believed strongly towards the brain hypothesis. -
Mind-Body Problem
The mind-body problem involves the question of whether our mind and body are separate or the are together. A French philosopher René Descartes proposed that the human mind and body are separate but inter-connected. He believed the pineal gland connected the mind and brain causing them to interact with each other. His saying was ' I think, therefore I am' -
Phrenology
Phrenology was first systematically developed by Franz Joseph Gall at the end of the eighteenth century. He made observations on hundreds of heads and skulls, and in 1796 lectured in Vienna on the anatomy of the brain and the elements of phrenology. Phrenology was exploited by some people as a means of making personality and behavioural assessments. -
Gustav Frisch and Eduard Hitzig: discover motor cortex
In the 1820's Gustav and his colleague Eduard both used recent improvements in the control of electricity to stimulate what is now called the motor cortex of a dog. They found five sites and when they stimulated them, they triggered a movement on the opposite side of the body. -
Brain Ablation Experiments
Brain ablation involves disabling, destroying or removing selected brain tissue followed by an assessment of subsequence changes in behaviour. French physiologist Pierre Flourens is credited for introducing brain ablation experiments. He worked mainly on pigeons and rabbits, developing techniques of damaging or removing small areas of brain tissue to observe the effects on behaviour. -
Karl Lashley; search for the location and memory
In the 1920's an American psychologist named Karl Lashley used the ablation technique through 30 years to find the location of memory and thinking in the brain. Rats, monkeys and chimps were taught various tasks then parts of their cortical tissue were removed producing amnesia for memory of the learnt tasks. His experiments led him to develop two principals of brain function that became very influential for many years. -
Wilder Penfield: maps the cerebral cortex
The Canadian neurosurgeon, Wilder Penfield used ESB to map where the cerebral cortex was in his patients. He invented a new treatment for severe epilepsy which was removing the area that was believed to be the source of seizures. He was able to stimulate different areas of the cerebral cortex once it was exposed using electrodes. Over time him and his colleagues had studied and gained data from over 300 patients. -
Split Brain Surgery
Split brain surgery involves cutting the band of nerve tissue called the corpus callosum to reduce severe symptoms of epilepsy. This is only performed in serious cases of epilepsy or when the drugs or other medical procedures are not being effective.
An American neuropsychologist, Roger Sperry was awarded the Nobel prize for his research between the brain and behaviour. He identified that the two hemispheres specialise different tasks.
The image represents Sperry's apparatus. -
Neuroimaging Techniques
There are two main types of Neuroimaging techniques and they are Structural and Functional. Structural Neuroimaging includes CT scans and MRI's and Functional Neuroimaging includes PET scans and fMRI's. -
Structural and Functional Neuroimaging
Structural:
CT scans- Computerised Temography, takes x-rays of the brain at different angles, able to locate tumors and strokes.
MRI- Magnetic Reasoning Imaging, able to show very fine tissue in detail, diagnoses structural abnormalities. Functional:
PET- Position Emission Tomography, shows brain function, measures brain activity.
fMRI- Functional MRI, measures brain activity, records levels of activity in different parts of the brain. -
Electrical Stimulation of the Brain
Electrical brain stimulation, is a form of electrotherapy and technique used in research and clinical neurobiology to stimulate a neuron or neural network in the brain through the direct or indirect excitation of its cell membrane by using an electric current.
In the early 1950's Walter Hess, who was a neuroscientist, pioneered the use of electrodes to stimulate structures deep within the brain. It was unethical to research with humans so he used cats.
