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Unformatted text preview: Neuroscience 2: Module 1: The Structure of the Brain: Dorsal/superior: near the top Ventral/inferior: near the bottom Anterior/rostral: closer to the front or nose Posterior/caudal: closer to the back Medial: towards the midline or more central Lateral: near the outside of the brain Ex. The medulla is a region in the hindbrain which can be further divided into several subregions. One is the rostral ventral medial medulla ; in simpler terms it is towards the front, near the bottom and towards the midline of the brain. Module 2: Studying the Brain: Lesion Studies: neuroscientists are interested in case studies which can link accidental brain injury with the associated cognitive and behavioural deficits. Ex. Phineas Gage, in 1848, was a foreman of a railway construction crew and was in charge of using explosives to remove large sections of rock in the way. Athletic, intelligent and full of life, he was well respected by his crew and liked by all that knew him. One fateful day, he was the victim of a tragic accident, resulting in the blasting of a 3 foot iron rod completely through his left cheekbone and through the top of his skull. He survived and except for some loss of vision and facial scarring, he completely recovered. However, his personality changed dramatically. Once an upbeat, polite and caring person, he became prone to selfish behaviour and bursts of profanity. He became erratic and unreliable and had trouble forming and executing plants. His case provided support for the view the brain has specialized structures for quite complex behaviours. Brain lesions are rarely isolated to specific brain structures. This makes is more difficult to assign impaired function to specific brain areas. This can be studied by using animals. In ablation studies , a researcher destroys or removes or inactivates a defined brain region and observes the resulting behaviour. Accuracy of this depends on how precise the lesion is. Because the brain is so highly interconnected, often a variety of behaviours are affected by a single lesion. Advantages: a direct measure of a brain structure’s function Disadvantages: hard to selectively target particular regions and draw conclusions Stimulation and Single Cell Recording: An alternative approach to lesioning is to electrically stimulate an area of the brain and observe the resulting behaviour. This was used by Canadian neurologist Penfield as he treated patients with severe epileptic seizures. Penfield revolutionized techniques in brain surgery as perfected his Montreal procedure to treat patients experiencing severe seizures. Because the brain itself does not have pain receptors, a patient could be under local anaesthetic and fully conscious, working with Penfield to probe the patient’s exposed brain as he tied to locate and remove the scarred tissue that caused the seizures. Before doing so, he has to be sure that critical areas of the brain were left intact. Penfield used a thin wire carrying a small electric charge to stimulate the cortex. This stimulation leads individual carrying a small electric charge to stimulate the cortex....
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This note was uploaded on 04/17/2009 for the course PSYCHOLOGY 1XX3 taught by Professor Kim during the Spring '09 term at McMaster University.
- Spring '09