Topic: Introduction to Neuropsychology.pptx

Introduction to Neuropsychology.pptx

1. Introduction to Neuropsychology Lecture 1 : History

2. History Draws on many disciplines, including anatomy, biology, pharmacology, physiology, and philosophy Donald Hebb first used the term in 1949, although it was not defined By 1957, it was a field in the neurosciences In 1960, it was again in the title of a book but still undefined Prehistoric Surgery Prehistoric Traumatic Brain Injury Cranial Trephination [( also known as trepanning or burr holing) is a surgical intervention where a hole is drilled, incised or scraped into the skull using simple surgical tools ] Trephination Methods Scraping Cutting Drilling

3. The Egyptians and The Greeks Egyptians noticed the relationship of contra-lateral design of the nervous system Aristotle believed that the heart was the seat of cognitive function. The Greeks observed the consequences of seizure Hippocrates made a number of correct observations about brain illness and generalized these to an understanding of brain function

4. The modern definition was influenced by two foci in brain research The brain hypothesis: brain is the sources of behavior The neuron hypothesis: the unit of brain structure and function is the neuron

5. Brain Hypothesis Earliest record occurred in 500 BC in which mental processes were thought to occur in the brain (i.e., brain hypothesis) At the same time, Emedocles located mental processes in the heart (i.e., cardiac hypothesis)

6. Plato (420-347 BC) rational part of the soul in the brain because it was closest to the heavens Aristotle (384-322 BC) heart was the source of mental processes because it was warm and active Hippocrates (430-379 BC) and Galan (AD 129-199) argued for brain hypothesis

7. Early Anatomy Studies The body functions according to the balance of four vital fluids (humors). The fluids flow through the ventricles and nerves . Once the brain hypothesis had been accepted, the next stage was to understand how the brain controls behavior

8. Modern thinking began with Rene Descartes (1596-1650) He originated the mind-body problem What is relation between the mind and body? How do they interact?

9. Phrenology Physiognomy Phrenology: the detailed study of the shape and size of the cranium as a supposed indication of character and mental abilities Physiognomy: the general form or appearance of something. Mental and Personality Traits are associated with specific organs of the brain.

10. Localization of Function Phrenologists Localization: the fact of being or becoming located or fixed in a particular place . Gall (1758-1828) and Spurzheim (1776-1832) brain is the center of high mental activity Function is localized

11. Important anatomical discoveries ( 1) cortex is made of functioning cells that are connected to subcortical structures (2) Spinal cord is made of gray and white matter (3) Neural pathways crossover at the pyramids (4) the 2 halves are connected by commissures Gall associated behaviors with characteristics of the skull Lead to the development of Phrenology the relationship between skulls features and mental faculties *Anatomy: study of the structure of organisms and their parts / dissection

12. Phrenology failed for several reasons (1) Faculties were difficult to objectively define (2) assumed that superficial features of the skull could be used to estimate brain size and shape gyral patterns were random wrinkles Localization of Function The First Experiments Flourens (1794-1867) conducted the first experiments that refuted Galls ideas Ablation technique: removed part of brain and observed subsequent behaviors *Mental faculty  - one of the inherent cognitive or perceptual powers of the mind.  faculty , module. ability, power - possession of the qualities (especially  mental qualities ) required to do something or get something done. The mind is a set of  cognitive  faculties including consciousness,  perception , thinking ,  judgement , and  memory . *In neuroanatomy , a  gyrus  (pl.  gyri ) is a ridge on the cerebral cortex. It is generally surrounded by one or more sulci (depressions or furrows; sg . sulcus ).   Gyri and sulci create the folded appearance of the brain in humans and other mammals

13. E lectrical Stimulation of the Brain Fritsch (1838-1929) Hitzig (1838-1907) developed the technique for electrically stimulating the brain Their results showed (1) applying an electrical current to neo-cortex resulted in movement on the contralateral side of the body (2) stimulation of small parts of neo-cortex resulted in movement of specific body parts (3) stimulation of the posterior neo-cortex produced no movements

14. Studies by Fritsch Hitzig refuted 3 dictums (a short statement that expresses a general truth or principle) by Flourens and showed that (1) cortex is excitable, (2) cortex plays an important role in movement , (3) function is localized

15. The studies of Benjamin Franklin in 1751 and others demonstrated basic properties of electricity Galvani and du Bois- Reymond demonstrated that muscles twitch when stimulated by electricity, and that the brain generates electricity. Nerves were then thought of as wires rather than fluid-filled conduits. Ferrier Munk (1900's) - identified areas for vision, audition, skin senses by experimental ablation of the brain tissue Muller - Advocated the use of experimental techniques in physiology developed the concept of specific nerve energies

16. Anti-Localization Movement Goltz Henry Head some behaviors too complex to be located in only one area of the brain Goltz provided important evidence for the anti-localization movement Goltz ablated neo-cortex of 3 dogs, Dogs lived for 57 days, 92 days, and 18 months Observed (a) hyperactivity (b) sleep -wake cycles (c) responses to temperature changes (d) walking, balance (e) responses to environment (f) able to differentiate between food/poison (g) Respond to light/sounds

17. Neuron Hypothesis Basis is that the nervous system is made of discrete, autonomous cells that interact but are not physically connected

18. Development of Modern Neuropsychology Reasons why psychologists did not become interested in the brain before the mid 1900s (1) Strong arguments by Head and others refuting localization of precise behaviors (2) World Wars interfered with development of science (3) Psychology comes from philosophy and thus they directed attention to behaviorism and psychoanalytical movements

19. Modern Developments There have been 3 modern developments that have contributed to the discipline of neuropsychology (1) Neurosurgery Anesthesia, antisepsis, and localization of function (2) Psychometrics and statistical evaluation Binet , IQ development Hebb ( sought to understand how the function of neurons contributed to psychological processes such as learning), frontal lesions (3) Advances in technology CT , MRI, fMRI, PET