Development of Neuropsychology: Understanding the Human Brain and Behavior

1. Notes: Syllabus Prereqs – Psych 260 OR 351 Office Hours – 11:00 to 12:00 T TH Class Question Website: http://www.ndsu.nodak.edu/ndsu/pavek/ Questionnaires Class Pictures

2. “The Development of Neuropsychology” . Human Neuropsychology (486 / 686) Lecture Chapter 1 2

3. Overview • What is Neuropsychology? • Human Brain • Divisions of the Nervous System • The Brain Hypothesis • The Neuron Hypothesis 3

4. What is Neuropsychology? Neuropsychology - Scientific study of the relationship between behavior and the brain - Draws from many disciplines, including anatomy, biology, pharmacology, and philosophy - Experimental results from neuropsychological investigations can be used to identify traumatic brain injury impairments and vice versa 4

5. What is Neuropsychology? Two ideas that influence experimental and theoretical investigations of brain function The Brain Hypothesis: • -The brain is the source of behavior The Neuron Hypothesis: - The unit of brain structure and function is the neuron

6. The Human Brain • What is the brain? • Brain = Old English word for tissue inside the skull • Inner hollow tube filled with cerebrospinal fluid (CSF) • Outer layer of wrinkled tissue known as cerebral cortex • Composed of two symmetrical hemispheres, the right hemisphere and the left hemisphere

7. The Human Brain • Three Major Divisions of CNS • Forebrain • Cerebral Cortex • Performs higher functions like thinking, perception and planning • Brainstem • Underlying tube • Performs regulatory and movement producing functions • Spinal Cord • Connected to brainstem and descends down the back • Performs regulatory and movement producing functions

8. Features of the Cortex

9. Features of the Cortex • Gyri • Folds of the cortex • Sucli • Creases between the folds • * Large sulci = fissures • Examples: Longitudinal Fissure and Lateral Fissure • Four Lobes: - Frontal - Temporal - Parietal - Occipital

10. Divisions of the Human Nervous System

11. The Brain Hypothesis • What is behavior? “Patterns in time” Movement of an organism - cause & function (purposeful?) - complexity & flexibility • How is behavior produced? Brain vs Heart • Brain Hypothesis - Alcmaeon of Croton • Cardiac Hypothesis - Empedocles of Acragas • Current neuropsychology accepts the brain hypothesis

12. Perspectives on Brain and Behavior • Aristotle* and Mind   • Descartes* and Dualism • Descartes’s Legacy • Darwin* and Materialism   • Darwin’s Legacy • Natural selection   • Linking Brain Function to Brain Disease  

13. Donald Hebb: “Modern psychology takes completely for granted that behavior and neural function are completely correlated, that one is completely caused by the other. There is no separate soul or life force to stick a finger into the brain now and then and make neural cells do what they would not otherwise. It is quite conceivable that some day the assumption will have to be rejected. But it is important also to see that we have not reached that day yet: the working assumption is a necessary one, and there is no real evidence to oppose it. One cannot logically be a determinist in physics and chemistry and biology, and a mystic in psychology.”

14. Experimental Approaches to Brain Function • Localization of Function - different parts of the brain perform different functions • Franz Josef Gall and Johann Casper Spurzheim •Phrenology

15. Phrenology • Problems • Impossible to define and quantify objectively • Features of the skull reveal little about the brain • Historical Importance • Laid foundation for modern localization of function • Phrenological map was the precursor for many maps of the brain

16. Localization and Lateralization of Language • Paul Broca* • Broca’s Area: anterior speech region of the brain • Lateralization: Functions can be localized to one side of the brain Tan’s Lesion

17. Sequential Programming and Disconnection • Carl Wernicke* • - Aphasic patients different from Broca’s • - Wernicke’s Area - Posterior speech region, located in the temporal lobe

18. Sequential Programming and Disconnection • Importance of Wernicke’s model • Identified disconnection syndromes • Regions of the brain have different functions but still must interact to work correctly • Identified the left hemisphere as dominant for language

19. Loss and Recovery of Function • Pierre Flourens • Removed areas of the cortex of animal brains and studied resulting changes in behavior • Findings • No specialization for areas of the cortex • Specialization for the brainstem • Findings refuted localization of function

20. Hierarchical Organization and Distributed Systems in the Brain • Hierarchical Organization • John Hughlings-Jackson* • Each successively higher level of • the nervous system controls more • complex aspects of behavior • Dissolution • Reverse of evolution • Occurs after damage to a higher level • Behavior becomes more simple

21. The Binding Problem • H.M. (Henry Molaison) • The brain analyzes sensory events through multiple channels, yet we have a unified perception of our experiences

22. The Split Brain • 1960s • Neurosurgeons began cutting the corpus callosum to prevent the spread of seizures • Roger Sperry • Conducted neuropsychological evaluations on “split brain” patients to discover how the right and left hemispheres function • Nobel prize in 1981

23. Conscious and Unconscious Neural Streams • The case of D.F. • Visual form agnosia • Inability to recognize objects by their shapes or see the shape of an object • Able to accurately reach for an object • Optic Ataxia • Can identify the shape of an object • Cannot accurately reach for an object

24. Neural Streams

25. The Neuron Hypothesis • The unit of brain structure and function is the neuron - Neurons are discrete - Neurons send an electrical signal - Neurons communicate with each other via a chemical signal, or a neurotransmitter

26. Identifying the Neuron • Camillo Golgi* • Proposed the Nerve Net Hypothesis • Santiago Ramón y Cajal* • Proposed that neurons were discrete

27. Nervous System Cells Neurons • Acquire information, process information, and act on information • Major parts include the cell body, dendrites, and axons Glia • Help neurons, hold them together • Carry out supportive functions

28. Relating Electrical Activity in Neurons to Behavior • Luigi Galvani • Discovered electrical stimulation caused muscular contraction • Gustav Theodor Fristch and Eduard Hitzig • Electrical stimulation of the cortex in the rabbit and dog to induce movement • Discovered topographic organization in the cortex

29. Relating Electrical Activity in Neurons to Behavior • Roberts Bartholow • First to report electrical stimulation of human cortex in a conscious person • Modern Approach • Transcranial magnetic stimulation (TMS)

30. Connections Between Neurons As the Basis of Learning • Alan Hodgkin and Andrew Huxley • Nobel prize in 1963 for discovery of the electrical signals generated by neurons • Charles Scott Sherrington • First description of the synapse • Otto Loewi • Discovered that chemicals carry the message across the synapse

31. Connections Between Neurons As the Basis of Learning • Donald Hebb* • When cells are activated at the same time they establish or strengthen the synapse • Hebb or plastic synapses • The brain is plastic and constantly changing • There is ongoing reorganization