COGNITIVE SCIENCE 107A MIDTERM EXAM 1 - FALL Name: PID: Total Pts: /100pts

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1 COGNITIVE SCIENCE 107A MIDTERM EXAM 1 - FALL 2009 Name: PID: Total Pts: /100pts I. SHORT ANSWERS (5 points each for a total of 30 points) 1. Label the three meningeal layers in the following diagram. Describe the function of the meninges? Pia mater Arachnoid mater Dura mater Serves as a protective mechanism; allows for CSF and blood vessels in the subarachnoid space 2. Explain the social intelligence hypothesis of brain evolution? Socialization requires an animal to keep track of individual members and their actions. Thus, increased socialization, requires more resources, and provides an evolutionary drive toward larger and more sophisticated brains. 3. During the differentiation phase of brain development, axons must find their way to their targets. Briefly describe three methods of long distance targeting. Chemotropism Guide post cells Preformed pathways 1

2 4. Describe two Hebbian learning rules that lead to the stabilization or withdrawal of synaptic connections. Synaptic efficacy increases when there is correlated activity between pre/post cells Synaptic efficacy decreases when there is uncorrelated activity between pre/post cells 5. Please explain why magnetoencephalography (MEG) is insensitive to gyral sources. MEG records from neurons in the cortex. Cortical neurons are oriented perpendicular to the surface of the cortex. Since the cortex is folded, this means that the neurons will be aligned perpendicularly to the skull along each gyrus and parallel to the skull within each sulcus. In active neurons, an electrical field is generated along their length. A corresponding magnetic field is generated according to the right hand rule, where the magnetic field wraps around the axis of the current in the same direction as the curled fingers wrap around the axis of the protruding thumb. Thus, only neurons within the sulcus have magnetic fields that project outside of the skull. 6. What is the function of Spemann s Organizer in brain development? It releases neural inducers beginning around embryonic day 18, which block morphogenic bone proteins from preventing ectodermal tissue from becoming neural tissue. Corpus callosum II. DIAGRAM (20 pts) neocortex Lateral ventricle Sylvian fissure Temporal cortex In the coronal view of the brain on the left identify each of the following areas labeling them with the appropriate name or letter: a) corpus callosum; b) neocortex; c) lateral ventricle; d) temporal cortex; e) Sylvian fissure. (5 pts) In the lateral view, label each of the following areas with the appropriate name or number: 1) central sulcus; 2) parietal lobe; 3) temporal lobe; 4) cerebellum; 5) inferior frontal gyrus (5 pts) 2

3 8. In the drawing below, label the 5 main subdivisions of the CNS during development (5 pts) telencephalon diencephalon mesencephalon metencephalon myelencephalon 9. Please label the five topographical regions of the corpus callosum. (5 pts) truncus isthmus genu splenium rostrum 3

4 III. MATCHING (20 pts) 10. Match the phases of brain development (1 st column) with processes going on during that phase (2 nd column). (10 pts) f Cell death a. neural plate!neural groove! neural tube c_ Migration b. G1-S-G2-M d,e Differentiation c. Reln protein g,i_ Synaptogenesis d. phenotype b Proliferation e. growth cone a,h,j Neurulation f. apoptosis g. Hebbian learning h. gastrulation i. activity-dependent synaptic modification j. anencephaly 11. Match the glial cell with its function (4 pts) c oligodendrocyte a. myelination of axons in PNS e astrocyte b. lines ventricles and involved in CSF production d microglia c. myelination of axons in CNS b ependymal d. mediators of immune response e. source of CAMs and growth factors 12. Please match the classes of structure to the description and the example. (6 pts) Descriptions: 1. Layered structures formed by a mixture of radial and tangential migration 2. Inside-out pattern, layered structures with predominantly radial migration 3. Non-layered structures Examples: A. Cerebral cortex, cerebellar cortex, and hippocampus B. Brainstem, thalamus, and hypothalamus C. Retina and spinal cord Description Example Class 1 2 A Class 2 1 C Class 3 3 B IV. MULTIPLE CHOICE (One point per correct answer. Only one answer per question. A total of 10 pts) 13. What are the three parts of MacLean s triune brain? (1 point) A. reptilian, avian, mammalian B. amphibian, reptilian, mammalian C. reptilian, paleomammalian, neomammalian D. archaeomammalian, paleomamalian, neomammalian 4

5 E. primary mammalian, secondary mammalian, tertiary mammalian 14. The Bell-Magendie Law refers to: A. The normal (i.e., bell-shaped) distribution of channels B. The same nerves serving both input and output function C. Different nerves serving input and output function D. The relationship between mind and brain E. The quality of sensory experience as determined by the levels of neurotransmitters in a specific circuit. 15. Which of the following is a lesson about the brain we have learned from studying evolution: A. The current (brain) model is the result of thousands of years of development. B. Evolution has a master plan. C. New capabilities replace existing capabilities. D. The brain is organized and specialized in at least three dimensions. E. Solutions to problems are optimal 16. Electroencephalographic (EEG) recordings that reflect the summed (or average) electrical activity of neuronal populations from different parts of the brain are called? A. Dendritic field potentials B. Event-related potentials (ERPs) C. Event-related magnetic field responses (ERFs) D. Blood oxygenation level-dependent (BOLD) signals E. EEG summated potentials 17. Which is NOT one of the three types of neurons in the neural circuits of the central nervous system? A. Ifferent B. Afferent C. Efferent D. Interneuron E. None of the above 18. During the proliferation phase of brain development: A. Cells acquire a phenotype B. Synaptogenesis begins C. Cells in the ventricular zone migrate to the cortical plate D. The neural plate becomes the neural groove and that becomes the neural tube E. Cells begin to divide at a very fast rate 19. Lamellipodia and filopodia are: A. Proteins involved in neural induction B. Signaling chemicals used during migration C. Components of the growth cone D. Markers for axonal growth E. Microtubule and microfilament proteins 20. Some primate brains became larger and smarter (through evolution) because of: 5

6 A. High nutrient diets B. Stay at home strategies C. Ease in getting to food D. Larger digestive system E. None of the above 21. According to the neuron doctrine: A. The brain is composed of cells that are structurally connected B. Electrical conduction of information is continuous across cells C. There are gaps between cells D. Cells are not functionally independent E. None of the above 22. One disadvantage of using naturally occurring lesions to learn about the cognitive correlates of the brain is: A. Not specific to functional areas B. No change in the distribution and extent of the damage C. Effects of recovery occur too quickly D. Too many subjects available and those available are homogeneous E. Does not require double dissociation to strongly confirm V. FILL-IN-THE -BLANK (1 point per answer for a total of 10 points) 23. The _foraging hypothesis proposes that the change in food sources from leaves to fruit provided an evolutionary drive toward increased intelligence. 24. The end point of the axon that helps guide it to its target during the differentiation phase of brain development is called the growth cone. 25. exuberancy refers to the increase in redundant connections made by a neuron during synaptogenesis - some of which are later retracted. 26. sulci refer to folds in the cortex, while gyri refer to cortical surface areas that are not folded. 27. _grey matter refers to the color associated with nuclei and/or cortices, which are rich in neuronal cell bodies and synapses; _white matter refers to axon tracts. 28. Excitatory (Type 2) synapses are asymmetric / symmetric, while inhibitory (Type 1) synapses are asymmetric / symmetric. 29. Luigi Galvani_ suggested that muscle movement may be due to electricity in the body. VI. TRUE/FALSE (1 point for each answer for a total of 10 points). 30. Cell death during brain development is normal. _T/F_ 31. Neurons differ from glial cells in that glial cells lose their ability to divide postnatally (i.e., after birth). _T/F_ 32. During local targeting, axons arborize widely in a non-selective, trial and error manner. _T/F_ 33. Spines on dendrites receive excitatory inputs. _ T/F_ 34. The first adaptive change distinguishing ancestral humans was their Ability to walk upright and on two feet (bipedal walking). _ T/F_ 35. Increased brain complexity produces increased lamination of cortex. _ T/F_ 36. The organization of the brain of many mammals suggests a common 6

7 ancestor. _ T/F_ 37. The radical microglia cells provide a scaffolding system for cell migration. _T/F 38. Ontogeny is the process by which an individual changes in the course of its lifetime. _ T/F_ 39. During interkinetic nuclear migration the neurons travel continuously in an outward direction from the ventricular zone to the marginal zone. T/F_ 7