Lecture2 Flashcards
Components of the brain
gray matter, white matter, reticular matter
nuclei and tracts
ventricles - cerebrospinal fluid (CSF)
Cellular components of the brain
Neurons, glia, vascular system
Neurons
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dendrite, cell body, axon
Methods of Organizing Brain Areas
- anatomy (cytoarchitecture) e.g., Brodmann area 17
- function e.g., visual area 1 (V1)
- developmental (ontogenetic) tracking embryonic and fetal
- comparative (phylogenetic) across animal species
- biochemical
Brain Anatomy
Brainstem
hindbrain (rhombencephalon)
cerebellum; pons
medulla
midbrain (mesencephalon)
tectum (superior colliculus; inferior colliculus)
tegmentum
front brain (prosencephalon)
telencephalon (neocortex, basal ganglia, limbic)
diencephalon (thalamus, hypothalamus, pineal)
IMAGES OF BRAIN
LABEL PARTS
Basal ganglia
Label parts* pic
LIMBIC SYSTEM
Label parts* pic
Human CNS Organization
Rhombencephalon etc. ADD PIC
Central Nervous System Function
SPINAL CORD
spinal cord
segmented
area on body that is paralyzed or numb
dermatome
cross section: white outside, gray inside
dorsal (back): sensory, afferent
ventral (belly): motor, efferent
spinal cord
PIC FROM SLIDE- label
neuropsychology.
Study of the relations between brain function and behavior. (Kolb 2)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
brain theory.
Principle that the brain produces behavior.
neuron theory.
Principle that the unit of brain structure and function is the neuron.
neuron.
A nerve cell that transmits and stores information: the basic unit of the nervous system; includes the cell body (soma), many processes (dendrites), and an axon. (Kolb 2)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
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Brain
cerebrospinal fluid (CSF).
Clear solution of sodium chloride and other salts that cushions the brain and may play a role in removing metabolic waste. CSF fills the ventricles inside the brain and circulates around the brain beneath the arachnoid layer in the subarachnoid space.
cerebral cortex.
Outer layer of gray matter on the surface of the cerebral hemispheres and composed of neurons and their synaptic connections that forms six sublayers. See also cortex, neocortex; compare cingulate cortex.
The folds, or bumps, in the cortex are called gyri (gyrus is Greek for “circle”), and the creases between them are called sulci (sulcus is Greek for “trench”). Some large sulci are called fissures: the longitudinal fissure, shown in the Figure 1.1 frontal view, divides the two hemispheres, and the lateral fissure divides each hemisphere into halves. (In our fist analogy, the lateral fissure is the crease separating the thumb from the other fingers.) Pathways called commissures, the largest of which is the corpus callosum, connect the brain’s hemispheres.
gyrus (pl. gyri).
Convolution (bump) in the neocortex produced by folding.
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sulcus (pl. sulci).
Cleft in the cortex produced by folding.
longitudinal fissure.
Deep cleft that divides the brain’s two hemispheres. Also known as the sagittal fissure.
lateral fissure.
Deep cleft in the cortical surface of the brain that separates the temporal and parietal lobes. Also called Sylvian fissure.
corpus callosum.
Commissure (fiber system) that connects homotopic areas in the two hemispheres. A split-brain patient is one whose corpus callosum has been severed.
The cortex of each hemisphere forms four lobes, each named after the skull bones beneath which they lie. The temporal lobe is located below the lateral fissure at approximately the same place as the thumb on your upraised fist (Figure 1.1B). Lying immediately above the temporal lobe is the frontal lobe, so called because it is located at the front of the brain beneath the frontal bones. The parietal lobe is located behind the frontal lobe, and the occipital lobe constitutes the area at the back of each hemisphere.
temporal lobe.
Area of the cortex and connections below the lateral fissure, adjacent to the temporal bones.
frontal lobes.
All the neocortex and connections forward of the central sulcus.
parietal lobe.
General region of the brain lying behind the frontal lobe, beneath the parietal bone.
occipital lobe.
General area of the cortex lying in the back part of the head.
The cerebral cortex constitutes most of the forebrain, so named bec (Kolb 3)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
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forebrain.
Cerebral hemispheres, basal ganglia, thalamus, amygdala, hippocampus, and septum.
brainstem
Hypothalamus, midbrain, and hindbrain. (Some authorities also include the thalamus and basal ganglia.)
spinal cord.
Part of the central nervous system enclosed within the vertebral column. (Kolb 3)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
central nervous system (CNS).
The brain and spinal cord that are encased in bone—the skull and vertebrae, respec-tively—and cannot regrow after damage. (Kolb 4)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
somatic nervous system (SNS).
Nerve fibers that are extensively connected to sensory receptors on the body’s surface and to muscles and that carry information to the CNS. Subdivision of the peripheral nervous system.
sensory pathway.
Nerve fibers that convey sensory information to the brain.
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
(Kolb 4)
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motor pathway.
Nerve fibers that connect the brain and spinal cord to the body’s muscles through the somatic nervous system.
Sensory and motor pathways also influence the muscles of your internal organs—the beating of your heart, contractions of your stomach, raising and lowering of your diaphragm to inflate and deflate your lungs. The pathways that control these organs are a subdivision of the PNS called the autonomic nervous system (ANS). Figure 1.2 diagrams these major divisions of the human nervous system.
autonomic nervous system (ANS).
Division of the peripheral nervous system that regulates the functioning of the body’s internal organs and glands. (Kolb 4)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
epigenetics.
Differences in gene expression related to environment and experience. (Kolb 8)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
Neuroplasticity
Differences in gene expression related to environment and experience. (Kolb 8)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
Localization of Function
The first general theory to propose that different parts of the brain have different functions was developed in the early 1800s by German anatomist Franz Josef Gall (1758–1828) and his partner Johann Casper Spurzheim (1776–1832) (Critchley, 1965). Gall and Spurzheim proposed that the cortex and its gyri were functioning parts of the brain and not just coverings for the pineal body. They supported their position by showing through dissection that the brain’s most distinctive motor pathway, the corticospinal (cortex to spinal cord) tract, leads from the cortex of each hemisphere to the spinal cord on the opposite side of the body. Thus, they suggested, the cortex sends instructions to the spinal cord to command muscles to move. They also recognized that the two symmetrical hemispheres of the brain are connected by the corpus callosum and can thus interact.
Gall’s ideas about behavior began with an observation made in his youth. Reportedly, he observed that students with good memories had large, protruding eyes and surmised that a well-developed memory area of the cortex located behind the eyes would cause them to protrude. Thus, he developed his hypothesis, called localization of function, that a different, specific brain area controls each kind of behavior.
(Kolb 8-9)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
PHRENOLOGY (define and history)
phrenology.
Long-discredited study of the relation between mental faculties and the skull’s surface features. (Kolb 9)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
Gall and Spurzheim furthered this idea by collecting instances of individual differences that they related to other prominent features of the head and skull. They proposed that a bump on the skull indicated a well-developed underlying cortical gyrus and therefore a greater capacity for a particular behavior; a depression in the same area indicated an underdeveloped gyrus and a concomitantly reduced faculty.
Thus, just as a person with a good memory had protruding eyes, a person with a high degree of musical ability, artistic talent, sense of color, combativeness, or mathematical skill would have large bumps in other areas of the skull. Figure 1.4 shows where Gall and Spurzheim located the trait of amativeness (sexiness). A person with a bump there would be predicted to have a strong sex drive, whereas a person low in this trait would have a depression in the same region. (Kolb 9)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
cranioscopy,
in which a device was placed around the skull to measure its bumps and depressions. These measures were then correlated with the phrenological map to determine the person’s likely behavioral traits. The faculties described in phrenology—characteristics such as faith, self-love, and veneration—are impossible to define and to quantify objectively. Phrenologists also failed to recognize that the superficial features on the skull reveal little about the underlying brain. Gall’s notion of localization of function, although inaccurate scientifically, laid the conceptual foundation for modern views of functional localization, beginning with the localization of language. (Kolb 9)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
lateralization.
Process by which functions become located primarily on one side of the brain. (Kolb 10)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
Lateralization of Function
A now legendary chain of observations and speculations led to confirmation that language is both localized in the brain and lateralized, that is, located on one side of the brain. This discovery led to the principle of lateralization of function, that one cerebral hemisphere can perform a function not shared by the other (Benton, 1964). We begin on February 21, 1825, as French physician Jean Baptiste Bouillaud (1796–1881) read a paper before the Royal Academy of Medicine in France. Bouillaud argued from clinical studies that certain functions are localized in the cortex and, specifically, that speech is localized in the frontal lobes, in accordance with Gall’s theory.
(Kolb 10)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
Broca’s area
As a result of his studies, Broca located speech in the third convolution (gyrus) of the frontal lobe on the left side of the brain (Figure 1.6A). By demonstrating that speech is located only in one hemisphere, Broca discovered the brain property of functional lateralization (Kolb 11)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
(A) Broca’s area is located in the posterior third of the inferior, or third, convolution (gyrus) of the frontal lobe in the left hemisphere. (B) Photograph of the left hemisphere of the brain of Leborgne (“Tan”), Broca’s first aphasic patient. (Part B, Paul Broca’s historic cases: High resolution MR imaging of the brains of Leborgne and Lelong, from n. F. Dronkers, O. Plaisant, M. T. Iba-Zizen, and E. A.Cabanis, Brain, Oxford university Press, May 1, 2007.)
Broca’s area.
Anterior speech area in the left hemisphere (frontal operculum) that functions with the motor cortex to produce movements needed for speaking. Damage to this area results in Broca’s aphasia.
left hemisphere is frequently referred to as the
dominant hemisphere to recognize its special role in language (Joynt, 1964). In recognition of Broca’s contribution, the anterior speech region of the brain is called Broca’s area, and the syndrome that results from its damage is called Broca’s aphasia (from the Greek a, for “not,” and phasia, for “speech”). (Kolb 11)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
Broca’s aphasia.
Inability to speak fluently despite the presence of normal comprehension and intact vocal mechanisms; results from a lesion to Broca’s area. Also called expressive, or nonfluent, aphasia. (Kolb 11)
Broca’s aphasia is frequently associated with paralysis of the right arm and leg, as described for Tan.) They could speak fluently, but what they said was confused and made little sense. (Broca’s patients could not articulate, but they seemed to understand the meaning of words.) (Kolb 11)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
A Lateralized Language Model
German anatomist Carl Wernicke (1848–1904) created the first model of how the brain produces language in 1874. Wernicke was aware that the part of the cortex into which the sensory pathway from the ear projects—the auditory cortex—is located in the temporal lobe behind Broca’s area. He therefore suspected a relation between hearing and speech functioning, and he described cases in which aphasic patients had lesions in this auditory area of the temporal lobe. (Kolb 11)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
fluent aphasia.
Speech disorder in which a person articulates words in a languagelike fashion, but what is said actually makes little sense; usually results from damage to the left posterior cortex. See also Wernicke’s aphasia.
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
Wernicke’s aphasia.
Inability to comprehend or to produce meaningful speech even though the production of words remains intact. Also called sensory aphasia. See also fluent aphasia.
) Although Wernicke’s patients could hear, they could neither understand nor repeat what was said to them. Wernicke’s syndrome is sometimes called temporal-lobe aphasia or fluent aphasia, to emphasize that the person can say words, but is more frequently called Wernicke’s aphasia. The associated region of the temporal lobe is called Wernicke’s area. (Kolb 11)
According to Wernicke’s model, if the temporal lobe is damaged, speech movements are preserved in Broca’s area, but the speech makes no sense because the person cannot monitor words. Damage to Broca’s area produces a loss of speech movements without the loss of sound images, and therefore Broca’s aphasia is not accompanied by a loss of understanding. (Kolb 12)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
Wernicke’s area.
Secondary auditory cortex (part of the planum temporale, roughly equivalent to Brodmann’s area 22), that regulates language comprehension; also called posterior speech zone. (Kolb 11)
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Wernicke’s model of language organization
Wernicke’s model of language organization in the left hemisphere is illustrated in Figure 1.7 A. He proposed that auditory information travels to the temporal lobes from the auditory receptors in the ears. In Wernicke’s area, sounds are processed into auditory images or ideas of objects and stored. From Wernicke’s original model Wernicke’s area, auditory ideas flow through a pathway, the arcuate fasciculus (from the Latin arc, for “bow,” and fasciculus, for “band of tissue,” because the pathway arcs around the lateral fissure, as shown in Figure 1.7B). The pathway leads to Broca’s area, where representations of speech movements are stored, and may link brain regions related to intelligence (see Figure 16.17). To produce the appropriate sounds, neural instructions are sent from Broca’s area to muscles that control mouth movements. (Kolb 12)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
conduction aphasia.
Type of fluent aphasia resulting from severing fiber connections between anterior and posterior speech zones; speech sounds and movements are retained, but speech is impaired because it cannot be conducted from one region to the other. (Kolb 12)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
Alexia and apraxia define and history
ench neurologist Joseph Dejerine (1849–1917) described a case in which the loss of the ability to read (alexia, meaning “word blindness,” from the Greek lexia, for “word”) resulted from a disconnection between the brain’s visual area and Wernicke’s area. Similarly, Wernicke’s student Hugo Liepmann (1863–1925) showed that an inability to make sequences of movements (apraxia, from the Greek praxis, for “movement”) results from the disconnection of motor areas from sensory areas.
alexia.
Inability to read.
apraxia
Inability, in the absence of paralysis or other motor or sensory impairment, to make or copy voluntary movements, especially an inability to make proper use of an object. (Kolb 12)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
hierarchical organization.
Principle of cerebral organization in which information is processed serially, with each level of processing assumed to represent the elaboration of some hypothetical process. (Kolb 13)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
persistent vegetative state (PVS).
Condition in which a person is alive but unable to communicate or to function independently at even the most basic level. (Kolb 14)
Kolb, Bryan. Fundamentals of Human Neuropsychology, 7th Edition. Worth Publishers, 20150207. VitalBook file.
minimally conscious state (MCS).
Condition in which a person can display some rudimentary behaviors but is otherwise not conscious.
clinical trial.
Consensual experiment directed toward developing a treatment.
(Kolb 14)
Blue highlights
Not entered
Anterior
Also ventral*
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Posterial
(Also dorsal)
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