Week1. 3 Neuroanatomy review-Q.pdf

From Hux, 2011, Encyclopedia of Clinical Neuropsychology Wernicke-Lichtheim Model of Aphasia Brain-behavior relationships Traditional Views  There are “centers” in the brain that represent various language functions, and connections between them  If you damage these centers and get a specific symp...

From Hux, 2011, Encyclopedia of Clinical Neuropsychology Wernicke-Lichtheim Model of Aphasia Brain-behavior relationships Traditional Views  There are “centers” in the brain that represent various language functions, and connections between them  If you damage these centers and get a specific symptom, you’ve found the location that is responsible for that function  Damage to language centers will result in a predictable form of aphasia  Evidence to support traditional views:  Most patients with damage to specific language regions do indeed have predictable aphasic language disturbances Contemporary Views  There is no strict 1:1 correspondence between linguistic components and regions of the brain  Language areas represent “critical bottlenecks” for language processing, rather than storage areas  Damage to brain regions → disruption to a complex network that involves several brain regions, as opposed to destroying a “center for reading” or “center for language comprehension” Support for contemporary view  Many individuals with Broca’s aphasia and Wernicke’s aphasia do not have lesions in the expected areas (Dronkers et al., 2004; Bates et al., 2003; Dronkers, 2000)  Only 50-60% of patients with lesions in Broca’s area have a persistent Broca’s aphasia  Only 30% of patients with lesions in Wernicke’s areas have a persistent Wernicke’s aphasia  Aphasia can result from damage to areas not traditionally considered “language areas” Language and the brain Specific neuro-structures never function in complete isolation from other parts of the brain  Complex functions, such as language, arise from interaction of multiple anatomical regions Parallel distributed processing:  Overlapping & interconnected neural networks widely distributed through the brain carry out specific neural functions both sequentially & in parallel Task Processing: Example Sequential Parallel Processing Example: How we choose words Semantic Concepts Clim btree s Fish Lemma Fog Pet Dog Wisk -ers 4 legs Rat Cat Purrs Boots Mat Phonetic f r d k m ae o t g Onward! With those caveats in mind, now we will review neuroanatomy… To understand the neural bases of the aphasia, we must begin with an understanding of normal brain anatomy The body and brain viewed from 3 anatomical planes coronal axial sagittal transvers e longitudinal horizonta l Terms of Direction Downloaded from: StudentConsult (on 5 January 2010 06:30 AM) © 2005 Elsevier Definitions Term (Latin Base) English definition Superior Above Inferior Low Anterior Before Posterior After/following Dorsal Back Ventral Belly Terms of Direction Rostral Posterior Dorsal Anterior Ventral Caudal Medial = towards the midline Lateral = towards the left/right side of body; opposite of medial Left Hemisphere (lateral view) superior or dorsal anterior posterior inferior or ventral Figure from Nolte, 2002 gyrus = outfolding of cortical tissue gyri sulci sulcus (or fissure) = enfolding of cortical tissue brain from J. Nolte Central (Rolandic) Sulcus M S Lateral (Sylvian) Fissure brain from J. Nolte Identify the sulci longitudinal fissure central sulcus (Rolandic fissure) precentral sulcus postcentral sulcus lateral sulcus (Sylvian fissure) intraparietal sulcus uses figure from Nolte (2002) Identify the sulci longitudinal fissure central sulcus (Rolandic fissure) precentral sulcus postcentral sulcus lateral sulcus (Sylvian fissure) intraparietal sulcus uses figure from Nolte (2002) Cerebrum parietal lobe frontal lobe occipital lobe temporal lobe cerebellum brainstem Frontal Lobe lateral surface precentral gyrus superior frontal gyrus middle frontal gyrus inferior frontal gyrus: orbital, triangular, opercular gurus rectus orbitofrontal cortex medial surface General functional areas of frontal lobe: Primary motor cortex (movements) Premotor, supplementary motor areas (initiation of voluntary movements) Broca’s area (language production) Prefrontal cortex (executive functions) Parietal Lobe postcentral gyrus superior parietal lobule supramarginal gyrus angular gyrus medial surface (precuneus) General functional areas of parietal lobe: primary somatosensory motor cortex language comprehension complex spatial orientation & perception Temporal Lobe superior temporal gyrus middle temporal gyrus inferior temporal gyrus lingual gyrus fusiform gyrus General Functional Areas of Temporal Lobe: Primary auditory cortex Wernicke’s area Higher order visual processing (inferior surface) *medial temporal lobe → learning & memory ventra l surfac e Occipital Lobe lateral occipital cortex calcarine fissure cuneus lingual gyrus fusiform gyrus General Functional Areas of Occipital Lobe: Primary visual cortex (banks of calcarine fissure) Visual association areas Inferior temporo-occipital regions Inferior temporal lobe lingual gyrus fusiform gyrus inf. temporal gyrus Occipital lobe cuneus lingual gyrus fusiform gyrus These regions are important for written language-reading Limbic Lobe Functions: Important in emotional responses, driverelated behavior & memory Association Areas Unimodal Surround the primary cortical areas Modality specific     Motor Sensory Auditory Visual Multimodal Integrate information from multiple sources      Anterior (Prefrontal cortex) Posterior parietal cortex Perisylvian zone Lateral temporal cortex Parahippocampal gyrus Distinct regions not connected to each other Lesions in association cortex can produce apraxias and agnosias The Neuron Cell bodies (greyish in color)Axons (white in color from myelin) Cortex = grey matter Connecting fibers = white matter Internal Capsule cortex = gray matter axons = white matter Corpus Callosum Medial view Corpus callosum MRI image of brain View from above Midline Structures Lateral view showing cortical convexity Medial view showing midline structures Basal Ganglia Composed of three large nuclei  Caudate nucleus + Putamen = Striatum  Receives input from  cortex, thalamic nuclei, and substantia nigra  Globus Pallidus  Receives input from the caudate & putamen  Major efferent pathways originate here  Sends input to thalamus which relays back to the cortex Function: Motor control for speech and movement Basal Ganglia: Gray matter structures deep in the brain [from F. Netter (1983) Ciba Collections of Medical Illustrations] Subcortical Structures Caudate Nucleus Lenticular nucleus - putamen - globus pallidus caudate nucleus (head) putamen globus pallidus thalamu s caudate nucleus (tail) [from F. Netter (1983) Ciba Collections of Medical Illustrations] Thalamus Two oval masses deep in the center of the cerebrum  located on either side of the third ventricle  composed of 26 pairs of nuclei which relay sensory information from the periphery to the cortex or from one part of the brain to another  Sensory relay from peripheral nervous system to cerebral cortex  e.g., auditory input goes from brainstem nuclei to thalamic nuclei (medial geniculate), then to Heschl’s gyrus  e.g., somatosensory input from spinal cord and brainstem is relayed to thalamic nuclei (VPM-face and VPL-body), then on to the parietal cortex (post-central gyrus) Thalamus thalamus ventricles hippocampus Deep structures in the brain caudate nucleus limbic lobe uses figure from Nolte (2002) Circulation of cerebrospinal fluid Functions: - Protect the brain - Supply nutrition - Remove waste from the brain system [from F. Netter (1983) Ciba Collections of Medical Illustrations]