Cortex Flashcards
most common cells in the cortex, mostly present in layers III and V
pyramidal cells
interneurons of the cortex, usually inhibitory, that mediate connections between layers and short distances
granule cells
neuron fibers that originates in layer II of the cortex and connects neurons of closely adjoining gyri to the same lobe
short association fibers (u-shaped)
neuron fibers that originate in layer III, uniting widely separated cortical regions of the same hemisphere
long association fibers (ie, cingulum, superior/inferior longitudinal, arcuate, and uncinate fasciculi)
neuron fibers that originate in layer III, connecting homologous parts of opposite hemispheres
callosal (interhemispheric) [ie, corpus callosum, anterior commissure]
neuron fibers originating in layer V of the frontoinsular and anterior cingulate cortex of humans and great apes,
that permit rapid transfer of information between distant networks; are involved in empathy, social awareness, and self-control
Von Economo spindle neurons (VENs)
these fibers extend to or from the cerebral cortex, serving to connect the cerebral cortex with subcortical structures, down to the level of the spinal cord
corticofugal (projection) neurons
this is the smallest functional unit in the cortex and contains a column of neurons that have shared sensory modalities and the same receptive fields
minicolumns
Neurons within each ______ contain a full set of values for any given set of receptive field parameters, optimized for the same patch of body surface
macrocolumn
This is the concept that the two halves of the brain process different aspects of the external world
lateralization of function
refers to the ability to attend to external stimuli or
internal motivation, to identify the significance of such stimuli, and to plan meaningful responses to them
cognition
______ areas of the cortex receive multimodal thalamic input from association thalamic nuclei (e.g., pulvinar), as well as primary and secondary cortices, and the
brainstem, promoting complex integrative functions
association
a circular process that allows brain function to be inferred by studying the correspondence between clinical manifestations and lesion location
clinico-anatomical correlation method
the ____ visual stream is concerned with object and
relative body motion, the placing of objects in
external space (“where is it?”), and the control of
visually guided eye movements
dorsal
the ____ visual stream is associated with pattern and object recognition (“what is it?”)
ventral
caused by lesions of the ventral visual stream, this is the inability to recognize objects and discriminate between simple geometric shapes and their orientation; if it occurs on the left side it results in what symptoms?
visual form agnosia;
alexia (inability to understand written words) and agraphia (inability to communicate through writing)
caused by bilateral lesions (ie, MCA/PCA infarct) to the dorsal visual stream, this syndrome results in the inability to perceive more than a single object at a time (simultanagnosia), uncontrolled eye movements (optic apraxia), and loss of coordination between visual input and hand movement (optic ataxia)
Balint’s syndrome
This is a specialized region in the left posterior superior temporal gyrus for decoding verbal information; damage to this area results in sensory aphasia (fluent speech, but unintelligible)
Wernicke’s area
Lesions of the RIGHT posterior STG lead to sensory ____, an inability to detect prosodic elements (e.g., humor, sarcasm) in speech
aprosodia
Lesions to the left lateral temporal lobe lead to what kind off deficits
naming defecits (anomia); caudally, generic names; anteriorly, proper names
In the parietal lobe, lesions affecting the ______ area lead to tactile agnosia (patients cannot recognize objects by touch or cannot name them) while lesions affecting the _____ area cause constructional apraxia (difficulty with simple drawings, assembling blocks)
ventrolateral; dorsomedial
Damage to the RIGHT ______ leads to left visual and hemispatial neglect (sense of body and external world on the left side is ignored).
inferior parietal lobule (IPL)
Syndrome characterized by 4 signs, indicating damage to the LEFT inferior parietal lobule (IPL): loss of verbal working memory, agraphia, acalculia, and finger agnosia
Gerstmann’s syndrome
