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	Cortical column - Biocrawler (Site not responding. Last check: 2007-11-07)
		A cortical column is a group of neurons in the brain cortex which can be successively penetrated by a probe inserted perpendicularly to the cortical surface, and which have nearly identical receptive fields.
		This term is related to the way how the brain is inspected, unlike terms such as brainstem, cerebellum, etc.; i.e., it would be incorrect to say "the cortex has cortical columns".
		The discovery of the NCC (Neocortical Column) was awarded a Nobel Prize in 1981.
	www.biocrawler.com /encyclopedia/Cortical_column (189 words)

	Column (disambiguation) - Wikipedia, the free encyclopedia
		Columns are generally characterized by a combination of being long in only one direction, vertical, or a support structure.
		Vertebral column, a column of vertebrae situated in the dorsal aspect of the abdomen
		Cortical column, a group of neurons in the brain cortex
	en.wikipedia.org /wiki/Column_(disambiguation) (240 words)

	Cortical column - Wikipedia, the free encyclopedia
		A cortical column is a group of neurons in the brain cortex which can be successively penetrated by a probe inserted perpendicularly to the cortical surface, and which have nearly identical receptive fields.
		The cerebral cortez is a roughly 2 mm thick sheet of neuronal cell bodies that forms the external surface of the telencephalon.
		was that there were cortical columns in vision as well, and that the neighboring columns were also related in function in terms of the orientation of lines that evoked the maximal discharge.
	en.wikipedia.org /wiki/Cortical_column (340 words)

	McConnell: Research
		This radial stack of neurons forms the cortical column, a minimal unit of neurons and connections required to analyze a small portion of the sensory world.
		During the cell cycle, the nuclei of cortical progenitor cells undergo a series of "elevator movements" that correlate with their progression through the cycle.
		Neurons are generated in an orderly progression, with cells of the deepest cortical layers born first, followed by cells of the middle and finally the upper layers.
	www.stanford.edu /group/skmlab/research/rsum.html (666 words)

	An Adaptive Neural Network: the Cerebral Cortex
		The column is oriented perpendicular to the cortical surface, and consists of six distinct layers of neurons.
		All neurons inside the column are tightly connected, although neurons connections extend to adjacent columns and columns far across the cortex and into subcortical areas, particularly the thalamus.
		Cortical columns are capable of memorizing relations and performing more complex operations than individual neurons; to extend the information processing analogy, if a neuron is analogous to a logic gate, a cortical column is more analogous to a small subroutine.
	www.ruf.rice.edu /~lngbrain/Farh/col.html (1034 words)

	BASIC CEREBRAL CORTEX FUNCTION WITH EMPHASIS ON VISION
		These rich interconnections between layers, and the organization of these connections into vertical columns, have led to models of the cortex in which billions of cortical columns act as the functional units.
		Columns of neurons within a stripe correspond to a region of the retina in one eye and are therefore known as ocular dominance columns.
		To complicate matters further, color-sensitive columns known as blobs pierce the centres of the ocular dominance columns resulting in interblob neurons which are orientation-sensitive, and blob neurons, which are not.
	www.benbest.com /science/anatmind/anatmd5.html (3336 words)

	Computation in the Cortical Column: Abstract (Site not responding. Last check: 2007-11-07)
		Understanding computation in the cortical column is a holy grail for both experimental and theoretical neuroscience.
		It is a great time for cortical anatomists, physiologists, modellers, and theoreticians to join forces in attempting to decipher computation in the cortical column.
		Speakers and panelists in the afternoon session considered the functional significance of the cortical column in light of their expert knowledge of two columnar systems which have attracted intensive experimental attention to date: the visual cortex of cats and primates, and the barrel cortex of rodents.
	www.keck.ucsf.edu /~linden/ColumnWorkshop/abstract.html (520 words)

	Untitled
		To test the hypothesis, we may consider the properties of cortical columns, descriptions of cortical cells, and how the structure and connectivity of columns correspond (or fail to correspond) to the requirements of the model.
		The cerebral cortex is approximately 3-6 mm thick and neuroanatomists have observed that the cortical neurons appear to be organized in columns (cf.
		Cortical columns (sometimes called minicolumns), oriented perpendicular to the cortical surface, can be likened to cylinders (of 30-50 um diameter) with length spanning the 3-6 mm depth.
	www.ruf.rice.edu /~lngbrain/Sidhya (1097 words)

	The "columns" myth
		The main evidence for 'columns' is that in the areas that get sensory input from outside the cortex, there are small areas (columns) in which the neurons tend to have the same receptive field (the area in the sensory organ that they respond to).
		The only observation that could be called 'evidence' for the existence of columns is that the density of neurons is not homogenuous in the cortex, and neurons tend to clusters in small regions.
		These may be called 'columns', but their dimensions (20-50 microns) are much smaller than the dimensions of the 'columns' which are normally discussed (several 100s of microns).
	human-brain.org /columns.html (2392 words)

	Defining Awareness by the Triangular Circuit Of Attention by David LaBerge
		Since most of the knowledge we have of cortical and thalamic circuitry has been obtained from studies of the primary visual cortex and its adjacent areas, the description given here of the triangular circuit is based on a schematic diagram of the triangular circuit involving areas V1 and V2.
		The forward connection from the first column (e.g., in area V1) to the second column (e.g., in area V2) occurs both directly and indirectly by means of a synapse in a thalamic nucleus, forming a triangular circuit.
		The results of the simulations in that study showed sharp increases in firing-rate trajectories in cortical cells corresponding to attended stimuli (relative to trajectories in cortical columns corresponding to neighboring unattended stimuli).
	psyche.cs.monash.edu.au /v4/psyche-4-07-laberge.html (3072 words)

	LAMINAR ORGANIZATION OF THE CORTICAL REPRESENTATIONS OF VIBRISSAL TEMPORAL INFORMATION
		The cortical column is often considered as a basic unit involved with a single thalamocortical computational task.
		Single and multi units were recorded from four cortical layers of the barrel cortex of anesthetized rats: L2/3, L4, L5a and L5b.
		These results indicate that neurons of the same cortical column represent stimulus features differently, according to the source of their afferents.
	www.wisdom.weizmann.ac.il /~sosnik/LAMINAR_ORGANIZATION.htm (249 words)

	Webvision: Visual Cortex
		Accidental and experimentally induced cortical lesions were correlated to symptomologies found in the patients and experimental animals, respectively, leading to the notion of localized cortical function.
		The term "cortical column" refers to the notion that cells arranged vertically from the surface of the cortex to the white matter might comprise functional or anatomical units.
		One conclusion from this work is that cells in the very first stage of cortical processing are already capable of responding to a single stimulus boundary in a complex manner that allows for object detection even as the cues defining the object change, or are partially occluded (Leventhal et al., 1998).
	webvision.med.utah.edu /VisualCortex.html (9250 words)

	Electroencephalogram - Scholarpedia
		Cortical morphology is characterized by its columnar structure with pyramidal cell axons aligned normal to the local cortical surface.
		Highly localized cortical rhythms are not recorded on the scalp; for example, cortical beta rhythms are often strongly attenuated between cortex and scalp because they are more localized than the globally coherent alpha band activity.
		The cortical surface was constructed from the MRI of one subject.
	www.scholarpedia.org /article/Electroencephalogram (4263 words)

	PSYC2022: Cortical Connections Diagram (Site not responding. Last check: 2007-11-07)
		These non-specific inputs provide a general modulatory influence over the activity of a cortical column.
		These "association" connections between 2 regions of cortex within the same hemisphere are primarily made by pyramidal cells whose cell bodies are located in layer 2.
		These "callosal" connections between 2 regions of cortex in opposite hemispheres are primarily made by pyramidal cells whose cell bodies are located in layer 3.
	psych.colorado.edu /~spencer/psyc2022/CTXconnect.html (193 words)

	Complexity Digest - The Cortical Column: A Structure Without A Function
		The Cortical Column: A Structure Without A Function, Phil.
		Excerpt: This year, the field of neuroscience celebrates the 50th anniversary of Mountcastle's discovery of the cortical column.
		Subsequently, examples of columns have been uncovered in numerous cortical areas, expanding the original concept to embrace a variety of different structures and principles.
	www.comdig.org /article.php?id_article=21420 (137 words)

	Choas in the CNS Paper - sec3
		Spatial integration is the mechanism by which neurons in a local neighborhood corresponding to a cortical "column" make their own spatial ensemble average, and thereby establish the basis for cooperative collective action.
		Spatial integration also occurs between cortical areas, as for example in the divergence of the axon projection from the bulb to the olfactory cortex, which is important for the readout of the population (see "Readout of percepts"), but divergence alone and parallel action alone are not sufficient.
		At present their instrumental noise levels are so high that they cannot be used without time ensemble averaging or narrow band pass filtering, so the use of these methods is restricted to measuring time ensemble averaged evoked potentials and not the unaveraged traces.
	sulcus.berkeley.edu /FLM/MS/WJF_man1.text/WJF_man1.sec3.html (1208 words)

	Neonatal lead exposure impairs development of rodent barrel field cortex -- Wilson et al. 97 (10): 5540 -- Proceedings ...
		The area of individual barrels in columns 1-4 of rows A-E was measured; individual barrel areas were summed within rows, and the litter mean value for each row was plotted against lead exposure level.
		The area of individual barrels in columns 1-4 of rows A-E was measured; individual barrel areas were summed within columns, and the litter mean value for each column was plotted against lead exposure level.
		Cortical columns in the barrel field of the developing rat exhibit a dose-related reduction in size after exposure to low
	www.pnas.org /cgi/content/full/97/10/5540 (3557 words)

	Untitled Document
		Each whisker correlates one-to-one with an anatomically defined group of cortical neurons, called a barrel, that represents a morphological correlate of a functional cortical column.
		Computer-controlled whisker stimuli and single cell recording techniques are used to examine how information is integrated by cortical neurons, with a strong emphasis on processing in thalamocortical circuits and the effects of corticothalamic feedback.
		Pinto, D.J., Hartings, J.A., Brumberg, J.C., and Simons, D.J. Cortical damping: Analysis of thalamocortical response transformations in the rodent barrel cortex.
	www.neurobio.pitt.edu /faculty/simons.htm (376 words)

	Citebase - Noise-enhanced computation in a model of a cortical column (Site not responding. Last check: 2007-11-07)
		Noise-enhanced computation in a model of a cortical column
		We show in a simplified model of cortical tissue, that complex arithmetical calculations can be carried out and are enhanced in the presence of a stochastic background.
		The performance is shown to be positively correlated to the susceptibility of the network, defined as its sensitivity to a variation of the mean of its inputs.
	citebase.eprints.org /cgi-bin/citations?id=oai:arXiv.org:q-bio/0505008 (580 words)

	EUROGRAPHICS96
		The cortical column as defined by Professor Burnod is a set of complex filters which can be simulated and integrated as well as classic digital filters.
		In the cortical model, interesting tools can be derived for fusion of different algorithms extracting such a surface and movement information, for perceptual grouping to define homogeneous zones, and for fuzzy description of surfaces of objects allowing more natural aspects in a synthesized image.
		The cortical model provides a tool to estimate the "low level attractiveness" and to establish a hierachy of the "points of interest" in the image where spatial and temporal variations are the "richest for perception".
	perso.wanadoo.fr /pascal.leray/eurographics96.htm (4106 words)

	Computation in The Cortical Column: Post-Workshop Summary (Site not responding. Last check: 2007-11-07)
		Cortical columns and other modular structures in cortex represent discontinuities in the receptor sheet or multiplexed representations of decorrelated inputs.
		While the factors responsible for creation of cortical modules may be genetically specified, the modules themselves may be an emergent property of cortex, specified only by the statistical structure of cortical inputs.
		Computation within visual cortical columns is likely to occur primarily along the dimensions of the receptive field which are represented differently by cells within the column.
	keck.ucsf.edu /~linden/ColumnWorkshop/summary.html (1671 words)

	Synaptic connections between layer 4 spiny neurone- layer 2/3 pyramidal cell pairs in juvenile rat barrel cortex: ...
		In the barrel cortex, a cortical column is taken to be a barrel in layer 4 and the region of the supra- and infragranular layers just above and below it; these are believed to function as a unit in the signal transformation process.
		However, within a single column the cortical layers are likely to be the smallest processing unit of sensory cortices (Mountcastle, 1957; Mountcastle and Powell, 1959; Hubel and Wiesel, 1962; for review see Mountcastle, 1997; Rockland, 1998).
		Understanding whisker movement 'representation' in terms of neuronal firing within a barrel column of the somatosensory cortex requires knowledge of both the anatomical connections between those neurones responding to the deflection of a whisker and their functional properties.
	jp.physoc.org /cgi/content/full/538/3/803 (9807 words)

	abstract (Site not responding. Last check: 2007-11-07)
		In this review we re-examine the concept of a cortical column in macaque primary visual cortex, and consider to what extent a functionally defined column reflects any sort of anatomical entity that subdivides cortical territory.
		In contrast to the functional column, an anatomically-based cortical column is defined most clearly in terms of the reciprocal connections it makes, both via intra-areal lateral connections and inter-areal feed-back/ feed-forward pathways.
		The column boundaries are reinforced by interplay between lateral inhibition spreading beyond the column boundary and dis-inhibition within the column.
	www.math.utah.edu /~bresslof/publications/03-1abs.html (225 words)

	Modified Sensory Processing in the Barrel Cortex of the Adult Mouse After Chronic Whisker Stimulation -- Quairiaux et ...
		Mean spontaneous activity of neurons in layer IV and layers II and III of the C2, C1, and D2 barrel columns from the 3 groups of mice studied.
		Note that in both barrel columns, the PW response is unaltered for cells in layer IV and layer III/III, whereas the response to the C2 whisker was significantly decreased in layers II and III but not in layer IV.
		We propose that the increase in the density of inhibitory synapses (+) in the stimulated barrel is responsible for the decreased responses of layer IV neurons, which in turn reduces the propagation of excitation in the stimulated barrel column as well as in the transcolumnar projections of layers II and III pyramidal cells (–).
	jn.physiology.org /cgi/content/full/97/3/2130 (9539 words)

	Anatomical Substrates for Functional Columns in Macaque Monkey Primary Visual Cortex -- Lund et al. 13 (1): 15 -- ...
		The same offset spiny stellate neuron in mid-4C that gives the center 4C column its orientation specificity also provides input to layer 3 of the same column; thus, the vertical orientation preference (but not direction preference) is given to the column at this level.
		Lateral connections converge to the center column from a cortical territory of ~3 mm radius.
		Hubel DH, Wiesel TN (1974a) Sequence regularity and geometry of orientation columns in the monkey striate cortex.
	cercor.oxfordjournals.org /cgi/content/full/13/1/15 (8110 words)

	Experience-dependent Plasticity of Rat Barrel Cortex: Redistribution of Activity across Barrel-columns -- Lebedev et ...
		Fox K (1994) The cortical component of experience-dependent synaptic plasticity in the rat barrel cortex.
		Moore CI, Nelson SB (1998) Spatio-temporal subthreshold receptive fields in the vibrissa representation of rat primary somatosensory cortex.
		Woolsey TA, Van der Loos H (1970) The structural organization of layer IV in the somatosensory region (SI) of mouse cerebral cortex.
	cercor.oxfordjournals.org /cgi/content/full/10/1/23 (4794 words)

	WorldChanging: Tools, Models and Ideas for Building a Bright Green Future: I, For One, Welcome Our New Post-Singularity ...
		IBM will be spending the next two-to-three years retooling one of its "Blue Gene" supercomputer -- in this case, the 8th fastest in the world, operating at over 22 teraflops -- to function as a mammal brain simulator.
		The "Blue Brain" project will simulate a single "neo-cortical column" down to a molecular level; the neo-cortical column is considered the key difference between mammalian brains and reptilian brains.
		Each neo-cortical column -- there are millions in a human brain -- has about 10,000 neurons and 10,000 synapses.
	www.worldchanging.com /archives/003196.html (376 words)

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