A Wisdom Archive on Cortical Column

The cerebral cortex develops from the neural plate, a specialised part of the embryonic ectoderm. The neural plate folds and closes to form the neural tube. From the cavity inside the neural tube develops the ventricular system, and from the epithelial cells of its walls, the neurones and glial cells. The most frontal part of the neural tube, the telencephalon gives rise to the cerebral hemispheres and the neocortex. Most cortical neurones are generated within the ventricular zone close to the ventricles. Initially, progenitor cells i ...

Read more here: » Cerebral cortex: Encyclopedia II - Cerebral cortex - Development

The standard areas of cortex (isocortex) is characterized as having six distinct layers. From outside inward: Molecular layer External granular layer External pyramidal layer Internal granular layer Internal pyramidal layer Multiform layer After migration (interestingly, the inner layers are formed first during development), neurons form efferents and receive afferent connections characteristic of its layer. The molecular layer I contains few scattered neuro ...

Read more here: » Cerebral cortex: Encyclopedia II - Cerebral cortex - Laminar pattern

Based on the differences in lamination the cerebral cortex can be classified into two major groups: Isocortex (homotypical cortex), the part of the cortex with six layers. Allocortex (heterotypical cortex) with variable number of layers, e.g., olfactory cortex and hippocampus. Auxiliary classes are: Mesocortex, classification between isocortex and allocortex where layers 2, 3 and 4 are merged. Proisocortex, Brodmann areas 24, 25, 32. Periallocorte ...

Read more here: » Cerebral cortex: Encyclopedia II - Cerebral cortex - Classification

Evolutionarily, the neopallium is the newest part of the cerebral cortex (whence the name "neo"); the other parts of the cerebral cortex are the paleocortex and archicortex, collectively known as the allocortex. The cellular organization of the allocortex is different from the six-layered structure mentioned above. In humans, 90% of the cerebral cortex is neopallium. The six-layer neopallium appears to be a distinguishing feature of mammals: It has been found in the brains of all mammals but not in any other animals. There is some deb ...

Read more here: » Neopallium: Encyclopedia II - Neopallium - Evolution

The primary visual cortex is the most well-studied visual area in the brain. It is the part of the cerebral cortex that is responsible for processing visual stimuli. It is the simplest, earliest cortical visual area. It is highly specialized for processing information about static and moving objects and is excellent in pattern recognition. The functionally defined primary visual cortex is approximately equivalent to the anatomically defined striate cortex. The name "striate cortex" is derived from the stria of Gennari ...

Read more here: » Visual cortex: Encyclopedia II - Visual cortex - Primary visual cortex V1

The hierarchies described above are theorized to occur primarily in mammalian neocortex. In particular, neocortex is assumed to consist of a large number of columns (as surmised also by Mountcastle from anatomical and theoretical considerations). Each column is attuned to a particular feature at a given level in a hierarchy. It receives bottom-up inputs from lower levels, and top-down inputs from higher levels. (Other columns at the same level also feed into a given column, and serve mostly to inhibit the activiation exclusive representation ...

Read more here: » Memory-prediction framework: Encyclopedia II - Memory-prediction framework - Neurophysiological implementation

By design, the current theory builds on the work of numerous neurobiologists, and it may be argued that most of these ideas have already been proposed by researchers such as Grossberg and Mountcastle. On the other hand, the novel separation of the conceptual machinery of bidirectional processing and invariant recognition from the biological details of neural layers, columns and structures lays the ...

Read more here: » Memory-prediction framework: Encyclopedia II - Memory-prediction framework - Contribution and limitations