Function Cerebral cortex

1 function

1.1 connections
1.2 cortical areas

1.2.1 sensory areas
1.2.2 motor areas
1.2.3 association areas

function
connections

the cerebral cortex connected various subcortical structures such thalamus , basal ganglia, sending information them along efferent connections , receiving information them via afferent connections. sensory information routed cerebral cortex via thalamus. olfactory information, however, passes through olfactory bulb olfactory cortex (piriform cortex). majority of connections 1 area of cortex another, rather subcortical areas; braitenberg , schüz (1998) claim in primary sensory areas, @ cortical level input fibres terminate, 20% of synapses supplied extracortical afferents in other areas , other layers percentage lower.

cortical areas

lateral surface of human cerebral cortex



medial surface of human cerebral cortex

the cortex commonly described comprising 3 parts: sensory, motor, , association areas.

sensory areas

the sensory areas cortical areas receive , process information senses. parts of cortex receive sensory inputs thalamus called primary sensory areas. senses of vision, audition, , touch served primary visual cortex, primary auditory cortex , primary somatosensory cortex respectively. in general, 2 hemispheres receive information opposite (contralateral) side of body. example, right primary somatosensory cortex receives information left limbs, , right visual cortex receives information left visual field. organization of sensory maps in cortex reflects of corresponding sensing organ, in known topographic map. neighboring points in primary visual cortex, example, correspond neighboring points in retina. topographic map called retinotopic map. in same way, there exists tonotopic map in primary auditory cortex , somatotopic map in primary sensory cortex. last topographic map of body onto posterior central gyrus has been illustrated deformed human representation, somatosensory homunculus, size of different body parts reflects relative density of innervation. areas lots of sensory innervation, such fingertips , lips, require more cortical area process finer sensation.

motor areas

the motor areas located in both hemispheres of cortex. shaped pair of headphones stretching ear ear. motor areas closely related control of voluntary movements, fine fragmented movements performed hand. right half of motor area controls left side of body, , vice versa.

two areas of cortex commonly referred motor:

primary motor cortex, executes voluntary movements
supplementary motor areas , premotor cortex, select voluntary movements.

in addition, motor functions have been described for:

posterior parietal cortex, guides voluntary movements in space
dorsolateral prefrontal cortex, decides voluntary movements make according higher-order instructions, rules, , self-generated thoughts.

just underneath cerebral cortex interconnected subcortical masses of grey matter called basal ganglia (or nuclei). basal ganglia receive input substantia nigra of midbrain , motor areas of cerebral cortex, , send signals both of these locations. involved in motor control. found lateral thalamus. main components of basal ganglia caudate nucleus, putamen, globus pallidus, substantia nigra, nucleus accumbens, , subthalamic nucleus. putamen , globus pallidus collectively known lentiform nucleus, because form lens-shaped body. putamen , caudate nucleus collectively called corpus striatum after striped appearance.

association areas

the association areas parts of cerebral cortex not belong primary regions. function produce meaningful perceptual experience of world, enable interact effectively, , support abstract thinking , language. parietal, temporal, , occipital lobes - located in posterior part of cortex - integrate sensory information , information stored in memory. frontal lobe or prefrontal association complex involved in planning actions , movement, abstract thought. globally, association areas organized distributed networks. each network connects areas distributed across spaced regions of cortex. distinct networks positioned adjacent 1 yielding complex series of interwoven networks. specific organization of association networks debated evidence interactions, hierarchical relationships, , competition between networks. in humans, association networks particularly important language function. in past theorized language abilities localized in left hemisphere in areas 44/45, broca s area, language expression , area 22, wernicke s area, language reception. however, language no longer limited identifiable areas. more recent research suggests processes of language expression , reception occur in areas other structures around lateral sulcus, including frontal lobe, basal ganglia, cerebellum, , pons.