The primary somatosensory cortex is divided into multiple areas based on the delineations of the German neuroscientist Korbinian Brodmann. Brodmann identified 52 distinct regions of the brain according to differences in cellular composition; these divisions are still widely used today and the regions they form are referred to as Brodmann's areas.
Brodmann divided the primary somatosensory cortex into areas 3 which is subdivided into 3a and 3b , 1, and 2. The numbers Brodmann assigned to the somatosensory cortex are based on the order in which he examined the postcentral gyrus and thus are not indicative of any ranking of importance. Indeed, area 3 is generally considered the primary area of the somatosensory cortex. Area 3 receives the majority of somatosensory input directly from the thalamus, and the initial processing of this information occurs here.
Area 3b specifically is concerned with basic processing of touch sensations, while area 3a responds to information from proprioceptors. Area 3b is densely connected to areas 1 and 2. Thus, while area 3b acts as a primary area for touch information, that information is then also sent to areas 1 and 2 for more complex processing. Area 1, for example, seems to be important to sensing the texture of an object while area 2 appears to play a role in perceiving size and shape. Area 2 also is involved with proprioception.
Yet despite the strong anatomical similarities, the functions of each cortical hemisphere are distinct. The hemispheres of the cerebral cortex : The human brain is divided into two hemispheres—left and right. Scientists continue to explore how some cognitive functions tend to be dominated by one side or the other; that is, how they are lateralized.
But although measurable lateral dominance occurs, most functions are present in both hemispheres. The extent of specialization by hemisphere remains under investigation. When injury interferes with pathways from one area to another, alternative indirect connections may develop to communicate information with detached areas, despite the inefficiencies.
While many functions are lateralized, this is only a tendency. The implementation of a specific brain function significantly varies by individual. The areas of exploration of this causal or effectual difference of a particular brain function include gross anatomy, dendritic structure, and neurotransmitter distribution. The structural and chemical variance of a particular brain function, between the two hemispheres of one brain or between the same hemisphere of two different brains, is still being studied.
Additionally, Even within various language functions e. Language functions such as grammar, vocabulary and literal meaning are typically lateralized to the left hemisphere, especially in right-handed individuals. In contrast, prosodic language functions, such as intonation and accentuation, often are lateralized to the right hemisphere of the brain.
The processing of visual and auditory stimuli, spatial manipulation, facial perception, and artistic ability are represented bilaterally, but may show right-hemisphere dominance. Numerical estimation, comparison, and online calculation depend on bilateral parietal regions. Exact calculation and fact retrieval are associated with left parietal regions, perhaps due to their ties to linguistic processing. Dyscalculia is a neurological syndrome associated with damage to the left temporoparietal junction.
This syndrome is associated with poor numeric manipulation, poor mental arithmetic skill, and the inability to understand or apply mathematical concepts. Specialization of the two hemispheres is general in vertebrates including fish, frogs, reptiles, birds, and mammals, with the left hemisphere specialized to categorize information and control routine behavior. The right hemisphere is responsible for responses to novel events and behavior in emergencies, including the expression of intense emotions.
Feeding is an example of a routine left-hemisphere behavior, while escape from predators is an example of a right-hemisphere behavior. This suggests that the evolutionary advantage of lateralization comes from the capacity to perform separate parallel tasks in each hemisphere of the brain. Patients with split-brain are individuals who have undergone corpus callosotomy, a severing of a large part of the corpus callosum usually as a treatment for severe epilepsy.
The corpus callosum connects the two hemispheres of the brain and allows them to communicate. When these connections are cut, the two halves of the brain have a reduced capacity to communicate with each other.
The widespread lateralization of many vertebrate animals indicates an evolutionary advantage associated with the specialization of each hemisphere. The evolutionary advantage of lateralization comes from the capacity to perform separate parallel tasks in each hemisphere of the brain. In a study published in the journal of Brain Behavioral Research, lateralization of a few specific functions as opposed to overall brain lateralization was correlated with parallel tasks efficiency.
Privacy Policy. Skip to main content. Central Nervous System. Search for:. Functional Systems of the Cerebral Cortex. Learning Objectives Describe the sensory areas of the cerebral cortex. Key Takeaways Key Points The cortex can be divided into three functionally distinct areas: sensory, motor, and associative. The main sensory areas of the brain include the primary auditory cortex, primary somatosensory cortex, and primary visual cortex.
In general, the two hemispheres receive information from the opposite side of the body. Sensory areas are often represented in a manner that makes topographical sense. These individuals would not be able to identify whether an object was heavy or light after carrying it.
Likewise, people with this damage would find difficulty in judging physical pressure. These individuals may be able to know that pressure has been applied to their body but would not be able to identify the degree or severity of the pressure applied.
It is relatively common for people who have had a limb amputated to experienced sensations in their amputated limb. This is called phantom limb and it can cause some pain to individuals who suffer from this. Studies have found that this pain shows correlations to changes in the primary somatosensory cortex which is no longer receiving expecting input from the amputated limb Flor, Olivia has been working as a support worker for adults with learning disabilities in Bristol for the last four years.
Guy-Evans, O. Somatosensory cortex. Simply Psychology. Flor, H. Remapping somatosensory cortex after injury. Advances in neurology, 93 , Neuroscientifically Challenged. Know your brain: Primary somatosensory cortex. Purves, D. Neuroscience 2nd edition. Types of Eye Movements and Their Functions. Raju, H. Neuroanatomy, Somatosensory Cortex. StatPearls [Internet]. The Human Memory.
Somatosensory Cortex. Toggle navigation. Parietal Lobe Somatosensory Cortex Somatosensory Cortex By Olivia Guy-Evans , published June 11, The somatosensory cortex is a region of the brain which is responsible for receiving and processing sensory information from across the body, such as touch, temperature, and pain.
Somatosensory Pathway Somatosensory pathways are typically comprised of three neurons: primary, secondary, and tertiary.
Somatosensory Cortex Area Function It comprises the primary somatosensory cortex and the secondary somatosensory cortex. Primary Somatosensory Cortex. Secondary Somatosensory Cortex. How to reference this article: How to reference this article: Guy-Evans, O. Further Information.
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