Welcome to 2 minute neuroscience, where I simplistically explain neuroscience topics
in 2 minutes or less.
In this installment I will discuss the primary somatosensory cortex.
The primary somatosensory cortex is located in a ridge of cortex called the postcentral
It is situated just posterior to the central sulcus, a prominent fissure that runs down
the side of the cerebral cortex.
The primary somatosensory cortex is responsible for processing somatic sensations, or sensations
from the body that include touch, proprioception or the position of the body in space, nociception
or pain, and temperature.
When receptors detect one of these sensations, the information is sent to the thalamus and
then to the primary somatosensory cortex.
The primary somatosensory cortex is typically divided into 4 areas: area 3a, 3b, 1, and
Area 3 receives the majority of somatosensory input directly from the thalamus, and the
initial processing of information occurs here.
Area 3b is primarily 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, and when area 3b receives touch information,
that information is then sent to areas 1 and 2 for more complex processing.
Area 2 is also involved with proprioception.
Each of the four areas of the primary somatosensory cortex is arranged such that a particular
location in that area receives information from a particular part of the body.
This arrangement is referred to as somatotopic, and the full body is represented in this way
in each of the four regions of the somatosensory cortex.
More sensitive areas of the body take up a disproportionate amount of space in this somatotopic