The primary somatosensory cortex is the white matter area of the brain that receives and processes signals from our senses – tactile senses in particular. That area is located in the post-central gyrus – a convolution of brain tissue located just behind a valley that runs roughly from one ear to the other and is called the central sulcus. I know, it is too much information and makes little sense without a diagram. Here you go. I hope that helps.
The somatosensory cortex is on my mind this evening for a couple of reasons. The first is that my thalamic stroke last year, resulted in the interruption of normal communication of somatosensory signals originating in skin receptors and sent through the spinal cord to the thalamus and from there sent to somatosensory cortex. Those skin sensations include touch, vibration, temperature and pain. All of these signals are sent to the somatosensory cortex where we interpret them as tingling, burning, pressure, and so forth. I suspect that the brain does a good bit of signal processing through which the basic sensations are interpreted as holistic experiences.
Such processing allows me to experience the pleasure of Maia’s purr as I hold her. The sensory experience of purring is auditory as well as tactile vibration, the softness of her fur and the warmth of her body – it’s a medley of sensory inputs. My stroke left me with a loss of normal tactile sensation from the right side of my body. Mostly, I feel tingling (a very mild form of pain). There is an imbalance between that sensation, which dominates, and the other sensations (touch, temperature, vibration) which are now attenuated. Alas, at least the left side of my body is unaffected.
The second reason I’m thinking about this brain area this evening is that I read a medical item today that reported on the research of neuroscientists who have recently mapped the C-spot in the female brain. Think of the C-spot as that part of the somatosensory cortex that processes sensations that emerge from the female genitalia – the clitoris, more precisely.
I suspect that a corresponding P-spot for male genitalia probably occupies somewhere between 90 and 100% of the somatosensory cortex. 😉