SOMATOSENSORY CORTEX
Somatosensory Cortex:
The somatosensory cortex receives information from the general senses (touch, temperature, pressure, pain, vibration). Behind this area, the somatosensory association area interprets the stimuli. A lesion (such as that resulting from a stroke) in the somatosensory cortex prevents you from feeling that body part while a lesion in the association area prevents you from interpreting stimuli there (such as recognizing what you hold in your hand without looking). When an area of the somatosensory cortex is activated by sensation in the contralateral region of the body, the corresponding ipsilateral region of the somatosensory cortex is inhibited (perhaps via a projection from the contralateral SII region through the corpus callosum) (Kastrup, 2008). Degeneration of the somatosensory cortex is one of the first signs of multiple system atrophy (Mochizuki, 2008).

SII
The secondary somatosensory cortex (SII) responds to bilateral inputs of general sensations, unlike the primary somatosensory cortex which only responds to contralateral stimuli. SII is located above the lateral sulcus. Painful and nonpainful stimuli are separated into distinct regions of SII (Chen, 2008). The SII region plays a role in the recognition of an object's orientation (Hsaio, 2002). It is believed that different regions of the brain function in focusing attention, depending on the nature of stimulus. The SII region is involved in selective attention of somatosensory stimuli (Fujiwara, 2002).


Special Senses

The special senses include sight, smell, taste, and hearing. This sensory information is recognized at specific areas: the visual, auditory, and olfactory cortices. After each cortex recognizes the incoming stimuli, the information is then interpreted and meaning is attached at the association areas near these cortexes (the visual association area, auditory association area, olfactory association area).
Lesions in the cortices for the special senses can obliterate that sense (cortical blindness occurs after damage to the visual cortices although the eyes and their input are still normal). Lesions in the association areas might prevent you from recognizing familiar faces or sounds, for example. The auditory association area (Wernicke's area) also translates sounds into thoughts. Those with lesions here can have trouble comprehending speech. Lesions in some areas of the visual association area can cause colorblindness; large lesions result in someone who can see but doesn't know what they're looking at.

AUDITORY
A substantial amount of processing of sound information occurs in the brainstem, midbrain, and thalamus before it reaches the auditory cortex.

Regions of the auditory cortex respond most strongly to human voice (as opposed to animal vocalizations and other sounds). This is an example of species-specific stimulus processing (Fecteau, 2004).


Schizophrenia, a disorder characterized by auditory hallucinations, is associated with abnormal structure of the auditory cortex and a progressive deterioration of this, and other, regions of the brain (Kasai, 2004).

VISION
In blind individuals, the visual cortex may adopt alternate processing functions, such as a monitoring of auditory stimuli or language processing (Kujala, 2004; Gilbert, 2004).

During ejaculation, virtually all of the cerebral cortex undergoes decreased activity while certain areas, such as the right prefrontal cortex, septum, midbrain-diencephalon region, putamen, insula, and cerebellum, increase their activity. The visual cortex shows increased activity even if a subject's eyes are closed (Bianchi-Demicheli, 2007). Some studies have identified gender differences in activated areas with the medial amygdala, hypothalamus, preoptic area, and anterior cingulated being more active in women and the visual cortex more active in men (Bianchi-Demicheli, 2007; Levin, 2007).


OLFACTION

The recollection of memories of specific events can be associated with activation of the hippocampus and olfactory cortex (Gottfried, 2004).